Commit 8b42b7e5 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo

perf tools: Add is_compressed callback to compressions array

Add is_compressed callback to the compressions array, that returns 0 if
the file is compressed or != 0 if not.

The new callback is used to recognize the situation when we have a
'compressed' object, like:

  /lib/modules/.../drivers/net/ethernet/intel/igb/igb.ko.xz

but we need to read its debug data from debuginfo files, which might not
be compressed, like:

  /root/.debug/.build-id/d6/...c4b301f/debug

So even for a 'compressed' object we read debug data from a plain
uncompressed object. To keep this transparent, we detect this in
decompress_kmodule() and return the file descriptor to the uncompressed
file.
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817094813.15086-11-jolsa@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c9a8a613
...@@ -4,10 +4,12 @@ ...@@ -4,10 +4,12 @@
#ifdef HAVE_ZLIB_SUPPORT #ifdef HAVE_ZLIB_SUPPORT
int gzip_decompress_to_file(const char *input, int output_fd); int gzip_decompress_to_file(const char *input, int output_fd);
bool gzip_is_compressed(const char *input);
#endif #endif
#ifdef HAVE_LZMA_SUPPORT #ifdef HAVE_LZMA_SUPPORT
int lzma_decompress_to_file(const char *input, int output_fd); int lzma_decompress_to_file(const char *input, int output_fd);
bool lzma_is_compressed(const char *input);
#endif #endif
#endif /* PERF_COMPRESS_H */ #endif /* PERF_COMPRESS_H */
...@@ -196,15 +196,16 @@ enum { ...@@ -196,15 +196,16 @@ enum {
static const struct { static const struct {
const char *fmt; const char *fmt;
int (*decompress)(const char *input, int output); int (*decompress)(const char *input, int output);
bool (*is_compressed)(const char *input);
} compressions[] = { } compressions[] = {
[COMP_ID__NONE] = { .fmt = NULL, }, [COMP_ID__NONE] = { .fmt = NULL, },
#ifdef HAVE_ZLIB_SUPPORT #ifdef HAVE_ZLIB_SUPPORT
{ "gz", gzip_decompress_to_file }, { "gz", gzip_decompress_to_file, gzip_is_compressed },
#endif #endif
#ifdef HAVE_LZMA_SUPPORT #ifdef HAVE_LZMA_SUPPORT
{ "xz", lzma_decompress_to_file }, { "xz", lzma_decompress_to_file, lzma_is_compressed },
#endif #endif
{ NULL, NULL }, { NULL, NULL, NULL },
}; };
static int is_supported_compression(const char *ext) static int is_supported_compression(const char *ext)
...@@ -262,6 +263,22 @@ static int decompress_kmodule(struct dso *dso, const char *name, ...@@ -262,6 +263,22 @@ static int decompress_kmodule(struct dso *dso, const char *name,
if (dso->comp == COMP_ID__NONE) if (dso->comp == COMP_ID__NONE)
return -1; return -1;
/*
* We have proper compression id for DSO and yet the file
* behind the 'name' can still be plain uncompressed object.
*
* The reason is behind the logic we open the DSO object files,
* when we try all possible 'debug' objects until we find the
* data. So even if the DSO is represented by 'krava.xz' module,
* we can end up here opening ~/.debug/....23432432/debug' file
* which is not compressed.
*
* To keep this transparent, we detect this and return the file
* descriptor to the uncompressed file.
*/
if (!compressions[dso->comp].is_compressed(name))
return open(name, O_RDONLY);
fd = mkstemp(tmpbuf); fd = mkstemp(tmpbuf);
if (fd < 0) { if (fd < 0) {
dso->load_errno = errno; dso->load_errno = errno;
......
...@@ -99,3 +99,8 @@ int lzma_decompress_to_file(const char *input, int output_fd) ...@@ -99,3 +99,8 @@ int lzma_decompress_to_file(const char *input, int output_fd)
fclose(infile); fclose(infile);
return err; return err;
} }
bool lzma_is_compressed(const char *input __maybe_unused)
{
return true;
}
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
#include <sys/stat.h> #include <sys/stat.h>
#include <sys/mman.h> #include <sys/mman.h>
#include <zlib.h> #include <zlib.h>
#include <linux/compiler.h>
#include "util/compress.h" #include "util/compress.h"
#include "util/util.h" #include "util/util.h"
...@@ -79,3 +80,8 @@ int gzip_decompress_to_file(const char *input, int output_fd) ...@@ -79,3 +80,8 @@ int gzip_decompress_to_file(const char *input, int output_fd)
return ret == Z_STREAM_END ? 0 : -1; return ret == Z_STREAM_END ? 0 : -1;
} }
bool gzip_is_compressed(const char *input __maybe_unused)
{
return true;
}
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