perf tools: Add lzma decompression support for kernel module

In short, Fedora compresses kernel modules now (since version 21) with
lzma compression.

Adding lzma decompress support into the dso.c:compressions array
introduced by Namhyung earlier.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2glp65kdtbrk0gblmirsjsnt@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile.perf

@@ -71,6 +71,8 @@ include config/utilities.mak
 #
 # Define NO_LIBBABELTRACE if you do not want libbabeltrace support
 # for CTF data format.
+#
+# Define NO_LZMA if you do not want to support compressed (xz) kernel modules
 
 ifeq ($(srctree),)
 srctree := $(patsubst %/,%,$(dir $(shell pwd)))

tools/perf/config/Makefile

@@ -541,6 +541,17 @@ ifndef NO_ZLIB
   endif
 endif
 
+ifndef NO_LZMA
+  ifeq ($(feature-lzma), 1)
+    CFLAGS += -DHAVE_LZMA_SUPPORT
+    EXTLIBS += -llzma
+    $(call detected,CONFIG_LZMA)
+  else
+    msg := $(warning No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev);
+    NO_LZMA := 1
+  endif
+endif
+
 ifndef NO_BACKTRACE
   ifeq ($(feature-backtrace), 1)
     CFLAGS += -DHAVE_BACKTRACE_SUPPORT

tools/perf/util/Build

@@ -94,6 +94,7 @@ libperf-y += scripting-engines/
 
 libperf-$(CONFIG_PERF_REGS) += perf_regs.o
 libperf-$(CONFIG_ZLIB) += zlib.o
+libperf-$(CONFIG_LZMA) += lzma.o
 
 CFLAGS_config.o   += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_exec_cmd.o += -DPERF_EXEC_PATH="BUILD_STR($(perfexecdir_SQ))" -DPREFIX="BUILD_STR($(prefix_SQ))"

tools/perf/util/dso.c

@@ -147,6 +147,9 @@ static const struct {
 } compressions[] = {
 #ifdef HAVE_ZLIB_SUPPORT
 	{ "gz", gzip_decompress_to_file },
+#endif
+#ifdef HAVE_LZMA_SUPPORT
+	{ "xz", lzma_decompress_to_file },
 #endif
 	{ NULL, NULL },
 };

tools/perf/util/lzma.c

@@ -0,0 +1,95 @@
+#include <lzma.h>
+#include <stdio.h>
+#include <linux/compiler.h>
+#include "util.h"
+#include "debug.h"
+
+#define BUFSIZE 8192
+
+static const char *lzma_strerror(lzma_ret ret)
+{
+	switch ((int) ret) {
+	case LZMA_MEM_ERROR:
+		return "Memory allocation failed";
+	case LZMA_OPTIONS_ERROR:
+		return "Unsupported decompressor flags";
+	case LZMA_FORMAT_ERROR:
+		return "The input is not in the .xz format";
+	case LZMA_DATA_ERROR:
+		return "Compressed file is corrupt";
+	case LZMA_BUF_ERROR:
+		return "Compressed file is truncated or otherwise corrupt";
+	default:
+		return "Unknown error, possibly a bug";
+	}
+}
+
+int lzma_decompress_to_file(const char *input, int output_fd)
+{
+	lzma_action action = LZMA_RUN;
+	lzma_stream strm   = LZMA_STREAM_INIT;
+	lzma_ret ret;
+
+	u8 buf_in[BUFSIZE];
+	u8 buf_out[BUFSIZE];
+	FILE *infile;
+
+	infile = fopen(input, "rb");
+	if (!infile) {
+		pr_err("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_err("lzma: lzma_stream_decoder failed %s (%d)\n",
+			lzma_strerror(ret), ret);
+		return -1;
+	}
+
+	strm.next_in   = NULL;
+	strm.avail_in  = 0;
+	strm.next_out  = buf_out;
+	strm.avail_out = sizeof(buf_out);
+
+	while (1) {
+		if (strm.avail_in == 0 && !feof(infile)) {
+			strm.next_in  = buf_in;
+			strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
+
+			if (ferror(infile)) {
+				pr_err("lzma: read error: %s\n", strerror(errno));
+				return -1;
+			}
+
+			if (feof(infile))
+				action = LZMA_FINISH;
+		}
+
+		ret = lzma_code(&strm, action);
+
+		if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
+			ssize_t write_size = sizeof(buf_out) - strm.avail_out;
+
+			if (writen(output_fd, buf_out, write_size) != write_size) {
+				pr_err("lzma: write error: %s\n", strerror(errno));
+				return -1;
+			}
+
+			strm.next_out  = buf_out;
+			strm.avail_out = sizeof(buf_out);
+		}
+
+		if (ret != LZMA_OK) {
+			if (ret == LZMA_STREAM_END)
+				return 0;
+
+			pr_err("lzma: failed %s\n", lzma_strerror(ret));
+			return -1;
+		}
+	}
+
+	fclose(infile);
+	return 0;
+}

tools/perf/util/util.h

@@ -329,4 +329,8 @@ bool find_process(const char *name);
 int gzip_decompress_to_file(const char *input, int output_fd);
 #endif
 
+#ifdef HAVE_LZMA_SUPPORT
+int lzma_decompress_to_file(const char *input, int output_fd);
+#endif
+
 #endif /* GIT_COMPAT_UTIL_H */