From 5e3992fe72748ed3892be876f09d4d990548b7af Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:27:47 -0700 Subject: objtool: Limit unreachable warnings to once per function Unreachable instruction warnings are limited to once per object file. That no longer makes sense for vmlinux validation, which might have more unreachable instructions lurking in other places. Change it to once per function. Note this affects some other (much rarer) non-fatal warnings as well. In general I think one-warning-per-function makes sense, as related warnings can accumulate quickly and we want to eventually get back to failing the build with -Werror anyway. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/9d38f881bfc34e031c74e4e90064ccb3e49f599a.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/check.c | 5 +++-- tools/objtool/include/objtool/elf.h | 1 + tools/objtool/include/objtool/warn.h | 7 ++++++- 3 files changed, 10 insertions(+), 3 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 0fcf99c91400..98e6c3b5fefc 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4514,6 +4514,7 @@ static int validate_sls(struct objtool_file *file) static int validate_reachable_instructions(struct objtool_file *file) { struct instruction *insn; + int warnings = 0; if (file->ignore_unreachables) return 0; @@ -4523,10 +4524,10 @@ static int validate_reachable_instructions(struct objtool_file *file) continue; WARN_INSN(insn, "unreachable instruction"); - return 1; + warnings++; } - return 0; + return warnings; } int check(struct objtool_file *file) diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index e1ca588eb69d..78e2d0fc21ca 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -61,6 +61,7 @@ struct symbol { u8 return_thunk : 1; u8 fentry : 1; u8 profiling_func : 1; + u8 warned : 1; struct list_head pv_target; struct list_head reloc_list; }; diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index b1c920dc9516..f195deab456e 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -55,7 +55,12 @@ static inline char *offstr(struct section *sec, unsigned long offset) #define WARN_INSN(insn, format, ...) \ ({ \ - WARN_FUNC(format, insn->sec, insn->offset, ##__VA_ARGS__); \ + struct instruction *_insn = (insn); \ + if (!_insn->sym || !_insn->sym->warned) \ + WARN_FUNC(format, _insn->sec, _insn->offset, \ + ##__VA_ARGS__); \ + if (_insn->sym) \ + _insn->sym->warned = 1; \ }) #define BT_FUNC(format, insn, ...) \ -- cgit v1.2.3