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* [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data
@ 2017-06-01  9:06 Namhyung Kim
  2017-06-01  9:06 ` [PATCH 2/2] perf test: Decompress kernel module before objdump Namhyung Kim
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Namhyung Kim @ 2017-06-01  9:06 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Ingo Molnar, Peter Zijlstra, Jiri Olsa, LKML, kernel-team,
	David Ahern, Adrian Hunter

Currently perf decompresses kernel modules when loading symbol table but
it missed to do it when reading raw data.  Move decompress_kmodule() to
util/dso.c and do not unlink it immediately.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/dso.c        | 56 ++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/dso.h        |  2 ++
 tools/perf/util/symbol-elf.c | 40 ++++---------------------------
 3 files changed, 63 insertions(+), 35 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index b27d127cdf68..8dc1f147547c 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -350,6 +350,45 @@ void dso__set_module_info(struct dso *dso, struct kmod_path *m,
 	dso__set_short_name(dso, strdup(m->name), true);
 }
 
+int dso__decompress_kmodule(struct dso *dso, const char *filename,
+			    char *buf, size_t sz)
+{
+	struct kmod_path m = {};
+	int ret = -1;
+	int fd = -1;
+
+	if (!dso__needs_decompress(dso))
+		return -1;
+
+	if (kmod_path__parse_ext(&m, filename) < 0)
+		goto out;
+
+	if (!is_supported_compression(m.ext))
+		goto out;
+
+	snprintf(buf, sz, "/tmp/perf-kmod-XXXXXX");
+
+	fd = mkstemp(buf);
+	if (fd < 0) {
+		dso->load_errno = errno;
+		goto out;
+	}
+
+	pr_debug("decompressing to %s\n", buf);
+	if (!decompress_to_file(m.ext, filename, fd)) {
+		dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
+		unlink(buf);
+		close(fd);
+		goto out;
+	}
+	ret = fd;
+
+out:
+	free(m.ext);
+
+	return ret;
+}
+
 /*
  * Global list of open DSOs and the counter.
  */
@@ -399,6 +438,7 @@ static int __open_dso(struct dso *dso, struct machine *machine)
 	int fd;
 	char *root_dir = (char *)"";
 	char *name = malloc(PATH_MAX);
+	bool needs_unlink = false;
 
 	if (!name)
 		return -ENOMEM;
@@ -415,7 +455,23 @@ static int __open_dso(struct dso *dso, struct machine *machine)
 	if (!is_regular_file(name))
 		return -EINVAL;
 
+	if (dso__needs_decompress(dso)) {
+		char buf[32];
+
+		fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
+		if (fd < 0)
+			return -1;
+
+		close(fd);
+		strcpy(name, buf);
+		needs_unlink = true;
+	}
+
 	fd = do_open(name);
+
+	if (needs_unlink)
+		unlink(name);
+
 	free(name);
 	return fd;
 }
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 5fe2ab5877bd..c1e4b94d41aa 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -244,6 +244,8 @@ bool is_supported_compression(const char *ext);
 bool is_kernel_module(const char *pathname, int cpumode);
 bool decompress_to_file(const char *ext, const char *filename, int output_fd);
 bool dso__needs_decompress(struct dso *dso);
+int dso__decompress_kmodule(struct dso *dso, const char *filename,
+			    char *buf, size_t sz);
 
 struct kmod_path {
 	char *name;
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 1fb2efae4f02..b335f91f0cb3 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -637,40 +637,6 @@ static int dso__swap_init(struct dso *dso, unsigned char eidata)
 	return 0;
 }
 
-static int decompress_kmodule(struct dso *dso, const char *name,
-			      enum dso_binary_type type)
-{
-	int fd = -1;
-	char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
-	struct kmod_path m;
-
-	if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
-	    type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
-	    type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
-		return -1;
-
-	if (kmod_path__parse_ext(&m, dso->long_name) || !m.comp)
-		return -1;
-
-	fd = mkstemp(tmpbuf);
-	if (fd < 0) {
-		dso->load_errno = errno;
-		goto out;
-	}
-
-	if (!decompress_to_file(m.ext, name, fd)) {
-		dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
-		close(fd);
-		fd = -1;
-	}
-
-	unlink(tmpbuf);
-
-out:
-	free(m.ext);
-	return fd;
-}
-
 bool symsrc__possibly_runtime(struct symsrc *ss)
 {
 	return ss->dynsym || ss->opdsec;
@@ -702,9 +668,13 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 	int fd;
 
 	if (dso__needs_decompress(dso)) {
-		fd = decompress_kmodule(dso, name, type);
+		char buf[32];
+
+		fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
 		if (fd < 0)
 			return -1;
+
+		unlink(buf);
 	} else {
 		fd = open(name, O_RDONLY);
 		if (fd < 0) {
-- 
2.13.0

