From 4759670bc3e670069c055c2b33174813099fea4f Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 24 Mar 2025 14:55:55 -0700 Subject: objtool: Fix CONFIG_OBJTOOL_WERROR for vmlinux.o With (!X86_KERNEL_IBT && !LTO_CLANG && NOINSTR_VALIDATION), objtool runs on both translation units and vmlinux.o. With CONFIG_OBJTOOL_WERROR, the TUs get --Werror but vmlinux.o doesn't. Fix that. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/4f71ab9b947ffc47b6a87dd3b9aff4bb32b36d0a.1742852846.git.jpoimboe@kernel.org --- scripts/Makefile.vmlinux_o | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'scripts') diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index 0b6e2ebf60dc..f476f5605029 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -30,12 +30,20 @@ endif # objtool for vmlinux.o # --------------------------------------------------------------------------- # -# For LTO and IBT, objtool doesn't run on individual translation units. -# Run everything on vmlinux instead. +# For delay-objtool (IBT or LTO), objtool doesn't run on individual translation +# units. Instead it runs on vmlinux.o. +# +# For !delay-objtool + CONFIG_NOINSTR_VALIDATION, it runs on both translation +# units and vmlinux.o, with the latter only used for noinstr/unret validation. objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) -vmlinux-objtool-args-$(delay-objtool) += $(objtool-args-y) +ifeq ($(delay-objtool),y) +vmlinux-objtool-args-y += $(objtool-args-y) +else +vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror +endif + vmlinux-objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr \ $(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret) -- cgit v1.2.3 From d39f82a058c0269392a797cb04f2a6064e5dcab6 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 24 Mar 2025 14:56:00 -0700 Subject: objtool: Reduce CONFIG_OBJTOOL_WERROR verbosity Remove the following from CONFIG_OBJTOOL_WERROR: * backtrace * "upgraded warnings to errors" message * cmdline args This makes the default output less cluttered and makes it easier to spot the actual warnings. Note the above options are still are available with --verbose or OBJTOOL_VERBOSE=1. Also, do the cmdline arg printing on all warnings, regardless of werror. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org --- scripts/Makefile.lib | 2 +- tools/objtool/builtin-check.c | 113 ++++++++++++++++---------------- tools/objtool/check.c | 23 ++++--- tools/objtool/include/objtool/builtin.h | 6 +- 4 files changed, 73 insertions(+), 71 deletions(-) (limited to 'scripts') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 57620b439a1f..b93597420daf 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -277,7 +277,7 @@ objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES) -objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror --backtrace +objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror objtool-args = $(objtool-args-y) \ $(if $(delay-objtool), --link) \ diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index c973a751fb7d..2bdff910430e 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -15,8 +15,11 @@ #include #include -const char *objname; +#define ORIG_SUFFIX ".orig" +int orig_argc; +static char **orig_argv; +const char *objname; struct opts opts; static const char * const check_usage[] = { @@ -224,39 +227,73 @@ static int copy_file(const char *src, const char *dst) return 0; } -static char **save_argv(int argc, const char **argv) +static void save_argv(int argc, const char **argv) { - char **orig_argv; - orig_argv = calloc(argc, sizeof(char *)); if (!orig_argv) { WARN_GLIBC("calloc"); - return NULL; + exit(1); } for (int i = 0; i < argc; i++) { orig_argv[i] = strdup(argv[i]); if (!orig_argv[i]) { WARN_GLIBC("strdup(%s)", orig_argv[i]); - return NULL; + exit(1); } }; - - return orig_argv; } -#define ORIG_SUFFIX ".orig" +void print_args(void) +{ + char *backup = NULL; + + if (opts.output || opts.dryrun) + goto print; + + /* + * Make a backup before kbuild deletes the file so the error + * can be recreated without recompiling or relinking. + */ + backup = malloc(strlen(objname) + strlen(ORIG_SUFFIX) + 1); + if (!backup) { + WARN_GLIBC("malloc"); + goto print; + } + + strcpy(backup, objname); + strcat(backup, ORIG_SUFFIX); + if (copy_file(objname, backup)) { + backup = NULL; + goto print; + } + +print: + /* + * Print the cmdline args to make it easier to recreate. If '--output' + * wasn't used, add it to the printed args with the backup as input. + */ + fprintf(stderr, "%s", orig_argv[0]); + + for (int i = 1; i < orig_argc; i++) { + char *arg = orig_argv[i]; + + if (backup && !strcmp(arg, objname)) + fprintf(stderr, " %s -o %s", backup, objname); + else + fprintf(stderr, " %s", arg); + } + + fprintf(stderr, "\n"); +} int objtool_run(int argc, const char **argv) { struct objtool_file *file; - char *backup = NULL; - char **orig_argv; int ret = 0; - orig_argv = save_argv(argc, argv); - if (!orig_argv) - return 1; + orig_argc = argc; + save_argv(argc, argv); cmd_parse_options(argc, argv, check_usage); @@ -279,59 +316,19 @@ int objtool_run(int argc, const char **argv) file = objtool_open_read(objname); if (!file) - goto err; + return 1; if (!opts.link && has_multiple_files(file->elf)) { WARN("Linked object requires --link"); - goto err; + return 1; } ret = check(file); if (ret) - goto err; + return ret; if (!opts.dryrun && file->elf->changed && elf_write(file->elf)) - goto err; - - return 0; - -err: - if (opts.dryrun) - goto err_msg; - - if (opts.output) { - unlink(opts.output); - goto err_msg; - } - - /* - * Make a backup before kbuild deletes the file so the error - * can be recreated without recompiling or relinking. - */ - backup = malloc(strlen(objname) + strlen(ORIG_SUFFIX) + 1); - if (!backup) { - WARN_GLIBC("malloc"); return 1; - } - - strcpy(backup, objname); - strcat(backup, ORIG_SUFFIX); - if (copy_file(objname, backup)) - return 1; - -err_msg: - fprintf(stderr, "%s", orig_argv[0]); - - for (int i = 1; i < argc; i++) { - char *arg = orig_argv[i]; - if (backup && !strcmp(arg, objname)) - fprintf(stderr, " %s -o %s", backup, objname); - else - fprintf(stderr, " %s", arg); - } - - fprintf(stderr, "\n"); - - return 1; + return 0; } diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f4e7ee8e8fb5..ac21f2846ebc 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4732,9 +4732,6 @@ int check(struct objtool_file *file) free_insns(file); - if (opts.verbose) - disas_warned_funcs(file); - if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); printf("nr_cfi: %ld\n", nr_cfi); @@ -4743,19 +4740,25 @@ int check(struct objtool_file *file) } out: + if (!ret && !warnings) + return 0; + + if (opts.verbose) { + if (opts.werror && warnings) + WARN("%d warning(s) upgraded to errors", warnings); + print_args(); + disas_warned_funcs(file); + } + /* * CONFIG_OBJTOOL_WERROR upgrades all warnings (and errors) to actual * errors. * - * Note that even "fatal" type errors don't actually return an error - * without CONFIG_OBJTOOL_WERROR. That probably needs improved at some - * point. + * Note that even fatal errors don't yet actually return an error + * without CONFIG_OBJTOOL_WERROR. That will be fixed soon-ish. */ - if (opts.werror && (ret || warnings)) { - if (warnings) - WARN("%d warning(s) upgraded to errors", warnings); + if (opts.werror) return 1; - } return 0; } diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 0fafd0f7a209..6b08666fa69d 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -43,8 +43,10 @@ struct opts { extern struct opts opts; -extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]); +int cmd_parse_options(int argc, const char **argv, const char * const usage[]); -extern int objtool_run(int argc, const char **argv); +int objtool_run(int argc, const char **argv); + +void print_args(void); #endif /* _BUILTIN_H */ -- cgit v1.2.3 From 876a4bce3849b235d752d13ec3180e15a35e52de Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 24 Mar 2025 14:56:02 -0700 Subject: objtool: Remove --no-unreachable for noinstr-only vmlinux.o runs For (!X86_KERNEL_IBT && !LTO_CLANG && NOINSTR_VALIDATION), objtool runs on both translation units and vmlinux.o. The vmlinux.o run only does noinstr/noret validation. In that case --no-unreachable has no effect. Remove it. Note that for ((X86_KERNEL_IBT || LTO_CLANG) && KCOV), --no-unreachable still gets set in objtool-args-y by scripts/Makefile.lib. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/05414246a0124db2f21b0d071b652aa9043d039d.1742852847.git.jpoimboe@kernel.org --- scripts/Makefile.vmlinux_o | 1 - 1 file changed, 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index f476f5605029..938c7457717e 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -44,7 +44,6 @@ else vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror endif -vmlinux-objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr \ $(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret) -- cgit v1.2.3 From 55c78035a1a8dfb05f1472018ce2a651701adb7d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 31 Mar 2025 21:26:36 -0700 Subject: objtool: Silence more KCOV warnings, part 2 Similar to GCOV, KCOV can leave behind dead code and undefined behavior. Warnings related to those should be ignored. The previous commit: 6b023c784204 ("objtool: Silence more KCOV warnings") ... only did so for CONFIG_CGOV_KERNEL. Also do it for CONFIG_KCOV, but for real this time. Fixes the following warning: vmlinux.o: warning: objtool: synaptics_report_mt_data: unexpected end of section .text.synaptics_report_mt_data Fixes: 6b023c784204 ("objtool: Silence more KCOV warnings") Reported-by: kernel test robot Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/a44ba16e194bcbc52c1cef3d3cd9051a62622723.1743481539.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/oe-kbuild-all/202503282236.UhfRsF3B-lkp@intel.com/ --- scripts/Makefile.lib | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index b93597420daf..4d543054f723 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -275,7 +275,7 @@ objtool-args-$(CONFIG_MITIGATION_SLS) += --sls objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess -objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable +objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV)) += --no-unreachable objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES) objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror -- cgit v1.2.3