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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:32:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:32:38 +0200 |
| commit | 70139ad9eba06eec22aa4a03d6198dce7b1d7963 (patch) | |
| tree | 869cb46a94bfae79f97cf941297b37f0652e6869 /arch/x86/include/asm/sighandling.h | |
| parent | 0cb30e3f5e2fdff1c4271330db21cec387d3d85c (diff) | |
| parent | 23fdf46589db718d538fa3e65ab0d57362d50b4a (diff) | |
Merge v6.12.34linux-rolling-lts
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/asm/sighandling.h')
| -rw-r--r-- | arch/x86/include/asm/sighandling.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h index e770c4fc47f4..8727c7e21dd1 100644 --- a/arch/x86/include/asm/sighandling.h +++ b/arch/x86/include/asm/sighandling.h @@ -24,4 +24,26 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs); int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs); int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs); +/* + * To prevent immediate repeat of single step trap on return from SIGTRAP + * handler if the trap flag (TF) is set without an external debugger attached, + * clear the software event flag in the augmented SS, ensuring no single-step + * trap is pending upon ERETU completion. + * + * Note, this function should be called in sigreturn() before the original + * state is restored to make sure the TF is read from the entry frame. + */ +static __always_inline void prevent_single_step_upon_eretu(struct pt_regs *regs) +{ + /* + * If the trap flag (TF) is set, i.e., the sigreturn() SYSCALL instruction + * is being single-stepped, do not clear the software event flag in the + * augmented SS, thus a debugger won't skip over the following instruction. + */ +#ifdef CONFIG_X86_FRED + if (!(regs->flags & X86_EFLAGS_TF)) + regs->fred_ss.swevent = 0; +#endif +} + #endif /* _ASM_X86_SIGHANDLING_H */ |