mirror of
https://github.com/torvalds/linux.git
synced 2026-03-14 02:06:15 +01:00
User visible changes:
- Add an entry into MAINTAINERS file for RUST versions of code
There's now RUST code for tracing and static branches. To differentiate
that code from the C code, add entries in for the RUST version (with "[RUST]"
around it) so that the right maintainers get notified on changes.
- New bitmask-list option added to tracefs
When this is set, bitmasks in trace event are not displayed as hex
numbers, but instead as lists: e.g. 0-5,7,9 instead of 0000015f
- New show_event_filters file in tracefs
Instead of having to search all events/*/*/filter for any active filters
enabled in the trace instance, the file show_event_filters will list them
so that there's only one file that needs to be examined to see if any
filters are active.
- New show_event_triggers file in tracefs
Instead of having to search all events/*/*/trigger for any active triggers
enabled in the trace instance, the file show_event_triggers will list them
so that there's only one file that needs to be examined to see if any
triggers are active.
- Have traceoff_on_warning disable trace pintk buffer too
Recently recording of trace_printk() could go to other trace instances
instead of the top level instance. But if traceoff_on_warning triggers, it
doesn't stop the buffer with trace_printk() and that data can easily be
lost by being overwritten. Have traceoff_on_warning also disable the
instance that has trace_printk() being written to it.
- Update the hist_debug file to show what function the field uses
When CONFIG_HIST_TRIGGERS_DEBUG is enabled, a hist_debug file exists for
every event. This displays the internal data of any histogram enabled for
that event. But it is lacking the function that is called to process one
of its fields. This is very useful information that was missing when
debugging histograms.
- Up the histogram stack size from 16 to 31
Stack traces can be used as keys for event histograms. Currently the size
of the stack that is stored is limited to just 16 entries. But the storage
space in the histogram is 256 bytes, meaning that it can store up to 31
entries (plus one for the count of entries). Instead of letting that space
go to waste, up the limit from 16 to 31. This makes the keys much more
useful.
- Fix permissions of per CPU file buffer_size_kb
The per CPU file of buffer_size_kb was incorrectly set to read only in a
previous cleanup. It should be writable.
- Reset "last_boot_info" if the persistent buffer is cleared
The last_boot_info shows address information of a persistent ring buffer
if it contains data from a previous boot. It is cleared when recording
starts again, but it is not cleared when the buffer is reset. The data is
useless after a reset so clear it on reset too.
Internal changes:
- A change was made to allow tracepoint callbacks to have preemption
enabled, and instead be protected by SRCU. This required some updates to
the callbacks for perf and BPF.
perf needed to disable preemption directly in its callback because it
expects preemption disabled in the later code.
BPF needed to disable migration, as its code expects to run completely on
the same CPU.
- Have irq_work wake up other CPU if current CPU is "isolated"
When there's a waiter waiting on ring buffer data and a new event happens,
an irq work is triggered to wake up that waiter. This is noisy on isolated
CPUs (running NO_HZ_FULL). Trigger an IPI to a house keeping CPU instead.
- Use proper free of trigger_data instead of open coding it in.
- Remove redundant call of event_trigger_reset_filter()
It was called immediately in a function that was called right after it.
- Workqueue cleanups
- Report errors if tracing_update_buffers() were to fail.
- Make the enum update workqueue generic for other parts of tracing
On boot up, a work queue is created to convert enum names into their
numbers in the trace event format files. This work queue can also be used
for other aspects of tracing that takes some time and shouldn't be called
by the init call code.
The blk_trace initialization takes a bit of time. Have the initialization
code moved to the new tracing generic work queue function.
- Skip kprobe boot event creation call if there's no kprobes defined on cmdline
The kprobe initialization to set up kprobes if they are defined on the
cmdline requires taking the event_mutex lock. This can be held by other
tracing code doing initialization for a long time. Since kprobes added to
the kernel command line need to be setup immediately, as they may be
tracing early initialization code, they cannot be postponed in a work
queue and must be setup in the initcall code.
If there's no kprobe on the kernel cmdline, there's no reason to take the
mutex and slow down the boot up code waiting to get the lock only to find
out there's nothing to do. Simply exit out early if there's no kprobes on
the kernel cmdline.
If there are kprobes on the cmdline, then someone cares more about tracing
over the speed of boot up.
- Clean up the trigger code a bit
- Move code out of trace.c and into their own files
trace.c is now over 11,000 lines of code and has become more difficult to
maintain. Start splitting it up so that related code is in their own
files.
Move all the trace_printk() related code into trace_printk.c.
Move the __always_inline stack functions into trace.h.
Move the pid filtering code into a new trace_pid.c file.
- Better define the max latency and snapshot code
The latency tracers have a "max latency" buffer that is a copy of the main
buffer and gets swapped with it when a new high latency is detected. This
keeps the trace up to the highest latency around where this max_latency
buffer is never written to. It is only used to save the last max latency
trace.
A while ago a snapshot feature was added to tracefs to allow user space to
perform the same logic. It could also enable events to trigger a
"snapshot" if one of their fields hit a new high. This was built on top of
the latency max_latency buffer logic.
Because snapshots came later, they were dependent on the latency tracers
to be enabled. In reality, the latency tracers depend on the snapshot code
and not the other way around. It was just that they came first.
Restructure the code and the kconfigs to have the latency tracers depend
on snapshot code instead. This actually simplifies the logic a bit and
allows to disable more when the latency tracers are not defined and the
snapshot code is.
- Fix a "false sharing" in the hwlat tracer code
The loop to search for latency in hardware was using a variable that could
be changed by user space for each sample. If the user change this
variable, it could cause a bus contention, and reading that variable can
show up as a large latency in the trace causing a false positive. Read
this variable at the start of the sample with a READ_ONCE() into a local
variable and keep the code from sharing cache lines with readers.
- Fix function graph tracer static branch optimization code
When only one tracer is defined for function graph tracing, it uses a
static branch to call that tracer directly. When another tracer is added,
it goes into loop logic to call all the registered callbacks.
The code was incorrect when going back to one tracer and never re-enabled
the static branch again to do the optimization code.
- And other small fixes and cleanups.
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Merge tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
"User visible changes:
- Add an entry into MAINTAINERS file for RUST versions of code
There's now RUST code for tracing and static branches. To
differentiate that code from the C code, add entries in for the
RUST version (with "[RUST]" around it) so that the right
maintainers get notified on changes.
- New bitmask-list option added to tracefs
When this is set, bitmasks in trace event are not displayed as hex
numbers, but instead as lists: e.g. 0-5,7,9 instead of 0000015f
- New show_event_filters file in tracefs
Instead of having to search all events/*/*/filter for any active
filters enabled in the trace instance, the file show_event_filters
will list them so that there's only one file that needs to be
examined to see if any filters are active.
- New show_event_triggers file in tracefs
Instead of having to search all events/*/*/trigger for any active
triggers enabled in the trace instance, the file
show_event_triggers will list them so that there's only one file
that needs to be examined to see if any triggers are active.
- Have traceoff_on_warning disable trace pintk buffer too
Recently recording of trace_printk() could go to other trace
instances instead of the top level instance. But if
traceoff_on_warning triggers, it doesn't stop the buffer with
trace_printk() and that data can easily be lost by being
overwritten. Have traceoff_on_warning also disable the instance
that has trace_printk() being written to it.
- Update the hist_debug file to show what function the field uses
When CONFIG_HIST_TRIGGERS_DEBUG is enabled, a hist_debug file
exists for every event. This displays the internal data of any
histogram enabled for that event. But it is lacking the function
that is called to process one of its fields. This is very useful
information that was missing when debugging histograms.
- Up the histogram stack size from 16 to 31
Stack traces can be used as keys for event histograms. Currently
the size of the stack that is stored is limited to just 16 entries.
But the storage space in the histogram is 256 bytes, meaning that
it can store up to 31 entries (plus one for the count of entries).
Instead of letting that space go to waste, up the limit from 16 to
31. This makes the keys much more useful.
- Fix permissions of per CPU file buffer_size_kb
The per CPU file of buffer_size_kb was incorrectly set to read only
in a previous cleanup. It should be writable.
- Reset "last_boot_info" if the persistent buffer is cleared
The last_boot_info shows address information of a persistent ring
buffer if it contains data from a previous boot. It is cleared when
recording starts again, but it is not cleared when the buffer is
reset. The data is useless after a reset so clear it on reset too.
Internal changes:
- A change was made to allow tracepoint callbacks to have preemption
enabled, and instead be protected by SRCU. This required some
updates to the callbacks for perf and BPF.
perf needed to disable preemption directly in its callback because
it expects preemption disabled in the later code.
BPF needed to disable migration, as its code expects to run
completely on the same CPU.
- Have irq_work wake up other CPU if current CPU is "isolated"
When there's a waiter waiting on ring buffer data and a new event
happens, an irq work is triggered to wake up that waiter. This is
noisy on isolated CPUs (running NO_HZ_FULL). Trigger an IPI to a
house keeping CPU instead.
- Use proper free of trigger_data instead of open coding it in.
- Remove redundant call of event_trigger_reset_filter()
It was called immediately in a function that was called right after
it.
- Workqueue cleanups
- Report errors if tracing_update_buffers() were to fail.
- Make the enum update workqueue generic for other parts of tracing
On boot up, a work queue is created to convert enum names into
their numbers in the trace event format files. This work queue can
also be used for other aspects of tracing that takes some time and
shouldn't be called by the init call code.
The blk_trace initialization takes a bit of time. Have the
initialization code moved to the new tracing generic work queue
function.
- Skip kprobe boot event creation call if there's no kprobes defined
on cmdline
The kprobe initialization to set up kprobes if they are defined on
the cmdline requires taking the event_mutex lock. This can be held
by other tracing code doing initialization for a long time. Since
kprobes added to the kernel command line need to be setup
immediately, as they may be tracing early initialization code, they
cannot be postponed in a work queue and must be setup in the
initcall code.
If there's no kprobe on the kernel cmdline, there's no reason to
take the mutex and slow down the boot up code waiting to get the
lock only to find out there's nothing to do. Simply exit out early
if there's no kprobes on the kernel cmdline.
If there are kprobes on the cmdline, then someone cares more about
tracing over the speed of boot up.
- Clean up the trigger code a bit
- Move code out of trace.c and into their own files
trace.c is now over 11,000 lines of code and has become more
difficult to maintain. Start splitting it up so that related code
is in their own files.
Move all the trace_printk() related code into trace_printk.c.
Move the __always_inline stack functions into trace.h.
Move the pid filtering code into a new trace_pid.c file.
- Better define the max latency and snapshot code
The latency tracers have a "max latency" buffer that is a copy of
the main buffer and gets swapped with it when a new high latency is
detected. This keeps the trace up to the highest latency around
where this max_latency buffer is never written to. It is only used
to save the last max latency trace.
A while ago a snapshot feature was added to tracefs to allow user
space to perform the same logic. It could also enable events to
trigger a "snapshot" if one of their fields hit a new high. This
was built on top of the latency max_latency buffer logic.
Because snapshots came later, they were dependent on the latency
tracers to be enabled. In reality, the latency tracers depend on
the snapshot code and not the other way around. It was just that
they came first.
Restructure the code and the kconfigs to have the latency tracers
depend on snapshot code instead. This actually simplifies the logic
a bit and allows to disable more when the latency tracers are not
defined and the snapshot code is.
- Fix a "false sharing" in the hwlat tracer code
The loop to search for latency in hardware was using a variable
that could be changed by user space for each sample. If the user
change this variable, it could cause a bus contention, and reading
that variable can show up as a large latency in the trace causing a
false positive. Read this variable at the start of the sample with
a READ_ONCE() into a local variable and keep the code from sharing
cache lines with readers.
- Fix function graph tracer static branch optimization code
When only one tracer is defined for function graph tracing, it uses
a static branch to call that tracer directly. When another tracer
is added, it goes into loop logic to call all the registered
callbacks.
The code was incorrect when going back to one tracer and never
re-enabled the static branch again to do the optimization code.
- And other small fixes and cleanups"
* tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (46 commits)
function_graph: Restore direct mode when callbacks drop to one
tracing: Fix indentation of return statement in print_trace_fmt()
tracing: Reset last_boot_info if ring buffer is reset
tracing: Fix to set write permission to per-cpu buffer_size_kb
tracing: Fix false sharing in hwlat get_sample()
tracing: Move d_max_latency out of CONFIG_FSNOTIFY protection
tracing: Better separate SNAPSHOT and MAX_TRACE options
tracing: Add tracer_uses_snapshot() helper to remove #ifdefs
tracing: Rename trace_array field max_buffer to snapshot_buffer
tracing: Move pid filtering into trace_pid.c
tracing: Move trace_printk functions out of trace.c and into trace_printk.c
tracing: Use system_state in trace_printk_init_buffers()
tracing: Have trace_printk functions use flags instead of using global_trace
tracing: Make tracing_update_buffers() take NULL for global_trace
tracing: Make printk_trace global for tracing system
tracing: Move ftrace_trace_stack() out of trace.c and into trace.h
tracing: Move __trace_buffer_{un}lock_*() functions to trace.h
tracing: Make tracing_selftest_running global to the tracing subsystem
tracing: Make tracing_disabled global for tracing system
tracing: Clean up use of trace_create_maxlat_file()
...
