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-rw-r--r--include/linux/ftrace_event.h9
-rw-r--r--include/linux/perf_event.h4
-rw-r--r--include/trace/ftrace.h23
-rw-r--r--kernel/perf_event.c68
-rw-r--r--kernel/trace/trace_event_profile.c14
-rw-r--r--kernel/trace/trace_kprobe.c48
-rw-r--r--kernel/trace/trace_syscalls.c47
7 files changed, 106 insertions, 107 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 43360c1d8f70..47bbdf9c38d0 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -137,13 +137,8 @@ struct ftrace_event_call {
#define FTRACE_MAX_PROFILE_SIZE 2048
-struct perf_trace_buf {
- char buf[FTRACE_MAX_PROFILE_SIZE];
- int recursion;
-};
-
-extern struct perf_trace_buf *perf_trace_buf;
-extern struct perf_trace_buf *perf_trace_buf_nmi;
+extern char *perf_trace_buf;
+extern char *perf_trace_buf_nmi;
#define MAX_FILTER_PRED 32
#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 36fe89f72641..74e98b1d3391 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -874,6 +874,8 @@ extern int perf_output_begin(struct perf_output_handle *handle,
extern void perf_output_end(struct perf_output_handle *handle);
extern void perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
+extern int perf_swevent_get_recursion_context(int **recursion);
+extern void perf_swevent_put_recursion_context(int *recursion);
#else
static inline void
perf_event_task_sched_in(struct task_struct *task, int cpu) { }
@@ -902,6 +904,8 @@ static inline void perf_event_mmap(struct vm_area_struct *vma) { }
static inline void perf_event_comm(struct task_struct *tsk) { }
static inline void perf_event_fork(struct task_struct *tsk) { }
static inline void perf_event_init(void) { }
+static int perf_swevent_get_recursion_context(int **recursion) { return -1; }
+static void perf_swevent_put_recursion_context(int *recursion) { }
#endif
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 4945d1c99864..c222ef5238bf 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -724,16 +724,19 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
static void ftrace_profile_##call(proto) \
{ \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
+ extern int perf_swevent_get_recursion_context(int **recursion); \
+ extern void perf_swevent_put_recursion_context(int *recursion); \
struct ftrace_event_call *event_call = &event_##call; \
extern void perf_tp_event(int, u64, u64, void *, int); \
struct ftrace_raw_##call *entry; \
- struct perf_trace_buf *trace_buf; \
u64 __addr = 0, __count = 1; \
unsigned long irq_flags; \
struct trace_entry *ent; \
int __entry_size; \
int __data_size; \
+ char *trace_buf; \
char *raw_data; \
+ int *recursion; \
int __cpu; \
int pc; \
\
@@ -749,6 +752,10 @@ static void ftrace_profile_##call(proto) \
return; \
\
local_irq_save(irq_flags); \
+ \
+ if (perf_swevent_get_recursion_context(&recursion)) \
+ goto end_recursion; \
+ \
__cpu = smp_processor_id(); \
\
if (in_nmi()) \
@@ -759,13 +766,7 @@ static void ftrace_profile_##call(proto) \
if (!trace_buf) \
goto end; \
\
- trace_buf = per_cpu_ptr(trace_buf, __cpu); \
- if (trace_buf->recursion++) \
- goto end_recursion; \
- \
- barrier(); \
- \
- raw_data = trace_buf->buf; \
+ raw_data = per_cpu_ptr(trace_buf, __cpu); \
\
*(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL; \
entry = (struct ftrace_raw_##call *)raw_data; \
@@ -780,9 +781,9 @@ static void ftrace_profile_##call(proto) \
perf_tp_event(event_call->id, __addr, __count, entry, \
__entry_size); \
\
-end_recursion: \
- trace_buf->recursion--; \
-end: \
+end: \
+ perf_swevent_put_recursion_context(recursion); \
+end_recursion: \
local_irq_restore(irq_flags); \
\
}
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 718fa939b1a7..aba822722300 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3880,34 +3880,42 @@ static void perf_swevent_ctx_event(struct perf_event_context *ctx,
}
}
-static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx)
+/*
+ * Must be called with preemption disabled
+ */
+int perf_swevent_get_recursion_context(int **recursion)
{
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+
if (in_nmi())
- return &cpuctx->recursion[3];
+ *recursion = &cpuctx->recursion[3];
+ else if (in_irq())
+ *recursion = &cpuctx->recursion[2];
+ else if (in_softirq())
+ *recursion = &cpuctx->recursion[1];
+ else
+ *recursion = &cpuctx->recursion[0];
