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perf trace beauty: Allow accessing syscall args values in a syscall arg formatter

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For instance, fcntl's upcoming 'arg' formatter needs to look at the
'cmd' value to decide how to format its value, sometimes it is a file
flags, sometimes an fd, a pointer to a structure, etc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2tw2jfaqm48dtw8a4addghze@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2017-07-14 10:13:56 -03:00
parent 9cb7cf8644
commit f9f83b3344
2 changed files with 29 additions and 7 deletions
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23
tools/perf/builtin-trace.c
View File

@ -1369,19 +1369,32 @@ out:
* variable to read it. Most notably this avoids extended load instructions
* on unaligned addresses
*/
static unsigned long __syscall_arg__val(unsigned char *args, u8 idx)
{
unsigned long val;
unsigned char *p = args + sizeof(unsigned long) * idx;
memcpy(&val, p, sizeof(val));
return val;
}
unsigned long syscall_arg__val(struct syscall_arg *arg, u8 idx)
{
return __syscall_arg__val(arg->args, idx);
}
static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
unsigned char *args, struct trace *trace,
struct thread *thread)
{
size_t printed = 0;
unsigned char *p;
unsigned long val;
if (sc->args != NULL) {
struct format_field *field;
u8 bit = 1;
struct syscall_arg arg = {
.args = args,
.idx = 0,
.mask = 0,
.trace = trace,
@ -1393,9 +1406,7 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
if (arg.mask & bit)
continue;
/* special care for unaligned accesses */
p = args + sizeof(unsigned long) * arg.idx;
memcpy(&val, p, sizeof(val));
val = syscall_arg__val(&arg, arg.idx);
/*
* Suppress this argument if its value is zero and
@ -1431,9 +1442,7 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
int i = 0;
while (i < 6) {
/* special care for unaligned accesses */
p = args + sizeof(unsigned long) * i;
memcpy(&val, p, sizeof(val));
val = __syscall_arg__val(args, i);
printed += scnprintf(bf + printed, size - printed,
"%sarg%d: %ld",
printed ? ", " : "", i, val);

13
tools/perf/trace/beauty/beauty.h
View File

@ -6,8 +6,19 @@
struct trace;
struct thread;
/**
* @val: value of syscall argument being formatted
* @args: All the args, use syscall_args__val(arg, nth) to access one
* @thread: tid state (maps, pid, tid, etc)
* @trace: 'perf trace' internals: all threads, etc
* @parm: private area, may be an strarray, for instance
* @idx: syscall arg idx (is this the first?)
* @mask: a syscall arg may mask another arg, see syscall_arg__scnprintf_futex_op
*/
struct syscall_arg {
unsigned long val;
unsigned char *args;
struct thread *thread;
struct trace *trace;
void *parm;
@ -15,6 +26,8 @@ struct syscall_arg {
u8 mask;
};
unsigned long syscall_arg__val(struct syscall_arg *arg, u8 idx);
size_t syscall_arg__scnprintf_strarrays(char *bf, size_t size, struct syscall_arg *arg);
#define SCA_STRARRAYS syscall_arg__scnprintf_strarrays