3594 lines
92 KiB
C
3594 lines
92 KiB
C
// SPDX-License-Identifier: GPL-2.0
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|
/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
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* Copyright (c) 2016 Facebook
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/bpf.h>
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#include <linux/bpf_verifier.h>
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#include <linux/bpf_perf_event.h>
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#include <linux/btf.h>
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#include <linux/filter.h>
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#include <linux/uaccess.h>
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#include <linux/ctype.h>
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#include <linux/kprobes.h>
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#include <linux/spinlock.h>
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#include <linux/syscalls.h>
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#include <linux/error-injection.h>
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#include <linux/btf_ids.h>
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#include <linux/bpf_lsm.h>
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#include <linux/fprobe.h>
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#include <linux/bsearch.h>
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#include <linux/sort.h>
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#include <linux/key.h>
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#include <linux/namei.h>
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|
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#include <net/bpf_sk_storage.h>
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|
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#include <uapi/linux/bpf.h>
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#include <uapi/linux/btf.h>
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|
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#include <asm/tlb.h>
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|
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#include "trace_probe.h"
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#include "trace.h"
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|
|
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#define CREATE_TRACE_POINTS
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#include "bpf_trace.h"
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|
|
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#define bpf_event_rcu_dereference(p) \
|
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rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
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|
|
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#define MAX_UPROBE_MULTI_CNT (1U << 20)
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|
#define MAX_KPROBE_MULTI_CNT (1U << 20)
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|
|
|
#ifdef CONFIG_MODULES
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struct bpf_trace_module {
|
|
struct module *module;
|
|
struct list_head list;
|
|
};
|
|
|
|
static LIST_HEAD(bpf_trace_modules);
|
|
static DEFINE_MUTEX(bpf_module_mutex);
|
|
|
|
static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
|
|
{
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|
struct bpf_raw_event_map *btp, *ret = NULL;
|
|
struct bpf_trace_module *btm;
|
|
unsigned int i;
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|
|
|
mutex_lock(&bpf_module_mutex);
|
|
list_for_each_entry(btm, &bpf_trace_modules, list) {
|
|
for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
|
|
btp = &btm->module->bpf_raw_events[i];
|
|
if (!strcmp(btp->tp->name, name)) {
|
|
if (try_module_get(btm->module))
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|
ret = btp;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
out:
|
|
mutex_unlock(&bpf_module_mutex);
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|
return ret;
|
|
}
|
|
#else
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static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
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{
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|
return NULL;
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|
}
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#endif /* CONFIG_MODULES */
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|
|
|
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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|
|
|
static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
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|
u64 flags, const struct btf **btf,
|
|
s32 *btf_id);
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|
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
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|
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
|
|
|
|
static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
|
|
static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
|
|
|
|
/**
|
|
* trace_call_bpf - invoke BPF program
|
|
* @call: tracepoint event
|
|
* @ctx: opaque context pointer
|
|
*
|
|
* kprobe handlers execute BPF programs via this helper.
|
|
* Can be used from static tracepoints in the future.
|
|
*
|
|
* Return: BPF programs always return an integer which is interpreted by
|
|
* kprobe handler as:
|
|
* 0 - return from kprobe (event is filtered out)
|
|
* 1 - store kprobe event into ring buffer
|
|
* Other values are reserved and currently alias to 1
|
|
*/
|
|
unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
|
|
{
|
|
unsigned int ret;
|
|
|
|
cant_sleep();
|
|
|
|
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
|
|
/*
|
|
* since some bpf program is already running on this cpu,
|
|
* don't call into another bpf program (same or different)
|
|
* and don't send kprobe event into ring-buffer,
|
|
* so return zero here
|
|
*/
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|
rcu_read_lock();
|
|
bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
|
|
rcu_read_unlock();
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
|
|
* to all call sites, we did a bpf_prog_array_valid() there to check
|
|
* whether call->prog_array is empty or not, which is
|
|
* a heuristic to speed up execution.
|
|
*
|
|
* If bpf_prog_array_valid() fetched prog_array was
|
|
* non-NULL, we go into trace_call_bpf() and do the actual
|
|
* proper rcu_dereference() under RCU lock.
|
|
* If it turns out that prog_array is NULL then, we bail out.
|
|
* For the opposite, if the bpf_prog_array_valid() fetched pointer
|
|
* was NULL, you'll skip the prog_array with the risk of missing
|
|
* out of events when it was updated in between this and the
|
|
* rcu_dereference() which is accepted risk.
|
|
*/
|
|
rcu_read_lock();
|
|
ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
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|
ctx, bpf_prog_run);
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|
rcu_read_unlock();
|
|
|
|
out:
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|
__this_cpu_dec(bpf_prog_active);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
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|
BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
|
|
{
|
|
regs_set_return_value(regs, rc);
|
|
override_function_with_return(regs);
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_override_return_proto = {
|
|
.func = bpf_override_return,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_ANYTHING,
|
|
};
|
|
#endif
|
|
|
|
static __always_inline int
|
|
bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
|
|
{
|
|
int ret;
|
|
|
|
ret = copy_from_user_nofault(dst, unsafe_ptr, size);
|
|
if (unlikely(ret < 0))
|
|
memset(dst, 0, size);
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
|
|
const void __user *, unsafe_ptr)
|
|
{
|
|
return bpf_probe_read_user_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_probe_read_user_proto = {
|
|
.func = bpf_probe_read_user,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static __always_inline int
|
|
bpf_probe_read_user_str_common(void *dst, u32 size,
|
|
const void __user *unsafe_ptr)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* NB: We rely on strncpy_from_user() not copying junk past the NUL
|
|
* terminator into `dst`.
|
|
*
|
|
* strncpy_from_user() does long-sized strides in the fast path. If the
|
|
* strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
|
|
* then there could be junk after the NUL in `dst`. If user takes `dst`
|
|
* and keys a hash map with it, then semantically identical strings can
|
|
* occupy multiple entries in the map.
|
|
*/
|
|
ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
|
|
if (unlikely(ret < 0))
|
|
memset(dst, 0, size);
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
|
|
const void __user *, unsafe_ptr)
|
|
{
|
|
return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_probe_read_user_str_proto = {
|
|
.func = bpf_probe_read_user_str,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
|
|
const void *, unsafe_ptr)
|
|
{
|
|
return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_probe_read_kernel_proto = {
|
|
.func = bpf_probe_read_kernel,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static __always_inline int
|
|
bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* The strncpy_from_kernel_nofault() call will likely not fill the
|
|
* entire buffer, but that's okay in this circumstance as we're probing
|
|
* arbitrary memory anyway similar to bpf_probe_read_*() and might
|
|
* as well probe the stack. Thus, memory is explicitly cleared
|
|
* only in error case, so that improper users ignoring return
|
|
* code altogether don't copy garbage; otherwise length of string
|
|
* is returned that can be used for bpf_perf_event_output() et al.
|
|
*/
|
|
ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
|
|
if (unlikely(ret < 0))
|
|
memset(dst, 0, size);
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
|
|
const void *, unsafe_ptr)
|
|
{
|
|
return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
|
|
.func = bpf_probe_read_kernel_str,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
|
|
BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
|
|
const void *, unsafe_ptr)
|
|
{
|
|
if ((unsigned long)unsafe_ptr < TASK_SIZE) {
|
|
return bpf_probe_read_user_common(dst, size,
|
|
(__force void __user *)unsafe_ptr);
|
|
}
|
|
return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_probe_read_compat_proto = {
|
|
.func = bpf_probe_read_compat,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
|
|
const void *, unsafe_ptr)
|
|
{
|
|
if ((unsigned long)unsafe_ptr < TASK_SIZE) {
|
|
return bpf_probe_read_user_str_common(dst, size,
|
|
(__force void __user *)unsafe_ptr);
|
|
}
|
|
return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
|
|
.func = bpf_probe_read_compat_str,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
|
|
|
|
BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
|
|
u32, size)
|
|
{
|
|
/*
|
|
* Ensure we're in user context which is safe for the helper to
|
|
* run. This helper has no business in a kthread.
|
|
*
|
|
* access_ok() should prevent writing to non-user memory, but in
|
|
* some situations (nommu, temporary switch, etc) access_ok() does
|
|
* not provide enough validation, hence the check on KERNEL_DS.
|
|
*
|
|
* nmi_uaccess_okay() ensures the probe is not run in an interim
|
|
* state, when the task or mm are switched. This is specifically
|
|
* required to prevent the use of temporary mm.
|
|
*/
|
|
|
|
if (unlikely(in_interrupt() ||
|
|
current->flags & (PF_KTHREAD | PF_EXITING)))
|
|
return -EPERM;
|
|
if (unlikely(!nmi_uaccess_okay()))
|
|
return -EPERM;
|
|
|
|
return copy_to_user_nofault(unsafe_ptr, src, size);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_probe_write_user_proto = {
|
|
.func = bpf_probe_write_user,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
#define MAX_TRACE_PRINTK_VARARGS 3
|
|
#define BPF_TRACE_PRINTK_SIZE 1024
|
|
|
|
BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
|
|
u64, arg2, u64, arg3)
|
|
{
|
|
u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
|
|
struct bpf_bprintf_data data = {
|
|
.get_bin_args = true,
|
|
.get_buf = true,
|
|
};
|
|
int ret;
|
|
|
|
ret = bpf_bprintf_prepare(fmt, fmt_size, args,
|
|
MAX_TRACE_PRINTK_VARARGS, &data);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
|
|
|
|
trace_bpf_trace_printk(data.buf);
|
|
|
|
bpf_bprintf_cleanup(&data);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_trace_printk_proto = {
|
|
.func = bpf_trace_printk,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg2_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
static void __set_printk_clr_event(struct work_struct *work)
|
|
{
|
|
/*
|
|
* This program might be calling bpf_trace_printk,
|
|
* so enable the associated bpf_trace/bpf_trace_printk event.
|
|
* Repeat this each time as it is possible a user has
|
|
* disabled bpf_trace_printk events. By loading a program
|
|
* calling bpf_trace_printk() however the user has expressed
|
|
* the intent to see such events.
