From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH 01/11] x86: compressed: avoid gcc-11 -Wstringop-overread warning Date: Mon, 22 Mar 2021 17:02:39 +0100 Message-ID: <20210322160253.4032422-2-arnd@kernel.org> References: <20210322160253.4032422-1-arnd@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616429000; bh=3vH1tW/3dz/29rKeu66QIybhctPu7u2aaTt+yHw+ixQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VRbsfgY+z8kWvWs+txugnu/XzSTF1os4UBObTbMaVvuShG2tPdw5ChRNTsdoitI1c Os5gXEmTV19Hh0dH4sglqm/fSEpSE1o+cdD5mtmVZ292EJ017mpHo8q2zl1C63RDvy 9IP52tHZwWSskub+gnvqqJxnuA90avLg12n2yst/hTpywQNyH7pGS5SlpLOCg1l1zv SC2S1tGwIlfSqI7YXPTsk7il0mAFtLumFo7AO2H+payHYwT3xe1jEFpNJbjQ5KEMrV fL6MEJv6J7008Lwon/8167XZUtB/IGdDaiFW7a3KldjWew3Xisi5j0MtsrpiR6liOq jy3MXhpKCZK+w== In-Reply-To: <20210322160253.4032422-1-arnd-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-ID: Content-Type: text/plain; charset="utf-8" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Martin Sebor , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: Arnd Bergmann , Ning Sun , Jani Nikula , Kalle Valo , Simon Kelley , James Smart , "James E.J. Bottomley" , Anders Larsen , Tejun Heo , Serge Hallyn , Imre Deak , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, tboot-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, intel-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, ath11k-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "H. Peter Anvin" , Kees Cook From: Arnd Bergmann gcc gets confused by the comparison of a pointer to an integer listeral, with the assumption that this is an offset from a NULL pointer and that dereferencing it is invalid: In file included from arch/x86/boot/compressed/misc.c:18: In function ‘parse_elf’, inlined from ‘extract_kernel’ at arch/x86/boot/compressed/misc.c:442:2: arch/x86/boot/compressed/../string.h:15:23: error: ‘__builtin_memcpy’ reading 64 bytes from a region of size 0 [-Werror=stringop-overread] 15 | #define memcpy(d,s,l) __builtin_memcpy(d,s,l) | ^~~~~~~~~~~~~~~~~~~~~~~ arch/x86/boot/compressed/misc.c:283:9: note: in expansion of macro ‘memcpy’ 283 | memcpy(&ehdr, output, sizeof(ehdr)); | ^~~~~~ I could not find any good workaround for this, but as this is only a warning for a failure during early boot, removing the line entirely works around the warning. This should probably get addressed in gcc instead, before 11.1 gets released. Signed-off-by: Arnd Bergmann --- arch/x86/boot/compressed/misc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 3a214cc3239f..9ada64e66cb7 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -430,8 +430,6 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, error("Destination address too large"); #endif #ifndef CONFIG_RELOCATABLE - if ((unsigned long)output != LOAD_PHYSICAL_ADDR) - error("Destination address does not match LOAD_PHYSICAL_ADDR"); if (virt_addr != LOAD_PHYSICAL_ADDR) error("Destination virtual address changed when not relocatable"); #endif -- 2.29.2