- if (in_irq())
- return &cpuctx->recursion[2];
+ if (**recursion)
+ return -1;
- if (in_softirq())
- return &cpuctx->recursion[1];
+ (**recursion)++;
- return &cpuctx->recursion[0];
+ return 0;
}
-static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
- u64 nr, int nmi,
- struct perf_sample_data *data,
- struct pt_regs *regs)
+void perf_swevent_put_recursion_context(int *recursion)
{
- struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
- int *recursion = perf_swevent_recursion_context(cpuctx);
- struct perf_event_context *ctx;
-
- if (*recursion)
- goto out;
+ (*recursion)--;
+}
- (*recursion)++;
- barrier();
+static void __do_perf_sw_event(enum perf_type_id type, u32 event_id,
+ u64 nr, int nmi,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct perf_event_context *ctx;
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
rcu_read_lock();
perf_swevent_ctx_event(&cpuctx->ctx, type, event_id,
@@ -3920,12 +3928,25 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
if (ctx)
perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs);
rcu_read_unlock();
+}
- barrier();
- (*recursion)--;
+static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
+ u64 nr, int nmi,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ int *recursion;
+
+ preempt_disable();
+
+ if (perf_swevent_get_recursion_context(&recursion))
+ goto out;
+
+ __do_perf_sw_event(type, event_id, nr, nmi, data, regs);
+ perf_swevent_put_recursion_context(recursion);
out:
- put_cpu_var(perf_cpu_context);
+ preempt_enable();
}
void __perf_sw_event(u32 event_id, u64 nr, int nmi,
@@ -4159,7 +4180,8 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
if (!regs)
regs = task_pt_regs(current);
- do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
+ /* Trace events already protected against recursion */
+ __do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
&data, regs);
}
EXPORT_SYMBOL_GPL(perf_tp_event);
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index e0d351b01f5a..d9c60f80aa0d 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -9,31 +9,33 @@
#include "trace.h"
-struct perf_trace_buf *perf_trace_buf;
+char *perf_trace_buf;
EXPORT_SYMBOL_GPL(perf_trace_buf);
-struct perf_trace_buf *perf_trace_buf_nmi;
+char *perf_trace_buf_nmi;
EXPORT_SYMBOL_GPL(perf_trace_buf_nmi);
+typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ;
+
/* Count the events in use (per event id, not per instance) */
static int total_profile_count;
static int ftrace_profile_enable_event(struct ftrace_event_call *event)
{
- struct perf_trace_buf *buf;
+ char *buf;
int ret = -ENOMEM;
if (atomic_inc_return(&event->profile_count))
return 0;
if (!total_profile_count) {
- buf = alloc_percpu(struct perf_trace_buf);
+ buf = (char *)alloc_percpu(perf_trace_t);
if (!buf)
goto fail_buf;
rcu_assign_pointer(perf_trace_buf, buf);
- buf = alloc_percpu(struct perf_trace_buf);
+ buf = (char *)alloc_percpu(perf_trace_t);
if (!buf)
goto fail_buf_nmi;
@@ -79,7 +81,7 @@ int ftrace_profile_enable(int event_id)
static void ftrace_profile_disable_event(struct ftrace_event_call *event)
{
- struct perf_trace_buf *buf, *nmi_buf;
+ char *buf, *nmi_buf;
if (!atomic_add_negative(-1, &event->profile_count))
return;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3696476f307d..22e6f68b05b3 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1208,11 +1208,12 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
struct ftrace_event_call *call = &tp->call;
struct kprobe_trace_entry *entry;
- struct perf_trace_buf *trace_buf;
struct trace_entry *ent;
int size, __size, i, pc, __cpu;
unsigned long irq_flags;
+ char *trace_buf;
char *raw_data;
+ int *recursion;
pc = preempt_count();
__size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
@@ -1227,6 +1228,10 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
* This also protects the rcu read side
*/
local_irq_save(irq_flags);
+
+ if (perf_swevent_get_recursion_context(&recursion))
+ goto end_recursion;
+
__cpu = smp_processor_id();
if (in_nmi())
@@ -1237,18 +1242,7 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
if (!trace_buf)
goto end;
- trace_buf = per_cpu_ptr(trace_buf, __cpu);
-
- if (trace_buf->recursion++)
- goto end_recursion;
-
- /*
- * Make recursion update visible before entering perf_tp_event
- * so that we protect from perf recursions.