|
|
*/
|
|
if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
|
|
pr_warn_ratelimited("could not enable bpf_trace_printk events");
|
|
}
|
|
static DECLARE_WORK(set_printk_work, __set_printk_clr_event);
|
|
|
|
const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
|
|
{
|
|
schedule_work(&set_printk_work);
|
|
return &bpf_trace_printk_proto;
|
|
}
|
|
|
|
BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
|
|
u32, data_len)
|
|
{
|
|
struct bpf_bprintf_data data = {
|
|
.get_bin_args = true,
|
|
.get_buf = true,
|
|
};
|
|
int ret, num_args;
|
|
|
|
if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
|
|
(data_len && !args))
|
|
return -EINVAL;
|
|
num_args = data_len / 8;
|
|
|
|
ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
|
|
|
|
trace_bpf_trace_printk(data.buf);
|
|
|
|
bpf_bprintf_cleanup(&data);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_trace_vprintk_proto = {
|
|
.func = bpf_trace_vprintk,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg2_type = ARG_CONST_SIZE,
|
|
.arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
|
|
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
|
|
{
|
|
schedule_work(&set_printk_work);
|
|
return &bpf_trace_vprintk_proto;
|
|
}
|
|
|
|
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
|
|
const void *, args, u32, data_len)
|
|
{
|
|
struct bpf_bprintf_data data = {
|
|
.get_bin_args = true,
|
|
};
|
|
int err, num_args;
|
|
|
|
if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
|
|
(data_len && !args))
|
|
return -EINVAL;
|
|
num_args = data_len / 8;
|
|
|
|
err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
seq_bprintf(m, fmt, data.bin_args);
|
|
|
|
bpf_bprintf_cleanup(&data);
|
|
|
|
return seq_has_overflowed(m) ? -EOVERFLOW : 0;
|
|
}
|
|
|
|
BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
|
|
|
|
static const struct bpf_func_proto bpf_seq_printf_proto = {
|
|
.func = bpf_seq_printf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
.arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
|
|
{
|
|
return seq_write(m, data, len) ? -EOVERFLOW : 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_seq_write_proto = {
|
|
.func = bpf_seq_write,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
|
|
u32, btf_ptr_size, u64, flags)
|
|
{
|
|
const struct btf *btf;
|
|
s32 btf_id;
|
|
int ret;
|
|
|
|
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
|
|
.func = bpf_seq_printf_btf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static __always_inline int
|
|
get_map_perf_counter(struct bpf_map *map, u64 flags,
|
|
u64 *value, u64 *enabled, u64 *running)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
unsigned int cpu = smp_processor_id();
|
|
u64 index = flags & BPF_F_INDEX_MASK;
|
|
struct bpf_event_entry *ee;
|
|
|
|
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
|
|
return -EINVAL;
|
|
if (index == BPF_F_CURRENT_CPU)
|
|
index = cpu;
|
|
if (unlikely(index >= array->map.max_entries))
|
|
return -E2BIG;
|
|
|
|
ee = READ_ONCE(array->ptrs[index]);
|
|
if (!ee)
|
|
return -ENOENT;
|
|
|
|
return perf_event_read_local(ee->event, value, enabled, running);
|
|
}
|
|
|
|
BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
|
|
{
|
|
u64 value = 0;
|
|
int err;
|
|
|
|
err = get_map_perf_counter(map, flags, &value, NULL, NULL);
|
|
/*
|
|
* this api is ugly since we miss [-22..-2] range of valid
|
|
* counter values, but that's uapi
|
|
*/
|
|
if (err)
|
|
return err;
|
|
return value;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_perf_event_read_proto = {
|
|
.func = bpf_perf_event_read,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
|
|
struct bpf_perf_event_value *, buf, u32, size)
|
|
{
|
|
int err = -EINVAL;
|
|
|
|
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
|
|
goto clear;
|
|
err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
|
|
&buf->running);
|
|
if (unlikely(err))
|
|
goto clear;
|
|
return 0;
|
|
clear:
|
|
memset(buf, 0, size);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
|
|
.func = bpf_perf_event_read_value,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg4_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
|
|
{
|
|
return &bpf_perf_event_read_value_proto;
|
|
}
|
|
|
|
static __always_inline u64
|
|
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
|
|
u64 flags, struct perf_raw_record *raw,
|
|
struct perf_sample_data *sd)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
unsigned int cpu = smp_processor_id();
|
|
u64 index = flags & BPF_F_INDEX_MASK;
|
|
struct bpf_event_entry *ee;
|
|
struct perf_event *event;
|
|
|
|
if (index == BPF_F_CURRENT_CPU)
|
|
index = cpu;
|
|
if (unlikely(index >= array->map.max_entries))
|
|
return -E2BIG;
|
|
|
|
ee = READ_ONCE(array->ptrs[index]);
|
|
if (!ee)
|
|
return -ENOENT;
|
|
|
|
event = ee->event;
|
|
if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
|
|
event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(event->oncpu != cpu))
|
|
return -EOPNOTSUPP;
|
|
|
|
perf_sample_save_raw_data(sd, event, raw);
|
|
|
|
return perf_event_output(event, sd, regs);
|
|
}
|
|
|
|
/*
|
|
* Support executing tracepoints in normal, irq, and nmi context that each call
|
|
* bpf_perf_event_output
|
|
*/
|
|
struct bpf_trace_sample_data {
|
|
struct perf_sample_data sds[3];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
|
|
static DEFINE_PER_CPU(int, bpf_trace_nest_level);
|
|
BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
|
|
u64, flags, void *, data, u64, size)
|
|
{
|
|
struct bpf_trace_sample_data *sds;
|
|
struct perf_raw_record raw = {
|
|
.frag = {
|
|
.size = size,
|
|
.data = data,
|
|
},
|
|
};
|
|
struct perf_sample_data *sd;
|
|
int nest_level, err;
|
|
|
|
preempt_disable();
|
|
sds = this_cpu_ptr(&bpf_trace_sds);
|
|
nest_level = this_cpu_inc_return(bpf_trace_nest_level);
|
|
|
|
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
sd = &sds->sds[nest_level - 1];
|
|
|
|
if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
perf_sample_data_init(sd, 0, 0);
|
|
|
|
err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
|
|
out:
|
|
this_cpu_dec(bpf_trace_nest_level);
|
|
preempt_enable();
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto = {
|
|
.func = bpf_perf_event_output,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
|
|
struct bpf_nested_pt_regs {
|
|
struct pt_regs regs[3];
|
|
};
|
|
static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
|
|
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
|
|
|
|
u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
|
|
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
|
|
{
|
|
struct perf_raw_frag frag = {
|
|
.copy = ctx_copy,
|
|
.size = ctx_size,
|
|
.data = ctx,
|
|
};
|
|
struct perf_raw_record raw = {
|
|
.frag = {
|
|
{
|
|
.next = ctx_size ? &frag : NULL,
|
|
},
|
|
.size = meta_size,
|
|
.data = meta,
|
|
},
|
|
};
|
|
struct perf_sample_data *sd;
|
|
struct pt_regs *regs;
|
|
int nest_level;
|
|
u64 ret;
|
|
|
|
preempt_disable();
|
|
nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
|
|
|
|
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
|
|
regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
perf_sample_data_init(sd, 0, 0);
|
|
|
|
ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
|
|
out:
|
|
this_cpu_dec(bpf_event_output_nest_level);
|
|
preempt_enable();
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_0(bpf_get_current_task)
|
|
{
|
|
return (long) current;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_current_task_proto = {
|
|
.func = bpf_get_current_task,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
BPF_CALL_0(bpf_get_current_task_btf)
|
|
{
|
|
return (unsigned long) current;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_current_task_btf_proto = {
|
|
.func = bpf_get_current_task_btf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
|
|
.ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
|
|
};
|
|
|
|
BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
|
|
{
|
|
return (unsigned long) task_pt_regs(task);
|
|
}
|
|
|
|
BTF_ID_LIST_SINGLE(bpf_task_pt_regs_ids, struct, pt_regs)
|
|
|
|
const struct bpf_func_proto bpf_task_pt_regs_proto = {
|
|
.func = bpf_task_pt_regs,
|
|
.gpl_only = true,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
|
|
.ret_type = RET_PTR_TO_BTF_ID,
|
|
.ret_btf_id = &bpf_task_pt_regs_ids[0],
|
|
};
|
|
|
|
struct send_signal_irq_work {
|
|
struct irq_work irq_work;
|
|
struct task_struct *task;
|
|
u32 sig;
|
|
enum pid_type type;
|
|
bool has_siginfo;
|
|
struct kernel_siginfo info;
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
|
|
|
|
static void do_bpf_send_signal(struct irq_work *entry)
|
|
{
|
|
struct send_signal_irq_work *work;
|
|
struct kernel_siginfo *siginfo;
|
|
|
|
work = container_of(entry, struct send_signal_irq_work, irq_work);
|
|
siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;
|
|
|
|
group_send_sig_info(work->sig, siginfo, work->task, work->type);
|
|
put_task_struct(work->task);
|
|
}
|
|
|
|
static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
|
|
{
|
|
struct send_signal_irq_work *work = NULL;
|
|
struct kernel_siginfo info;
|
|
struct kernel_siginfo *siginfo;
|
|
|
|
if (!task) {
|
|
task = current;
|
|
siginfo = SEND_SIG_PRIV;
|
|
} else {
|
|
clear_siginfo(&info);
|
|
info.si_signo = sig;
|
|
info.si_errno = 0;
|
|
info.si_code = SI_KERNEL;
|
|
info.si_pid = 0;
|
|
info.si_uid = 0;
|
|
info.si_value.sival_ptr = (void __user __force *)(unsigned long)value;
|
|
siginfo = &info;
|
|
}
|
|
|
|
/* Similar to bpf_probe_write_user, task needs to be
|
|
* in a sound condition and kernel memory access be
|
|
* permitted in order to send signal to the current
|
|
* task.
|
|
*/
|
|
if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING)))
|
|
return -EPERM;
|
|
if (unlikely(!nmi_uaccess_okay()))
|
|
return -EPERM;
|
|
/* Task should not be pid=1 to avoid kernel panic. */
|
|
if (unlikely(is_global_init(task)))
|
|
return -EPERM;
|
|
|
|
if (preempt_count() != 0 || irqs_disabled()) {
|
|
/* Do an early check on signal validity. Otherwise,
|
|
* the error is lost in deferred irq_work.
|
|
*/
|
|
if (unlikely(!valid_signal(sig)))
|
|
return -EINVAL;
|
|
|
|
work = this_cpu_ptr(&send_signal_work);
|
|
if (irq_work_is_busy(&work->irq_work))
|
|
return -EBUSY;
|
|
|
|
/* Add the current task, which is the target of sending signal,
|
|
* to the irq_work. The current task may change when queued
|
|
* irq works get executed.
|
|
*/
|
|
work->task = get_task_struct(task);
|
|
work->has_siginfo = siginfo == &info;
|
|
if (work->has_siginfo)
|
|
copy_siginfo(&work->info, &info);
|
|
work->sig = sig;
|
|
work->type = type;
|
|
irq_work_queue(&work->irq_work);
|
|
return 0;
|
|
}
|
|
|
|
return group_send_sig_info(sig, siginfo, task, type);
|
|
}
|
|
|
|
BPF_CALL_1(bpf_send_signal, u32, sig)
|
|
{
|
|
return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_send_signal_proto = {
|
|
.func = bpf_send_signal,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_send_signal_thread, u32, sig)
|
|
{
|
|
return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_send_signal_thread_proto = {
|
|
.func = bpf_send_signal_thread,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_d_path, const struct path *, path, char *, buf, u32, sz)
|
|
{
|
|
struct path copy;
|
|
long len;
|
|
char *p;
|
|
|
|
if (!sz)
|
|
return 0;
|
|
|
|
/*
|
|
* The path pointer is verified as trusted and safe to use,
|
|
* but let's double check it's valid anyway to workaround
|
|
* potentially broken verifier.
