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-rw-r--r--include/linux/ftrace_event.h2
-rw-r--r--include/linux/perf_event.h28
-rw-r--r--include/trace/ftrace.h7
-rw-r--r--kernel/events/core.c23
-rw-r--r--kernel/sched/core.c2
-rw-r--r--kernel/trace/trace_event_perf.c4
-rw-r--r--kernel/trace/trace_kprobe.c4
-rw-r--r--kernel/trace/trace_syscalls.c4
-rw-r--r--kernel/trace/trace_uprobe.c2
9 files changed, 52 insertions, 24 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 0bebb5c348b8..d36f68b08acc 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -595,7 +595,7 @@ extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
char *filter_str);
extern void ftrace_profile_free_filter(struct perf_event *event);
extern void *perf_trace_buf_prepare(int size, unsigned short type,
- struct pt_regs *regs, int *rctxp);
+ struct pt_regs **regs, int *rctxp);
static inline void
perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 4f7a61ca4b39..3a7bd80b4db8 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -665,6 +665,7 @@ static inline int is_software_event(struct perf_event *event)
extern struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
+extern void ___perf_sw_event(u32, u64, struct pt_regs *, u64);
extern void __perf_sw_event(u32, u64, struct pt_regs *, u64);
#ifndef perf_arch_fetch_caller_regs
@@ -689,14 +690,25 @@ static inline void perf_fetch_caller_regs(struct pt_regs *regs)
static __always_inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
- struct pt_regs hot_regs;
+ if (static_key_false(&perf_swevent_enabled[event_id]))
+ __perf_sw_event(event_id, nr, regs, addr);
+}
+
+DECLARE_PER_CPU(struct pt_regs, __perf_regs[4]);
+/*
+ * 'Special' version for the scheduler, it hard assumes no recursion,
+ * which is guaranteed by us not actually scheduling inside other swevents
+ * because those disable preemption.
+ */
+static __always_inline void
+perf_sw_event_sched(u32 event_id, u64 nr, u64 addr)
+{
if (static_key_false(&perf_swevent_enabled[event_id])) {
- if (!regs) {
- perf_fetch_caller_regs(&hot_regs);
- regs = &hot_regs;
- }
- __perf_sw_event(event_id, nr, regs, addr);
+ struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]);
+
+ perf_fetch_caller_regs(regs);
+ ___perf_sw_event(event_id, nr, regs, addr);
}
}
@@ -712,7 +724,7 @@ static inline void perf_event_task_sched_in(struct task_struct *prev,
static inline void perf_event_task_sched_out(struct task_struct *prev,
struct task_struct *next)
{
- perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0);
+ perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0);
if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_out(prev, next);
@@ -823,6 +835,8 @@ static inline int perf_event_refresh(struct perf_event *event, int refresh)
static inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) { }
static inline void
+perf_sw_event_sched(u32 event_id, u64 nr, u64 addr) { }
+static inline void
perf_bp_event(struct perf_event *event, void *data) { }
static inline int perf_register_guest_info_callbacks
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 139b5067345b..27609dfcce25 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -763,7 +763,7 @@ perf_trace_##call(void *__data, proto) \
struct ftrace_event_call *event_call = __data; \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
struct ftrace_raw_##call *entry; \
- struct pt_regs __regs; \
+ struct pt_regs *__regs; \
u64 __addr = 0, __count = 1; \
struct task_struct *__task = NULL; \
struct hlist_head *head; \
@@ -782,18 +782,19 @@ perf_trace_##call(void *__data, proto) \
sizeof(u64)); \
__entry_size -= sizeof(u32); \
\
- perf_fetch_caller_regs(&__regs); \
entry = perf_trace_buf_prepare(__entry_size, \
event_call->event.type, &__regs, &rctx); \
if (!entry) \
return; \
\
+ perf_fetch_caller_regs(__regs); \
+ \
tstruct \
\
{ assign; } \
\
perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \
- __count, &__regs, head, __task); \
+ __count, __regs, head, __task); \
}
/*
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 882f835a0d85..c10124b772c4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5889,6 +5889,8 @@ end:
rcu_read_unlock();
}
+DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
+
int perf_swevent_get_recursion_context(void)
{
struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
@@ -5904,21 +5906,30 @@ inline void perf_swevent_put_recursion_context(int rctx)
put_recursion_context(swhash->recursion, rctx);
}
-void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
+void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
struct perf_sample_data data;
- int rctx;
- preempt_disable_notrace();
- rctx = perf_swevent_get_recursion_context();
- if (rctx < 0)
+ if (WARN_ON_ONCE(!regs))
return;
perf_sample_data_init(&data, addr, 0);
-
do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
+}
+
+void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
+{
+ int rctx;
+
+ preempt_disable_notrace();
+ rctx = perf_swevent_get_recursion_context();
+ if (unlikely(rctx < 0))
+ goto fail;
+
+ ___perf_sw_event(event_id, nr, regs, addr);
perf_swevent_put_recursion_context(rctx);
+fail:
preempt_enable_notrace();
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c0accc00566e..d22fb16a7153 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1082,7 +1082,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
if (p->sched_class->migrate_task_rq)
p->sched_class->migrate_task_rq(p, new_cpu);
p->se.nr_migrations++;
- perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0);
+ perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0);
}
__set_task_cpu(p, new_cpu);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 4b9c114ee9de..6fa484de2ba1 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -261,7 +261,7 @@ void perf_trace_del(struct perf_event *p_event, int flags)
}
void *perf_trace_buf_prepare(int size, unsigned short type,
- struct pt_regs *regs, int *rctxp)
+ struct pt_regs **regs, int *rctxp)
{
struct trace_entry *entry;
unsigned long flags;
@@ -280,6 +280,8 @@ void *perf_trace_buf_prepare(int size, unsigned short type,
if (*rctxp < 0)
return NULL;
+ if (regs)
+ *regs = this_cpu_ptr(&__perf_regs[*rctxp]);
raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]);
/* zero the dead bytes from align to not leak stack to user */
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5edb518be345..296079ae6583 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1148,7 +1148,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
+ entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
if (!entry)
return;
@@ -1179,7 +1179,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
+ entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
if (!entry)
return;
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index c6ee36fcbf90..f97f6e3a676c 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -574,7 +574,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
size -= sizeof(u32);
rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
- sys_data->enter_event->event.type, regs, &rctx);
+ sys_data->enter_event->event.type, NULL, &rctx);
if (!rec)
return;
@@ -647,7 +647,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
size -= sizeof(u32);
rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
- sys_data->exit_event->event.type, regs, &rctx);
+ sys_data->exit_event->event.type, NULL, &rctx);
if (!rec)
return;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 8520acc34b18..b11441321e7a 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1111,7 +1111,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
if (hlist_empty(head))
goto out;
- entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
+ entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
if (!entry)
goto out;
generated by cgit (git 2.34.1) at 2024-07-02 20:47:27 +0000