[PATCH v2 2/3] Revert "perf session: Avoid infinite loop when seeing invalid header.size"

[Petr Malat]

An event may be split by a buffer boundary, we should not abort processing
if that happens.

Fixes: bb1835a3b86c ("perf session: Fix decompression of PERF_RECORD_COMPRESSED 
records")
Fixes: 57fc032ad643 ("perf session: Avoid infinite loop when seeing invalid 
header.size")
Signed-off-by: Petr Malat <o...@malat.biz>
---
 tools/perf/util/session.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 0d7a59c1aeb6..5f7bc5ad620f 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
-#include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/zalloc.h>
 #include <api/fs/fs.h>
@@ -2059,9 +2058,7 @@ fetch_mmaped_event(struct perf_session *session,
                /* We're not fetching the event so swap back again */
                if (session->header.needs_swap)
                        perf_event_header__bswap(&event->header);
-               pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, 
mmap_size=%#zx: fuzzed perf.data?\n",
-                        __func__, head, event->header.size, mmap_size);
-               return ERR_PTR(-EINVAL);
+               return NULL;
        }
 
        return event;
@@ -2079,9 +2076,6 @@ static int __perf_session__process_decomp_events(struct 
perf_session *session)
        while (decomp->head < decomp->size && !session_done()) {
                union perf_event *event = fetch_mmaped_event(session, 
decomp->head, decomp->size, decomp->data);
 
-               if (IS_ERR(event))
-                       return PTR_ERR(event);
-
                if (!event)
                        break;
 
@@ -2181,9 +2175,6 @@ reader__process_events(struct reader *rd, struct 
perf_session *session,
 
 more:
        event = fetch_mmaped_event(session, head, mmap_size, buf);
-       if (IS_ERR(event))
-               return PTR_ERR(event);
-
        if (!event) {
                if (mmaps[map_idx]) {
                        munmap(mmaps[map_idx], mmap_size);
-- 
2.20.1