From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC4D5264611; Mon, 7 Apr 2025 18:14:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744049647; cv=none; b=ZgSJA8QI+wvkbddB7ngnNRbWAmKWzjm5rp2YE5201hUx44sugPsPitFpbOjfD5YcqecAGcT3lYeHdsNRFSCbHBy9ABUHQv8MyxHnJH/iLAH+eojBscQpj09p6V88tdgLVZAZGDDlA0y3da03S9ZcAsbsA6QJIZpfu2w67M7VLQ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744049647; c=relaxed/simple; bh=AbOXdHJBmNO1CtoZoXvVG0k8OS6oOG8Sg5FFo/5VLgU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=WdNGgVjeB+aeDd9sdMoerIkuFEasMw1vshni8MryQR9bMKUtmdckvTWS+MVI7U/iUqsotUyIjAclxCV8pWREQxGw+f/HH8Sx3fLva8ZK7hhVK5XWn5AMp+4KbIkpVRWy5UHf/WrH8Oa7w7UPPhBHUt4Q0ci32M4k1KRHnw4sqFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pdSgejzM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pdSgejzM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D943BC4CEE9; Mon, 7 Apr 2025 18:14:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744049646; bh=AbOXdHJBmNO1CtoZoXvVG0k8OS6oOG8Sg5FFo/5VLgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pdSgejzMV2C8hfEEgQbRxIhAADP+PCqUdiLhqRdtmjz4+MI/14Oei3OcPinGFgeUe lnyvpRuK1Vod2RUS3ftK1LoLy0vBhRvByTqs9TZ0+13r8c+SfFVe7O/ZUAaL/gdsIw RPrGXiRTH3eOI+7tOg3X9ucbc4SqOG+A/TBH4V7Ja4HlryINscqxVBkb9wHdYuBrjc ziir5xsPBGtlqQT2ryR8QqeDI378TK6yc3CNDToogldLvic6Rk59NH3pY6i19g+JrS MAHkEu6kFQgcGW+vfWG3qnON0Xn9IexxkUPdg0kH20Plh1dH45+/Ujku6XYOckD+mw uXtmIhfdYYEaQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josh Poimboeuf , Ingo Molnar , kernel test robot , Linus Torvalds , Sasha Levin , peterz@infradead.org Subject: [PATCH AUTOSEL 6.12 18/22] objtool: Silence more KCOV warnings Date: Mon, 7 Apr 2025 14:13:28 -0400 Message-Id: <20250407181333.3182622-18-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250407181333.3182622-1-sashal@kernel.org> References: <20250407181333.3182622-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.22 Content-Transfer-Encoding: 8bit From: Josh Poimboeuf [ Upstream commit 6b023c7842048c4bbeede802f3cf36b96c7a8b25 ] In the past there were issues with KCOV triggering unreachable instruction warnings, which is why unreachable warnings are now disabled with CONFIG_KCOV. Now some new KCOV warnings are showing up with GCC 14: vmlinux.o: warning: objtool: cpuset_write_resmask() falls through to next function cpuset_update_active_cpus.cold() drivers/usb/core/driver.o: error: objtool: usb_deregister() falls through to next function usb_match_device() sound/soc/codecs/snd-soc-wcd934x.o: warning: objtool: .text.wcd934x_slim_irq_handler: unexpected end of section All are caused by GCC KCOV not finishing an optimization, leaving behind a never-taken conditional branch to a basic block which falls through to the next function (or end of section). At a high level this is similar to the unreachable warnings mentioned above, in that KCOV isn't fully removing dead code. Treat it the same way by adding these to the list of warnings to ignore with CONFIG_KCOV. Reported-by: Ingo Molnar Reported-by: kernel test robot Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/66a61a0b65d74e072d3dc02384e395edb2adc3c5.1742852846.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/Z9iTsI09AEBlxlHC@gmail.com Closes: https://lore.kernel.org/oe-kbuild-all/202503180044.oH9gyPeg-lkp@intel.com/ Signed-off-by: Sasha Levin --- tools/objtool/check.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 3c3e5760e81b8..6eabc3d3bcb2f 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3633,6 +3633,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, !strncmp(func->name, "__pfx_", 6)) return 0; + if (file->ignore_unreachables) + return 0; + WARN("%s() falls through to next function %s()", func->name, insn_func(insn)->name); return 1; @@ -3852,6 +3855,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, if (!next_insn) { if (state.cfi.cfa.base == CFI_UNDEFINED) return 0; + if (file->ignore_unreachables) + return 0; + WARN("%s: unexpected end of section", sec->name); return 1; } -- 2.39.5