|
|
*/
|
|
len = copy_from_kernel_nofault(©, path, sizeof(*path));
|
|
if (len < 0)
|
|
return len;
|
|
|
|
p = d_path(©, buf, sz);
|
|
if (IS_ERR(p)) {
|
|
len = PTR_ERR(p);
|
|
} else {
|
|
len = buf + sz - p;
|
|
memmove(buf, p, len);
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
BTF_SET_START(btf_allowlist_d_path)
|
|
#ifdef CONFIG_SECURITY
|
|
BTF_ID(func, security_file_permission)
|
|
BTF_ID(func, security_inode_getattr)
|
|
BTF_ID(func, security_file_open)
|
|
#endif
|
|
#ifdef CONFIG_SECURITY_PATH
|
|
BTF_ID(func, security_path_truncate)
|
|
#endif
|
|
BTF_ID(func, vfs_truncate)
|
|
BTF_ID(func, vfs_fallocate)
|
|
BTF_ID(func, dentry_open)
|
|
BTF_ID(func, vfs_getattr)
|
|
BTF_ID(func, filp_close)
|
|
BTF_SET_END(btf_allowlist_d_path)
|
|
|
|
static bool bpf_d_path_allowed(const struct bpf_prog *prog)
|
|
{
|
|
if (prog->type == BPF_PROG_TYPE_TRACING &&
|
|
prog->expected_attach_type == BPF_TRACE_ITER)
|
|
return true;
|
|
|
|
if (prog->type == BPF_PROG_TYPE_LSM)
|
|
return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
|
|
|
|
return btf_id_set_contains(&btf_allowlist_d_path,
|
|
prog->aux->attach_btf_id);
|
|
}
|
|
|
|
BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
|
|
|
|
static const struct bpf_func_proto bpf_d_path_proto = {
|
|
.func = bpf_d_path,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &bpf_d_path_btf_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_WRITE,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.allowed = bpf_d_path_allowed,
|
|
};
|
|
|
|
#define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
|
|
BTF_F_PTR_RAW | BTF_F_ZERO)
|
|
|
|
static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
|
|
u64 flags, const struct btf **btf,
|
|
s32 *btf_id)
|
|
{
|
|
const struct btf_type *t;
|
|
|
|
if (unlikely(flags & ~(BTF_F_ALL)))
|
|
return -EINVAL;
|
|
|
|
if (btf_ptr_size != sizeof(struct btf_ptr))
|
|
return -EINVAL;
|
|
|
|
*btf = bpf_get_btf_vmlinux();
|
|
|
|
if (IS_ERR_OR_NULL(*btf))
|
|
return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
|
|
|
|
if (ptr->type_id > 0)
|
|
*btf_id = ptr->type_id;
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (*btf_id > 0)
|
|
t = btf_type_by_id(*btf, *btf_id);
|
|
if (*btf_id <= 0 || !t)
|
|
return -ENOENT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
|
|
u32, btf_ptr_size, u64, flags)
|
|
{
|
|
const struct btf *btf;
|
|
s32 btf_id;
|
|
int ret;
|
|
|
|
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
|
|
flags);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_snprintf_btf_proto = {
|
|
.func = bpf_snprintf_btf,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_MEM | MEM_WRITE,
|
|
.arg2_type = ARG_CONST_SIZE,
|
|
.arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg4_type = ARG_CONST_SIZE,
|
|
.arg5_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
return ((u64 *)ctx)[-2];
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
|
|
.func = bpf_get_func_ip_tracing,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
static inline unsigned long get_entry_ip(unsigned long fentry_ip)
|
|
{
|
|
#ifdef CONFIG_X86_KERNEL_IBT
|
|
if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE)))
|
|
fentry_ip -= ENDBR_INSN_SIZE;
|
|
#endif
|
|
return fentry_ip;
|
|
}
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
|
|
{
|
|
struct bpf_trace_run_ctx *run_ctx __maybe_unused;
|
|
struct kprobe *kp;
|
|
|
|
#ifdef CONFIG_UPROBES
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
|
|
if (run_ctx->is_uprobe)
|
|
return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
|
|
#endif
|
|
|
|
kp = kprobe_running();
|
|
|
|
if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
|
|
return 0;
|
|
|
|
return get_entry_ip((uintptr_t)kp->addr);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
|
|
.func = bpf_get_func_ip_kprobe,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
|
|
.func = bpf_get_func_ip_kprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_kprobe_multi_cookie(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
|
|
.func = bpf_get_attach_cookie_kprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
|
|
.func = bpf_get_func_ip_uprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_uprobe_multi_cookie(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
|
|
.func = bpf_get_attach_cookie_uprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
|
|
{
|
|
struct bpf_trace_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
|
|
return run_ctx->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
|
|
.func = bpf_get_attach_cookie_trace,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
|
|
{
|
|
return ctx->event->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
|
|
.func = bpf_get_attach_cookie_pe,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
|
|
{
|
|
struct bpf_trace_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
|
|
return run_ctx->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
|
|
.func = bpf_get_attach_cookie_tracing,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
|
|
{
|
|
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
|
|
u32 entry_cnt = size / br_entry_size;
|
|
|
|
entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
|
|
|
|
if (unlikely(flags))
|
|
return -EINVAL;
|
|
|
|
if (!entry_cnt)
|
|
return -ENOENT;
|
|
|
|
return entry_cnt * br_entry_size;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
|
|
.func = bpf_get_branch_snapshot,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
u64 nr_args = ((u64 *)ctx)[-1] & 0xFF;
|
|
|
|
if ((u64) n >= nr_args)
|
|
return -EINVAL;
|
|
*value = ((u64 *)ctx)[n];
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_arg_proto = {
|
|
.func = get_func_arg,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
|
|
.arg3_size = sizeof(u64),
|
|
};
|
|
|
|
BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
u64 nr_args = ((u64 *)ctx)[-1] & 0xFF;
|
|
|
|
*value = ((u64 *)ctx)[nr_args];
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ret_proto = {
|
|
.func = get_func_ret,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
|
|
.arg2_size = sizeof(u64),
|
|
};
|
|
|
|
BPF_CALL_1(get_func_arg_cnt, void *, ctx)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
return ((u64 *)ctx)[-1] & 0xFF;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
|
|
.func = get_func_arg_cnt,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *func_proto;
|
|
|
|
switch (func_id) {
|
|
case BPF_FUNC_get_smp_processor_id:
|
|
return &bpf_get_smp_processor_id_proto;
|
|
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
|
|
case BPF_FUNC_probe_read:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_compat_proto;
|
|
case BPF_FUNC_probe_read_str:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_compat_str_proto;
|
|
#endif
|
|
case BPF_FUNC_get_func_ip:
|
|
return &bpf_get_func_ip_proto_tracing;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
func_proto = bpf_base_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
|
|
return NULL;
|
|
|
|
switch (func_id) {
|
|
case BPF_FUNC_probe_write_user:
|
|
return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
|
|
NULL : &bpf_probe_write_user_proto;
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
static bool is_kprobe_multi(const struct bpf_prog *prog)
|
|
{
|
|
return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
|
|
prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
|
|
}
|
|
|
|
static inline bool is_kprobe_session(const struct bpf_prog *prog)
|
|
{
|
|
return prog->type == BPF_PROG_TYPE_KPROBE &&
|
|
prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
|
|
}
|
|
|
|
static inline bool is_uprobe_multi(const struct bpf_prog *prog)
|
|
{
|
|
return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
|
|
prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
|
|
}
|
|
|
|
static inline bool is_uprobe_session(const struct bpf_prog *prog)
|
|
{
|
|
return prog->type == BPF_PROG_TYPE_KPROBE &&
|
|
prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
|
|
}
|
|
|
|
static inline bool is_trace_fsession(const struct bpf_prog *prog)
|
|
{
|
|
return prog->type == BPF_PROG_TYPE_TRACING &&
|
|
prog->expected_attach_type == BPF_TRACE_FSESSION;
|
|
}
|
|
|
|
static const struct bpf_func_proto *
|
|
kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto;
|
|
case BPF_FUNC_get_stack:
|
|
return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
|
|
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
|
|
case BPF_FUNC_override_return:
|
|
return &bpf_override_return_proto;
|
|
#endif
|
|
case BPF_FUNC_get_func_ip:
|
|
if (is_kprobe_multi(prog))
|
|
return &bpf_get_func_ip_proto_kprobe_multi;
|
|
if (is_uprobe_multi(prog))
|
|
return &bpf_get_func_ip_proto_uprobe_multi;
|
|
return &bpf_get_func_ip_proto_kprobe;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
if (is_kprobe_multi(prog))
|
|
return &bpf_get_attach_cookie_proto_kmulti;
|
|
if (is_uprobe_multi(prog))
|
|
return &bpf_get_attach_cookie_proto_umulti;
|
|
return &bpf_get_attach_cookie_proto_trace;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
/* bpf+kprobe programs can access fields of 'struct pt_regs' */
|
|
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off < 0 || off >= sizeof(struct pt_regs))
|
|
return false;
|
|
if (off % size != 0)
|
|
return false;
|
|
/*
|
|
* Assertion for 32 bit to make sure last 8 byte access
|
|
* (BPF_DW) to the last 4 byte member is disallowed.
|
|
*/
|
|
if (off + size > sizeof(struct pt_regs))
|
|
return false;
|
|
|
|
if (type == BPF_WRITE)
|
|
prog->aux->kprobe_write_ctx = true;
|
|
|
|
return true;
|
|
}
|
|
|
|
const struct bpf_verifier_ops kprobe_verifier_ops = {
|
|
.get_func_proto = kprobe_prog_func_proto,
|
|
.is_valid_access = kprobe_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops kprobe_prog_ops = {
|
|
};
|
|
|
|
BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
|
|
u64, flags, void *, data, u64, size)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
/*
|
|
* r1 points to perf tracepoint buffer where first 8 bytes are hidden
|
|
* from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
|
|
* from there and call the same bpf_perf_event_output() helper inline.
|
|
*/
|
|
return ____bpf_perf_event_output(regs, map, flags, data, size);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
|
|
.func = bpf_perf_event_output_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
|
|
u64, flags)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
/*
|
|
* Same comment as in bpf_perf_event_output_tp(), only that this time
|
|
* the other helper's function body cannot be inlined due to being
|
|
* external, thus we need to call raw helper function.
|
|
*/
|
|
return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
|
|
flags, 0, 0);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
|
|
.func = bpf_get_stackid_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
|
|
u64, flags)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
|
|
(unsigned long) size, flags, 0);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stack_proto_tp = {
|
|
.func = bpf_get_stack_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_tp;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_tp;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return &bpf_get_attach_cookie_proto_trace;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
|
|
return false;
|
|
if (type != BPF_READ)
|
|
return false;
|
|
if (off % size != 0)
|
|
return false;
|
|
|
|
BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
|
|
return true;
|
|
}
|
|
|
|
const struct bpf_verifier_ops tracepoint_verifier_ops = {
|
|
.get_func_proto = tp_prog_func_proto,
|
|
.is_valid_access = tp_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops tracepoint_prog_ops = {
|
|
};
|
|
|
|
BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
|
|
struct bpf_perf_event_value *, buf, u32, size)
|
|
{
|
|
int err = -EINVAL;
|
|
|
|
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
|
|
goto clear;
|
|
err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
|
|
&buf->running);
|
|
if (unlikely(err))
|
|
goto clear;
|
|
return 0;
|
|
clear:
|
|
memset(buf, 0, size);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
|
|
.func = bpf_perf_prog_read_value,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
|
|
void *, buf, u32, size, u64, flags)
|
|
{
|
|
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
|
|
struct perf_branch_stack *br_stack = ctx->data->br_stack;
|
|
u32 to_copy;
|
|
|
|
if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
|
|
return -ENOENT;
|
|
|
|
if (unlikely(!br_stack))
|
|
return -ENOENT;
|
|
|
|
if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
|
|
return br_stack->nr * br_entry_size;
|
|
|
|
if (!buf || (size % br_entry_size != 0))
|
|
return -EINVAL;
|
|
|
|
to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
|
|
memcpy(buf, br_stack->entries, to_copy);
|
|
|
|
return to_copy;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_read_branch_records_proto = {
|
|
.func = bpf_read_branch_records,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_MEM_OR_NULL | MEM_WRITE,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_pe;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_pe;
|
|
case BPF_FUNC_perf_prog_read_value:
|
|
return &bpf_perf_prog_read_value_proto;
|
|
case BPF_FUNC_read_branch_records:
|
|
return &bpf_read_branch_records_proto;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return &bpf_get_attach_cookie_proto_pe;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
|
|
* to avoid potential recursive reuse issue when/if tracepoints are added
|
|
* inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
|
|
*
|
|
* Since raw tracepoints run despite bpf_prog_active, support concurrent usage
|
|
* in normal, irq, and nmi context.
