diff options
| author | Roland McGrath <roland@redhat.com> | 2008-07-09 01:33:14 -0700 |
|---|---|---|
| committer | Roland McGrath <roland@redhat.com> | 2008-07-16 12:15:16 -0700 |
| commit | 64f097331928b01d704047c1dbc738bb6d2a9bf9 (patch) | |
| tree | 402fe071f26a9bbdbffdc98c2f592ff9eeb6a404 | |
| parent | 6718d0d6da2749d3bff522e6057e97e6aa85e4d1 (diff) | |
| download | linux-64f097331928b01d704047c1dbc738bb6d2a9bf9.tar.bz2 | |
x86 ptrace: unify TIF_SINGLESTEP
This unifies the treatment of TIF_SINGLESTEP on i386 and x86_64.
The bit is now excluded from _TIF_WORK_MASK on i386 as it has been
on x86_64. This means the do_notify_resume() path using it is never
used, so TIF_SINGLESTEP is not cleared on returning to user mode.
Both now leave TIF_SINGLESTEP set when returning to user, so that
it's already set on an int $0x80 system call entry. This removes
the need for testing TF on the system_call path. Doing it this way
fixes the regression for PTRACE_SINGLESTEP into a sigreturn syscall,
introduced by commit 1e2e99f0e4aa6363e8515ed17011c210c8f1b52a.
The clear_TF_reenable case that sets TIF_SINGLESTEP can only happen
on a non-exception kernel entry, i.e. sysenter/syscall instruction.
That will always get to the syscall exit tracing path.
Signed-off-by: Roland McGrath <roland@redhat.com>
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_32.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_64.c | 6 | ||||
| -rw-r--r-- | include/asm-x86/thread_info.h | 4 |
4 files changed, 2 insertions, 18 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 6bc07f0f1202..0ad987d02b72 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -383,10 +383,6 @@ syscall_exit: # setting need_resched or sigpending # between sampling and the iret TRACE_IRQS_OFF - testl $X86_EFLAGS_TF,PT_EFLAGS(%esp) # If tracing set singlestep flag on exit - jz no_singlestep - orl $_TIF_SINGLESTEP,TI_flags(%ebp) -no_singlestep: movl TI_flags(%ebp), %ecx testw $_TIF_ALLWORK_MASK, %cx # current->work jne syscall_exit_work diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index d92373630963..295b5f5c9389 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -657,12 +657,6 @@ static void do_signal(struct pt_regs *regs) void do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) { - /* Pending single-step? */ - if (thread_info_flags & _TIF_SINGLESTEP) { - regs->flags |= X86_EFLAGS_TF; - clear_thread_flag(TIF_SINGLESTEP); - } - /* deal with pending signal delivery */ if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index e53b267662e7..bf87684474f1 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -487,12 +487,6 @@ static void do_signal(struct pt_regs *regs) void do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) { - /* Pending single-step? */ - if (thread_info_flags & _TIF_SINGLESTEP) { - regs->flags |= X86_EFLAGS_TF; - clear_thread_flag(TIF_SINGLESTEP); - } - #ifdef CONFIG_X86_MCE /* notify userspace of pending MCEs */ if (thread_info_flags & _TIF_MCE_NOTIFY) diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h index 895339d2bc0b..fb8d3cdf143e 100644 --- a/include/asm-x86/thread_info.h +++ b/include/asm-x86/thread_info.h @@ -124,7 +124,7 @@ struct thread_info { /* work to do on interrupt/exception return */ #define _TIF_WORK_MASK \ (0x0000FFFF & \ - ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP| \ + ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \ _TIF_SECCOMP|_TIF_SYSCALL_EMU)) /* work to do on any return to user space */ @@ -132,7 +132,7 @@ struct thread_info { /* Only used for 64 bit */ #define _TIF_DO_NOTIFY_MASK \ - (_TIF_SIGPENDING|_TIF_SINGLESTEP|_TIF_MCE_NOTIFY|_TIF_HRTICK_RESCHED) + (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_HRTICK_RESCHED) /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW \ |