1853db0e02
After aligning the ftrace raw samples, there are dead bytes storing
random data from the stack. We don't want to leak these to userspace,
then zero these out.
Before:
0x2de88 [0x50]: event: 9
.
. ... raw event: size 80 bytes
. 0000: 09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff ......P........
. 0010: 68 01 00 00 68 01 00 00 2c 00 00 00 00 00 00 00 h...h...,......
. 0020: 2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00 ,...+...h...h..
. 0030: 6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00 kondemand/0....
. 0040: 68 01 00 00 40 7f 46 81 ff ff ff ff 00 10 1b 7f h...@.F........
^ ^ ^ ^
Leak
After:
0x2d318 [0x50]: event: 9
.
. ... raw event: size 80 bytes
. 0000: 09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff ......P........
. 0010: 68 01 00 00 68 01 00 00 68 14 00 00 00 00 00 00 h...h...h......
. 0020: 2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00 ,...+...h...h..
. 0030: 6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00 kondemand/0....
. 0040: 68 01 00 00 a0 80 46 81 ff ff ff ff 00 00 00 00 h.....F........
^ ^ ^ ^
Fixed
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1249915116-5210-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
|
||
|---|---|---|
| .. | ||
| events | ||
| boot.h | ||
| define_trace.h | ||
| ftrace.h | ||
| power.h | ||
| syscall.h | ||