|
|
*/
|
|
struct bpf_raw_tp_regs {
|
|
struct pt_regs regs[3];
|
|
};
|
|
static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
|
|
static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
|
|
static struct pt_regs *get_bpf_raw_tp_regs(void)
|
|
{
|
|
struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
|
|
int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
|
|
|
|
if (nest_level > ARRAY_SIZE(tp_regs->regs)) {
|
|
this_cpu_dec(bpf_raw_tp_nest_level);
|
|
return ERR_PTR(-EBUSY);
|
|
}
|
|
|
|
return &tp_regs->regs[nest_level - 1];
|
|
}
|
|
|
|
static void put_bpf_raw_tp_regs(void)
|
|
{
|
|
this_cpu_dec(bpf_raw_tp_nest_level);
|
|
}
|
|
|
|
BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
struct bpf_map *, map, u64, flags, void *, data, u64, size)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
ret = ____bpf_perf_event_output(regs, map, flags, data, size);
|
|
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
|
|
.func = bpf_perf_event_output_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
extern const struct bpf_func_proto bpf_skb_output_proto;
|
|
extern const struct bpf_func_proto bpf_xdp_output_proto;
|
|
extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
|
|
|
|
BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
struct bpf_map *, map, u64, flags)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
|
|
ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
|
|
flags, 0, 0);
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
|
|
.func = bpf_get_stackid_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
void *, buf, u32, size, u64, flags)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
|
|
(unsigned long) size, flags, 0);
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
|
|
.func = bpf_get_stack_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_raw_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_raw_tp;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_raw_tp;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return &bpf_get_attach_cookie_proto_tracing;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
const struct bpf_func_proto *
|
|
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *fn;
|
|
|
|
switch (func_id) {
|
|
#ifdef CONFIG_NET
|
|
case BPF_FUNC_skb_output:
|
|
return &bpf_skb_output_proto;
|
|
case BPF_FUNC_xdp_output:
|
|
return &bpf_xdp_output_proto;
|
|
case BPF_FUNC_skc_to_tcp6_sock:
|
|
return &bpf_skc_to_tcp6_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_sock:
|
|
return &bpf_skc_to_tcp_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_timewait_sock:
|
|
return &bpf_skc_to_tcp_timewait_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_request_sock:
|
|
return &bpf_skc_to_tcp_request_sock_proto;
|
|
case BPF_FUNC_skc_to_udp6_sock:
|
|
return &bpf_skc_to_udp6_sock_proto;
|
|
case BPF_FUNC_skc_to_unix_sock:
|
|
return &bpf_skc_to_unix_sock_proto;
|
|
case BPF_FUNC_skc_to_mptcp_sock:
|
|
return &bpf_skc_to_mptcp_sock_proto;
|
|
case BPF_FUNC_sk_storage_get:
|
|
return &bpf_sk_storage_get_tracing_proto;
|
|
case BPF_FUNC_sk_storage_delete:
|
|
return &bpf_sk_storage_delete_tracing_proto;
|
|
case BPF_FUNC_sock_from_file:
|
|
return &bpf_sock_from_file_proto;
|
|
case BPF_FUNC_get_socket_cookie:
|
|
return &bpf_get_socket_ptr_cookie_proto;
|
|
case BPF_FUNC_xdp_get_buff_len:
|
|
return &bpf_xdp_get_buff_len_trace_proto;
|
|
#endif
|
|
case BPF_FUNC_seq_printf:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_printf_proto :
|
|
NULL;
|
|
case BPF_FUNC_seq_write:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_write_proto :
|
|
NULL;
|
|
case BPF_FUNC_seq_printf_btf:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_printf_btf_proto :
|
|
NULL;
|
|
case BPF_FUNC_d_path:
|
|
return &bpf_d_path_proto;
|
|
case BPF_FUNC_get_func_arg:
|
|
if (bpf_prog_has_trampoline(prog) ||
|
|
prog->expected_attach_type == BPF_TRACE_RAW_TP)
|
|
return &bpf_get_func_arg_proto;
|
|
return NULL;
|
|
case BPF_FUNC_get_func_ret:
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
|
|
case BPF_FUNC_get_func_arg_cnt:
|
|
if (bpf_prog_has_trampoline(prog) ||
|
|
prog->expected_attach_type == BPF_TRACE_RAW_TP)
|
|
return &bpf_get_func_arg_cnt_proto;
|
|
return NULL;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
if (prog->type == BPF_PROG_TYPE_TRACING &&
|
|
prog->expected_attach_type == BPF_TRACE_RAW_TP)
|
|
return &bpf_get_attach_cookie_proto_tracing;
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
|
|
default:
|
|
fn = raw_tp_prog_func_proto(func_id, prog);
|
|
if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
|
|
fn = bpf_iter_get_func_proto(func_id, prog);
|
|
return fn;
|
|
}
|
|
}
|
|
|
|
static bool raw_tp_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
return bpf_tracing_ctx_access(off, size, type);
|
|
}
|
|
|
|
static bool tracing_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
|
|
}
|
|
|
|
int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
|
|
const union bpf_attr *kattr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
|
|
.get_func_proto = raw_tp_prog_func_proto,
|
|
.is_valid_access = raw_tp_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops raw_tracepoint_prog_ops = {
|
|
#ifdef CONFIG_NET
|
|
.test_run = bpf_prog_test_run_raw_tp,
|
|
#endif
|
|
};
|
|
|
|
const struct bpf_verifier_ops tracing_verifier_ops = {
|
|
.get_func_proto = tracing_prog_func_proto,
|
|
.is_valid_access = tracing_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops tracing_prog_ops = {
|
|
.test_run = bpf_prog_test_run_tracing,
|
|
};
|
|
|
|
static bool raw_tp_writable_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off == 0) {
|
|
if (size != sizeof(u64) || type != BPF_READ)
|
|
return false;
|
|
info->reg_type = PTR_TO_TP_BUFFER;
|
|
}
|
|
return raw_tp_prog_is_valid_access(off, size, type, prog, info);
|
|
}
|
|
|
|
const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
|
|
.get_func_proto = raw_tp_prog_func_proto,
|
|
.is_valid_access = raw_tp_writable_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
|
|
};
|
|
|
|
static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
const int size_u64 = sizeof(u64);
|
|
|
|
if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
|
|
return false;
|
|
if (type != BPF_READ)
|
|
return false;
|
|
if (off % size != 0) {
|
|
if (sizeof(unsigned long) != 4)
|
|
return false;
|
|
if (size != 8)
|
|
return false;
|
|
if (off % size != 4)
|
|
return false;
|
|
}
|
|
|
|
switch (off) {
|
|
case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
|
|
bpf_ctx_record_field_size(info, size_u64);
|
|
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
|
|
return false;
|
|
break;
|
|
case bpf_ctx_range(struct bpf_perf_event_data, addr):
|
|
bpf_ctx_record_field_size(info, size_u64);
|
|
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
|
|
return false;
|
|
break;
|
|
default:
|
|
if (size != sizeof(long))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
|
|
const struct bpf_insn *si,
|
|
struct bpf_insn *insn_buf,
|
|
struct bpf_prog *prog, u32 *target_size)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
|
|
switch (si->off) {
|
|
case offsetof(struct bpf_perf_event_data, sample_period):
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
data), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, data));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
|
|
bpf_target_off(struct perf_sample_data, period, 8,
|
|
target_size));
|
|
break;
|
|
case offsetof(struct bpf_perf_event_data, addr):
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
data), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, data));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
|
|
bpf_target_off(struct perf_sample_data, addr, 8,
|
|
target_size));
|
|
break;
|
|
default:
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
regs), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, regs));
|
|
*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
|
|
si->off);
|
|
break;
|
|
}
|
|
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
const struct bpf_verifier_ops perf_event_verifier_ops = {
|
|
.get_func_proto = pe_prog_func_proto,
|
|
.is_valid_access = pe_prog_is_valid_access,
|
|
.convert_ctx_access = pe_prog_convert_ctx_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops perf_event_prog_ops = {
|
|
};
|
|
|
|
static DEFINE_MUTEX(bpf_event_mutex);
|
|
|
|
#define BPF_TRACE_MAX_PROGS 64
|
|
|
|
int perf_event_attach_bpf_prog(struct perf_event *event,
|
|
struct bpf_prog *prog,
|
|
u64 bpf_cookie)
|
|
{
|
|
struct bpf_prog_array *old_array;
|
|
struct bpf_prog_array *new_array;
|
|
int ret = -EEXIST;
|
|
|
|
/*
|
|
* Kprobe override only works if they are on the function entry,
|
|
* and only if they are on the opt-in list.
|
|
*/
|
|
if (prog->kprobe_override &&
|
|
(!trace_kprobe_on_func_entry(event->tp_event) ||
|
|
!trace_kprobe_error_injectable(event->tp_event)))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
|
|
if (event->prog)
|
|
goto unlock;
|
|
|
|
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
if (old_array &&
|
|
bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
|
|
ret = -E2BIG;
|
|
goto unlock;
|
|
}
|
|
|
|
ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
|
|
if (ret < 0)
|
|
goto unlock;
|
|
|
|
/* set the new array to event->tp_event and set event->prog */
|
|
event->prog = prog;
|
|
event->bpf_cookie = bpf_cookie;
|
|
rcu_assign_pointer(event->tp_event->prog_array, new_array);
|
|
bpf_prog_array_free_sleepable(old_array);
|
|
|
|
unlock:
|
|
mutex_unlock(&bpf_event_mutex);
|
|
return ret;
|
|
}
|
|
|
|
void perf_event_detach_bpf_prog(struct perf_event *event)
|
|
{
|
|
struct bpf_prog_array *old_array;
|
|
struct bpf_prog_array *new_array;
|
|
struct bpf_prog *prog = NULL;
|
|
int ret;
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
|
|
if (!event->prog)
|
|
goto unlock;
|
|
|
|
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
if (!old_array)
|
|
goto put;
|
|
|
|
ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
|
|
if (ret < 0) {
|
|
bpf_prog_array_delete_safe(old_array, event->prog);
|
|
} else {
|
|
rcu_assign_pointer(event->tp_event->prog_array, new_array);
|
|
bpf_prog_array_free_sleepable(old_array);
|
|
}
|
|
|
|
put:
|
|
prog = event->prog;
|
|
event->prog = NULL;
|
|
|
|
unlock:
|
|
mutex_unlock(&bpf_event_mutex);
|
|
|
|
if (prog) {
|
|
/*
|
|
* It could be that the bpf_prog is not sleepable (and will be freed
|
|
* via normal RCU), but is called from a point that supports sleepable
|
|
* programs and uses tasks-trace-RCU.
|
|
*/
|
|
synchronize_rcu_tasks_trace();
|
|
|
|
bpf_prog_put(prog);
|
|
}
|
|
}
|
|
|
|
int perf_event_query_prog_array(struct perf_event *event, void __user *info)
|
|
{
|
|
struct perf_event_query_bpf __user *uquery = info;
|
|
struct perf_event_query_bpf query = {};
|
|
struct bpf_prog_array *progs;
|
|
u32 *ids, prog_cnt, ids_len;
|
|
int ret;
|
|
|
|
if (!perfmon_capable())
|
|
return -EPERM;
|
|
if (event->attr.type != PERF_TYPE_TRACEPOINT)
|
|
return -EINVAL;
|
|
if (copy_from_user(&query, uquery, sizeof(query)))
|
|
return -EFAULT;
|
|
|
|
ids_len = query.ids_len;
|
|
if (ids_len > BPF_TRACE_MAX_PROGS)
|
|
return -E2BIG;
|
|
ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
|
|
if (!ids)
|
|
return -ENOMEM;
|
|
/*
|
|
* The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
|
|
* is required when user only wants to check for uquery->prog_cnt.
|
|
* There is no need to check for it since the case is handled
|
|
* gracefully in bpf_prog_array_copy_info.
|
|
*/
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
|
|
mutex_unlock(&bpf_event_mutex);
|
|
|
|
if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
|
|
copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
|
|
ret = -EFAULT;
|
|
|
|
kfree(ids);
|
|
return ret;
|
|
}
|
|
|
|
extern struct bpf_raw_event_map __start__bpf_raw_tp[];
|
|
extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
|
|
|
|
struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
|
|
{
|
|
struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
|
|
|
|
for (; btp < __stop__bpf_raw_tp; btp++) {
|
|
if (!strcmp(btp->tp->name, name))
|
|
return btp;
|
|
}
|
|
|
|
