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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/process_32.c | |
| parent | 7796931f542518092d1fd2fb7cf1f1d96e0cd4b5 (diff) | |
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/process_32.c')
| -rw-r--r-- | arch/x86/kernel/process_32.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 5350763a2d03..2b9db9371060 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -614,11 +614,21 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, struct tss_struct *tss) { struct thread_struct *prev, *next; + unsigned long debugctl; prev = &prev_p->thread; next = &next_p->thread; - if (next->debugctlmsr != prev->debugctlmsr) + debugctl = prev->debugctlmsr; + if (next->ds_area_msr != prev->ds_area_msr) { + /* we clear debugctl to make sure DS + * is not in use when we change it */ + debugctl = 0; + wrmsrl(MSR_IA32_DEBUGCTLMSR, 0); + wrmsr(MSR_IA32_DS_AREA, next->ds_area_msr, 0); + } + + if (next->debugctlmsr != debugctl) wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0); if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { @@ -642,6 +652,13 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, } #endif + if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS)) + ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS); + + if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS)) + ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES); + + if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) { /* * Disable the bitmap via an invalid offset. We still cache |