From 64f097331928b01d704047c1dbc738bb6d2a9bf9 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 9 Jul 2008 01:33:14 -0700 Subject: 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 --- arch/x86/kernel/entry_32.S | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/x86/kernel/entry_32.S') diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 6bc07f0f120..0ad987d02b7 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 -- cgit v1.2.3