return bpf_get_raw_tracepoint_module(name);
|
|
}
|
|
|
|
void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
|
|
{
|
|
struct module *mod;
|
|
|
|
guard(rcu)();
|
|
mod = __module_address((unsigned long)btp);
|
|
module_put(mod);
|
|
}
|
|
|
|
static __always_inline
|
|
void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
|
|
{
|
|
struct bpf_prog *prog = link->link.prog;
|
|
struct bpf_run_ctx *old_run_ctx;
|
|
struct bpf_trace_run_ctx run_ctx;
|
|
|
|
rcu_read_lock_dont_migrate();
|
|
if (unlikely(!bpf_prog_get_recursion_context(prog))) {
|
|
bpf_prog_inc_misses_counter(prog);
|
|
goto out;
|
|
}
|
|
|
|
run_ctx.bpf_cookie = link->cookie;
|
|
old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
|
|
|
|
(void) bpf_prog_run(prog, args);
|
|
|
|
bpf_reset_run_ctx(old_run_ctx);
|
|
out:
|
|
bpf_prog_put_recursion_context(prog);
|
|
rcu_read_unlock_migrate();
|
|
}
|
|
|
|
#define UNPACK(...) __VA_ARGS__
|
|
#define REPEAT_1(FN, DL, X, ...) FN(X)
|
|
#define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
|
|
#define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
|
|
|
|
#define SARG(X) u64 arg##X
|
|
#define COPY(X) args[X] = arg##X
|
|
|
|
#define __DL_COM (,)
|
|
#define __DL_SEM (;)
|
|
|
|
#define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
|
|
|
|
#define BPF_TRACE_DEFN_x(x) \
|
|
void bpf_trace_run##x(struct bpf_raw_tp_link *link, \
|
|
REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
|
|
{ \
|
|
u64 args[x]; \
|
|
REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
|
|
__bpf_trace_run(link, args); \
|
|
} \
|
|
EXPORT_SYMBOL_GPL(bpf_trace_run##x)
|
|
BPF_TRACE_DEFN_x(1);
|
|
BPF_TRACE_DEFN_x(2);
|
|
BPF_TRACE_DEFN_x(3);
|
|
BPF_TRACE_DEFN_x(4);
|
|
BPF_TRACE_DEFN_x(5);
|
|
BPF_TRACE_DEFN_x(6);
|
|
BPF_TRACE_DEFN_x(7);
|
|
BPF_TRACE_DEFN_x(8);
|
|
BPF_TRACE_DEFN_x(9);
|
|
BPF_TRACE_DEFN_x(10);
|
|
BPF_TRACE_DEFN_x(11);
|
|
BPF_TRACE_DEFN_x(12);
|
|
|
|
int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
|
|
{
|
|
struct tracepoint *tp = btp->tp;
|
|
struct bpf_prog *prog = link->link.prog;
|
|
|
|
/*
|
|
* check that program doesn't access arguments beyond what's
|
|
* available in this tracepoint
|
|
*/
|
|
if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
|
|
return -EINVAL;
|
|
|
|
if (prog->aux->max_tp_access > btp->writable_size)
|
|
return -EINVAL;
|
|
|
|
return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
|
|
}
|
|
|
|
int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
|
|
{
|
|
return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
|
|
}
|
|
|
|
int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
|
|
u32 *fd_type, const char **buf,
|
|
u64 *probe_offset, u64 *probe_addr,
|
|
unsigned long *missed)
|
|
{
|
|
bool is_tracepoint, is_syscall_tp;
|
|
struct bpf_prog *prog;
|
|
int flags, err = 0;
|
|
|
|
prog = event->prog;
|
|
if (!prog)
|
|
return -ENOENT;
|
|
|
|
/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
|
|
if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
|
|
return -EOPNOTSUPP;
|
|
|
|
*prog_id = prog->aux->id;
|
|
flags = event->tp_event->flags;
|
|
is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
|
|
is_syscall_tp = is_syscall_trace_event(event->tp_event);
|
|
|
|
if (is_tracepoint || is_syscall_tp) {
|
|
*buf = is_tracepoint ? event->tp_event->tp->name
|
|
: event->tp_event->name;
|
|
/* We allow NULL pointer for tracepoint */
|
|
if (fd_type)
|
|
*fd_type = BPF_FD_TYPE_TRACEPOINT;
|
|
if (probe_offset)
|
|
*probe_offset = 0x0;
|
|
if (probe_addr)
|
|
*probe_addr = 0x0;
|
|
} else {
|
|
/* kprobe/uprobe */
|
|
err = -EOPNOTSUPP;
|
|
#ifdef CONFIG_KPROBE_EVENTS
|
|
if (flags & TRACE_EVENT_FL_KPROBE)
|
|
err = bpf_get_kprobe_info(event, fd_type, buf,
|
|
probe_offset, probe_addr, missed,
|
|
event->attr.type == PERF_TYPE_TRACEPOINT);
|
|
#endif
|
|
#ifdef CONFIG_UPROBE_EVENTS
|
|
if (flags & TRACE_EVENT_FL_UPROBE)
|
|
err = bpf_get_uprobe_info(event, fd_type, buf,
|
|
probe_offset, probe_addr,
|
|
event->attr.type == PERF_TYPE_TRACEPOINT);
|
|
#endif
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int __init send_signal_irq_work_init(void)
|
|
{
|
|
int cpu;
|
|
struct send_signal_irq_work *work;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
work = per_cpu_ptr(&send_signal_work, cpu);
|
|
init_irq_work(&work->irq_work, do_bpf_send_signal);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(send_signal_irq_work_init);
|
|
|
|
#ifdef CONFIG_MODULES
|
|
static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
|
|
void *module)
|
|
{
|
|
struct bpf_trace_module *btm, *tmp;
|
|
struct module *mod = module;
|
|
int ret = 0;
|
|
|
|
if (mod->num_bpf_raw_events == 0 ||
|
|
(op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
|
|
goto out;
|
|
|
|
mutex_lock(&bpf_module_mutex);
|
|
|
|
switch (op) {
|
|
case MODULE_STATE_COMING:
|
|
btm = kzalloc(sizeof(*btm), GFP_KERNEL);
|
|
if (btm) {
|
|
btm->module = module;
|
|
list_add(&btm->list, &bpf_trace_modules);
|
|
} else {
|
|
ret = -ENOMEM;
|
|
}
|
|
break;
|
|
case MODULE_STATE_GOING:
|
|
list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
|
|
if (btm->module == module) {
|
|
list_del(&btm->list);
|
|
kfree(btm);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&bpf_module_mutex);
|
|
|
|
out:
|
|
return notifier_from_errno(ret);
|
|
}
|
|
|
|
static struct notifier_block bpf_module_nb = {
|
|
.notifier_call = bpf_event_notify,
|
|
};
|
|
|
|
static int __init bpf_event_init(void)
|
|
{
|
|
register_module_notifier(&bpf_module_nb);
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(bpf_event_init);
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
struct bpf_session_run_ctx {
|
|
struct bpf_run_ctx run_ctx;
|
|
bool is_return;
|
|
void *data;
|
|
};
|
|
|
|
#ifdef CONFIG_FPROBE
|
|
struct bpf_kprobe_multi_link {
|
|
struct bpf_link link;
|
|
struct fprobe fp;
|
|
unsigned long *addrs;
|
|
u64 *cookies;
|
|
u32 cnt;
|
|
u32 mods_cnt;
|
|
struct module **mods;
|
|
};
|
|
|
|
struct bpf_kprobe_multi_run_ctx {
|
|
struct bpf_session_run_ctx session_ctx;
|
|
struct bpf_kprobe_multi_link *link;
|
|
unsigned long entry_ip;
|
|
};
|
|
|
|
struct user_syms {
|
|
const char **syms;
|
|
char *buf;
|
|
};
|
|
|
|
#ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
|
|
static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
|
|
#define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
|
|
#else
|
|
#define bpf_kprobe_multi_pt_regs_ptr() (NULL)
|
|
#endif
|
|
|
|
static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
|
|
{
|
|
unsigned long ip = ftrace_get_symaddr(fentry_ip);
|
|
|
|
return ip ? : fentry_ip;
|
|
}
|
|
|
|
static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
|
|
{
|
|
unsigned long __user usymbol;
|
|
const char **syms = NULL;
|
|
char *buf = NULL, *p;
|
|
int err = -ENOMEM;
|
|
unsigned int i;
|
|
|
|
syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
|
|
if (!syms)
|
|
goto error;
|
|
|
|
buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
|
|
if (!buf)
|
|
goto error;
|
|
|
|
for (p = buf, i = 0; i < cnt; i++) {
|
|
if (__get_user(usymbol, usyms + i)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
|
|
if (err == KSYM_NAME_LEN)
|
|
err = -E2BIG;
|
|
if (err < 0)
|
|
goto error;
|
|
syms[i] = p;
|
|
p += err + 1;
|
|
}
|
|
|
|
us->syms = syms;
|
|
us->buf = buf;
|
|
return 0;
|
|
|
|
error:
|
|
if (err) {
|
|
kvfree(syms);
|
|
kvfree(buf);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
|
|
{
|
|
u32 i;
|
|
|
|
for (i = 0; i < cnt; i++)
|
|
module_put(mods[i]);
|
|
}
|
|
|
|
static void free_user_syms(struct user_syms *us)
|
|
{
|
|
kvfree(us->syms);
|
|
kvfree(us->buf);
|
|
}
|
|
|
|
static void bpf_kprobe_multi_link_release(struct bpf_link *link)
|
|
{
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
unregister_fprobe(&kmulti_link->fp);
|
|
kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
|
|
}
|
|
|
|
static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
|
|
{
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
kvfree(kmulti_link->addrs);
|
|
kvfree(kmulti_link->cookies);
|
|
kfree(kmulti_link->mods);
|
|
kfree(kmulti_link);
|
|
}
|
|
|
|
static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
|
|
struct bpf_link_info *info)
|
|
{
|
|
u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
|
|
u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
u32 ucount = info->kprobe_multi.count;
|
|
int err = 0, i;
|
|
|
|
if (!uaddrs ^ !ucount)
|
|
return -EINVAL;
|
|
if (ucookies && !ucount)
|
|
return -EINVAL;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
info->kprobe_multi.count = kmulti_link->cnt;
|
|
info->kprobe_multi.flags = kmulti_link->link.flags;
|
|
info->kprobe_multi.missed = kmulti_link->fp.nmissed;
|
|
|
|
if (!uaddrs)
|
|
return 0;
|
|
if (ucount < kmulti_link->cnt)
|
|
err = -ENOSPC;
|
|
else
|
|
ucount = kmulti_link->cnt;
|
|
|
|
if (ucookies) {
|
|
if (kmulti_link->cookies) {
|
|
if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
|
|
return -EFAULT;
|
|
} else {
|
|
for (i = 0; i < ucount; i++) {
|
|
if (put_user(0, ucookies + i))
|
|
return -EFAULT;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (kallsyms_show_value(current_cred())) {
|
|
if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
|
|
return -EFAULT;
|
|
} else {
|
|
for (i = 0; i < ucount; i++) {
|
|
if (put_user(0, uaddrs + i))
|
|
return -EFAULT;
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link,
|
|
struct seq_file *seq)
|
|
{
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
|
|
seq_printf(seq,
|
|
"kprobe_cnt:\t%u\n"
|
|
"missed:\t%lu\n",
|
|
kmulti_link->cnt,
|
|
kmulti_link->fp.nmissed);
|
|
|
|
seq_printf(seq, "%s\t %s\n", "cookie", "func");
|
|
for (int i = 0; i < kmulti_link->cnt; i++) {
|
|
seq_printf(seq,
|
|
"%llu\t %pS\n",
|
|
kmulti_link->cookies[i],
|
|
(void *)kmulti_link->addrs[i]);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
|
|
.release = bpf_kprobe_multi_link_release,
|
|
.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
|
|
.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = bpf_kprobe_multi_show_fdinfo,
|
|
#endif
|
|
};
|
|
|
|
static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
|
|
{
|
|
const struct bpf_kprobe_multi_link *link = priv;
|
|
unsigned long *addr_a = a, *addr_b = b;
|
|
u64 *cookie_a, *cookie_b;
|
|
|
|
cookie_a = link->cookies + (addr_a - link->addrs);
|
|
cookie_b = link->cookies + (addr_b - link->addrs);
|
|
|
|
/* swap addr_a/addr_b and cookie_a/cookie_b values */
|
|
swap(*addr_a, *addr_b);
|
|
swap(*cookie_a, *cookie_b);
|
|
}
|
|
|
|
static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
|
|
{
|
|
const unsigned long *addr_a = a, *addr_b = b;
|
|
|
|
if (*addr_a == *addr_b)
|
|
return 0;
|
|
return *addr_a < *addr_b ? -1 : 1;
|
|
}
|
|
|
|
static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
|
|
{
|
|
return bpf_kprobe_multi_addrs_cmp(a, b);
|
|
}
|
|
|
|
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx *run_ctx;
|
|
struct bpf_kprobe_multi_link *link;
|
|
u64 *cookie, entry_ip;
|
|
unsigned long *addr;
|
|
|
|
if (WARN_ON_ONCE(!ctx))
|
|
return 0;
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
|
|
session_ctx.run_ctx);
|
|
link = run_ctx->link;
|
|
if (!link->cookies)
|
|
return 0;
|
|
entry_ip = run_ctx->entry_ip;
|
|
addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
|
|
bpf_kprobe_multi_addrs_cmp);
|
|
if (!addr)
|
|
return 0;
|
|
cookie = link->cookies + (addr - link->addrs);
|
|
return *cookie;
|
|
}
|
|
|
|
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
|
|
session_ctx.run_ctx);
|
|
return run_ctx->entry_ip;
|
|
}
|
|
|
|
static __always_inline int
|
|
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
|
|
unsigned long entry_ip, struct ftrace_regs *fregs,
|
|
bool is_return, void *data)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx run_ctx = {
|
|
.session_ctx = {
|
|
.is_return = is_return,
|
|
.data = data,
|
|
},
|
|
.link = link,
|
|
.entry_ip = entry_ip,
|
|
};
|
|
struct bpf_run_ctx *old_run_ctx;
|
|
struct pt_regs *regs;
|
|
int err;
|
|
|
|
/*
|
|
* graph tracer framework ensures we won't migrate, so there is no need
|
|
* to use migrate_disable for bpf_prog_run again. The check here just for
|
|
* __this_cpu_inc_return.