- */
- barrier();
-
- raw_data = trace_buf->buf;
+ raw_data = per_cpu_ptr(trace_buf, __cpu);
/* Zero dead bytes from alignment to avoid buffer leak to userspace */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
@@ -1263,9 +1257,9 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ip, 1, entry, size);
-end_recursion:
- trace_buf->recursion--;
end:
+ perf_swevent_put_recursion_context(recursion);
+end_recursion:
local_irq_restore(irq_flags);
return 0;
@@ -1278,10 +1272,11 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
struct ftrace_event_call *call = &tp->call;
struct kretprobe_trace_entry *entry;
- struct perf_trace_buf *trace_buf;
struct trace_entry *ent;
int size, __size, i, pc, __cpu;
unsigned long irq_flags;
+ char *trace_buf;
+ int *recursion;
char *raw_data;
pc = preempt_count();
@@ -1297,6 +1292,10 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
* This also protects the rcu read side
*/
local_irq_save(irq_flags);
+
+ if (perf_swevent_get_recursion_context(&recursion))
+ goto end_recursion;
+
__cpu = smp_processor_id();
if (in_nmi())
@@ -1307,18 +1306,7 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
if (!trace_buf)
goto end;
- trace_buf = per_cpu_ptr(trace_buf, __cpu);
-
- if (trace_buf->recursion++)
- goto end_recursion;
-
- /*
- * Make recursion update visible before entering perf_tp_event
- * so that we protect from perf recursions.
- */
- barrier();
-
- raw_data = trace_buf->buf;
+ raw_data = per_cpu_ptr(trace_buf, __cpu);
/* Zero dead bytes from alignment to avoid buffer leak to userspace */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
@@ -1334,9 +1322,9 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
-end_recursion:
- trace_buf->recursion--;
end:
+ perf_swevent_put_recursion_context(recursion);
+end_recursion:
local_irq_restore(irq_flags);
return 0;
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 51213b0aa81b..0bb934875263 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -477,10 +477,11 @@ static int sys_prof_refcount_exit;
static void prof_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_metadata *sys_data;
- struct perf_trace_buf *trace_buf;
struct syscall_trace_enter *rec;
unsigned long flags;
+ char *trace_buf;
char *raw_data;
+ int *recursion;
int syscall_nr;
int size;
int cpu;
@@ -505,6 +506,9 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
/* Protect the per cpu buffer, begin the rcu read side */
local_irq_save(flags);
+ if (perf_swevent_get_recursion_context(&recursion))
+ goto end_recursion;
+
cpu = smp_processor_id();
if (in_nmi())
@@ -515,18 +519,7 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
if (!trace_buf)
goto end;
- trace_buf = per_cpu_ptr(trace_buf, cpu);
-
- if (trace_buf->recursion++)
- goto end_recursion;
-
- /*
- * Make recursion update visible before entering perf_tp_event
- * so that we protect from perf recursions.
- */
- barrier();
-
- raw_data = trace_buf->buf;
+ raw_data = per_cpu_ptr(trace_buf, cpu);
/* zero the dead bytes from align to not leak stack to user */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
@@ -539,9 +532,9 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
(unsigned long *)&rec->args);
perf_tp_event(sys_data->enter_id, 0, 1, rec, size);
-end_recursion:
- trace_buf->recursion--;
end:
+ perf_swevent_put_recursion_context(recursion);
+end_recursion:
local_irq_restore(flags);
}
@@ -588,10 +581,11 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_metadata *sys_data;
struct syscall_trace_exit *rec;
- struct perf_trace_buf *trace_buf;
unsigned long flags;
int syscall_nr;
+ char *trace_buf;
char *raw_data;
+ int *recursion;
int size;
int cpu;
@@ -617,6 +611,10 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
/* Protect the per cpu buffer, begin the rcu read side */
local_irq_save(flags);
+
+ if (perf_swevent_get_recursion_context(&recursion))
+ goto end_recursion;
+
cpu = smp_processor_id();
if (in_nmi())
@@ -627,18 +625,7 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
if (!trace_buf)
goto end;
- trace_buf = per_cpu_ptr(trace_buf, cpu);
-
- if (trace_buf->recursion++)
- goto end_recursion;
-
- /*
- * Make recursion update visible before entering perf_tp_event
- * so that we protect from perf recursions.
- */
- barrier();
-
- raw_data = trace_buf->buf;
+ raw_data = per_cpu_ptr(trace_buf, cpu);
/* zero the dead bytes from align to not leak stack to user */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
@@ -652,9 +639,9 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
perf_tp_event(sys_data->exit_id, 0, 1, rec, size);
-end_recursion:
- trace_buf->recursion--;
end:
+ perf_swevent_put_recursion_context(recursion);
+end_recursion:
local_irq_restore(flags);
}
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