]> asedeno.scripts.mit.edu Git - linux.git/commitdiff
perf trace beauty ioctl: Fix off-by-one error in cmd->string table
authorBenjamin Peterson <benjamin@python.org>
Fri, 23 Aug 2019 03:36:25 +0000 (20:36 -0700)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Mon, 26 Aug 2019 14:58:29 +0000 (11:58 -0300)
While tracing a program that calls isatty(3), I noticed that strace
reported TCGETS for the request argument of the underlying ioctl(2)
syscall while perf trace reported TCSETS. strace is corrrect. The bug in
perf was due to the tty ioctl beauty table starting at 0x5400 rather
than 0x5401.

Committer testing:

  Using augmented_raw_syscalls.o and settings to make 'perf trace'
  use strace formatting, i.e. with this in ~/.perfconfig

  # cat ~/.perfconfig
  [trace]
add_events = /home/acme/git/linux/tools/perf/examples/bpf/augmented_raw_syscalls.c
show_zeros = yes
show_duration = no
no_inherit = yes
show_timestamp = no
show_arg_names = no
args_alignment = 40
show_prefix = yes

  # strace -e ioctl stty > /dev/null
  ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
  ioctl(1, TIOCGWINSZ, 0x7fff8a9b0860)    = -1 ENOTTY (Inappropriate ioctl for device)
  ioctl(1, TCGETS, 0x7fff8a9b0540)        = -1 ENOTTY (Inappropriate ioctl for device)
  +++ exited with 0 +++
  #

Before:

  # perf trace -e ioctl stty > /dev/null
  ioctl(0, TCSETS, 0x7fff2cf79f20)        = 0
  ioctl(1, TIOCSWINSZ, 0x7fff2cf79f40)    = -1 ENOTTY (Inappropriate ioctl for device)
  ioctl(1, TCSETS, 0x7fff2cf79c20)        = -1 ENOTTY (Inappropriate ioctl for device)
  #

After:

  # perf trace -e ioctl stty > /dev/null
  ioctl(0, TCGETS, 0x7ffed0763920)        = 0
  ioctl(1, TIOCGWINSZ, 0x7ffed0763940)    = -1 ENOTTY (Inappropriate ioctl for device)
  ioctl(1, TCGETS, 0x7ffed0763620)        = -1 ENOTTY (Inappropriate ioctl for device)
  #

Signed-off-by: Benjamin Peterson <benjamin@python.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 1cc47f2d46206d67285aea0ca7e8450af571da13 ("perf trace beauty ioctl: Improve 'cmd' beautifier")
Link: http://lkml.kernel.org/r/20190823033625.18814-1-benjamin@python.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/trace/beauty/ioctl.c

index 52242fa4072b054f76b34cd39e89a1b57e9a3b76..e19eb6ea361d72a740153dc7ea7d7a9f44f54e04 100644 (file)
@@ -21,7 +21,7 @@
 static size_t ioctl__scnprintf_tty_cmd(int nr, int dir, char *bf, size_t size)
 {
        static const char *ioctl_tty_cmd[] = {
-       "TCGETS", "TCSETS", "TCSETSW", "TCSETSF", "TCGETA", "TCSETA", "TCSETAW",
+       [_IOC_NR(TCGETS)] = "TCGETS", "TCSETS", "TCSETSW", "TCSETSF", "TCGETA", "TCSETA", "TCSETAW",
        "TCSETAF", "TCSBRK", "TCXONC", "TCFLSH", "TIOCEXCL", "TIOCNXCL", "TIOCSCTTY",
        "TIOCGPGRP", "TIOCSPGRP", "TIOCOUTQ", "TIOCSTI", "TIOCGWINSZ", "TIOCSWINSZ",
        "TIOCMGET", "TIOCMBIS", "TIOCMBIC", "TIOCMSET", "TIOCGSOFTCAR", "TIOCSSOFTCAR",