lkml.org 
[lkml]   [2010]   [Jan]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 2/3 v2] perf_event: cleanup for event profile buffer operation
Introduce ftrace_perf_buf_prepare() and ftrace_perf_buf_submit() to
operate event profile buffer, clean up redundant code

Changlog v1->v2:
- Rename function name address Masami and Frederic's suggestion
- Add __kprobes for ftrace_perf_buf_prepare() and make
ftrace_perf_buf_submit() inline address Masami's suggestion
- Export ftrace_perf_buf_prepare since module will use it

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
include/linux/ftrace_event.h | 18 ++++++-
include/trace/ftrace.h | 48 +++-----------------
kernel/trace/trace_event_profile.c | 52 +++++++++++++++++++--
kernel/trace/trace_kprobe.c | 86 ++++-------------------------------
kernel/trace/trace_syscalls.c | 71 ++++-------------------------
5 files changed, 88 insertions(+), 187 deletions(-)
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 3ca9485..6b7c444 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -5,6 +5,7 @@
#include <linux/trace_seq.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
+#include <linux/perf_event.h>

struct trace_array;
struct tracer;
@@ -137,9 +138,6 @@ struct ftrace_event_call {

#define FTRACE_MAX_PROFILE_SIZE 2048

-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 */

@@ -194,6 +192,20 @@ extern void ftrace_profile_disable(int event_id);
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 *
+ftrace_perf_buf_prepare(int size, unsigned short type, int *rctxp,
+ unsigned long *irq_flags);
+
+static inline void
+ftrace_perf_buf_submit(void *raw_data, int size, int rctx, u64 addr,
+ u64 count, unsigned long irq_flags)
+{
+ struct trace_entry *entry = raw_data;
+
+ perf_tp_event(entry->type, addr, count, raw_data, size);
+ perf_swevent_put_recursion_context(rctx);
+ local_irq_restore(irq_flags);
+}
#endif

#endif /* _LINUX_FTRACE_EVENT_H */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 5b46cf9..fb2c5bd 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -755,22 +755,12 @@ ftrace_profile_templ_##call(struct ftrace_event_call *event_call, \
proto) \
{ \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
- extern int perf_swevent_get_recursion_context(void); \
- extern void perf_swevent_put_recursion_context(int rctx); \
- extern void perf_tp_event(int, u64, u64, void *, int); \
struct ftrace_raw_##call *entry; \
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 __cpu; \
int rctx; \
- int pc; \
- \
- pc = preempt_count(); \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
@@ -780,42 +770,16 @@ ftrace_profile_templ_##call(struct ftrace_event_call *event_call, \
if (WARN_ONCE(__entry_size > FTRACE_MAX_PROFILE_SIZE, \
"profile buffer not large enough")) \
return; \
- \
- local_irq_save(irq_flags); \
- \
- rctx = perf_swevent_get_recursion_context(); \
- if (rctx < 0) \
- goto end_recursion; \
- \
- __cpu = smp_processor_id(); \
- \
- if (in_nmi()) \
- trace_buf = rcu_dereference(perf_trace_buf_nmi); \
- else \
- trace_buf = rcu_dereference(perf_trace_buf); \
- \
- if (!trace_buf) \
- goto end; \
- \
- raw_data = per_cpu_ptr(trace_buf, __cpu); \
- \
- *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL; \
- entry = (struct ftrace_raw_##call *)raw_data; \
- ent = &entry->ent; \
- tracing_generic_entry_update(ent, irq_flags, pc); \
- ent->type = event_call->id; \
- \
+ entry = (struct ftrace_raw_##call *)ftrace_perf_buf_prepare( \
+ __entry_size, event_call->id, &rctx, &irq_flags); \
+ if (!entry) \
+ return; \
tstruct \
\
{ assign; } \
\
- perf_tp_event(event_call->id, __addr, __count, entry, \
- __entry_size); \
- \
-end: \
- perf_swevent_put_recursion_context(rctx); \
-end_recursion: \
- local_irq_restore(irq_flags); \
+ ftrace_perf_buf_submit(entry, __entry_size, rctx, __addr, \
+ __count, irq_flags); \
}

