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| author | Markus Metzger <markus.t.metzger@intel.com> | 2008-01-30 13:31:09 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:31:09 +0100 |
| commit | eee3af4a2c83a97fff107ddc445d9df6fded9ce4 (patch) | |
| tree | a7e9179b82b4df9e4cf6e810c54309324589395b /arch/x86/kernel/step.c | |
| parent | 7796931f542518092d1fd2fb7cf1f1d96e0cd4b5 (diff) | |
| download | linux-eee3af4a2c83a97fff107ddc445d9df6fded9ce4.tar.bz2 | |
x86, ptrace: support for branch trace store(BTS)
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Changes to the last version:
- split implementation into two layers: ds/bts and ptrace
- renamed TIF's
- save/restore ds save area msr in __switch_to_xtra()
- make block-stepping only look at BTF bit
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.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 | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index f55c003f5b63..21ea22fda5fc 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -169,9 +169,14 @@ static void enable_step(struct task_struct *child, bool block) */ if (enable_single_step(child) && block) { set_tsk_thread_flag(child, TIF_DEBUGCTLMSR); - write_debugctlmsr(child, DEBUGCTLMSR_BTF); - } else if (test_and_clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR)) { - write_debugctlmsr(child, 0); + write_debugctlmsr(child, + child->thread.debugctlmsr | DEBUGCTLMSR_BTF); + } else { + write_debugctlmsr(child, + child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR); + + if (!child->thread.debugctlmsr) + clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); } } @@ -190,8 +195,11 @@ void user_disable_single_step(struct task_struct *child) /* * Make sure block stepping (BTF) is disabled. */ - if (test_and_clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR)) - write_debugctlmsr(child, 0); + write_debugctlmsr(child, + child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR); + + if (!child->thread.debugctlmsr) + clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); /* Always clear TIF_SINGLESTEP... */ clear_tsk_thread_flag(child, TIF_SINGLESTEP); |