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 B13F82673AD; Mon, 7 Apr 2025 18:14:38 +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=1744049678; cv=none; b=obBo+ZeMPEpzsAxHJ9W5bN5cX/SEi67cnZs6ZYvXetAm8xi1mUbmyUA29Us4kHFK1CaHAblW2EknUjq6APoLKrPGMYR/+kTOrdLq2kgmHgY3+TCb+ys4+fmnHfjfMu+ySmTsWs9eQBGLmNOdmlmT3+fqfTSNCcjjonfKdLT37E8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744049678; c=relaxed/simple; bh=q5csLpQ+mh9o7lfCI1dsQaiQJ46R0m+uYFH+7vEOer4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=UEBN2M47tV8BpsW21YHrAG9fAUFQrGX4winOKImtJ9H2UVjeFqc0EqHg8azQQbcv2HZnTylzkrNBmCuIiq78itnt6Mf33938W194maHmoHFiffJCiTz7GHrJ88849Doy+SwKnisfd5GBEOtwyJ8QdB5MEN4LZX9YYXTPoINKKio= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QzK1n5dm; 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="QzK1n5dm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B6E2C4CEEF; Mon, 7 Apr 2025 18:14:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744049678; bh=q5csLpQ+mh9o7lfCI1dsQaiQJ46R0m+uYFH+7vEOer4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QzK1n5dmDiII7ci/SSgurdqsX1hC3DB8CFP69YwyxLJ9KAvsbsgNGuPQH1wQOYYDv jtP6eBGV0nK4L4nTmMI6Fk4kCMWzAbsWuzDBzASMG8R94SCn6aRGfDC7wpXSrcXL4P QR234cWVh5O5kMODDA2ojmDqJ8UwqcDbaeu0L/I7iLDS+Nd9jOi9xWyeeQEh2T5zBj YAfJg8TwQipamSnfKbS/KpcpfXpSnnIRj7nlBXI8uiONstkJ7eqz+B85L0bHhoUdCL HLciLwp6mI4ZzLBoGj4MNEOjmbOUfgUM3tiUlJWFqvShkRqhQheWdPnpi5J52Rxvrs hvHKSd2MD6I4A== 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 6.6 11/15] objtool: Silence more KCOV warnings Date: Mon, 7 Apr 2025 14:14:11 -0400 Message-Id: <20250407181417.3183475-11-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250407181417.3183475-1-sashal@kernel.org> References: <20250407181417.3183475-1-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 6.6.86 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 6e59e7f578ffe..665dccdd6b0af 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3569,6 +3569,9 @@ 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; @@ -3788,6 +3791,9 @@ 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