On 07/10/2018 06:58 PM, Jiri Olsa wrote:
> On Tue, Jul 10, 2018 at 02:27:16PM -0400, William Cohen wrote:
>> Newer versions of GCC perform static analysis to determine whether
>> string truncation is possible with functions such as snprintf and
>> provide a warning if truncation could occur. The make for
>> jvmti_agent.c uses the compiler option that treats any compiler
>> warnings as compiler errors. For GCC-8.1.1 in Fedora 28 this causes
>> the build to fail. The return value of the snprint is now checked to
>> ensure snprintf produced a NULL-terminated string. If the string for
>> the path is invalid, the code does attempt to use the string.
>
> hi,
> I posted fix for this recently:
> https://lore.kernel.org/lkml/20180702134202.17745-1-jo...@kernel.org/
>
> it also covers the perf_regs.c, which was failing with gcc8 for me
>
> should be pulled in soon
>
> thanks,
> jirka
Hi Jirka,
Thanks. I hadn't seen the patch, and this failing to build for the past week
has been bugging me. Glad to hear there is already a fix queued up.
-Will
>
>>
>> Signed-off-by: William Cohen <wco...@redhat.com>
>> ---
>> tools/perf/jvmti/jvmti_agent.c | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c
>> index 0c6d1002b524..30f14eafe4b3 100644
>> --- a/tools/perf/jvmti/jvmti_agent.c
>> +++ b/tools/perf/jvmti/jvmti_agent.c
>> @@ -227,7 +227,7 @@ void *jvmti_open(void)
>> {
>> char dump_path[PATH_MAX];
>> struct jitheader header;
>> - int fd;
>> + int retlen, fd;
>> FILE *fp;
>>
>> init_arch_timestamp();
>> @@ -249,7 +249,10 @@ void *jvmti_open(void)
>> /*
>> * jitdump file name
>> */
>> - snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
>> + retlen = snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump",
>> + jit_path, getpid());
>> + if (retlen <= 0 || ((int) sizeof(dump_path)) <= retlen)
>> + return NULL;
>>
>> fd = open(dump_path, O_CREAT|O_TRUNC|O_RDWR, 0666);
>> if (fd == -1)
>> --
>> 2.17.1
>>