#undef DEFINE_EVENT
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 9e25573..f0d6930 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -6,14 +6,12 @@
*/

#include <linux/module.h>
+#include <linux/kprobes.h>
#include "trace.h"


-char *perf_trace_buf;
-EXPORT_SYMBOL_GPL(perf_trace_buf);
-
-char *perf_trace_buf_nmi;
-EXPORT_SYMBOL_GPL(perf_trace_buf_nmi);
+static char *perf_trace_buf;
+static char *perf_trace_buf_nmi;

typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ;

@@ -120,3 +118,47 @@ void ftrace_profile_disable(int event_id)
}
mutex_unlock(&event_mutex);
}
+
+__kprobes void *ftrace_perf_buf_prepare(int size, unsigned short type,
+ int *rctxp, unsigned long *irq_flags)
+{
+ struct trace_entry *entry;
+ char *trace_buf, *raw_data;
+ int pc, cpu;
+
+ pc = preempt_count();
+
+ /* Protect the per cpu buffer, begin the rcu read side */
+ local_irq_save(*irq_flags);
+
+ *rctxp = perf_swevent_get_recursion_context();
+ if (*rctxp < 0)
+ goto err_recursion;
+
+ cpu = smp_processor_id();
+
+ if (in_nmi())
+ trace_buf = rcu_dereference(perf_trace_buf_nmi);
+ else
+ trace_buf = rcu_dereference(perf_trace_buf);
+
+ if (!trace_buf)
+ goto err;
+
+ 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;
+
+ entry = (struct trace_entry *)raw_data;
+ tracing_generic_entry_update(entry, *irq_flags, pc);
+ entry->type = type;
+
+ return raw_data;
+err:
+ perf_swevent_put_recursion_context(*rctxp);
+err_recursion:
+ local_irq_restore(*irq_flags);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(ftrace_perf_buf_prepare);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index aa19b6a..2714d23 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1223,14 +1223,10 @@ 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 trace_entry *ent;
- int size, __size, i, pc, __cpu;
+ int size, __size, i;
unsigned long irq_flags;
- char *trace_buf;
- char *raw_data;
int rctx;

- pc = preempt_count();
__size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1238,45 +1234,16 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
"profile buffer not large enough"))
return 0;

- /*
- * Protect the non nmi buffer
- * This also protects the rcu read side
- */
- local_irq_save(irq_flags);
-
- rctx = perf_swevent_get_recursion_context();
- if (rctx < 0)
- goto end_recursion;
-
- __cpu = smp_processor_id();
-
- if (in_nmi())
- trace_buf = rcu_dereference(perf_trace_buf_nmi);
- else
- trace_buf = rcu_dereference(perf_trace_buf);
-
- if (!trace_buf)
- goto end;
-
- 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;
- entry = (struct kprobe_trace_entry *)raw_data;
- ent = &entry->ent;
+ entry = ftrace_perf_buf_prepare(size, call->id, &rctx, &irq_flags);
+ if (!entry)
+ return 0;

- tracing_generic_entry_update(ent, irq_flags, pc);
- ent->type = call->id;
entry->nargs = tp->nr_args;
entry->ip = (unsigned long)kp->addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
- perf_tp_event(call->id, entry->ip, 1, entry, size);

-end:
- perf_swevent_put_recursion_context(rctx);
-end_recursion:
- local_irq_restore(irq_flags);
+ ftrace_perf_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags);

return 0;
}
@@ -1288,14 +1255,10 @@ 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 trace_entry *ent;
- int size, __size, i, pc, __cpu;
+ int size, __size, i;
unsigned long irq_flags;
- char *trace_buf;
- char *raw_data;
int rctx;

- pc = preempt_count();
__size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1303,46 +1266,17 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
"profile buffer not large enough"))
return 0;

