From: Josh Poimboeuf Date: Mon, 26 Jan 2026 05:56:39 +0000 (-0800) Subject: objtool/klp: Fix bug table handling for __WARN_printf() X-Git-Tag: v6.19-rc8~4^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f2dba60339a6299e181671e95293efe312237e2d;p=thirdparty%2Flinux.git objtool/klp: Fix bug table handling for __WARN_printf() Running objtool klp-diff on a changed function which uses WARN() can fail with: vmlinux.o: error: objtool: md_run+0x866: failed to convert reloc sym '__bug_table' to its proper format The problem is that since commit 5b472b6e5bd9 ("x86_64/bug: Implement __WARN_printf()"), each __WARN_printf() call site now directly references its bug table entry. klp-diff errors out when it can't convert such section-based references to object symbols (because bug table entries don't have symbols). Luckily, klp-diff already has code to create symbols for bug table entries. Move that code earlier, before function diffing. Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files") Fixes: 5b472b6e5bd9 ("x86_64/bug: Implement __WARN_printf()") Reported-by: Song Liu Tested-by: Song Liu Link: https://patch.msgid.link/a8e0a714b9da962858842b9aecd63b4900927c88.1769406850.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index 4d1f9e9977eb..d94531e3f64e 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -1425,9 +1425,6 @@ static int clone_special_sections(struct elfs *e) { struct section *patched_sec; - if (create_fake_symbols(e->patched)) - return -1; - for_each_sec(e->patched, patched_sec) { if (is_special_section(patched_sec)) { if (clone_special_section(e, patched_sec)) @@ -1704,6 +1701,17 @@ int cmd_klp_diff(int argc, const char **argv) if (!e.out) return -1; + /* + * Special section fake symbols are needed so that individual special + * section entries can be extracted by clone_special_sections(). + * + * Note the fake symbols are also needed by clone_included_functions() + * because __WARN_printf() call sites add references to bug table + * entries in the calling functions. + */ + if (create_fake_symbols(e.patched)) + return -1; + if (clone_included_functions(&e)) return -1;