Re: [Crash-utility] [PATCH] address compiler warning for extensions/trace.c

Hello Dave, On 07/07/2015 11:20 PM, Dave Anderson wrote: > Hello Qiao, > > With more recent versions of gcc, extensions/trace.c generates this > warning: > > $ make extensions > ... > gcc -Wall -g -shared -rdynamic -o trace.so trace.c -fPIC -DX86_64 -DLZO -DSNAPPY -DGDB_7_6 > /tmp/ccSOIphT.o: In function 'ftrace_show': > /root/crash.git/extensions/trace.c:1560: warning: the use of 'mktemp' is dangerous, better use 'mkstemp' > ... > $ > > I've attached an untested patch that replaces the mktemp() call with mkstemp(). > I believe the only behavioral difference is that mkstemp() will create the file > automatically with permissions 600 and open flags of O_EXCL, whereas it is > currently being opened with permissions 644 and flags (O_WRONLY | O_CREAT | > O_TRUNC). It seems good to me. Acked-by: Qiao Nuohan <qiaonuohan(a)cn.fujitsu.com&gt;

> > Can you either ACK the patch, or address the warning as you would prefer? > > Thanks, > Dave > > > use_mkstemp.patch > > > diff --git a/extensions/trace.c b/extensions/trace.c > index 8639fb2..9f81568 100644 > --- a/extensions/trace.c > +++ b/extensions/trace.c > @@ -1533,7 +1533,6 @@ static void ftrace_show(int argc, char *argv[]) > FILE *file; > size_t ret; > size_t nitems __attribute__ ((__unused__)); > - char *unused __attribute__ ((__unused__)); > > /* check trace-cmd */ > if (env_trace_cmd) > @@ -1557,8 +1556,9 @@ static void ftrace_show(int argc, char *argv[]) > } > > /* dump trace.dat to the temp file */ > - unused = mktemp(tmp); > - fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 0644); > + fd = mkstemp(tmp); "tmp" will be modified to the path of the temporary file, good. > + if (fd < 0) > + return; > if (trace_cmd_data_output(fd) < 0) > goto out; > -- Regards Qiao Nuohan