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Message-Id: <20161220001137.26773-2-alexis.berlemont@gmail.com>
Date: Tue, 20 Dec 2016 01:11:37 +0100
From: Alexis Berlemont <alexis.berlemont@...il.com>
To: linux-kernel@...r.kernel.org
Cc: Alexis Berlemont <alexis.berlemont@...il.com>,
peterz@...radead.org, mingo@...hat.com, acme@...nel.org,
alexander.shishkin@...ux.intel.com
Subject: [PATCH v2 1/1] perf annotate: check that objdump correctly works
Before disassembling, the tool objdump is called just to be sure:
* objdump is available in the path;
* objdump is an executable binary;
* objdump has no dependency issue or anything else.
This objdump "pre-"command is only necessary because the real objdump
command is followed by some " | grep ..."; this prevents the shell
from returning the exit code of objdump execution.
Signed-off-by: Alexis Berlemont <alexis.berlemont@...il.com>
---
tools/perf/util/annotate.c | 69 +++++++++++++++++++++++++++++++++++++++++++---
tools/perf/util/annotate.h | 3 ++
2 files changed, 68 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index ea7e0de4b9c1..6fbaabbc9d2a 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -20,9 +20,12 @@
#include "block-range.h"
#include "arch/common.h"
#include <regex.h>
+#include <unistd.h>
#include <pthread.h>
#include <linux/bitops.h>
#include <sys/utsname.h>
+#include <sys/types.h>
+#include <sys/wait.h>
const char *disassembler_style;
const char *objdump_path;
@@ -1286,6 +1289,21 @@ int symbol__strerror_disassemble(struct symbol *sym __maybe_unused, struct map *
" --vmlinux vmlinux\n", build_id_msg ?: "");
}
break;
+
+ case SYMBOL_ANNOTATE_ERRNO__NO_OBJDUMP:
+ scnprintf(buf, buflen, "No objdump tool available in $PATH\n");
+ break;
+
+ case SYMBOL_ANNOTATE_ERRNO__NO_EXEC_OBJDUMP:
+ scnprintf(buf, buflen,
+ "The objdump tool found in $PATH cannot be executed\n");
+ break;
+
+ case SYMBOL_ANNOTATE_ERRNO__NO_OUTPUT:
+ scnprintf(buf, buflen,
+ "The objdump tool returned no disassembled code\n");
+ break;
+
default:
scnprintf(buf, buflen, "Internal error: Invalid %d error code\n", errnum);
break;
@@ -1329,6 +1347,44 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
return 0;
}
+static int annotate__check_exec(int pid, const char *command)
+{
+ int wstatus, err;
+
+ err = waitpid(pid, &wstatus, 0);
+ if (err < 0) {
+ pr_err("Failure calling waitpid: %s: (%s)\n",
+ strerror(errno), command);
+ return -1;
+ }
+
+ pr_debug("%s: %d %d\n", command, pid, WEXITSTATUS(wstatus));
+
+ switch (WEXITSTATUS(wstatus)) {
+ case 0:
+ /* Success */
+ err = 0;
+ break;
+ case 127:
+ /* The shell did not find objdump in the path */
+ err = SYMBOL_ANNOTATE_ERRNO__NO_OBJDUMP;
+ break;
+ default:
+ /*
+ * In the default case, we consider that objdump
+ * cannot be executed; so it gathers many fault
+ * scenarii:
+ * - objdump is not an executable (126);
+ * - objdump has some dependency issue;
+ * - ...
+ */
+ err = SYMBOL_ANNOTATE_ERRNO__NO_EXEC_OBJDUMP;
+ break;
+ }
+
+ return err;
+}
+
static const char *annotate__norm_arch(const char *arch_name)
{
struct utsname uts;
@@ -1426,7 +1482,8 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
snprintf(command, sizeof(command),
"%s %s%s --start-address=0x%016" PRIx64
" --stop-address=0x%016" PRIx64
- " -l -d %s %s -C %s 2>/dev/null|grep -v %s|expand",
+ " -l -d %s %s -C %s 2>/dev/null | "
+ "{ grep -v %s || true; } | expand",
objdump_path ? objdump_path : "objdump",
disassembler_style ? "-M " : "",
disassembler_style ? disassembler_style : "",
@@ -1454,7 +1511,7 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
close(stdout_fd[0]);
dup2(stdout_fd[1], 1);
close(stdout_fd[1]);
- execl("/bin/sh", "sh", "-c", command, NULL);
+ execl("/bin/sh", "sh", "-o", "pipefail", "-c", command, NULL);
perror(command);
exit(-1);
}
@@ -1479,8 +1536,12 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
nline++;
}
- if (nline == 0)
+ err = annotate__check_exec(pid, command);
+
+ if (err == 0 && nline == 0) {
pr_err("No output from %s\n", command);
+ err = SYMBOL_ANNOTATE_ERRNO__NO_OUTPUT;
+ }
/*
* kallsyms does not have symbol sizes so there may a nop at the end.
@@ -1490,7 +1551,7 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
delete_last_nop(sym);
fclose(file);
- err = 0;
+
out_remove_tmp:
close(stdout_fd[0]);
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 87e4cadc5d27..123f60c509a9 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -172,6 +172,9 @@ enum symbol_disassemble_errno {
__SYMBOL_ANNOTATE_ERRNO__START = -10000,
SYMBOL_ANNOTATE_ERRNO__NO_VMLINUX = __SYMBOL_ANNOTATE_ERRNO__START,
+ SYMBOL_ANNOTATE_ERRNO__NO_EXEC_OBJDUMP,
+ SYMBOL_ANNOTATE_ERRNO__NO_OBJDUMP,
+ SYMBOL_ANNOTATE_ERRNO__NO_OUTPUT,
__SYMBOL_ANNOTATE_ERRNO__END,
};
--
2.11.0
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