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Benjamin Peterson authored
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: 1cc47f2d ("perf trace beauty ioctl: Improve 'cmd' beautifier") Link: http://lkml.kernel.org/r/20190823033625.18814-1-benjamin@python.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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