5 files changed, 181 insertions, 2 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 91e27ac297c2..1ca533f06a4c 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1258,6 +1258,9 @@ repeat:
         if (session == NULL)
                 return -1;
 
+        if (zstd_init(&(session->zstd_data), 0) < 0)
+                pr_warning("Decompression initialization failed. Reported data may be incomplete.\n");
+
         if (report.queue_size) {
                 ordered_events__set_alloc_size(&session->ordered_events,
                                                report.queue_size);
@@ -1448,7 +1451,7 @@ repeat:
 error:
         if (report.ptime_range)
                 zfree(&report.ptime_range);
-
+        zstd_fini(&(session->zstd_data));
         perf_session__delete(session);
         return ret;
 }
diff --git a/tools/perf/util/compress.h b/tools/perf/util/compress.h
index 1041a4fd81e2..0cd3369af2a4 100644
--- a/tools/perf/util/compress.h
+++ b/tools/perf/util/compress.h
@@ -20,6 +20,7 @@ bool lzma_is_compressed(const char *input);
 struct zstd_data {
 #ifdef HAVE_ZSTD_SUPPORT
         ZSTD_CStream    *cstream;
+        ZSTD_DStream    *dstream;
 #endif
 };
 
@@ -31,6 +32,9 @@ int zstd_fini(struct zstd_data *data);
 size_t zstd_compress_stream_to_records(struct zstd_data *data, void *dst, size_t dst_size,
                                        void *src, size_t src_size, size_t max_record_size,
                                        size_t process_header(void *record, size_t increment));
+
+size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size,
+                              void *dst, size_t dst_size);
 #else /* !HAVE_ZSTD_SUPPORT */
 
 static inline int zstd_init(struct zstd_data *data __maybe_unused, int level __maybe_unused)
@@ -52,6 +56,13 @@ size_t zstd_compress_stream_to_records(struct zstd_data *data __maybe_unused,
 {
         return 0;
 }
+
+static inline size_t zstd_decompress_stream(struct zstd_data *data __maybe_unused, void *src __maybe_unused,
+                                            size_t src_size __maybe_unused, void *dst __maybe_unused,
+                                            size_t dst_size __maybe_unused)
+{
+        return 0;
+}
 #endif
 
 #endif /* PERF_COMPRESS_H */
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index ec1dec86d0e1..2310a1752983 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -29,6 +29,61 @@
 #include "stat.h"
 #include "arch/common.h"
 
+#ifdef HAVE_ZSTD_SUPPORT
+static int perf_session__process_compressed_event(struct perf_session *session,
+                                                  union perf_event *event, u64 file_offset)
+{
+        void *src;
+        size_t decomp_size, src_size;
+        u64 decomp_last_rem = 0;
+        size_t decomp_len = session->header.env.comp_mmap_len;
+        struct decomp *decomp, *decomp_last = session->decomp_last;
+
+        decomp = mmap(NULL, sizeof(struct decomp) + decomp_len, PROT_READ|PROT_WRITE,
+                      MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+        if (decomp == MAP_FAILED) {
+                pr_err("Couldn't allocate memory for decompression\n");
+                return -1;
+        }
+
+        decomp->file_pos = file_offset;
+        decomp->head = 0;
+
+        if (decomp_last) {
+                decomp_last_rem = decomp_last->size - decomp_last->head;
+                memcpy(decomp->data, &(decomp_last->data[decomp_last->head]), decomp_last_rem);
+                decomp->size = decomp_last_rem;
+        }
+
+        src = (void *)event + sizeof(struct compressed_event);
+        src_size = event->pack.header.size - sizeof(struct compressed_event);
+
+        decomp_size = zstd_decompress_stream(&(session->zstd_data), src, src_size,
+                                &(decomp->data[decomp_last_rem]), decomp_len - decomp_last_rem);
+        if (!decomp_size) {
+                munmap(decomp, sizeof(struct decomp) + decomp_len);
+                pr_err("Couldn't decompress data\n");
+                return -1;
+        }
+
+        decomp->size += decomp_size;
+
+        if (session->decomp == NULL) {
+                session->decomp = decomp;
+                session->decomp_last = decomp;
+        } else {
+                session->decomp_last->next = decomp;
+                session->decomp_last = decomp;
+        }
+
+        pr_debug("decomp (B): %ld to %ld\n", src_size, decomp_size);
+
+        return 0;
+}
+#else /* !HAVE_ZSTD_SUPPORT */
+#define perf_session__process_compressed_event perf_session__process_compressed_event_stub
+#endif
+
 static int perf_session__deliver_event(struct perf_session *session,
                                        union perf_event *event,
                                        struct perf_tool *tool,
@@ -197,6 +252,21 @@ static void perf_session__delete_threads(struct perf_session *session)
         machine__delete_threads(&session->machines.host);
 }
 
