diff options
Diffstat (limited to 'arch/x86/kernel/traps_64.c')
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index aa248d75453..874aca397b0 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -865,27 +865,14 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs, tsk->thread.debugreg6 = condition; - /* Mask out spurious TF errors due to lazy TF clearing */ + + /* + * Single-stepping through TF: make sure we ignore any events in + * kernel space (but re-enable TF when returning to user mode). + */ if (condition & DR_STEP) { - /* - * The TF error should be masked out only if the current - * process is not traced and if the TRAP flag has been set - * previously by a tracing process (condition detected by - * the PT_DTRACE flag); remember that the i386 TRAP flag - * can be modified by the process itself in user mode, - * allowing programs to debug themselves without the ptrace() - * interface. - */ if (!user_mode(regs)) goto clear_TF_reenable; - /* - * Was the TF flag set by a debugger? If so, clear it now, - * so that register information is correct. - */ - if (tsk->ptrace & PT_DTRACE) { - regs->eflags &= ~TF_MASK; - tsk->ptrace &= ~PT_DTRACE; - } } /* Ok, finally something we can handle */ |