1 files changed, 70 insertions, 5 deletions

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index d5359e3384e3..5e6d4d29a7a3 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -62,6 +62,7 @@ struct perf_file_attr {
 struct feat_fd {
         struct perf_header      *ph;
         int                     fd;
+        void                    *buf;   /* Either buf != NULL or fd >= 0 */
         ssize_t                 offset;
         size_t                  size;
 };
@@ -81,19 +82,52 @@ bool perf_header__has_feat(const struct perf_header *header, int feat)
         return test_bit(feat, header->adds_features);
 }
 
-/* Return: 0 if succeded, -ERR if failed. */
-int do_write(struct feat_fd *ff, const void *buf, size_t size)
+static int __do_write_fd(struct feat_fd *ff, const void *buf, size_t size)
 {
-        ssize_t ret;
+        ssize_t ret = writen(ff->fd, buf, size);
 
-        ret  = writen(ff->fd, buf, size);
         if (ret != (ssize_t)size)
                 return ret < 0 ? (int)ret : -1;
+        return 0;
+}
+
+static int __do_write_buf(struct feat_fd *ff,  const void *buf, size_t size)
+{
+        /* struct perf_event_header::size is u16 */
+        const size_t max_size = 0xffff - sizeof(struct perf_event_header);
+        size_t new_size = ff->size;
+        void *addr;
+
+        if (size + ff->offset > max_size)
+                return -E2BIG;
+
+        while (size > (new_size - ff->offset))
+                new_size <<= 1;
+        new_size = min(max_size, new_size);
+
+        if (ff->size < new_size) {
+                addr = realloc(ff->buf, new_size);
+                if (!addr)
+                        return -ENOMEM;
+                ff->buf = addr;
+                ff->size = new_size;
+        }
+
+        memcpy(ff->buf + ff->offset, buf, size);
+        ff->offset += size;
 
         return 0;
 }
 
 /* Return: 0 if succeded, -ERR if failed. */
+int do_write(struct feat_fd *ff, const void *buf, size_t size)
+{
+        if (!ff->buf)
+                return __do_write_fd(ff, buf, size);
+        return __do_write_buf(ff, buf, size);
+}
+
+/* Return: 0 if succeded, -ERR if failed. */
 int write_padded(struct feat_fd *ff, const void *bf,
                  size_t count, size_t count_aligned)
 {
@@ -126,7 +160,7 @@ static int do_write_string(struct feat_fd *ff, const char *str)
         return write_padded(ff, str, olen, len);
 }
 
-static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)
+static int __do_read_fd(struct feat_fd *ff, void *addr, ssize_t size)
 {
         ssize_t ret = readn(ff->fd, addr, size);
 
@@ -135,6 +169,25 @@ static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)
         return 0;
 }
 
+static int __do_read_buf(struct feat_fd *ff, void *addr, ssize_t size)
+{
+        if (size > (ssize_t)ff->size - ff->offset)
+                return -1;
+
+        memcpy(addr, ff->buf + ff->offset, size);
+        ff->offset += size;
+
+        return 0;
+
+}
+
+static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)
+{
+        if (!ff->buf)
+                return __do_read_fd(ff, addr, size);
+        return __do_read_buf(ff, addr, size);
+}
+
 static int do_read_u32(struct feat_fd *ff, u32 *addr)
 {
         int ret;
@@ -189,6 +242,9 @@ static char *do_read_string(struct feat_fd *ff)
 static int write_tracing_data(struct feat_fd *ff,
                               struct perf_evlist *evlist)
 {
+        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+                return -1;
+
         return read_tracing_data(ff->fd, &evlist->entries);
 }
 
@@ -203,6 +259,9 @@ static int write_build_id(struct feat_fd *ff,
         if (!perf_session__read_build_ids(session, true))
                 return -1;
 
+        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+                return -1;
+
         err = perf_session__write_buildid_table(session, ff);
         if (err < 0) {
                 pr_debug("failed to write buildid table\n");
@@ -912,6 +971,9 @@ static int write_auxtrace(struct feat_fd *ff,
         struct perf_session *session;
         int err;
 
+        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+                return -1;
+
         session = container_of(ff->ph, struct perf_session, header);
 
         err = auxtrace_index__write(ff->fd, &session->auxtrace_index);
@@ -2197,6 +2259,9 @@ static int do_write_feat(struct feat_fd *ff, int type,
                 if (!feat_ops[type].write)
                         return -1;
 
+                if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+                        return -1;
+
                 (*p)->offset = lseek(ff->fd, 0, SEEK_CUR);
 
                 err = feat_ops[type].write(ff, evlist);