Re: kernel/trace/rv/rv.c:812:2-8: preceding lock on line 790 (fwd)
From: Gabriele Monaco
Date: Wed Apr 02 2025 - 02:25:42 EST
On Sun, 2025-03-30 at 20:37 +0200, Julia Lawall wrote:
> Please check on whether line 812 needs an unlock.
>
Hi,
thanks for reporting!
Indeed that needs an unlock, I missed it after moving some code around,
preparing the fix.
Gabriele
> julia
>
> ---------- Forwarded message ----------
> Date: Mon, 31 Mar 2025 02:25:17 +0800
> From: kernel test robot <lkp@xxxxxxxxx>
> To: oe-kbuild@xxxxxxxxxxxxxxx
> Cc: lkp@xxxxxxxxx, Julia Lawall <julia.lawall@xxxxxxxx>
> Subject: kernel/trace/rv/rv.c:812:2-8: preceding lock on line 790
>
> BCC: lkp@xxxxxxxxx
> CC: oe-kbuild-all@xxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> TO: Gabriele Monaco <gmonaco@xxxxxxxxxx>
> CC: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
>
> tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ma
> ster
> head: 7f2ff7b6261742ed52aa973ccdf99151b7cc3a50
> commit: cb85c660fcd4b3a03ed993affa0b2d1a8af2f06b rv: Add option for
> nested monitors and include sched
> date: 6 days ago
> :::::: branch date: 17 hours ago
> :::::: commit date: 6 days ago
> config: loongarch-randconfig-r061-20250330
> (https://download.01.org/0day-ci/archive/20250331/202503310200.UBXGit
> B4-lkp@xxxxxxxxx/config)
> compiler: loongarch64-linux-gcc (GCC) 14.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new
> version of
> the same patch/commit), kindly add following tags
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Julia Lawall <julia.lawall@xxxxxxxx>
> > Closes:
> > https://lore.kernel.org/r/202503310200.UBXGitB4-lkp@xxxxxxxxx/
>
> cocci warnings: (new ones prefixed by >>)
> > > kernel/trace/rv/rv.c:812:2-8: preceding lock on line 790
>
> vim +812 kernel/trace/rv/rv.c
>
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 771
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 772 /**
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 773 *
> rv_register_monitor - register a rv monitor.
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 774 *
> @monitor: The rv_monitor to be registered.
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 775 *
> @parent: The parent of the monitor to be registered, NULL if not
> nested.
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 776 *
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 777 *
> Returns 0 if successful, error otherwise.
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 778 */
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 779 int
> rv_register_monitor(struct rv_monitor *monitor, struct rv_monitor
> *parent)
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 780 {
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 781 struct rv_monitor_def *r, *p = NULL;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 782 int
> retval = 0;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 783
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 784 if
> (strlen(monitor->name) >= MAX_RV_MONITOR_NAME_SIZE) {
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 785 pr_info("Monitor %s has a name longer than %d\n", monitor->name,
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 786 MAX_RV_MONITOR_NAME_SIZE);
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 787 return -EINVAL;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 788 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 789
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> @790 mutex_lock(&rv_interface_lock);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 791
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 792 list_for_each_entry(r, &rv_monitors_list, list) {
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 793 if (strcmp(monitor->name, r->monitor->name) == 0) {
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 794 pr_info("Monitor %s is already registered\n", monitor->name);
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 795 retval = -EEXIST;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 796 goto out_unlock;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 797 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 798 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 799
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 800 if
> (parent) {
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 801 list_for_each_entry(r, &rv_monitors_list, list) {
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 802 if (strcmp(parent->name, r->monitor->name) == 0) {
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 803 p = r;
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 804 break;
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 805 }
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 806 }
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 807 }
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 808
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 809 if
> (p && rv_is_nested_monitor(p)) {
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 810 pr_info("Parent monitor %s is already nested, cannot nest further\n",
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 811 parent->name);
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> @812 return -EINVAL;
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 813 }
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 814
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 815 r =
> kzalloc(sizeof(struct rv_monitor_def), GFP_KERNEL);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 816 if
> (!r) {
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 817 retval = -ENOMEM;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 818 goto out_unlock;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 819 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 820
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 821 r-
> >monitor = monitor;
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 822 r-
> >parent = parent;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 823
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 824 retval = create_monitor_dir(r, p);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 825 if
> (retval) {
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 826 kfree(r);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 827 goto out_unlock;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 828 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 829
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 830 /*
> keep children close to the parent for easier visualisation */
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 831 if
> (p)
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05
> 832 list_add(&r->list, &p->list);
> cb85c660fcd4b3a Gabriele Monaco 2025-03-05 833 else
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 834 list_add_tail(&r->list, &rv_monitors_list);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 835
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 836
> out_unlock:
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 837 mutex_unlock(&rv_interface_lock);
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29
> 838 return retval;
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 839 }
> 102227b970a1525 Daniel Bristot de Oliveira 2022-07-29 840
>