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 2/2] perf test: Decompress kernel module before objdump
  2017-06-01  9:06 [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Namhyung Kim
@ 2017-06-01  9:06 ` Namhyung Kim
  2017-06-01 11:29 ` [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Jiri Olsa
  2017-06-01 11:29 ` Jiri Olsa
  2 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2017-06-01  9:06 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Ingo Molnar, Peter Zijlstra, Jiri Olsa, LKML, kernel-team,
	David Ahern, Adrian Hunter

If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly.  This fixes a failure of
object code reading test for me.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/code-reading.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 1f14e7612cbb..5031acdf56dd 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -229,6 +229,7 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
 	unsigned char buf2[BUFSZ];
 	size_t ret_len;
 	u64 objdump_addr;
+	const char *objdump_name;
 	int ret;
 
 	pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
@@ -289,9 +290,35 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
 		state->done[state->done_cnt++] = al.map->start;
 	}
 
+	objdump_name = al.map->dso->long_name;
+	if (dso__needs_decompress(al.map->dso)) {
+		char buf[32];  /* for "/tmp/perf-kmod-XXXXXX" */
+		int fd;
+
+		fd = dso__decompress_kmodule(al.map->dso, objdump_name,
+					     buf, sizeof(buf));
+		if (fd < 0) {
+			pr_debug("decompression failed\n");
+			return -1;
+		}
+		close(fd);
+
+		objdump_name = strdup(buf);
+		if (objdump_name == NULL) {
+			pr_debug("memory allocation failed\n");
+			return -1;
+		}
+	}
+
 	/* Read the object code using objdump */
 	objdump_addr = map__rip_2objdump(al.map, al.addr);
-	ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
+	ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
+
+	if (objdump_name != al.map->dso->long_name) {
+		unlink(objdump_name);
+		free((void *)objdump_name);
+	}
+
 	if (ret > 0) {
 		/*
 		 * The kernel maps are inaccurate - assume objdump is right in
-- 
2.13.0

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data
  2017-06-01  9:06 [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Namhyung Kim
  2017-06-01  9:06 ` [PATCH 2/2] perf test: Decompress kernel module before objdump Namhyung Kim
@ 2017-06-01 11:29 ` Jiri Olsa
  2017-06-03  1:41   ` Namhyung Kim
  2017-06-01 11:29 ` Jiri Olsa
  2 siblings, 1 reply; 6+ messages in thread
From: Jiri Olsa @ 2017-06-01 11:29 UTC (permalink / raw)
  To: Namhyung Kim
  Cc: Arnaldo Carvalho de Melo, Ingo Molnar, Peter Zijlstra, Jiri Olsa,
	LKML, kernel-team, David Ahern, Adrian Hunter

On Thu, Jun 01, 2017 at 06:06:04PM +0900, Namhyung Kim wrote:

SNIP

> @@ -399,6 +438,7 @@ static int __open_dso(struct dso *dso, struct machine *machine)
>  	int fd;
>  	char *root_dir = (char *)"";
>  	char *name = malloc(PATH_MAX);
> +	bool needs_unlink = false;
>  
>  	if (!name)
>  		return -ENOMEM;
> @@ -415,7 +455,23 @@ static int __open_dso(struct dso *dso, struct machine *machine)
>  	if (!is_regular_file(name))
>  		return -EINVAL;
>  
> +	if (dso__needs_decompress(dso)) {
> +		char buf[32];
> +
> +		fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
> +		if (fd < 0)

			free(name)

> +			return -1;
> +
> +		close(fd);
> +		strcpy(name, buf);

also why not use name directly instead of buf?

jirka

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data
  2017-06-01  9:06 [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Namhyung Kim
  2017-06-01  9:06 ` [PATCH 2/2] perf test: Decompress kernel module before objdump Namhyung Kim
  2017-06-01 11:29 ` [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Jiri Olsa
@ 2017-06-01 11:29 ` Jiri Olsa
  2017-06-03  1:43   ` Namhyung Kim
  2 siblings, 1 reply; 6+ messages in thread
From: Jiri Olsa @ 2017-06-01 11:29 UTC (permalink / raw)
  To: Namhyung Kim
  Cc: Arnaldo Carvalho de Melo, Ingo Molnar, Peter Zijlstra, Jiri Olsa,
	LKML, kernel-team, David Ahern, Adrian Hunter

