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From: Jiri Olsa <jolsa@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Michael Petlan <mpetlan@redhat.com>,
	Song Liu <songliubraving@fb.com>, Ian Rogers <irogers@google.com>,
	Stephane Eranian <eranian@google.com>,
	Alexey Budankov <alexey.budankov@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>
Subject: [PATCH 10/25] perf tools: Add check for existing link in buildid dir
Date: Tue, 24 Nov 2020 00:04:57 +0100	[thread overview]
Message-ID: <20201123230512.2097312-11-jolsa@kernel.org> (raw)
In-Reply-To: <20201123230512.2097312-1-jolsa@kernel.org>

When adding new build id link we fail if the link is already
there. Adding check for existing link and output debug message
that the build id is already linked.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/build-id.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 2aacc8b29f7e..4a391f13f40d 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -755,8 +755,25 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 	tmp = dir_name + strlen(buildid_dir) - 5;
 	memcpy(tmp, "../..", 5);
 
-	if (symlink(tmp, linkname) == 0)
+	if (symlink(tmp, linkname) == 0) {
 		err = 0;
+	} else if (errno == EEXIST) {
+		char path[PATH_MAX];
+		ssize_t len;
+
+		len = readlink(linkname, path, sizeof(path) - 1);
+		if (len <= 0) {
+			pr_err("Cant read link: %s\n", linkname);
+			goto out_free;
+		}
+		path[len] = '\0';
+
+		if (strcmp(tmp, path)) {
+			pr_debug("build <%s> already linked to %s\n",
+				 sbuild_id, linkname);
+		}
+		err = 0;
+	}
 
 	/* Update SDT cache : error is just warned */
 	if (realname &&
-- 
2.26.2


  parent reply	other threads:[~2020-11-23 23:06 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-23 23:04 [PATCHv3 00/25] perf: Add mmap2 build id support Jiri Olsa
2020-11-23 23:04 ` [PATCH 01/25] bpf: Move stack_map_get_build_id into lib Jiri Olsa
2020-11-23 23:04 ` [PATCH 02/25] bpf: Add size arg to build_id_parse function Jiri Olsa
2020-11-23 23:04 ` [PATCH 03/25] perf: Add build id data in mmap2 event Jiri Olsa
2020-11-23 23:04 ` [PATCH 04/25] tools headers uapi: Sync tools/include/uapi/linux/perf_event.h Jiri Olsa
2020-11-23 23:04 ` [PATCH 05/25] tools lib: Adopt memchr_inv() from kernel Jiri Olsa
2020-11-23 23:04 ` [PATCH 06/25] perf tools: Do not swap mmap2 fields in case it contains build id Jiri Olsa
2020-11-23 23:04 ` [PATCH 07/25] perf tools: Add build_id__is_defined function Jiri Olsa
2020-11-23 23:04 ` [PATCH 08/25] perf tools: Add filename__decompress function Jiri Olsa
2020-11-23 23:04 ` [PATCH 09/25] perf tools: Add support to read build id from compressed elf Jiri Olsa
2020-11-23 23:04 ` Jiri Olsa [this message]
2020-11-23 23:04 ` [PATCH 11/25] perf tools: Use struct extra_kernel_map in machine__process_kernel_mmap_event Jiri Olsa
2020-11-23 23:04 ` [PATCH 12/25] perf tools: Try to load vmlinux from buildid database Jiri Olsa
2020-11-23 23:05 ` [PATCH 13/25] perf tools: Store build id from mmap2 events Jiri Olsa
2020-11-25 12:56   ` Namhyung Kim
2020-11-25 14:15     ` Jiri Olsa
2020-11-23 23:05 ` [PATCH 14/25] perf tools: Allow mmap2 event to synthesize kernel image Jiri Olsa
2020-11-23 23:05 ` [PATCH 15/25] perf tools: Allow mmap2 event to synthesize modules Jiri Olsa
2020-11-23 23:05 ` [PATCH 16/25] perf tools: Synthesize build id for kernel/modules/tasks Jiri Olsa
2020-11-23 23:05 ` [PATCH 17/25] perf tools: Add support to display build id for mmap2 events Jiri Olsa
2020-11-23 23:05 ` [PATCH 18/25] perf tools: Use machine__for_each_dso in perf_session__cache_build_ids Jiri Olsa
2020-11-23 23:05 ` [PATCH 19/25] perf tools: Add __perf_session__cache_build_ids function Jiri Olsa
2020-11-23 23:05 ` [PATCH 20/25] perf tools: Add is_perf_data function Jiri Olsa
2020-11-23 23:05 ` [PATCH 21/25] perf tools: Add build_id_cache__add function Jiri Olsa
2020-11-23 23:05 ` [PATCH 22/25] perf buildid-cache: Add support to add build ids from perf data Jiri Olsa
2020-11-25 13:00   ` Namhyung Kim
2020-11-25 13:04     ` Namhyung Kim
2020-11-25 16:36     ` Jiri Olsa
2020-11-26  4:49       ` Namhyung Kim
2020-11-25 13:29   ` Namhyung Kim
2020-11-25 14:20     ` Jiri Olsa
2020-11-23 23:05 ` [PATCH 23/25] perf buildid-cache: Add --debuginfod option Jiri Olsa
2020-11-23 23:05 ` [PATCH 24/25] perf buildid-list: Add support for mmap2's buildid events Jiri Olsa
2020-11-23 23:05 ` [PATCH 25/25] perf record: Add --buildid-mmap option to enable mmap's build id Jiri Olsa
2020-11-25 12:54 ` [PATCHv3 00/25] perf: Add mmap2 build id support Namhyung Kim
2020-11-26 17:00 [PATCHv4 " Jiri Olsa
2020-11-26 17:00 ` [PATCH 10/25] perf tools: Add check for existing link in buildid dir Jiri Olsa
2020-11-26 17:47   ` Arnaldo Carvalho de Melo

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