| Message ID | 20190108150015.21327-3-kaslevs@vmware.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Add VM guest kernel tracing using vsock sockets for transport | expand |
On Tue, 8 Jan 2019 17:00:11 +0200 Slavomir Kaslev <kaslevs@vmware.com> wrote: > Compiling trace-cmd with gcc 8.2 reports: > > trace-read.c: In function ‘append_pid_filter’: > trace-read.c:414:3: warning: passing argument 1 to restrict-qualified parameter aliases with argument 3 [-Wrestrict] > sprintf(filter, "%s||" FILTER_FMT, filter, pid, pid, pid); > ^~~~~~~ > > since `snprintf` declares its first argument as __restrict but `buf` is also > passed as argument #5. > > Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> FYI, I took this patch but changed the subject and description to this: From: Slavomir Kaslev <kaslevs@vmware.com> Subject: [PATCH] trace-cmd: Do not use target string pointer as parameter to sprintf() Compiling trace-cmd with gcc 8.2 reports: trace-read.c: In function ‘append_pid_filter’: trace-read.c:414:3: warning: passing argument 1 to restrict-qualified parameter aliases with argument 3 [-Wrestrict] sprintf(filter, "%s||" FILTER_FMT, filter, pid, pid, pid); ^~~~~~~ since `snprintf` declares its first argument as __restrict but `buf` is also passed as argument #5. The code just concatenates to the filter string. Use the original string length as the position to write to filter. Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> -- Steve
diff --git a/tracecmd/trace-read.c b/tracecmd/trace-read.c index c406d66..1f91fff 100644 --- a/tracecmd/trace-read.c +++ b/tracecmd/trace-read.c @@ -386,7 +386,7 @@ static void add_pid_filter(const char *arg) static char *append_pid_filter(char *curr_filter, char *pid) { char *filter; - int len; + int len, curr_len; #define FILTER_FMT "(common_pid==" __STR ")||(pid==" __STR ")||(next_pid==" __STR ")" @@ -405,13 +405,13 @@ static char *append_pid_filter(char *curr_filter, char *pid) die("Failed to allocate for filter %s", curr_filter); sprintf(filter, ".*:" FILTER_FMT, pid, pid, pid); } else { - - len += strlen(curr_filter); + curr_len = strlen(curr_filter); + len += curr_len; filter = realloc(curr_filter, len); if (!filter) die("realloc"); - sprintf(filter, "%s||" FILTER_FMT, filter, pid, pid, pid); + sprintf(filter + curr_len, "||" FILTER_FMT, pid, pid, pid); } return filter;
Compiling trace-cmd with gcc 8.2 reports: trace-read.c: In function ‘append_pid_filter’: trace-read.c:414:3: warning: passing argument 1 to restrict-qualified parameter aliases with argument 3 [-Wrestrict] sprintf(filter, "%s||" FILTER_FMT, filter, pid, pid, pid); ^~~~~~~ since `snprintf` declares its first argument as __restrict but `buf` is also passed as argument #5. Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com> --- tracecmd/trace-read.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)