diff options
author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-08-11 22:22:53 +0400 |
---|---|---|
committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-08-11 22:35:30 +0400 |
commit | 19007a67a64f9b3cbbd7024f972654ebf14daade (patch) | |
tree | a993570902eb009cf6bdbc5bccfa485ff6ec960a /kernel/trace/trace_syscalls.c | |
parent | dc4ddb4c0b7348f1c9759ae8a9e7d734dc1cda82 (diff) | |
download | linux-19007a67a64f9b3cbbd7024f972654ebf14daade.tar.xz |
tracing: Support for syscall events raw records in perfcounters
This bring the support for raw syscall events in perfcounters.
The arguments or exit value are saved as a raw sample using
the PERF_SAMPLE_RAW attribute in a perf counter.
Example (for now you must explicitly set the PERF_SAMPLE_RAW flag
in perf record):
perf record -e syscalls:sys_enter_open -f -F 1 -a
perf report -D
0x2cbb8 [0x50]: event: 9
.
. ... raw event: size 80 bytes
. 0000: 09 00 00 00 02 00 50 00 20 e9 39 ab 0a 7f 00 00 ......P. .9....
. 0010: bc 14 00 00 bc 14 00 00 01 00 00 00 00 00 00 00 ...............
. 0020: 2c 00 00 00 15 01 01 00 bc 14 00 00 bc 14 00 00 ,..............
^ ^ ^ ^ ^ ^ ^ ..........................
Event Size struct trace_entry
. 0030: 00 00 00 00 46 98 43 02 00 00 00 00 80 08 00 00 ....F.C........
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
ptr to file name open flags
. 0040: 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 ...............
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
. open mode padding
0x2cbb8 [0x50]: PERF_EVENT_SAMPLE (IP, 2): 5308: 0x7f0aab39e920 period: 1
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Diffstat (limited to 'kernel/trace/trace_syscalls.c')
-rw-r--r-- | kernel/trace/trace_syscalls.c | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 9ee6386cf842..f837cccabcf7 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -301,6 +301,17 @@ struct trace_event event_syscall_exit = { }; #ifdef CONFIG_EVENT_PROFILE + +struct syscall_enter_record { + struct trace_entry entry; + unsigned long args[0]; +}; + +struct syscall_exit_record { + struct trace_entry entry; + unsigned long ret; +}; + static DECLARE_BITMAP(enabled_prof_enter_syscalls, FTRACE_SYSCALL_MAX); static DECLARE_BITMAP(enabled_prof_exit_syscalls, FTRACE_SYSCALL_MAX); static int sys_prof_refcount_enter; @@ -308,8 +319,10 @@ static int sys_prof_refcount_exit; static void prof_syscall_enter(struct pt_regs *regs, long id) { + struct syscall_enter_record *rec; struct syscall_metadata *sys_data; int syscall_nr; + int size; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_enter_syscalls)) @@ -319,7 +332,24 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) if (!sys_data) return; - perf_tpcounter_event(sys_data->enter_id, 0, 1, NULL, 0); + /* get the size after alignment with the u32 buffer size field */ + size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); + size = ALIGN(size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + + do { + char raw_data[size]; + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_enter_record *) raw_data; + tracing_generic_entry_update(&rec->entry, 0, 0); + rec->entry.type = sys_data->enter_id; + syscall_get_arguments(current, regs, 0, sys_data->nb_args, + (unsigned long *)&rec->args); + perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); + } while(0); } int reg_prof_syscall_enter(char *name) @@ -364,6 +394,7 @@ void unreg_prof_syscall_enter(char *name) static void prof_syscall_exit(struct pt_regs *regs, long ret) { struct syscall_metadata *sys_data; + struct syscall_exit_record rec; int syscall_nr; syscall_nr = syscall_get_nr(current, regs); @@ -374,7 +405,11 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) if (!sys_data) return; - perf_tpcounter_event(sys_data->exit_id, 0, 1, NULL, 0); + tracing_generic_entry_update(&rec.entry, 0, 0); + rec.entry.type = sys_data->exit_id; + rec.ret = syscall_get_return_value(current, regs); + + perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); } int reg_prof_syscall_exit(char *name) |