|
|
*/
|
|
cant_sleep();
|
|
|
|
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
|
|
bpf_prog_inc_misses_counter(link->link.prog);
|
|
err = 1;
|
|
goto out;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
|
|
old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
|
|
err = bpf_prog_run(link->link.prog, regs);
|
|
bpf_reset_run_ctx(old_run_ctx);
|
|
ftrace_partial_regs_update(fregs, bpf_kprobe_multi_pt_regs_ptr());
|
|
rcu_read_unlock();
|
|
|
|
out:
|
|
__this_cpu_dec(bpf_prog_active);
|
|
return err;
|
|
}
|
|
|
|
static int
|
|
kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
|
|
unsigned long ret_ip, struct ftrace_regs *fregs,
|
|
void *data)
|
|
{
|
|
struct bpf_kprobe_multi_link *link;
|
|
int err;
|
|
|
|
link = container_of(fp, struct bpf_kprobe_multi_link, fp);
|
|
err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
|
|
fregs, false, data);
|
|
return is_kprobe_session(link->link.prog) ? err : 0;
|
|
}
|
|
|
|
static void
|
|
kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
|
|
unsigned long ret_ip, struct ftrace_regs *fregs,
|
|
void *data)
|
|
{
|
|
struct bpf_kprobe_multi_link *link;
|
|
|
|
link = container_of(fp, struct bpf_kprobe_multi_link, fp);
|
|
kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
|
|
fregs, true, data);
|
|
}
|
|
|
|
static int symbols_cmp_r(const void *a, const void *b, const void *priv)
|
|
{
|
|
const char **str_a = (const char **) a;
|
|
const char **str_b = (const char **) b;
|
|
|
|
return strcmp(*str_a, *str_b);
|
|
}
|
|
|
|
struct multi_symbols_sort {
|
|
const char **funcs;
|
|
u64 *cookies;
|
|
};
|
|
|
|
static void symbols_swap_r(void *a, void *b, int size, const void *priv)
|
|
{
|
|
const struct multi_symbols_sort *data = priv;
|
|
const char **name_a = a, **name_b = b;
|
|
|
|
swap(*name_a, *name_b);
|
|
|
|
/* If defined, swap also related cookies. */
|
|
if (data->cookies) {
|
|
u64 *cookie_a, *cookie_b;
|
|
|
|
cookie_a = data->cookies + (name_a - data->funcs);
|
|
cookie_b = data->cookies + (name_b - data->funcs);
|
|
swap(*cookie_a, *cookie_b);
|
|
}
|
|
}
|
|
|
|
struct modules_array {
|
|
struct module **mods;
|
|
int mods_cnt;
|
|
int mods_cap;
|
|
};
|
|
|
|
static int add_module(struct modules_array *arr, struct module *mod)
|
|
{
|
|
struct module **mods;
|
|
|
|
if (arr->mods_cnt == arr->mods_cap) {
|
|
arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
|
|
mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
|
|
if (!mods)
|
|
return -ENOMEM;
|
|
arr->mods = mods;
|
|
}
|
|
|
|
arr->mods[arr->mods_cnt] = mod;
|
|
arr->mods_cnt++;
|
|
return 0;
|
|
}
|
|
|
|
static bool has_module(struct modules_array *arr, struct module *mod)
|
|
{
|
|
int i;
|
|
|
|
for (i = arr->mods_cnt - 1; i >= 0; i--) {
|
|
if (arr->mods[i] == mod)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
|
|
{
|
|
struct modules_array arr = {};
|
|
u32 i, err = 0;
|
|
|
|
for (i = 0; i < addrs_cnt; i++) {
|
|
bool skip_add = false;
|
|
struct module *mod;
|
|
|
|
scoped_guard(rcu) {
|
|
mod = __module_address(addrs[i]);
|
|
/* Either no module or it's already stored */
|
|
if (!mod || has_module(&arr, mod)) {
|
|
skip_add = true;
|
|
break; /* scoped_guard */
|
|
}
|
|
if (!try_module_get(mod))
|
|
err = -EINVAL;
|
|
}
|
|
if (skip_add)
|
|
continue;
|
|
if (err)
|
|
break;
|
|
err = add_module(&arr, mod);
|
|
if (err) {
|
|
module_put(mod);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* We return either err < 0 in case of error, ... */
|
|
if (err) {
|
|
kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
|
|
kfree(arr.mods);
|
|
return err;
|
|
}
|
|
|
|
/* or number of modules found if everything is ok. */
|
|
*mods = arr.mods;
|
|
return arr.mods_cnt;
|
|
}
|
|
|
|
static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
|
|
{
|
|
u32 i;
|
|
|
|
for (i = 0; i < cnt; i++) {
|
|
if (!within_error_injection_list(addrs[i]))
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
struct bpf_kprobe_multi_link *link = NULL;
|
|
struct bpf_link_primer link_primer;
|
|
void __user *ucookies;
|
|
unsigned long *addrs;
|
|
u32 flags, cnt, size;
|
|
void __user *uaddrs;
|
|
u64 *cookies = NULL;
|
|
void __user *usyms;
|
|
int err;
|
|
|
|
/* no support for 32bit archs yet */
|
|
if (sizeof(u64) != sizeof(void *))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (attr->link_create.flags)
|
|
return -EINVAL;
|
|
|
|
if (!is_kprobe_multi(prog))
|
|
return -EINVAL;
|
|
|
|
/* Writing to context is not allowed for kprobes. */
|
|
if (prog->aux->kprobe_write_ctx)
|
|
return -EINVAL;
|
|
|
|
flags = attr->link_create.kprobe_multi.flags;
|
|
if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
|
|
return -EINVAL;
|
|
|
|
uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
|
|
usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
|
|
if (!!uaddrs == !!usyms)
|
|
return -EINVAL;
|
|
|
|
cnt = attr->link_create.kprobe_multi.cnt;
|
|
if (!cnt)
|
|
return -EINVAL;
|
|
if (cnt > MAX_KPROBE_MULTI_CNT)
|
|
return -E2BIG;
|
|
|
|
size = cnt * sizeof(*addrs);
|
|
addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
|
|
if (!addrs)
|
|
return -ENOMEM;
|
|
|
|
ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
|
|
if (ucookies) {
|
|
cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
|
|
if (!cookies) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
if (copy_from_user(cookies, ucookies, size)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
if (uaddrs) {
|
|
if (copy_from_user(addrs, uaddrs, size)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
} else {
|
|
struct multi_symbols_sort data = {
|
|
.cookies = cookies,
|
|
};
|
|
struct user_syms us;
|
|
|
|
err = copy_user_syms(&us, usyms, cnt);
|
|
if (err)
|
|
goto error;
|
|
|
|
if (cookies)
|
|
data.funcs = us.syms;
|
|
|
|
sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
|
|
symbols_swap_r, &data);
|
|
|
|
err = ftrace_lookup_symbols(us.syms, cnt, addrs);
|
|
free_user_syms(&us);
|
|
if (err)
|
|
goto error;
|
|
}
|
|
|
|
if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
|
|
err = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL);
|
|
if (!link) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
|
|
&bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type);
|
|
|
|
err = bpf_link_prime(&link->link, &link_primer);
|
|
if (err)
|
|
goto error;
|
|
|
|
if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
|
|
link->fp.entry_handler = kprobe_multi_link_handler;
|
|
if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
|
|
link->fp.exit_handler = kprobe_multi_link_exit_handler;
|
|
if (is_kprobe_session(prog))
|
|
link->fp.entry_data_size = sizeof(u64);
|
|
|
|
link->addrs = addrs;
|
|
link->cookies = cookies;
|
|
link->cnt = cnt;
|
|
link->link.flags = flags;
|
|
|
|
if (cookies) {
|
|
/*
|
|
* Sorting addresses will trigger sorting cookies as well
|
|
* (check bpf_kprobe_multi_cookie_swap). This way we can
|
|
* find cookie based on the address in bpf_get_attach_cookie
|
|
* helper.
|
|
*/
|
|
sort_r(addrs, cnt, sizeof(*addrs),
|
|
bpf_kprobe_multi_cookie_cmp,
|
|
bpf_kprobe_multi_cookie_swap,
|
|
link);
|
|
}
|
|
|
|
err = get_modules_for_addrs(&link->mods, addrs, cnt);
|
|
if (err < 0) {
|
|
bpf_link_cleanup(&link_primer);
|
|
return err;
|
|
}
|
|
link->mods_cnt = err;
|
|
|
|
err = register_fprobe_ips(&link->fp, addrs, cnt);
|
|
if (err) {
|
|
kprobe_multi_put_modules(link->mods, link->mods_cnt);
|
|
bpf_link_cleanup(&link_primer);
|
|
return err;
|
|
}
|
|
|
|
return bpf_link_settle(&link_primer);
|
|
|
|
error:
|
|
kfree(link);
|
|
kvfree(addrs);
|
|
kvfree(cookies);
|
|
return err;
|
|
}
|
|
#else /* !CONFIG_FPROBE */
|
|
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_UPROBES
|
|
struct bpf_uprobe_multi_link;
|
|
|
|
struct bpf_uprobe {
|
|
struct bpf_uprobe_multi_link *link;
|
|
loff_t offset;
|
|
unsigned long ref_ctr_offset;
|
|
u64 cookie;
|
|
struct uprobe *uprobe;
|
|
struct uprobe_consumer consumer;
|
|
bool session;
|
|
};
|
|
|
|
struct bpf_uprobe_multi_link {
|
|
struct path path;
|
|
struct bpf_link link;
|
|
u32 cnt;
|
|
struct bpf_uprobe *uprobes;
|
|
struct task_struct *task;
|
|
};
|
|
|
|
struct bpf_uprobe_multi_run_ctx {
|
|
struct bpf_session_run_ctx session_ctx;
|
|
unsigned long entry_ip;
|
|
struct bpf_uprobe *uprobe;
|
|
};
|
|
|
|
static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
|
|
{
|
|
u32 i;
|
|
|
|
for (i = 0; i < cnt; i++)
|
|
uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
|
|
|
|
if (cnt)
|
|
uprobe_unregister_sync();
|
|
}
|
|
|
|
static void bpf_uprobe_multi_link_release(struct bpf_link *link)
|
|
{
|
|
struct bpf_uprobe_multi_link *umulti_link;
|
|
|
|
umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
|
|
bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
|
|
if (umulti_link->task)
|
|
put_task_struct(umulti_link->task);
|
|
path_put(&umulti_link->path);
|
|
}
|
|
|
|
static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
|
|
{
|
|
struct bpf_uprobe_multi_link *umulti_link;
|
|
|
|
umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
|
|
kvfree(umulti_link->uprobes);
|
|
kfree(umulti_link);
|
|
}
|
|
|
|
static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
|
|
struct bpf_link_info *info)
|
|
{
|
|
u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
|
|
u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
|
|
u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
|
|
u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
|
|
u32 upath_size = info->uprobe_multi.path_size;
|
|
struct bpf_uprobe_multi_link *umulti_link;
|
|
u32 ucount = info->uprobe_multi.count;
|
|
int err = 0, i;
|
|
char *p, *buf;
|
|
long left = 0;
|
|
|
|
if (!upath ^ !upath_size)
|
|
return -EINVAL;
|
|
|
|
if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
|
|
return -EINVAL;
|
|
|
|
umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
|
|
info->uprobe_multi.count = umulti_link->cnt;
|
|
info->uprobe_multi.flags = umulti_link->link.flags;
|
|
info->uprobe_multi.pid = umulti_link->task ?
|
|
task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
|
|
|
|
upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
|
|
buf = kmalloc(upath_size, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
p = d_path(&umulti_link->path, buf, upath_size);
|
|
if (IS_ERR(p)) {
|
|
kfree(buf);
|
|
return PTR_ERR(p);
|
|
}
|
|
upath_size = buf + upath_size - p;
|
|
|
|
if (upath)
|
|
left = copy_to_user(upath, p, upath_size);
|
|
kfree(buf);
|
|
if (left)
|
|
return -EFAULT;
|
|
info->uprobe_multi.path_size = upath_size;
|
|
|
|
if (!uoffsets && !ucookies && !uref_ctr_offsets)
|
|
return 0;
|
|
|
|
if (ucount < umulti_link->cnt)
|
|
err = -ENOSPC;
|
|
else
|
|
ucount = umulti_link->cnt;
|
|
|
|
for (i = 0; i < ucount; i++) {
|
|
if (uoffsets &&
|
|
put_user(umulti_link->uprobes[i].offset, uoffsets + i))
|
|
return -EFAULT;
|
|
if (uref_ctr_offsets &&
|
|
put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
|
|
return -EFAULT;
|
|
if (ucookies &&
|
|
put_user(umulti_link->uprobes[i].cookie, ucookies + i))
|
|
return -EFAULT;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link,
|
|
struct seq_file *seq)
|
|
{
|
|
struct bpf_uprobe_multi_link *umulti_link;
|
|
char *p, *buf;
|
|
pid_t pid;
|
|
|
|
umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
|
|
|
|
buf = kmalloc(PATH_MAX, GFP_KERNEL);
|
|
if (!buf)
|
|
return;
|
|
|
|
p = d_path(&umulti_link->path, buf, PATH_MAX);
|
|
if (IS_ERR(p)) {
|
|
kfree(buf);
|
|
return;
|
|
}
|
|
|
|
pid = umulti_link->task ?