- /*
- * Protect the non nmi buffer
- * This also protects the rcu read side
- */
- local_irq_save(irq_flags);
-
- rctx = perf_swevent_get_recursion_context();
- if (rctx < 0)
- goto end_recursion;
-
- __cpu = smp_processor_id();
-
- if (in_nmi())
- trace_buf = rcu_dereference(perf_trace_buf_nmi);
- else
- trace_buf = rcu_dereference(perf_trace_buf);
-
- if (!trace_buf)
- goto end;
-
- 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;
- entry = (struct kretprobe_trace_entry *)raw_data;
- ent = &entry->ent;
+ entry = ftrace_perf_buf_prepare(size, call->id, &rctx, &irq_flags);
+ if (!entry)
+ return 0;

- tracing_generic_entry_update(ent, irq_flags, pc);
- ent->type = call->id;
entry->nargs = tp->nr_args;
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
- perf_tp_event(call->id, entry->ret_ip, 1, entry, size);

-end:
- perf_swevent_put_recursion_context(rctx);
-end_recursion:
- local_irq_restore(irq_flags);
+ ftrace_perf_buf_submit(entry, size, rctx, entry->ret_ip, 1, irq_flags);

return 0;
}
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index f6b0712..6cce6a8 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -433,12 +433,9 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
struct syscall_metadata *sys_data;
struct syscall_trace_enter *rec;
unsigned long flags;
- char *trace_buf;
- char *raw_data;
int syscall_nr;
int rctx;
int size;
- int cpu;

syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
@@ -457,37 +454,15 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
"profile buffer not large enough"))
return;

- /* Protect the per cpu buffer, begin the rcu read side */
- local_irq_save(flags);
-
- rctx = perf_swevent_get_recursion_context();
- if (rctx < 0)
- goto end_recursion;
-
- cpu = smp_processor_id();
-
- trace_buf = rcu_dereference(perf_trace_buf);
-
- if (!trace_buf)
- goto end;
-
- 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;
+ rec = (struct syscall_trace_enter *)ftrace_perf_buf_prepare(size,
+ sys_data->enter_event->id, &rctx, &flags);
+ if (!rec)
+ return;

- rec = (struct syscall_trace_enter *) raw_data;
- tracing_generic_entry_update(&rec->ent, 0, 0);
- rec->ent.type = sys_data->enter_event->id;
rec->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args,
(unsigned long *)&rec->args);
- perf_tp_event(sys_data->enter_event->id, 0, 1, rec, size);
-
-end:
- perf_swevent_put_recursion_context(rctx);
-end_recursion:
- local_irq_restore(flags);
+ ftrace_perf_buf_submit(rec, size, rctx, 0, 1, flags);
}

int prof_sysenter_enable(struct ftrace_event_call *call)
@@ -531,11 +506,8 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
struct syscall_trace_exit *rec;
unsigned long flags;
int syscall_nr;
- char *trace_buf;
- char *raw_data;
int rctx;
int size;
- int cpu;

syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
@@ -557,38 +529,15 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
"exit event has grown above profile buffer size"))
return;

- /* Protect the per cpu buffer, begin the rcu read side */
- local_irq_save(flags);
-
- rctx = perf_swevent_get_recursion_context();
- if (rctx < 0)
- goto end_recursion;
-
- cpu = smp_processor_id();
-
- trace_buf = rcu_dereference(perf_trace_buf);
-
- if (!trace_buf)
- goto end;
-
- 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;
-
- rec = (struct syscall_trace_exit *)raw_data;
+ rec = (struct syscall_trace_exit *)ftrace_perf_buf_prepare(size,
+ sys_data->exit_event->id, &rctx, &flags);
+ if (!rec)
+ return;

- tracing_generic_entry_update(&rec->ent, 0, 0);
- rec->ent.type = sys_data->exit_event->id;
rec->nr = syscall_nr;
rec->ret = syscall_get_return_value(current, regs);

- perf_tp_event(sys_data->exit_event->id, 0, 1, rec, size);
-
-end:
- perf_swevent_put_recursion_context(rctx);
-end_recursion:
- local_irq_restore(flags);
+ ftrace_perf_buf_submit(rec, size, rctx, 0, 1, flags);
}

int prof_sysexit_enable(struct ftrace_event_call *call)
--
1.6.1.2



\
 
 \ /
  Last update: 2010-01-19 09:45    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site