linux-kernel - [tip: objtool/urgent] objtool: Fix false-positive "ignoring unreachables" warning

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Message-ID: <174431908613.31282.16929702486246710776.tip-bot2@tip-bot2>
Date: Thu, 10 Apr 2025 21:04:45 -0000
From: "tip-bot2 for Josh Poimboeuf" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: kernel test robot <lkp@...el.com>, Josh Poimboeuf <jpoimboe@...nel.org>,
 Ingo Molnar <mingo@...nel.org>, x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: objtool/urgent] objtool: Fix false-positive "ignoring
 unreachables" warning

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     87cb582d2f55d379ce95b5bcc4ec596e29b0a65e
Gitweb:        https://git.kernel.org/tip/87cb582d2f55d379ce95b5bcc4ec596e29b0a65e
Author:        Josh Poimboeuf <jpoimboe@...nel.org>
AuthorDate:    Wed, 09 Apr 2025 15:49:36 -07:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Thu, 10 Apr 2025 22:55:00 +02:00

objtool: Fix false-positive "ignoring unreachables" warning

There's no need to try to automatically disable unreachable warnings if
they've already been manually disabled due to CONFIG_KCOV quirks.

This avoids a spurious warning with a KCOV kernel:

  fs/smb/client/cifs_unicode.o: warning: objtool: cifsConvertToUTF16.part.0+0xce5: ignoring unreachables due to jump table quirk

Fixes: eeff7ac61526 ("objtool: Warn when disabling unreachable warnings")
Reported-by: kernel test robot <lkp@...el.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Link: https://lore.kernel.org/r/5eb28eeb6a724b7d945a961cfdcf8d41e6edf3dc.1744238814.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/r/202504090910.QkvTAR36-lkp@intel.com/
---
 tools/objtool/arch/x86/special.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
index 403e587..06ca4a2 100644
--- a/tools/objtool/arch/x86/special.c
+++ b/tools/objtool/arch/x86/special.c
@@ -126,7 +126,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file,
 	 * indicates a rare GCC quirk/bug which can leave dead
 	 * code behind.
 	 */
-	if (reloc_type(text_reloc) == R_X86_64_PC32) {
+	if (!file->ignore_unreachables && reloc_type(text_reloc) == R_X86_64_PC32) {
 		WARN_INSN(insn, "ignoring unreachables due to jump table quirk");
 		file->ignore_unreachables = true;
 	}