[PATCH v1] perf arm-spe: Unaligned pointer work around

From: Ian Rogers
Date: Tue May 14 2024 - 01:24:19 EST


Use get_unaligned_leXX instead of leXX_to_cpu to handle unaligned
pointers. Such pointers occur with libFuzzer testing.

A similar change for intel-pt was done in:
https://lore.kernel.org/r/20231005190451.175568-6-adrian.hunter@xxxxxxxxx

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
.../arm-spe-decoder/arm-spe-pkt-decoder.c | 23 ++++---------------
1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
index a454c6737563..7bf607d0f6d8 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
@@ -10,24 +10,11 @@
#include <byteswap.h>
#include <linux/bitops.h>
#include <stdarg.h>
+#include <linux/kernel.h>
+#include <asm-generic/unaligned.h>

#include "arm-spe-pkt-decoder.h"

-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#define le16_to_cpu bswap_16
-#define le32_to_cpu bswap_32
-#define le64_to_cpu bswap_64
-#define memcpy_le64(d, s, n) do { \
- memcpy((d), (s), (n)); \
- *(d) = le64_to_cpu(*(d)); \
-} while (0)
-#else
-#define le16_to_cpu
-#define le32_to_cpu
-#define le64_to_cpu
-#define memcpy_le64 memcpy
-#endif
-
static const char * const arm_spe_packet_name[] = {
[ARM_SPE_PAD] = "PAD",
[ARM_SPE_END] = "END",
@@ -70,9 +57,9 @@ static int arm_spe_get_payload(const unsigned char *buf, size_t len,

switch (payload_len) {
case 1: packet->payload = *(uint8_t *)buf; break;
- case 2: packet->payload = le16_to_cpu(*(uint16_t *)buf); break;
- case 4: packet->payload = le32_to_cpu(*(uint32_t *)buf); break;
- case 8: packet->payload = le64_to_cpu(*(uint64_t *)buf); break;
+ case 2: packet->payload = get_unaligned_le16(buf); break;
+ case 4: packet->payload = get_unaligned_le32(buf); break;
+ case 8: packet->payload = get_unaligned_le64(buf); break;
default: return ARM_SPE_BAD_PACKET;
}

--
2.45.0.rc1.225.g2a3ae87e7f-goog