Commit 19007a67 authored by Frederic Weisbecker's avatar Frederic Weisbecker

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: default avatarFrederic 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>
parent dc4ddb4c
......@@ -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)
......
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