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author | Roland McGrath <roland@redhat.com> | 2008-01-30 13:30:50 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:50 +0100 |
commit | e1f287735c1e58c653b516931b5d3dd899edcb77 (patch) | |
tree | 1a2948cfe8ff679135971e2c573d11b847fee93d /arch/x86/kernel/step.c | |
parent | 7122ec8158b0f88befd94f4da8feae2c8d08d1b4 (diff) | |
download | kernel_samsung_smdk4412-e1f287735c1e58c653b516931b5d3dd899edcb77.zip kernel_samsung_smdk4412-e1f287735c1e58c653b516931b5d3dd899edcb77.tar.gz kernel_samsung_smdk4412-e1f287735c1e58c653b516931b5d3dd899edcb77.tar.bz2 |
x86 single_step: TIF_FORCED_TF
This changes the single-step support to use a new thread_info flag
TIF_FORCED_TF instead of the PT_DTRACE flag in task_struct.ptrace.
This keeps arch implementation uses out of this non-arch field.
This changes the ptrace access to eflags to mask TF and maintain
the TIF_FORCED_TF flag directly if userland sets TF, instead of
relying on ptrace_signal_deliver. The 64-bit and 32-bit kernels
are harmonized on this same behavior. The ptrace_signal_deliver
approach works now, but this change makes the low-level register
access code reliable when called from different contexts than a
ptrace stop, which will be possible in the future.
The 64-bit do_debug exception handler is also changed not to clear TF
from user-mode registers. This matches the 32-bit kernel's behavior.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/step.c')
-rw-r--r-- | arch/x86/kernel/step.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 6732272..243bff6 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -135,7 +135,7 @@ void user_enable_single_step(struct task_struct *child) if (is_setting_trap_flag(child, regs)) return; - child->ptrace |= PT_DTRACE; + set_tsk_thread_flag(child, TIF_FORCED_TF); } void user_disable_single_step(struct task_struct *child) @@ -144,9 +144,6 @@ void user_disable_single_step(struct task_struct *child) clear_tsk_thread_flag(child, TIF_SINGLESTEP); /* But touch TF only if it was set by us.. */ - if (child->ptrace & PT_DTRACE) { - struct pt_regs *regs = task_pt_regs(child); - regs->eflags &= ~X86_EFLAGS_TF; - child->ptrace &= ~PT_DTRACE; - } + if (test_and_clear_tsk_thread_flag(child, TIF_FORCED_TF)) + task_pt_regs(child)->eflags &= ~X86_EFLAGS_TF; } |