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Date: Thu, 23 May 2024 13:09:30 -0700
From: Yury Norov <yury.norov@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Yoann Congal <yoann.congal@smile.fr>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Nhat Pham <nphamcs@gmail.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Alexander Lobakin <aleksander.lobakin@intel.com>,
	"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH] gcc: disable '-Warray-bounds' for gcc-9
Message-ID: <Zk+ievkF4huCOtCt@yury-ThinkPad>
References: <20240522225830.1201778-1-yury.norov@gmail.com>
 <20240523130026.c57a8e1e7f4140d2642c84d2@linux-foundation.org>
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In-Reply-To: <20240523130026.c57a8e1e7f4140d2642c84d2@linux-foundation.org>

On Thu, May 23, 2024 at 01:00:26PM -0700, Andrew Morton wrote:
> On Wed, 22 May 2024 15:58:30 -0700 Yury Norov <yury.norov@gmail.com> wrote:
> 
> > '-Warray-bounds' is already disabled for gcc-10+. Now that we've merged
> > bitmap_{read,write), I see the following error when building the kernel
> > with gcc-9.4 (Ubuntu 20.04.4 LTS) for x86_64 allmodconfig:
> > 
> > drivers/pinctrl/pinctrl-cy8c95x0.c: In function ‘cy8c95x0_read_regs_mask.isra.0’:
> > include/linux/bitmap.h:756:18: error: array subscript [1, 288230376151711744] is outside array bounds of ‘long unsigned int[1]’ [-Werror=array-bounds]
> >   756 |  value_high = map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits);
> >       |               ~~~^~~~~~~~~~~
> > 
> > The immediate reason is that the commit b44759705f7d ("bitmap: make
> > bitmap_{get,set}_value8() use bitmap_{read,write}()") switched the
> > bitmap_get_value8() to an alias of bitmap_read(); the same for 'set'.
> 
> So it seems that all kernels which contain b44759705f7d should have
> this change?  If so, and as b44759705f7d appears to be in the net tree
> then the net tree is a suitable place to carry this patch?
> 
> Or I can send it into Linus this -rc cycle and things will sort themselves out.
> 
> Thoughts?

This is a real build breaker, so yes - I would like to have the fix in
this -rc. No preference regarding the tree.