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-rw-r--r--arch/x86/events/intel/core.c3
-rw-r--r--arch/x86/events/intel/ds.c25
-rw-r--r--include/linux/perf_event.h1
-rw-r--r--include/uapi/linux/perf_event.h2
-rw-r--r--kernel/events/core.c6
5 files changed, 21 insertions, 16 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 707b2a96e516..86f0c15dcc2d 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2997,6 +2997,9 @@ static int intel_pmu_hw_config(struct perf_event *event)
}
if (x86_pmu.pebs_aliases)
x86_pmu.pebs_aliases(event);
+
+ if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
+ event->attr.sample_type |= __PERF_SAMPLE_CALLCHAIN_EARLY;
}
if (needs_branch_stack(event)) {
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 8cf03f101938..8dbba77e0518 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1186,16 +1186,20 @@ static void setup_pebs_sample_data(struct perf_event *event,
}
/*
+ * We must however always use iregs for the unwinder to stay sane; the
+ * record BP,SP,IP can point into thin air when the record is from a
+ * previous PMI context or an (I)RET happend between the record and
+ * PMI.
+ */
+ if (sample_type & PERF_SAMPLE_CALLCHAIN)
+ data->callchain = perf_callchain(event, iregs);
+
+ /*
* We use the interrupt regs as a base because the PEBS record does not
* contain a full regs set, specifically it seems to lack segment
* descriptors, which get used by things like user_mode().
*
* In the simple case fix up only the IP for PERF_SAMPLE_IP.
- *
- * We must however always use BP,SP from iregs for the unwinder to stay
- * sane; the record BP,SP can point into thin air when the record is
- * from a previous PMI context or an (I)RET happend between the record
- * and PMI.
*/
*regs = *iregs;
@@ -1214,15 +1218,8 @@ static void setup_pebs_sample_data(struct perf_event *event,
regs->si = pebs->si;
regs->di = pebs->di;
- /*
- * Per the above; only set BP,SP if we don't need callchains.
- *
- * XXX: does this make sense?
- */
- if (!(sample_type & PERF_SAMPLE_CALLCHAIN)) {
- regs->bp = pebs->bp;
- regs->sp = pebs->sp;
- }
+ regs->bp = pebs->bp;
+ regs->sp = pebs->sp;
#ifndef CONFIG_X86_32
regs->r8 = pebs->r8;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 1fa12887ec02..87f6db437e4a 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1130,6 +1130,7 @@ extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct
extern struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
u32 max_stack, bool crosstask, bool add_mark);
+extern struct perf_callchain_entry *perf_callchain(struct perf_event *event, struct pt_regs *regs);
extern int get_callchain_buffers(int max_stack);
extern void put_callchain_buffers(void);
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index b8e288a1f740..eeb787b1c53c 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -143,6 +143,8 @@ enum perf_event_sample_format {
PERF_SAMPLE_PHYS_ADDR = 1U << 19,
PERF_SAMPLE_MAX = 1U << 20, /* non-ABI */
+
+ __PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63,
};
/*
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8f0434a9951a..cdb32cf8e33c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6343,7 +6343,7 @@ static u64 perf_virt_to_phys(u64 virt)
static struct perf_callchain_entry __empty_callchain = { .nr = 0, };
-static struct perf_callchain_entry *
+struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
bool kernel = !event->attr.exclude_callchain_kernel;
@@ -6382,7 +6382,9 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
int size = 1;
- data->callchain = perf_callchain(event, regs);
+ if (!(sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+ data->callchain = perf_callchain(event, regs);
+
size += data->callchain->nr;
header->size += size * sizeof(u64);