Hi - > I think it's a good base, thanks a lot! > I made few comments before reading above, > feel free to post v2, if not we'll take over ;-) Thanks, see below. I tried to move the libdebuginfod feature test out of FEATURE_TEST_BASIC but couldn't get it going elsewhere in perf/Makefile.config, so it's back here for v2: Author: Frank Ch. Eigler <fche@xxxxxxxxxx> Date: Mon Mar 30 16:15:47 2020 -0400 perf build-ids: fall back to debuginfod query if debuginfo not found During a perf-record, use the -ldebuginfod API to query a debuginfod server, should the debug data not be found in the usual system locations. If successful, the usual $HOME/.debug dir is populated. v2: use #ifdef HAVE_DEBUGINFOD_SUPPORT guards include feature test source file Signed-off-by: Frank Ch. Eigler <fche@xxxxxxxxxx> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 574c2e0b9d20..51e051858d21 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -48,6 +48,7 @@ FEATURE_TESTS_BASIC := \ libelf-gelf_getnote \ libelf-getshdrstrndx \ libelf-mmap \ + libdebuginfod \ libnuma \ numa_num_possible_cpus \ libperl \ @@ -114,6 +115,7 @@ FEATURE_DISPLAY ?= \ libbfd \ libcap \ libelf \ + libdebuginfod \ libnuma \ numa_num_possible_cpus \ libperl \ diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 7ac0d8088565..1109f5ec96f7 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -26,6 +26,7 @@ FILES= \ test-libelf-gelf_getnote.bin \ test-libelf-getshdrstrndx.bin \ test-libelf-mmap.bin \ + test-libdebuginfod.bin \ test-libnuma.bin \ test-numa_num_possible_cpus.bin \ test-libperl.bin \ @@ -155,6 +156,9 @@ endif $(OUTPUT)test-libelf-getshdrstrndx.bin: $(BUILD) -lelf +$(OUTPUT)test-libdebuginfod.bin: + $(BUILD) -ldebuginfod + $(OUTPUT)test-libnuma.bin: $(BUILD) -lnuma diff --git a/tools/build/feature/test-libdebuginfod.c b/tools/build/feature/test-libdebuginfod.c new file mode 100644 index 000000000000..0d20b06b4b4f --- /dev/null +++ b/tools/build/feature/test-libdebuginfod.c @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <elfutils/debuginfod.h> + +int main(void) +{ + debuginfod_client* c = debuginfod_begin(); + return (long)c; +} diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 80e55e796be9..15eeecf4ff17 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -467,6 +467,11 @@ ifndef NO_LIBELF CFLAGS += -DHAVE_ELF_GETSHDRSTRNDX_SUPPORT endif + ifeq ($(feature-libdebuginfod), 1) + CFLAGS += -DHAVE_DEBUGINFOD_SUPPORT + EXTLIBS += -ldebuginfod + endif + ifndef NO_DWARF ifeq ($(origin PERF_HAVE_DWARF_REGS), undefined) msg := $(warning DWARF register mappings have not been defined for architecture $(SRCARCH), DWARF support disabled); diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index c076fc7fe025..31207b6e2066 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -31,6 +31,10 @@ #include "probe-file.h" #include "strlist.h" +#ifdef HAVE_DEBUGINFOD_SUPPORT +#include <elfutils/debuginfod.h> +#endif + #include <linux/ctype.h> #include <linux/zalloc.h> @@ -636,6 +640,21 @@ static char *build_id_cache__find_debug(const char *sbuild_id, if (realname && access(realname, R_OK)) zfree(&realname); nsinfo__mountns_exit(&nsc); + +#ifdef HAVE_DEBUGINFOD_SUPPORT + if (realname == NULL) { + debuginfod_client* c = debuginfod_begin(); + if (c != NULL) { + int fd = debuginfod_find_debuginfo(c, + (const unsigned char*)sbuild_id, 0, + &realname); + if (fd >= 0) + close(fd); /* retaining reference by realname */ + debuginfod_end(c); + } + } +#endif + out: free(debugfile); return realname;