[PATCH 14/19] perf trace: Beautify mode_t arguments

From: Arnaldo Carvalho de Melo
Date: Thu Apr 07 2016 - 17:00:39 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

When reading the syscall tracepoint /format file, look for arguments of type
"mode_t" and attach a beautifier:

[root@jouet ~]# cat ~/bin/tp_with_fields_of_type
#!/bin/bash
grep -w $1 /sys/kernel/tracing/events/syscalls/*/format | sed -r 's%.*sys_enter_(.*)/format.*%\1%g' | paste -d, -s
# tp_with_fields_of_type umode_t
chmod,creat,fchmodat,fchmod,mkdirat,mkdir,mknodat,mknod,mq_open,openat,open
#

Testing it:

#define S_ISUID 0004000
#define S_ISGID 0002000
#define S_ISVTX 0001000
#define S_IRWXU 0000700
#define S_IRUSR 0000400
#define S_IWUSR 0000200
#define S_IXUSR 0000100

#define S_IRWXG 0000070
#define S_IRGRP 0000040
#define S_IWGRP 0000020
#define S_IXGRP 0000010

#define S_IRWXO 0000007
#define S_IROTH 0000004
#define S_IWOTH 0000002
#define S_IXOTH 0000001

# for mode in 4000 2000 1000 700 400 200 100 70 40 20 10 7 4 2 1 ; do \
echo -n $mode '->' ; trace --no-inherit -e chmod,fchmodat,fchmod chmod $mode x; \
done
4000 -> 0.338 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: ISUID) = 0
2000 -> 0.438 ( 0.015 ms): fchmodat(dfd: CWD, filename: x, mode: ISGID) = 0
1000 -> 0.677 ( 0.040 ms): fchmodat(dfd: CWD, filename: x, mode: ISVTX) = 0
700 -> 0.394 ( 0.013 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXU) = 0
400 -> 0.337 ( 0.010 ms): fchmodat(dfd: CWD, filename: x, mode: IRUSR) = 0
200 -> 0.259 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IWUSR) = 0
100 -> 0.249 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXUSR) = 0
70 -> 0.266 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXG) = 0
40 -> 0.329 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IRGRP) = 0
20 -> 0.250 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IWGRP) = 0
10 -> 0.259 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXGRP) = 0
7 -> 0.249 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXO) = 0
4 -> 0.278 ( 0.011 ms): fchmodat(dfd: CWD, filename: x, mode: IROTH) = 0
2 -> 0.276 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IWOTH) = 0
1 -> 0.250 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXOTH) = 0
#
# trace --no-inherit -e chmod,fchmodat,fchmod chmod 7777 x
0.258 ( 0.011 ms): fchmodat(dfd: CWD, filename: x, mode: IALLUGO) = 0
# trace --no-inherit -e chmod,fchmodat,fchmod chmod 7770 x
0.258 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: ISUID|ISGID|ISVTX|IRWXU|IRWXG) = 0
# trace --no-inherit -e chmod,fchmodat,fchmod chmod 777 x
0.293 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXUGO
#

Now lets see if check by using the tracepoint for that specific syscall,
instead of raw_syscalls:sys_enter as 'trace' does for its strace fu:

# trace --no-inherit --ev syscalls:sys_enter_fchmodat -e fchmodat chmod 666 x
0.255 ( ): syscalls:sys_enter_fchmodat:dfd: 0xffffffffffffff9c, filename: 0x55db32a3f0f0, mode: 0x000001b6)
0.268 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: IRUGO|IWUGO ) = 0
#

Perfect, 0x1bc == 0666.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-18e8zfgbkj83xo87yoom43kd@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 3 ++
tools/perf/trace/beauty/mode_t.c | 68 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 71 insertions(+)
create mode 100644 tools/perf/trace/beauty/mode_t.c

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 57d4bb473add..8440e2b92c6c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1126,6 +1126,7 @@ static size_t syscall_arg__scnprintf_getrandom_flags(char *bf, size_t size,
.arg_parm = { [arg] = &strarray__##array, }

#include "trace/beauty/pid.c"
+#include "trace/beauty/mode_t.c"
#include "trace/beauty/sched_policy.c"
#include "trace/beauty/waitid_options.c"

@@ -1767,6 +1768,8 @@ static int syscall__set_arg_fmts(struct syscall *sc)
sc->arg_scnprintf[idx] = syscall_arg__scnprintf_hex;
else if (strcmp(field->type, "pid_t") == 0)
sc->arg_scnprintf[idx] = SCA_PID;
+ else if (strcmp(field->type, "umode_t") == 0)
+ sc->arg_scnprintf[idx] = SCA_MODE_T;
++idx;
}

diff --git a/tools/perf/trace/beauty/mode_t.c b/tools/perf/trace/beauty/mode_t.c
new file mode 100644
index 000000000000..930d8fef2400
--- /dev/null
+++ b/tools/perf/trace/beauty/mode_t.c
@@ -0,0 +1,68 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* From include/linux/stat.h */
+#ifndef S_IRWXUGO
+#define S_IRWXUGO (S_IRWXU|S_IRWXG|S_IRWXO)
+#endif
+#ifndef S_IALLUGO
+#define S_IALLUGO (S_ISUID|S_ISGID|S_ISVTX|S_IRWXUGO)
+#endif
+#ifndef S_IRUGO
+#define S_IRUGO (S_IRUSR|S_IRGRP|S_IROTH)
+#endif
+#ifndef S_IWUGO
+#define S_IWUGO (S_IWUSR|S_IWGRP|S_IWOTH)
+#endif
+#ifndef S_IXUGO
+#define S_IXUGO (S_IXUSR|S_IXGRP|S_IXOTH)
+#endif
+
+static size_t syscall_arg__scnprintf_mode_t(char *bf, size_t size, struct syscall_arg *arg)
+{
+ int printed = 0, mode = arg->val;
+
+#define P_MODE(n) \
+ if ((mode & S_##n) == S_##n) { \
+ printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
+ mode &= ~S_##n; \
+ }
+
+ P_MODE(IALLUGO);
+ P_MODE(IRWXUGO);
+ P_MODE(IRUGO);
+ P_MODE(IWUGO);
+ P_MODE(IXUGO);
+ P_MODE(IFMT);
+ P_MODE(IFSOCK);
+ P_MODE(IFLNK);
+ P_MODE(IFREG);
+ P_MODE(IFBLK);
+ P_MODE(IFDIR);
+ P_MODE(IFCHR);
+ P_MODE(IFIFO);
+ P_MODE(ISUID);
+ P_MODE(ISGID);
+ P_MODE(ISVTX);
+ P_MODE(IRWXU);
+ P_MODE(IRUSR);
+ P_MODE(IWUSR);
+ P_MODE(IXUSR);
+ P_MODE(IRWXG);
+ P_MODE(IRGRP);
+ P_MODE(IWGRP);
+ P_MODE(IXGRP);
+ P_MODE(IRWXO);
+ P_MODE(IROTH);
+ P_MODE(IWOTH);
+ P_MODE(IXOTH);
+#undef P_MODE
+
+ if (mode)
+ printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", mode);
+
+ return printed;
+}
+
+#define SCA_MODE_T syscall_arg__scnprintf_mode_t
--
2.5.5