Messages in this thread Patch in this message | | | From | Josh Poimboeuf <> | Subject | [PATCH 1/5] objtool: Add '--verbose' option for disassembling affected functions | Date | Mon, 27 Mar 2023 09:00:44 -0700 |
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When a warning is associated with a function, add an option to disassemble that function.
This makes it easier for reporters to submit the information needed to diagnose objtool warnings.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- tools/objtool/Documentation/objtool.txt | 5 ++++ tools/objtool/builtin-check.c | 1 + tools/objtool/include/objtool/builtin.h | 1 + tools/objtool/include/objtool/warn.h | 38 +++++++++++++++++++++++++ 4 files changed, 45 insertions(+)
diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 8e53fc6735ef..7c1a46af322f 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -244,6 +244,11 @@ To achieve the validation, objtool enforces the following rules: Objtool warnings ---------------- +NOTE: When requesting help with an objtool warning, please re-run the +kernel build with `OBJTOOL_ARGS="--verbose" make <whatever>` and send +the full warning output (including any function disassembly below the +warning) to the objtool maintainers. + For asm files, if you're getting an error which doesn't make sense, first make sure that the affected code follows the above rules. diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 7c175198d09f..b8de42f6778e 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -93,6 +93,7 @@ static const struct option check_options[] = { OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), + OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"), OPT_END(), }; diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 2a108e648b7a..fcca6662c8b4 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -37,6 +37,7 @@ struct opts { bool no_unreachable; bool sec_address; bool stats; + bool verbose; }; extern struct opts opts; diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index a3e79ae75f2e..b85aa440ee1f 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -11,6 +11,7 @@ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <unistd.h> #include <objtool/builtin.h> #include <objtool/elf.h> @@ -41,6 +42,41 @@ static inline char *offstr(struct section *sec, unsigned long offset) return str; } +static inline void objdump_func(struct section *sec, unsigned long offset) +{ + struct symbol *sym = find_func_containing(sec, offset); + const char *script_relative = "scripts/objdump-func"; + bool is_text = (sec->sh.sh_flags & SHF_EXECINSTR); + char *cmd, *srctree, *script; + + if (is_text) + sym = find_func_containing(sec, offset); + if (!sym) + sym = find_symbol_containing(sec, offset); + if (!sym) + return; + + srctree = getenv("abs_srctree"); + if (!srctree) + return; + + script = malloc(strlen(srctree) + strlen(script_relative) + 2); + if (!script) + return; + + sprintf(script, "%s/%s", srctree, script_relative); + + if (access(script, X_OK)) + return; + + cmd = malloc(strlen(script) + strlen(objname) + strlen(sym->name) + 10); + if (!cmd) + return; + + sprintf(cmd, "%s %s %s 1>&2", script, objname, sym->name); + system(cmd); +} + #define WARN(format, ...) \ fprintf(stderr, \ "%s: warning: objtool: " format "\n", \ @@ -51,6 +87,8 @@ static inline char *offstr(struct section *sec, unsigned long offset) char *_str = offstr(sec, offset); \ WARN("%s: " format, _str, ##__VA_ARGS__); \ free(_str); \ + if (opts.verbose) \ + objdump_func(sec, offset); \ }) #define BT_FUNC(format, insn, ...) \ -- 2.39.2
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