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From: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Kim Phillips <kim.phillips@amd.com>,
	Michael Petlan <mpetlan@redhat.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH] perf symbols: Don't try to find a vmlinux file when looking for kernel modules
Date: Mon, 2 Mar 2020 16:10:07 -0300	[thread overview]
Message-ID: <20200302191007.GD10335@kernel.org> (raw)

The dso->kernel value is now set to everything that is in
machine->kmaps, but that was being used to decide if vmlinux lookup is
needed, which ended up making that lookup be made for kernel modules,
that now have dso->kernel set, leading to these kinds of warnings when
running on a machine with compressed kernel modules, like fedora:31:
    
  [root@five ~]# perf record -F 10000 -a sleep 2
  [ perf record: Woken up 1 times to write data ]
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
  [root@five ~]#

This happens when collecting the buildid, when we find samples for
kernel modules, fix it by checking if the looked up DSO is a kernel
module by other means.

Fixes: 02213cec64bb ("perf maps: Mark module DSOs with kernel type")
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

---

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 1077013d8ce2..26bc6a0096ce 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1622,7 +1622,12 @@ int dso__load(struct dso *dso, struct map *map)
 		goto out;
 	}
 
-	if (dso->kernel) {
+	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
+
+	if (dso->kernel && !kmod) {
 		if (dso->kernel == DSO_TYPE_KERNEL)
 			ret = dso__load_kernel_sym(dso, map);
 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
@@ -1650,12 +1655,6 @@ int dso__load(struct dso *dso, struct map *map)
 	if (!name)
 		goto out;
 
-	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
-
-
 	/*
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work

             reply	other threads:[~2020-03-02 19:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-02 19:10 Arnaldo Carvalho de Melo [this message]
2020-03-02 19:20 ` [PATCH] perf symbols: Don't try to find a vmlinux file when looking for kernel modules Jiri Olsa
2020-03-02 20:02 ` Jiri Olsa
2020-03-02 20:21   ` Arnaldo Carvalho de Melo
2020-03-04 11:01 ` [tip: perf/urgent] " tip-bot2 for Arnaldo Carvalho de Melo

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