Hi Doug
On Fri, Oct 11, 2019 at 12:41:31AM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux.git
> kgdb/for-next
> head: 2277b492582d5525244519f60da6f9daea5ef41a
> commit: 2277b492582d5525244519f60da6f9daea5ef41a [4/4] kdb: Fix stack
> crawling on 'running' CPUs that aren't the master
> config: sh-allyesconfig (attached as .config)
> compiler: sh4-linux-gcc (GCC) 7.4.0
> reproduce:
> wget
> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
> ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout 2277b492582d5525244519f60da6f9daea5ef41a
> # save the attached .config to linux build tree
> GCC_VERSION=7.4.0 make.cross ARCH=sh
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <l...@intel.com>
>
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
>
> All warnings (new ones prefixed by >>):
>
> kernel/debug/debug_core.c: In function 'kdb_dump_stack_on_cpu':
> >> kernel/debug/debug_core.c:452:17: warning: array subscript is outside
> >> array bounds [-Warray-bounds]
> if (!(kgdb_info[cpu].exception_state & DCPU_IS_SLAVE)) {
> ~~~~~~~~~^~~~~
> kernel/debug/debug_core.c:469:33: warning: array subscript is outside
> array bounds [-Warray-bounds]
> kgdb_info[cpu].exception_state |= DCPU_WANT_BT;
> kernel/debug/debug_core.c:470:18: warning: array subscript is outside
> array bounds [-Warray-bounds]
> while (kgdb_info[cpu].exception_state & DCPU_WANT_BT)
> ~~~~~~~~~^~~~~
Thoughts on the following?
>From 9e0114bc9ae504c3a7e837c977d64f84b2010d8e Mon Sep 17 00:00:00 2001
From: Daniel Thompson <daniel.thomp...@linaro.org>
Date: Fri, 11 Oct 2019 08:49:29 +0100
Subject: [PATCH] kdb: Avoid array subscript warnings on non-SMP builds
Recent versions of gcc (reported on gcc-7.4) issue array subscript
warnings for builds where SMP is not enabled.
There is no bug here but there is scope to improve the code
generation for non-SMP systems (whilst also silencing the warning).
Reported-by: kbuild test robot <l...@intel.com>
Fixes: 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs that aren't the
master")
Signed-off-by: Daniel Thompson <daniel.thomp...@linaro.org>
---
kernel/debug/debug_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 70e86b4b4932..eccb7298a0b5 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -449,7 +449,8 @@ void kdb_dump_stack_on_cpu(int cpu)
return;
}
- if (!(kgdb_info[cpu].exception_state & DCPU_IS_SLAVE)) {
+ if (!IS_ENABLED(CONFIG_SMP) ||
+ !(kgdb_info[cpu].exception_state & DCPU_IS_SLAVE)) {
kdb_printf("ERROR: Task on cpu %d didn't stop in the
debugger\n",
cpu);
return;
--
2.21.0
