The following commit has been merged into the objtool/urgent branch of tip:
Commit-ID: eeff7ac61526a4a9c3916cf46885622078ad886b
Gitweb: https://git.kernel.org/tip/eeff7ac61526a4a9c3916cf46885622078ad886b
Author: Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate: Mon, 24 Mar 2025 14:55:52 -07:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 25 Mar 2025 09:20:25 +01:00
objtool: Warn when disabling unreachable warnings
Print a warning when disabling the unreachable warnings (due to a GCC
bug). This will help determine if recent GCCs still have the issue and
alert us if any other issues might be silently lurking behind the
unreachable disablement.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/df243063787596e6031367e6659e7e43409d6c6d.1742852846.git.jpoimboe@kernel.org
---
tools/objtool/arch/x86/special.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
index 9c1c9df..5f46d4e 100644
--- a/tools/objtool/arch/x86/special.c
+++ b/tools/objtool/arch/x86/special.c
@@ -3,6 +3,7 @@
#include <objtool/special.h>
#include <objtool/builtin.h>
+#include <objtool/warn.h>
#define X86_FEATURE_POPCNT (4 * 32 + 23)
#define X86_FEATURE_SMAP (9 * 32 + 20)
@@ -156,8 +157,10 @@ 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 (reloc_type(text_reloc) == R_X86_64_PC32) {
+ WARN_INSN(insn, "ignoring unreachables due to jump table quirk");
file->ignore_unreachables = true;
+ }
*table_size = 0;
return rodata_reloc;