On Thu, Jun 01, 2017 at 06:06:04PM +0900, Namhyung Kim wrote:

SNIP

> -	}
> -
> -	unlink(tmpbuf);
> -
> -out:
> -	free(m.ext);
> -	return fd;
> -}
> -
>  bool symsrc__possibly_runtime(struct symsrc *ss)
>  {
>  	return ss->dynsym || ss->opdsec;
> @@ -702,9 +668,13 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
>  	int fd;
>  
>  	if (dso__needs_decompress(dso)) {
> -		fd = decompress_kmodule(dso, name, type);
> +		char buf[32];
> +
> +		fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
>  		if (fd < 0)
>  			return -1;
> +
> +		unlink(buf);

I wonder we could make this more clear and add:

  dso__decompress_kmodule_fd
  dso__decompress_kmodule_path

_fd version would remove the file and _path version would close the descriptor

in any case, could you please split the change so the
changes to decompress_kmodule are apparent?

thanks,
jirka

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data
  2017-06-01 11:29 ` [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Jiri Olsa
@ 2017-06-03  1:41   ` Namhyung Kim
  0 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2017-06-03  1:41 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Ingo Molnar, Peter Zijlstra, Jiri Olsa,
	LKML, kernel-team, David Ahern, Adrian Hunter

Hi Jiri,

On Thu, Jun 1, 2017 at 8:29 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> On Thu, Jun 01, 2017 at 06:06:04PM +0900, Namhyung Kim wrote:
>
> SNIP
>
>> @@ -399,6 +438,7 @@ static int __open_dso(struct dso *dso, struct machine *machine)
>>       int fd;
>>       char *root_dir = (char *)"";
>>       char *name = malloc(PATH_MAX);
>> +     bool needs_unlink = false;
>>
>>       if (!name)
>>               return -ENOMEM;
>> @@ -415,7 +455,23 @@ static int __open_dso(struct dso *dso, struct machine *machine)
>>       if (!is_regular_file(name))
>>               return -EINVAL;
>>
>> +     if (dso__needs_decompress(dso)) {
>> +             char buf[32];
>> +
>> +             fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
>> +             if (fd < 0)
>
>                         free(name)

ok.

>
>> +                     return -1;
>> +
>> +             close(fd);
>> +             strcpy(name, buf);
>
> also why not use name directly instead of buf?

The name should have original compressed filename and buf will be set
to a new decompressed name.

Thanks,
Namhyung

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data
  2017-06-01 11:29 ` Jiri Olsa
@ 2017-06-03  1:43   ` Namhyung Kim
  0 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2017-06-03  1:43 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Ingo Molnar, Peter Zijlstra, Jiri Olsa,
	LKML, kernel-team, David Ahern, Adrian Hunter

On Thu, Jun 1, 2017 at 8:29 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> On Thu, Jun 01, 2017 at 06:06:04PM +0900, Namhyung Kim wrote:
>
> SNIP
>
>> -     }
>> -
>> -     unlink(tmpbuf);
>> -
>> -out:
>> -     free(m.ext);
>> -     return fd;
>> -}
>> -
>>  bool symsrc__possibly_runtime(struct symsrc *ss)
>>  {
>>       return ss->dynsym || ss->opdsec;
>> @@ -702,9 +668,13 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
>>       int fd;
>>
>>       if (dso__needs_decompress(dso)) {
>> -             fd = decompress_kmodule(dso, name, type);
>> +             char buf[32];
>> +
>> +             fd = dso__decompress_kmodule(dso, name, buf, sizeof(buf));
>>               if (fd < 0)
>>                       return -1;
>> +
>> +             unlink(buf);
>
> I wonder we could make this more clear and add:
>
>   dso__decompress_kmodule_fd
>   dso__decompress_kmodule_path
>
> _fd version would remove the file and _path version would close the descriptor
>
> in any case, could you please split the change so the
> changes to decompress_kmodule are apparent?

Will do.

Thanks,
Namhyung

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-06-03  1:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-01  9:06 [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Namhyung Kim
2017-06-01  9:06 ` [PATCH 2/2] perf test: Decompress kernel module before objdump Namhyung Kim
2017-06-01 11:29 ` [PATCH 1/2] perf tools: Decompress kernel module when reading DSO data Jiri Olsa
2017-06-03  1:41   ` Namhyung Kim
2017-06-01 11:29 ` Jiri Olsa
2017-06-03  1:43   ` Namhyung Kim

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