x86, bts: provide in-kernel branch-trace interface
Impact: cleanup
Move the BTS bits from ptrace.c into ds.c.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 24c2276..605eff9 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -252,11 +252,14 @@
put_cpu();
}
#ifdef CONFIG_X86_DS
- /* Free any DS contexts that have not been properly released. */
- if (unlikely(current->thread.ds_ctx)) {
- /* we clear debugctl to make sure DS is not used. */
- update_debugctlmsr(0);
- ds_free(current->thread.ds_ctx);
+ /* Free any BTS tracers that have not been properly released. */
+ if (unlikely(current->bts)) {
+ ds_release_bts(current->bts);
+ current->bts = NULL;
+
+ kfree(current->bts_buffer);
+ current->bts_buffer = NULL;
+ current->bts_size = 0;
}
#endif /* CONFIG_X86_DS */
}
@@ -420,48 +423,19 @@
return 0;
}
-#ifdef CONFIG_X86_DS
-static int update_debugctl(struct thread_struct *prev,
- struct thread_struct *next, unsigned long debugctl)
-{
- unsigned long ds_prev = 0;
- unsigned long ds_next = 0;
-
- if (prev->ds_ctx)
- ds_prev = (unsigned long)prev->ds_ctx->ds;
- if (next->ds_ctx)
- ds_next = (unsigned long)next->ds_ctx->ds;
-
- if (ds_next != ds_prev) {
- /* we clear debugctl to make sure DS
- * is not in use when we change it */
- debugctl = 0;
- update_debugctlmsr(0);
- wrmsr(MSR_IA32_DS_AREA, ds_next, 0);
- }
- return debugctl;
-}
-#else
-static int update_debugctl(struct thread_struct *prev,
- struct thread_struct *next, unsigned long debugctl)
-{
- return debugctl;
-}
-#endif /* CONFIG_X86_DS */
-
static noinline void
__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;
- debugctl = update_debugctl(prev, next, prev->debugctlmsr);
-
- if (next->debugctlmsr != debugctl)
+ if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
+ test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
+ ds_switch_to(prev_p, next_p);
+ else if (next->debugctlmsr != prev->debugctlmsr)
update_debugctlmsr(next->debugctlmsr);
if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
@@ -483,15 +457,6 @@
hard_enable_TSC();
}
-#ifdef CONFIG_X86_PTRACE_BTS
- 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);
-#endif /* CONFIG_X86_PTRACE_BTS */
-
-
if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
/*
* Disable the bitmap via an invalid offset. We still cache