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| author |   Jiri Olsa <jolsa@kernel.org> | 2020-09-11 15:00:05 +0200 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-09-14 18:26:45 -0300 |
| commit | 8a39e8c4d9baf65d88f66d49ac684df381e30055 (patch) | |
| tree | 8b3917c6fa126e78cd55e1d650ba20164ba2bf87 /tools/perf/tests/bp_signal.c | |
| parent | Linux 5.9-rc5 (diff) | |
| download | wireguard-linux-8a39e8c4d9baf65d88f66d49ac684df381e30055.tar.xz wireguard-linux-8a39e8c4d9baf65d88f66d49ac684df381e30055.zip | |
perf test: Fix the "signal" test inline assembly
When compiling with DEBUG=1 on Fedora 32 I'm getting crash for 'perf
test signal':
Program received signal SIGSEGV, Segmentation fault.
0x0000000000c68548 in __test_function ()
(gdb) bt
#0 0x0000000000c68548 in __test_function ()
#1 0x00000000004d62e9 in test_function () at tests/bp_signal.c:61
#2 0x00000000004d689a in test__bp_signal (test=0xa8e280 <generic_ ...
#3 0x00000000004b7d49 in run_test (test=0xa8e280 <generic_tests+1 ...
#4 0x00000000004b7e7f in test_and_print (t=0xa8e280 <generic_test ...
#5 0x00000000004b8927 in __cmd_test (argc=1, argv=0x7fffffffdce0, ...
...
It's caused by the symbol __test_function being in the ".bss" section:
$ readelf -a ./perf | less
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
...
[28] .bss NOBITS 0000000000c356a0 008346a0
00000000000511f8 0000000000000000 WA 0 0 32
$ nm perf | grep __test_function
0000000000c68548 B __test_function
I guess most of the time we're just lucky the inline asm ended up in the
".text" section, so making it specific explicit with push and pop
section clauses.
$ readelf -a ./perf | less
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
...
[13] .text PROGBITS 0000000000431240 00031240
0000000000306faa 0000000000000000 AX 0 0 16
$ nm perf | grep __test_function
00000000004d62c8 T __test_function
Committer testing:
$ readelf -wi ~/bin/perf | grep producer -m1
<c> DW_AT_producer : (indirect string, offset: 0x254a): GNU C99 10.2.1 20200723 (Red Hat 10.2.1-1) -mtune=generic -march=x86-64 -ggdb3 -std=gnu99 -fno-omit-frame-pointer -funwind-tables -fstack-protector-all
^^^^^
^^^^^
^^^^^
$
Before:
$ perf test signal
20: Breakpoint overflow signal handler : FAILED!
$
After:
$ perf test signal
20: Breakpoint overflow signal handler : Ok
$
Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/20200911130005.1842138-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/tests/bp_signal.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c index da8ec1e8e064..cc9fbcedb364 100644 --- a/tools/perf/tests/bp_signal.c +++ b/tools/perf/tests/bp_signal.c @@ -45,10 +45,13 @@ volatile long the_var; #if defined (__x86_64__) extern void __test_function(volatile long *ptr); asm ( + ".pushsection .text;" ".globl __test_function\n" + ".type __test_function, @function;" "__test_function:\n" "incq (%rdi)\n" - "ret\n"); + "ret\n" + ".popsection\n"); #else static void __test_function(volatile long *ptr) { |