Re: kernel/trace/fprobe.c:59 fprobe_handler() error: uninitialized symbol 'ret'.
From: Google
Date: Wed May 17 2023 - 18:07:26 EST
On Wed, 17 May 2023 20:47:02 +0300
Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> On Wed, May 17, 2023 at 08:45:05PM +0900, Masami Hiramatsu wrote:
> > Hi Dan,
> >
> > Sorry, I missed my fix :(
> >
> > https://lore.kernel.org/all/168100731160.79534.374827110083836722.stgit@devnote2/
> >
> > That will fix the problem, could you test it?
> >
>
> It's awkward for me to test it right now... :( The fix looks good
> to me though and will obviously silence the static checker warning.
Thanks for checking!
>
> Acked-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Regards,
>
> regards,
> dan carpenter
>
>
> > Thanks,
> >
> > On Mon, 8 May 2023 08:17:09 +0300
> > Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> >
> > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > head: 2e1e1337881b0e9844d687982aa54b31b1269b11
> > > commit: 39d954200bf6ad503c722e44d0be80c7b826fa42 fprobe: Skip exit_handler if entry_handler returns !0
> > > config: i386-randconfig-m041-20230501 (https://download.01.org/0day-ci/archive/20230506/202305061702.6h3JzCPA-lkp@xxxxxxxxx/config)
> > > compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
> > >
> > > If you fix the issue, kindly add following tag where applicable
> > > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > | Reported-by: Dan Carpenter <error27@xxxxxxxxx>
> > > | Link: https://lore.kernel.org/r/202305061702.6h3JzCPA-lkp@xxxxxxxxx/
> > >
> > > smatch warnings:
> > > kernel/trace/fprobe.c:59 fprobe_handler() error: uninitialized symbol 'ret'.
> > >
> > > vim +/ret +59 kernel/trace/fprobe.c
> > >
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 23 static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 24 struct ftrace_ops *ops, struct ftrace_regs *fregs)
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 25 {
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 26 struct fprobe_rethook_node *fpr;
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 27) struct rethook_node *rh = NULL;
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 28 struct fprobe *fp;
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 29) void *entry_data = NULL;
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 30) int bit, ret;
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 31
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 32 fp = container_of(ops, struct fprobe, ops);
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 33 if (fprobe_disabled(fp))
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 34 return;
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 35
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 36 bit = ftrace_test_recursion_trylock(ip, parent_ip);
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 37 if (bit < 0) {
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 38 fp->nmissed++;
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 39 return;
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 40 }
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 41
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 42 if (fp->exit_handler) {
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 43 rh = rethook_try_get(fp->rethook);
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 44 if (!rh) {
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 45 fp->nmissed++;
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 46 goto out;
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 47 }
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 48 fpr = container_of(rh, struct fprobe_rethook_node, node);
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 49 fpr->entry_ip = ip;
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 50) if (fp->entry_data_size)
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 51) entry_data = fpr->data;
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 52 }
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 53
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 54) if (fp->entry_handler)
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 55) ret = fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 56)
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 57) /* If entry_handler returns !0, nmissed is not counted. */
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 58) if (rh) {
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 @59) if (ret)
> > >
> > > I reported this one earlier. The code assumes that if there is an
> > > -exit_handler there is also an ->entry_handler(). You had said you
> > > would just initialized ret = 0;
> > >
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 60) rethook_recycle(rh);
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 61) else
> > > 76d0de5729c056 Masami Hiramatsu (Google 2023-02-02 62) rethook_hook(rh, ftrace_get_regs(fregs), true);
> > > 39d954200bf6ad Masami Hiramatsu (Google 2023-02-02 63) }
> > > 5b0ab78998e325 Masami Hiramatsu 2022-03-15 64 out:
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 65 ftrace_test_recursion_unlock(bit);
> > > cad9931f64dc7f Masami Hiramatsu 2022-03-15 66 }
> > >
> > > --
> > > 0-DAY CI Kernel Test Service
> > > https://github.com/intel/lkp-tests
> > >
> >
> >
> > --
> > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>