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| author | Markus Metzger <markus.t.metzger@intel.com> | 2008-01-30 15:31:09 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 15:31:09 +0300 |
| commit | eee3af4a2c83a97fff107ddc445d9df6fded9ce4 (patch) | |
| tree | a7e9179b82b4df9e4cf6e810c54309324589395b /arch/x86/kernel/process_64.c | |
| parent | 7796931f542518092d1fd2fb7cf1f1d96e0cd4b5 (diff) | |
| download | linux-eee3af4a2c83a97fff107ddc445d9df6fded9ce4.tar.xz | |
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_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 057b5442ffda..843bf0c978a4 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -568,11 +568,21 @@ static inline void __switch_to_xtra(struct task_struct *prev_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); + wrmsrl(MSR_IA32_DS_AREA, next->ds_area_msr); + } + + if (next->debugctlmsr != debugctl) wrmsrl(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr); if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { @@ -598,6 +608,16 @@ static inline void __switch_to_xtra(struct task_struct *prev_p, */ memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); } + + /* + * Last branch recording recofiguration of trace hardware and + * disentangling of trace data per task. + */ + 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); } /* @@ -701,8 +721,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) /* * Now maybe reload the debug registers and handle I/O bitmaps */ - if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW)) - || test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) + if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT || + task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) __switch_to_xtra(prev_p, next_p, tss); /* If the task has used fpu the last 5 timeslices, just do a full |