[PATCH 50/63] perf trace: Show NULL when syscall pointer args are 0

Arnaldo Carvalho de Melo
2018-12-18T22:15:13Z

Matching strace's output format. The 'format' file for the syscall
tracepoints have an indication if the arg is a pointer, with some
exceptions like 'mmap' that has its first arg as an 'unsigned long', so
use a heuristic using the argument name, i.e. if it contains the 'addr'
substring, format it with the pointer formatter.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ddghemr8qrm6i0sb8awznbze@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-trace.c | 28 ++++++++++++----------------
tools/perf/trace/beauty/beauty.h | 3 +++
2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 35d8fbe47ee4..6ba8290a0794 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -444,6 +444,13 @@ size_t syscall_arg__scnprintf_hex(char *bf, size_t size, struct syscall_arg *arg
return scnprintf(bf, size, "%#lx", arg->val);
}

+size_t syscall_arg__scnprintf_ptr(char *bf, size_t size, struct syscall_arg *arg)
+{
+ if (arg->val == 0)
+ return scnprintf(bf, size, "NULL");
+ return syscall_arg__scnprintf_hex(bf, size, arg);
+}
+
size_t syscall_arg__scnprintf_int(char *bf, size_t size, struct syscall_arg *arg)
{
return scnprintf(bf, size, "%d", arg->val);
@@ -660,7 +667,7 @@ static struct syscall_fmt {
{ .name = "bpf",
.arg = { [0] = STRARRAY(cmd, bpf_cmd), }, },
{ .name = "brk", .hexret = true,
- .arg = { [0] = { .scnprintf = SCA_HEX, /* brk */ }, }, },
+ .arg = { [0] = { .scnprintf = SCA_PTR, /* brk */ }, }, },
{ .name = "clock_gettime",
.arg = { [0] = STRARRAY(clk_id, clockid), }, },
{ .name = "clone", .errpid = true, .nr_args = 5,
@@ -738,17 +745,12 @@ static struct syscall_fmt {
.arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
{ .name = "mknodat",
.arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
- { .name = "mlock",
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
- { .name = "mlockall",
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
{ .name = "mmap", .hexret = true,
/* The standard mmap maps to old_mmap on s390x */
#if defined(__s390x__)
.alias = "old_mmap",
#endif
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ },
- [2] = { .scnprintf = SCA_MMAP_PROT, /* prot */ },
+ .arg = { [2] = { .scnprintf = SCA_MMAP_PROT, /* prot */ },
[3] = { .scnprintf = SCA_MMAP_FLAGS, /* flags */ }, }, },
{ .name = "mount",
.arg = { [0] = { .scnprintf = SCA_FILENAME, /* dev_name */ },
@@ -760,13 +762,7 @@ static struct syscall_fmt {
{ .name = "mq_unlink",
.arg = { [0] = { .scnprintf = SCA_FILENAME, /* u_name */ }, }, },
{ .name = "mremap", .hexret = true,
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ },
- [3] = { .scnprintf = SCA_MREMAP_FLAGS, /* flags */ },
- [4] = { .scnprintf = SCA_HEX, /* new_addr */ }, }, },
- { .name = "munlock",
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
- { .name = "munmap",
- .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
+ .arg = { [3] = { .scnprintf = SCA_MREMAP_FLAGS, /* flags */ }, }, },
{ .name = "name_to_handle_at",
.arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
{ .name = "newfstatat",
@@ -1350,8 +1346,8 @@ static int syscall__set_arg_fmts(struct syscall *sc)
strcmp(field->name, "path") == 0 ||
strcmp(field->name, "pathname") == 0))
sc->arg_fmt[idx].scnprintf = SCA_FILENAME;
- else if (field->flags & TEP_FIELD_IS_POINTER)
- sc->arg_fmt[idx].scnprintf = syscall_arg__scnprintf_hex;
+ else if ((field->flags & TEP_FIELD_IS_POINTER) || strstr(field->name, "addr"))
+ sc->arg_fmt[idx].scnprintf = SCA_PTR;
else if (strcmp(field->type, "pid_t") == 0)
sc->arg_fmt[idx].scnprintf = SCA_PID;
else if (strcmp(field->type, "umode_t") == 0)
diff --git a/tools/perf/trace/beauty/beauty.h b/tools/perf/trace/beauty/beauty.h
index ac25b6410bc8..1a93d9c626ef 100644
--- a/tools/perf/trace/beauty/beauty.h
+++ b/tools/perf/trace/beauty/beauty.h
@@ -98,6 +98,9 @@ size_t syscall_arg__scnprintf_fd(char *bf, size_t size, struct syscall_arg *arg)
size_t syscall_arg__scnprintf_hex(char *bf, size_t size, struct syscall_arg *arg);
#define SCA_HEX syscall_arg__scnprintf_hex

+size_t syscall_arg__scnprintf_ptr(char *bf, size_t size, struct syscall_arg *arg);
+#define SCA_PTR syscall_arg__scnprintf_ptr
+
size_t syscall_arg__scnprintf_int(char *bf, size_t size, struct syscall_arg *arg);
#define SCA_INT syscall_arg__scnprintf_int

--
2.19.2