lkml.org 
[lkml]   [2020]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH -next] tools build: Check return value of fwrite_unlocked in jvmti_agent.c
From


On July 29, 2020 8:47:36 PM GMT-03:00, Ian Rogers <irogers@google.com> wrote:
>On Fri, Jul 24, 2020 at 3:07 AM Wang ShaoBo
><bobo.shaobowang@huawei.com> wrote:
>>
>> Function jvmti_write_code called by compiled_method_load_cb may
>return
>> error in using fwrite_unlocked, this failure should be captured and
>> warned.
>>
>> Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
>> ---
>> tools/perf/jvmti/jvmti_agent.c | 23 +++++++++++++++--------
>> 1 file changed, 15 insertions(+), 8 deletions(-)
>>
>> diff --git a/tools/perf/jvmti/jvmti_agent.c
>b/tools/perf/jvmti/jvmti_agent.c
>> index 88108598d6e9..a1fe6aa16b6d 100644
>> --- a/tools/perf/jvmti/jvmti_agent.c
>> +++ b/tools/perf/jvmti/jvmti_agent.c
>> @@ -363,7 +363,7 @@ jvmti_write_code(void *agent, char const *sym,
>> struct jr_code_load rec;
>> size_t sym_len;
>> FILE *fp = agent;
>> - int ret = -1;
>> + int ret;
>>
>> /* don't care about 0 length function, no samples */
>> if (size == 0)
>> @@ -401,16 +401,23 @@ jvmti_write_code(void *agent, char const *sym,
>> rec.code_index = code_generation++;
>>
>> ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
>> - fwrite_unlocked(sym, sym_len, 1, fp);
>> + if (ret)
>> + goto error;
>
>Sorry, it seems I lost a reply to this. Won't ret here be the number
>of items written and not an error code? Consequently all writes will
>immediately goto error?

Good thing this is in tmp.perf/core, you're right, the test has to be (ret < 0)... I'll fix, thanks!

Also we need some 'perf test' for this :-/

- Arnaldo
>
>Thanks,
>Ian
>
>> + ret = fwrite_unlocked(sym, sym_len, 1, fp);
>> + if (ret)
>> + goto error;
>>
>> - if (code)
>> - fwrite_unlocked(code, size, 1, fp);
>> + if (code) {
>> + ret = fwrite_unlocked(code, size, 1, fp);
>> + if (ret)
>> + goto error;
>> + }
>>
>> funlockfile(fp);
>> -
>> - ret = 0;
>> -
>> - return ret;
>> + return 0;
>> +error:
>> + funlockfile(fp);
>> + return -1;
>> }
>>
>> int
>> --
>> 2.17.1
>>

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

\
 
 \ /
  Last update: 2020-07-30 03:13    [W:0.094 / U:0.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site