[msan] Fix wrong endianness when printing shadow.
llvm-svn: 210335
GitOrigin-RevId: ee98fb197be6c60e3bcf25aad3a9fcac0f47915c
diff --git a/lib/msan/msan.cc b/lib/msan/msan.cc
index 15714e7..4c58200 100644
--- a/lib/msan/msan.cc
+++ b/lib/msan/msan.cc
@@ -440,7 +440,11 @@
unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
for (uptr i = 0; i < size; i++) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ Printf("%x%x ", s[i] & 0xf, s[i] >> 4);
+#else
Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
+#endif
}
Printf("\n");
}
diff --git a/lib/msan/msan_report.cc b/lib/msan/msan_report.cc
index 8a3fd04..566034c 100644
--- a/lib/msan/msan_report.cc
+++ b/lib/msan/msan_report.cc
@@ -221,7 +221,11 @@
} else {
unsigned char v = *(unsigned char *)s;
if (v) last_quad_poisoned = true;
- Printf("%02x", v);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ Printf("%x%x", v & 0xf, v >> 4);
+#else
+ Printf("%x%x", v >> 4, v & 0xf);
+#endif
}
// Group end.
if (pos % 4 == 3 && with_origins) {
diff --git a/test/msan/msan_print_shadow3.cc b/test/msan/msan_print_shadow3.cc
new file mode 100644
index 0000000..c605ef1
--- /dev/null
+++ b/test/msan/msan_print_shadow3.cc
@@ -0,0 +1,16 @@
+// RUN: %clangxx_msan -m64 -O0 -g %s -o %t && %run %t >%t.out 2>&1
+// RUN: FileCheck %s < %t.out
+
+#include <stdint.h>
+#include <sanitizer/msan_interface.h>
+
+int main(void) {
+ unsigned long long x = 0; // For 8-byte alignment.
+ uint32_t x_s = 0x12345678U;
+ __msan_partial_poison(&x, &x_s, sizeof(x_s));
+ __msan_print_shadow(&x, sizeof(x_s));
+ return 0;
+}
+
+// CHECK: Shadow map of [{{.*}}), 4 bytes:
+// CHECK: 0x{{.*}}: 87654321 ........ ........ ........
