linux/arch/x86/include/asm/traps.h
Hou Wenlong a0cb371b52 x86/bug: Handle __WARN_printf() trap in early_fixup_exception()
The commit 5b472b6e5b ("x86_64/bug: Implement __WARN_printf()")
implemented __WARN_printf(), which changed the mechanism to use UD1
instead of UD2. However, it only handles the trap in the runtime IDT
handler, while the early booting IDT handler lacks this handling. As a
result, the usage of WARN() before the runtime IDT setup can lead to
kernel crashes. Since KMSAN is enabled after the runtime IDT setup, it
is safe to use handle_bug() directly in early_fixup_exception() to
address this issue.

Fixes: 5b472b6e5b ("x86_64/bug: Implement __WARN_printf()")
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/c4fb3645f60d3a78629d9870e8fcc8535281c24f.1768016713.git.houwenlong.hwl@antgroup.com
2026-02-23 11:19:11 +01:00

62 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_TRAPS_H
#define _ASM_X86_TRAPS_H
#include <linux/context_tracking_state.h>
#include <linux/kprobes.h>
#include <asm/debugreg.h>
#include <asm/idtentry.h>
#include <asm/siginfo.h> /* TRAP_TRACE, ... */
#include <asm/trap_pf.h>
#ifdef CONFIG_X86_64
asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
asmlinkage __visible notrace
struct pt_regs *fixup_bad_iret(struct pt_regs *bad_regs);
asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *eregs);
#endif
extern int ibt_selftest(void);
extern int ibt_selftest_noendbr(void);
#ifdef CONFIG_X86_F00F_BUG
/* For handling the FOOF bug */
void handle_invalid_op(struct pt_regs *regs);
#endif
noinstr bool handle_bug(struct pt_regs *regs);
static inline int get_si_code(unsigned long condition)
{
if (condition & DR_STEP)
return TRAP_TRACE;
else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3))
return TRAP_HWBKPT;
else
return TRAP_BRKPT;
}
void math_emulate(struct math_emu_info *);
bool fault_in_kernel_space(unsigned long address);
#ifdef CONFIG_VMAP_STACK
void __noreturn handle_stack_overflow(struct pt_regs *regs,
unsigned long fault_address,
struct stack_info *info);
#endif
static inline void cond_local_irq_enable(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
static inline void cond_local_irq_disable(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
}
#endif /* _ASM_X86_TRAPS_H */