+static void perf_session__release_decomp_events(struct perf_session *session)
+{
+        struct decomp *next, *decomp;
+        size_t decomp_len;
+        next = session->decomp;
+        decomp_len = session->header.env.comp_mmap_len;
+        do {
+                decomp = next;
+                if (decomp == NULL)
+                        break;
+                next = decomp->next;
+                munmap(decomp, decomp_len + sizeof(struct decomp));
+        } while (1);
+}
+
 void perf_session__delete(struct perf_session *session)
 {
         if (session == NULL)
@@ -205,6 +275,7 @@ void perf_session__delete(struct perf_session *session)
         auxtrace_index__free(&session->auxtrace_index);
         perf_session__destroy_kernel_maps(session);
         perf_session__delete_threads(session);
+        perf_session__release_decomp_events(session);
         perf_env__exit(&session->header.env);
         machines__exit(&session->machines);
         if (session->data)
@@ -439,7 +510,7 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
         if (tool->feature == NULL)
                 tool->feature = process_event_op2_stub;
         if (tool->compressed == NULL)
-                tool->compressed = perf_session__process_compressed_event_stub;
+                tool->compressed = perf_session__process_compressed_event;
 }
 
 static void swap_sample_id_all(union perf_event *event, void *data)
@@ -1725,6 +1796,8 @@ static int perf_session__flush_thread_stacks(struct perf_session *session)
 
 volatile int session_done;
 
+static int __perf_session__process_decomp_events(struct perf_session *session);
+
 static int __perf_session__process_pipe_events(struct perf_session *session)
 {
         struct ordered_events *oe = &session->ordered_events;
@@ -1805,6 +1878,10 @@ more:
         if (skip > 0)
                 head += skip;
 
+        err = __perf_session__process_decomp_events(session);
+        if (err)
+                goto out_err;
+
         if (!session_done())
                 goto more;
 done:
@@ -1853,6 +1930,39 @@ fetch_mmaped_event(struct perf_session *session,
         return event;
 }
 
+static int __perf_session__process_decomp_events(struct perf_session *session)
+{
+        s64 skip;
+        u64 size, file_pos = 0;
+        struct decomp *decomp = session->decomp_last;
+
+        if (!decomp)
+                return 0;
+
+        while (decomp->head < decomp->size && !session_done()) {
+                union perf_event *event = fetch_mmaped_event(session, decomp->head, decomp->size, decomp->data);
+
+                if (!event)
+                        break;
+
+                size = event->header.size;
+
+                if (size < sizeof(struct perf_event_header) ||
+                    (skip = perf_session__process_event(session, event, file_pos)) < 0) {
+                        pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
+                                decomp->file_pos + decomp->head, event->header.size, event->header.type);
+                        return -EINVAL;
+                }
+
+                if (skip)
+                        size += skip;
+
+                decomp->head += size;
+        }
+
+        return 0;
+}
+
 /*
  * On 64bit we can mmap the data file in one go. No need for tiny mmap
  * slices. On 32bit we use 32MB.
@@ -1962,6 +2072,10 @@ more:
         head += size;
         file_pos += size;
 
+        err = __perf_session__process_decomp_events(session);
+        if (err)
+                goto out;
+
         ui_progress__update(prog, size);
 
         if (session_done())
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 6c984c895924..dd8920b745bc 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -39,6 +39,16 @@ struct perf_session {
         u64                     bytes_transferred;
         u64                     bytes_compressed;
         struct zstd_data        zstd_data;
+        struct decomp           *decomp;
+        struct decomp           *decomp_last;
+};
+
+struct decomp {
+        struct decomp *next;
+        u64 file_pos;
+        u64 head;
+        size_t size;
+        char data[];
 };
 
 struct perf_tool;
diff --git a/tools/perf/util/zstd.c b/tools/perf/util/zstd.c
index 359ec9a9d306..23bdb9884576 100644
--- a/tools/perf/util/zstd.c
+++ b/tools/perf/util/zstd.c
@@ -9,6 +9,21 @@ int zstd_init(struct zstd_data *data, int level)
 {
         size_t ret;
 
+        data->dstream = ZSTD_createDStream();
+        if (data->dstream == NULL) {
+                pr_err("Couldn't create decompression stream.\n");
+                return -1;
+        }
+
+        ret = ZSTD_initDStream(data->dstream);
+        if (ZSTD_isError(ret)) {
+                pr_err("Failed to initialize decompression stream: %s\n", ZSTD_getErrorName(ret));
+                return -1;
+        }
+
+        if (!level)
+                return 0;
+
         data->cstream = ZSTD_createCStream();
         if (data->cstream == NULL) {
                 pr_err("Couldn't create compression stream.\n");
@@ -26,6 +41,11 @@ int zstd_init(struct zstd_data *data, int level)
 
 int zstd_fini(struct zstd_data *data)
 {
+        if (data->dstream) {
+                ZSTD_freeDStream(data->dstream);
+                data->dstream = NULL;
+        }
+
         if (data->cstream) {
                 ZSTD_freeCStream(data->cstream);
                 data->cstream = NULL;
@@ -68,3 +88,24 @@ size_t zstd_compress_stream_to_records(struct zstd_data *data, void *dst, size_t
 
         return compressed;
 }
+
+size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size,
+                              void *dst, size_t dst_size)
+{
+        size_t ret;
+        ZSTD_inBuffer input = { src, src_size, 0 };
+        ZSTD_outBuffer output = { dst, dst_size, 0 };
+
+        while (input.pos < input.size) {
+                ret = ZSTD_decompressStream(data->dstream, &output, &input);
+                if (ZSTD_isError(ret)) {
+                        pr_err("failed to decompress (B): %ld -> %ld : %s\n",
+                               src_size, output.size, ZSTD_getErrorName(ret));
+                        break;
+                }
+                output.dst  = dst + output.pos;
+                output.size = dst_size - output.pos;
+        }
+
+        return output.pos;
+}