|
|
task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
|
|
seq_printf(seq,
|
|
"uprobe_cnt:\t%u\n"
|
|
"pid:\t%u\n"
|
|
"path:\t%s\n",
|
|
umulti_link->cnt, pid, p);
|
|
|
|
seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset");
|
|
for (int i = 0; i < umulti_link->cnt; i++) {
|
|
seq_printf(seq,
|
|
"%llu\t %#llx\t %#lx\n",
|
|
umulti_link->uprobes[i].cookie,
|
|
umulti_link->uprobes[i].offset,
|
|
umulti_link->uprobes[i].ref_ctr_offset);
|
|
}
|
|
|
|
kfree(buf);
|
|
}
|
|
#endif
|
|
|
|
static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
|
|
.release = bpf_uprobe_multi_link_release,
|
|
.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
|
|
.fill_link_info = bpf_uprobe_multi_link_fill_link_info,
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = bpf_uprobe_multi_show_fdinfo,
|
|
#endif
|
|
};
|
|
|
|
static int uprobe_prog_run(struct bpf_uprobe *uprobe,
|
|
unsigned long entry_ip,
|
|
struct pt_regs *regs,
|
|
bool is_return, void *data)
|
|
{
|
|
struct bpf_uprobe_multi_link *link = uprobe->link;
|
|
struct bpf_uprobe_multi_run_ctx run_ctx = {
|
|
.session_ctx = {
|
|
.is_return = is_return,
|
|
.data = data,
|
|
},
|
|
.entry_ip = entry_ip,
|
|
.uprobe = uprobe,
|
|
};
|
|
struct bpf_prog *prog = link->link.prog;
|
|
bool sleepable = prog->sleepable;
|
|
struct bpf_run_ctx *old_run_ctx;
|
|
int err;
|
|
|
|
if (link->task && !same_thread_group(current, link->task))
|
|
return 0;
|
|
|
|
if (sleepable)
|
|
rcu_read_lock_trace();
|
|
else
|
|
rcu_read_lock();
|
|
|
|
migrate_disable();
|
|
|
|
old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
|
|
err = bpf_prog_run(link->link.prog, regs);
|
|
bpf_reset_run_ctx(old_run_ctx);
|
|
|
|
migrate_enable();
|
|
|
|
if (sleepable)
|
|
rcu_read_unlock_trace();
|
|
else
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
|
|
static bool
|
|
uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
|
|
{
|
|
struct bpf_uprobe *uprobe;
|
|
|
|
uprobe = container_of(con, struct bpf_uprobe, consumer);
|
|
return uprobe->link->task->mm == mm;
|
|
}
|
|
|
|
static int
|
|
uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
|
|
__u64 *data)
|
|
{
|
|
struct bpf_uprobe *uprobe;
|
|
int ret;
|
|
|
|
uprobe = container_of(con, struct bpf_uprobe, consumer);
|
|
ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
|
|
if (uprobe->session)
|
|
return ret ? UPROBE_HANDLER_IGNORE : 0;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
|
|
__u64 *data)
|
|
{
|
|
struct bpf_uprobe *uprobe;
|
|
|
|
uprobe = container_of(con, struct bpf_uprobe, consumer);
|
|
uprobe_prog_run(uprobe, func, regs, true, data);
|
|
return 0;
|
|
}
|
|
|
|
static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_uprobe_multi_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
|
|
session_ctx.run_ctx);
|
|
return run_ctx->entry_ip;
|
|
}
|
|
|
|
static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_uprobe_multi_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
|
|
session_ctx.run_ctx);
|
|
return run_ctx->uprobe->cookie;
|
|
}
|
|
|
|
int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
struct bpf_uprobe_multi_link *link = NULL;
|
|
unsigned long __user *uref_ctr_offsets;
|
|
struct bpf_link_primer link_primer;
|
|
struct bpf_uprobe *uprobes = NULL;
|
|
struct task_struct *task = NULL;
|
|
unsigned long __user *uoffsets;
|
|
u64 __user *ucookies;
|
|
void __user *upath;
|
|
u32 flags, cnt, i;
|
|
struct path path;
|
|
char *name;
|
|
pid_t pid;
|
|
int err;
|
|
|
|
/* no support for 32bit archs yet */
|
|
if (sizeof(u64) != sizeof(void *))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (attr->link_create.flags)
|
|
return -EINVAL;
|
|
|
|
if (!is_uprobe_multi(prog))
|
|
return -EINVAL;
|
|
|
|
flags = attr->link_create.uprobe_multi.flags;
|
|
if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* path, offsets and cnt are mandatory,
|
|
* ref_ctr_offsets and cookies are optional
|
|
*/
|
|
upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
|
|
uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
|
|
cnt = attr->link_create.uprobe_multi.cnt;
|
|
pid = attr->link_create.uprobe_multi.pid;
|
|
|
|
if (!upath || !uoffsets || !cnt || pid < 0)
|
|
return -EINVAL;
|
|
if (cnt > MAX_UPROBE_MULTI_CNT)
|
|
return -E2BIG;
|
|
|
|
uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
|
|
ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
|
|
|
|
name = strndup_user(upath, PATH_MAX);
|
|
if (IS_ERR(name)) {
|
|
err = PTR_ERR(name);
|
|
return err;
|
|
}
|
|
|
|
err = kern_path(name, LOOKUP_FOLLOW, &path);
|
|
kfree(name);
|
|
if (err)
|
|
return err;
|
|
|
|
if (!d_is_reg(path.dentry)) {
|
|
err = -EBADF;
|
|
goto error_path_put;
|
|
}
|
|
|
|
if (pid) {
|
|
rcu_read_lock();
|
|
task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
|
|
rcu_read_unlock();
|
|
if (!task) {
|
|
err = -ESRCH;
|
|
goto error_path_put;
|
|
}
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL);
|
|
uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
|
|
|
|
if (!uprobes || !link)
|
|
goto error_free;
|
|
|
|
for (i = 0; i < cnt; i++) {
|
|
if (__get_user(uprobes[i].offset, uoffsets + i)) {
|
|
err = -EFAULT;
|
|
goto error_free;
|
|
}
|
|
if (uprobes[i].offset < 0) {
|
|
err = -EINVAL;
|
|
goto error_free;
|
|
}
|
|
if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
|
|
err = -EFAULT;
|
|
goto error_free;
|
|
}
|
|
if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
|
|
err = -EFAULT;
|
|
goto error_free;
|
|
}
|
|
|
|
uprobes[i].link = link;
|
|
|
|
if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
|
|
uprobes[i].consumer.handler = uprobe_multi_link_handler;
|
|
if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
|
|
uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
|
|
if (is_uprobe_session(prog))
|
|
uprobes[i].session = true;
|
|
if (pid)
|
|
uprobes[i].consumer.filter = uprobe_multi_link_filter;
|
|
}
|
|
|
|
link->cnt = cnt;
|
|
link->uprobes = uprobes;
|
|
link->path = path;
|
|
link->task = task;
|
|
link->link.flags = flags;
|
|
|
|
bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
|
|
&bpf_uprobe_multi_link_lops, prog, attr->link_create.attach_type);
|
|
|
|
for (i = 0; i < cnt; i++) {
|
|
uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
|
|
uprobes[i].offset,
|
|
uprobes[i].ref_ctr_offset,
|
|
&uprobes[i].consumer);
|
|
if (IS_ERR(uprobes[i].uprobe)) {
|
|
err = PTR_ERR(uprobes[i].uprobe);
|
|
link->cnt = i;
|
|
goto error_unregister;
|
|
}
|
|
}
|
|
|
|
err = bpf_link_prime(&link->link, &link_primer);
|
|
if (err)
|
|
goto error_unregister;
|
|
|
|
return bpf_link_settle(&link_primer);
|
|
|
|
error_unregister:
|
|
bpf_uprobe_unregister(uprobes, link->cnt);
|
|
|
|
error_free:
|
|
kvfree(uprobes);
|
|
kfree(link);
|
|
if (task)
|
|
put_task_struct(task);
|
|
error_path_put:
|
|
path_put(&path);
|
|
return err;
|
|
}
|
|
#else /* !CONFIG_UPROBES */
|
|
int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_UPROBES */
|
|
|
|
__bpf_kfunc_start_defs();
|
|
|
|
__bpf_kfunc bool bpf_session_is_return(void *ctx)
|
|
{
|
|
struct bpf_session_run_ctx *session_ctx;
|
|
|
|
session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
|
|
return session_ctx->is_return;
|
|
}
|
|
|
|
__bpf_kfunc __u64 *bpf_session_cookie(void *ctx)
|
|
{
|
|
struct bpf_session_run_ctx *session_ctx;
|
|
|
|
session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
|
|
return session_ctx->data;
|
|
}
|
|
|
|
__bpf_kfunc_end_defs();
|
|
|
|
BTF_KFUNCS_START(session_kfunc_set_ids)
|
|
BTF_ID_FLAGS(func, bpf_session_is_return)
|
|
BTF_ID_FLAGS(func, bpf_session_cookie)
|
|
BTF_KFUNCS_END(session_kfunc_set_ids)
|
|
|
|
static int bpf_session_filter(const struct bpf_prog *prog, u32 kfunc_id)
|
|
{
|
|
if (!btf_id_set8_contains(&session_kfunc_set_ids, kfunc_id))
|
|
return 0;
|
|
|
|
if (!is_kprobe_session(prog) && !is_uprobe_session(prog) && !is_trace_fsession(prog))
|
|
return -EACCES;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct btf_kfunc_id_set bpf_session_kfunc_set = {
|
|
.owner = THIS_MODULE,
|
|
.set = &session_kfunc_set_ids,
|
|
.filter = bpf_session_filter,
|
|
};
|
|
|
|
static int __init bpf_trace_kfuncs_init(void)
|
|
{
|
|
int err = 0;
|
|
|
|
err = err ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_session_kfunc_set);
|
|
err = err ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_session_kfunc_set);
|
|
|
|
return err;
|
|
}
|
|
|
|
late_initcall(bpf_trace_kfuncs_init);
|
|
|
|
typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk);
|
|
|
|
/*
|
|
* The __always_inline is to make sure the compiler doesn't
|
|
* generate indirect calls into callbacks, which is expensive,
|
|
* on some kernel configurations. This allows compiler to put
|
|
* direct calls into all the specific callback implementations
|
|
* (copy_user_data_sleepable, copy_user_data_nofault, and so on)
|
|
*/
|
|
static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u64 doff, u64 size,
|
|
const void *unsafe_src,
|
|
copy_fn_t str_copy_fn,
|
|
struct task_struct *tsk)
|
|
{
|
|
struct bpf_dynptr_kern *dst;
|
|
u64 chunk_sz, off;
|
|
void *dst_slice;
|
|
int cnt, err;
|
|
char buf[256];
|
|
|
|
dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
|
|
if (likely(dst_slice))
|
|
return str_copy_fn(dst_slice, unsafe_src, size, tsk);
|
|
|
|
dst = (struct bpf_dynptr_kern *)dptr;
|
|
if (bpf_dynptr_check_off_len(dst, doff, size))
|
|
return -E2BIG;
|
|
|
|
for (off = 0; off < size; off += chunk_sz - 1) {
|
|
chunk_sz = min_t(u64, sizeof(buf), size - off);
|
|
/* Expect str_copy_fn to return count of copied bytes, including
|
|
* zero terminator. Next iteration increment off by chunk_sz - 1 to
|
|
* overwrite NUL.
|
|
*/
|
|
cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
|
|
if (cnt < 0)
|
|
return cnt;
|
|
err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0);
|
|
if (err)
|
|
return err;
|
|
if (cnt < chunk_sz || chunk_sz == 1) /* we are done */
|
|
return off + cnt;
|
|
}
|
|
return off;
|
|
}
|
|
|
|
static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u64 doff,
|
|
u64 size, const void *unsafe_src,
|
|
copy_fn_t copy_fn, struct task_struct *tsk)
|
|
{
|
|
struct bpf_dynptr_kern *dst;
|
|
void *dst_slice;
|
|
char buf[256];
|
|
u64 off, chunk_sz;
|
|
int err;
|
|
|
|
dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
|
|
if (likely(dst_slice))
|
|
return copy_fn(dst_slice, unsafe_src, size, tsk);
|
|
|
|
dst = (struct bpf_dynptr_kern *)dptr;
|
|
if (bpf_dynptr_check_off_len(dst, doff, size))
|
|
return -E2BIG;
|
|
|
|
for (off = 0; off < size; off += chunk_sz) {
|
|
chunk_sz = min_t(u64, sizeof(buf), size - off);
|
|
err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
|
|
if (err)
|
|
return err;
|
|
err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
|
|
}
|
|
|
|
static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
int ret;
|
|
|
|
if (!tsk) { /* Read from the current task */
|
|
ret = copy_from_user(dst, (const void __user *)unsafe_src, size);
|
|
if (ret)
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0);
|
|
if (ret != size)
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
return copy_from_kernel_nofault(dst, unsafe_src, size);
|
|
}
|
|
|
|
static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
|
|
}
|
|
|
|
static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(size == 0))
|
|
return 0;
|
|
|
|
if (tsk) {
|
|
ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0);
|
|
} else {
|
|
ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1);
|
|
/* strncpy_from_user does not guarantee NUL termination */
|
|
if (ret >= 0)
|
|
((char *)dst)[ret] = '\0';
|
|
}
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
return ret + 1;
|
|
}
|
|
|
|
static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src,
|
|
u32 size, struct task_struct *tsk)
|
|
{
|
|
return strncpy_from_kernel_nofault(dst, unsafe_src, size);
|
|
}
|
|
|
|
__bpf_kfunc_start_defs();
|
|
|
|
__bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
|
|
u64 value)
|
|
{
|
|
if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
|
|
return -EINVAL;
|
|
|
|
return bpf_send_signal_common(sig, type, task, value);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_data_nofault, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign,
|
|
copy_kernel_data_nofault, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_str_nofault, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign,
|
|
copy_kernel_str_nofault, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_data_sleepable, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign)
|
|
{
|
|
return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_str_sleepable, NULL);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign,
|
|
struct task_struct *tsk)
|
|
{
|
|
return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_data_sleepable, tsk);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u64 off,
|
|
u64 size, const void __user *unsafe_ptr__ign,
|
|
struct task_struct *tsk)
|
|
{
|
|
return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
|
|
copy_user_str_sleepable, tsk);
|
|
}
|
|
|
|
__bpf_kfunc_end_defs();
|