From 1bcb58a099938c33acda78b212ed67b06b3359ef Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 9 Mar 2016 00:07:01 -0600 Subject: objtool: Only print one warning per function When objtool discovers an issue, it's very common for it to flood the terminal with a lot of duplicate warnings. For example: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch warning: objtool: rtlwifi_rate_mapping()+0x2f3: frame pointer state mismatch warning: objtool: rtlwifi_rate_mapping()+0x2ff: frame pointer state mismatch warning: objtool: rtlwifi_rate_mapping()+0x30b: frame pointer state mismatch ... The first warning is usually all you need. Change it to only warn once per function. Suggested-by: Ingo Molnar Signed-off-by: Josh Poimboeuf Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Chris J Arges Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/c47f3ca38aa01e2a9b6601f9e38efd414c3f3c18.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/builtin-check.c | 48 ++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 23 deletions(-) (limited to 'tools/objtool/builtin-check.c') diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index bfeee227aaab..7515cb2e879a 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -800,7 +800,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *insn; struct section *sec; unsigned char state; - int ret, warnings = 0; + int ret; insn = first; sec = insn->sec; @@ -809,7 +809,7 @@ static int validate_branch(struct objtool_file *file, if (insn->alt_group && list_empty(&insn->alts)) { WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", sec, insn->offset); - warnings++; + return 1; } while (1) { @@ -817,10 +817,10 @@ static int validate_branch(struct objtool_file *file, if (frame_state(insn->state) != frame_state(state)) { WARN_FUNC("frame pointer state mismatch", sec, insn->offset); - warnings++; + return 1; } - return warnings; + return 0; } /* @@ -828,14 +828,15 @@ static int validate_branch(struct objtool_file *file, * the next function. */ if (is_fentry_call(insn) && (state & STATE_FENTRY)) - return warnings; + return 0; insn->visited = true; insn->state = state; list_for_each_entry(alt, &insn->alts, list) { ret = validate_branch(file, alt->insn, state); - warnings += ret; + if (ret) + return 1; } switch (insn->type) { @@ -845,7 +846,7 @@ static int validate_branch(struct objtool_file *file, if (state & STATE_FP_SAVED) { WARN_FUNC("duplicate frame pointer save", sec, insn->offset); - warnings++; + return 1; } state |= STATE_FP_SAVED; } @@ -856,7 +857,7 @@ static int validate_branch(struct objtool_file *file, if (state & STATE_FP_SETUP) { WARN_FUNC("duplicate frame pointer setup", sec, insn->offset); - warnings++; + return 1; } state |= STATE_FP_SETUP; } @@ -875,9 +876,9 @@ static int validate_branch(struct objtool_file *file, if (!nofp && has_modified_stack_frame(insn)) { WARN_FUNC("return without frame pointer restore", sec, insn->offset); - warnings++; + return 1; } - return warnings; + return 0; case INSN_CALL: if (is_fentry_call(insn)) { @@ -887,16 +888,16 @@ static int validate_branch(struct objtool_file *file, ret = dead_end_function(file, insn->call_dest); if (ret == 1) - return warnings; + return 0; if (ret == -1) - warnings++; + return 1; /* fallthrough */ case INSN_CALL_DYNAMIC: if (!nofp && !has_valid_stack_frame(insn)) { WARN_FUNC("call without frame pointer save/setup", sec, insn->offset); - warnings++; + return 1; } break; @@ -905,15 +906,16 @@ static int validate_branch(struct objtool_file *file, if (insn->jump_dest) { ret = validate_branch(file, insn->jump_dest, state); - warnings += ret; + if (ret) + return 1; } else if (has_modified_stack_frame(insn)) { WARN_FUNC("sibling call from callable instruction with changed frame pointer", sec, insn->offset); - warnings++; + return 1; } /* else it's a sibling call */ if (insn->type == INSN_JUMP_UNCONDITIONAL) - return warnings; + return 0; break; @@ -922,13 +924,13 @@ static int validate_branch(struct objtool_file *file, has_modified_stack_frame(insn)) { WARN_FUNC("sibling call from callable instruction with changed frame pointer", sec, insn->offset); - warnings++; + return 1; } - return warnings; + return 0; case INSN_BUG: - return warnings; + return 0; default: break; @@ -937,12 +939,11 @@ static int validate_branch(struct objtool_file *file, insn = next_insn_same_sec(file, insn); if (!insn) { WARN("%s: unexpected end of section", sec->name); - warnings++; - return warnings; + return 1; } } - return warnings; + return 0; } static bool is_gcov_insn(struct instruction *insn) @@ -1055,7 +1056,8 @@ static int validate_functions(struct objtool_file *file) if (insn->visited) continue; - if (!ignore_unreachable_insn(func, insn)) { + if (!ignore_unreachable_insn(func, insn) && + !warnings) { WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); warnings++; } -- cgit v1.2.3