perf tools: Add LZMA decompression from FILE

Internally lzma_decompress_to_file() creates a FILE from the filename.
Add an API that takes an existing FILE directly. This allows
decompressing already-open files and even buffers opened by fmemopen().
It is necessary for supporting .gnu_debugdata in the next patch.

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250307232206.2102440-3-stephen.s.brennan@oracle.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

2 files changed, 26 insertions, 11 deletions

diff --git a/tools/perf/util/compress.h b/tools/perf/util/compress.h
index a7650353c662..6cfecfca16f2 100644
--- a/tools/perf/util/compress.h
+++ b/tools/perf/util/compress.h
@@ -4,6 +4,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#include <stdio.h>
 #include <sys/types.h>
 #include <linux/compiler.h>
 #ifdef HAVE_ZSTD_SUPPORT
@@ -16,10 +17,17 @@ bool gzip_is_compressed(const char *input);
 #endif
 
 #ifdef HAVE_LZMA_SUPPORT
+int lzma_decompress_stream_to_file(FILE *input, int output_fd);
 int lzma_decompress_to_file(const char *input, int output_fd);
 bool lzma_is_compressed(const char *input);
 #else
 static inline
+int lzma_decompress_stream_to_file(FILE *input __maybe_unused,
+				   int output_fd __maybe_unused)
+{
+	return -1;
+}
+static inline
 int lzma_decompress_to_file(const char *input __maybe_unused,
 			    int output_fd __maybe_unused)
 {
diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
index af9a97612f9d..bbcd2ffcf4bd 100644
--- a/tools/perf/util/lzma.c
+++ b/tools/perf/util/lzma.c
@@ -32,7 +32,7 @@ static const char *lzma_strerror(lzma_ret ret)
 	}
 }
 
-int lzma_decompress_to_file(const char *input, int output_fd)
+int lzma_decompress_stream_to_file(FILE *infile, int output_fd)
 {
 	lzma_action action = LZMA_RUN;
 	lzma_stream strm   = LZMA_STREAM_INIT;
@@ -41,18 +41,11 @@ int lzma_decompress_to_file(const char *input, int output_fd)
 
 	u8 buf_in[BUFSIZE];
 	u8 buf_out[BUFSIZE];
-	FILE *infile;
-
-	infile = fopen(input, "rb");
-	if (!infile) {
-		pr_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno));
-		return -1;
-	}
 
 	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
 	if (ret != LZMA_OK) {
 		pr_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret);
-		goto err_fclose;
+		return err;
 	}
 
 	strm.next_in   = NULL;
@@ -100,11 +93,25 @@ int lzma_decompress_to_file(const char *input, int output_fd)
 	err = 0;
 err_lzma_end:
 	lzma_end(&strm);
-err_fclose:
-	fclose(infile);
 	return err;
 }
 
+int lzma_decompress_to_file(const char *input, int output_fd)
+{
+	FILE *infile;
+	int ret;
+
+	infile = fopen(input, "rb");
+	if (!infile) {
+		pr_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno));
+		return -1;
+	}
+
+	ret = lzma_decompress_stream_to_file(infile, output_fd);
+	fclose(infile);
+	return ret;
+}
+
 bool lzma_is_compressed(const char *input)
 {
 	int fd = open(input, O_RDONLY);