Hi Arnaldo,
On 05/19/2018 12:51 AM, Arnaldo Carvalho de Melo wrote:
> Em Fri, May 18, 2018 at 12:54:17PM +0530, Sandipan Das escreveu:
>> This test currently fails because the regular expressions for
>> matching the output of perf script do not consider the symbol
>> offsets to be part of the output.
>>
>> The symbol offsets are seen because of the default behaviour
>> introduced by commit 4140d2ea74b3 ("perf script: Show symbol
>> offsets by default").
>>
>> Before applying this patch:
>>
>> # perf test -v "probe libc's inet_pton & backtrace it with ping"
>>
>> 62: probe libc's inet_pton & backtrace it with ping :
>> --- start ---
>> test child forked, pid 30389
>> ping 30406 [002] 307144.280983: probe_libc:inet_pton: (7f4117adf220)
>> 7f4117adf220 __GI___inet_pton+0x0 (/usr/lib64/libc-2.25.so)
>> FAIL: expected backtrace entry 1
>> ".*inet_pton[[:space:]]\(/usr/lib64/libc-2.25.so|inlined\)$" got
>> "7f4117adf220 __GI___inet_pton+0x0 (/usr/lib64/libc-2.25.so)"
>> test child finished with -1
>> ---- end ----
>> probe libc's inet_pton & backtrace it with ping: FAILED!
>>
>> After applying this patch:
>>
>> # perf test -v "probe libc's inet_pton & backtrace it with ping"
>>
>> 62: probe libc's inet_pton & backtrace it with ping :
>> --- start ---
>> test child forked, pid 30539
>> ping 30556 [003] 307254.313217: probe_libc:inet_pton: (7fe19ab10220)
>> 7fe19ab10220 __GI___inet_pton+0x0 (/usr/lib64/libc-2.25.so)
>> 7fe19aad5ebd getaddrinfo+0x11d (/usr/lib64/libc-2.25.so)
>> 56351e3c1c71 main+0x891 (/usr/bin/ping)
>> test child finished with 0
>> ---- end ----
>> probe libc's inet_pton & backtrace it with ping: Ok
>
> Here it went from failing with:
>
> [root@seventh ~]# perf test -v pton
> 64: probe libc's inet_pton & backtrace it with ping :
> --- start ---
> test child forked, pid 22590
> ping 22607 [001] 12782.425689: probe_libc:inet_pton: (7f8686da4e40)
> 7f8686da4e40 __GI___inet_pton+0x0 (/usr/lib64/libc-2.26.so)
> FAIL: expected backtrace entry 1
> ".*inet_pton[[:space:]]\(/usr/lib64/libc-2.26.so|inlined\)$" got
> "7f8686da4e40 __GI___inet_pton+0x0 (/usr/lib64/libc-2.26.so)"
> test child finished with -1
> ---- end ----
> probe libc's inet_pton & backtrace it with ping: FAILED!
> [root@seventh ~]#
>
> To failing with:
>
> [root@seventh ~]# perf test -v pton
> 64: probe libc's inet_pton & backtrace it with ping :
> --- start ---
> test child forked, pid 28954
> ping 28971 [002] 14277.711200: probe_libc:inet_pton: (7fc9d66e3e40)
> 7fc9d66e3e40 __GI___inet_pton+0x0 (/usr/lib64/libc-2.26.so)
> 7fc9d66b02b4 getaddrinfo+0x124 (/usr/lib64/libc-2.26.so)
> 56075cb98f40 [unknown] (/usr/bin/ping)
> FAIL: expected backtrace entry 3
> ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" got "56075cb98f40
> [unknown] (/usr/bin/ping)"
> test child finished with -1
> ---- end ----
> probe libc's inet_pton & backtrace it with ping: FAILED!
> [root@seventh ~]#
>
> Trying to figure this out...
>
Looks like perf failed to resolve the symbol's name for the last entry
in the callchain. I did not consider this case. So, if this happens, we
would be better off using the original regex for the last line:
expected[3]=".*\(.*/bin/ping.*\)$"
- Sandipan
