diff --git a/compiler-rt/lib/msan/msan_interceptors.cpp b/compiler-rt/lib/msan/msan_interceptors.cpp index 6459c7a593eb..0a17828d2710 100644 --- a/compiler-rt/lib/msan/msan_interceptors.cpp +++ b/compiler-rt/lib/msan/msan_interceptors.cpp @@ -827,7 +827,7 @@ INTERCEPTOR(int, prlimit64, int pid, int resource, void *new_rlimit, INTERCEPTOR(int, gethostname, char *name, SIZE_T len) { ENSURE_MSAN_INITED(); int res = REAL(gethostname)(name, len); - if (!res) { + if (!res || (res == -1 && errno == errno_ENAMETOOLONG)) { SIZE_T real_len = REAL(strnlen)(name, len); if (real_len < len) ++real_len; diff --git a/compiler-rt/lib/msan/tests/msan_test.cpp b/compiler-rt/lib/msan/tests/msan_test.cpp index 1ece56e66571..e0b8a6a97b6a 100644 --- a/compiler-rt/lib/msan/tests/msan_test.cpp +++ b/compiler-rt/lib/msan/tests/msan_test.cpp @@ -3535,9 +3535,14 @@ TEST(MemorySanitizer, uname) { } TEST(MemorySanitizer, gethostname) { - char buf[100]; - int res = gethostname(buf, 100); - ASSERT_EQ(0, res); + char buf[1000]; + EXPECT_EQ(-1, gethostname(buf, 1)); + EXPECT_EQ(ENAMETOOLONG, errno); + EXPECT_NOT_POISONED(buf[0]); + EXPECT_POISONED(buf[1]); + + __msan_poison(buf, sizeof(buf)); + EXPECT_EQ(0, gethostname(buf, sizeof(buf))); EXPECT_NOT_POISONED(strlen(buf)); } diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_errno_codes.h b/compiler-rt/lib/sanitizer_common/sanitizer_errno_codes.h index f388d0d36463..192e9392d494 100644 --- a/compiler-rt/lib/sanitizer_common/sanitizer_errno_codes.h +++ b/compiler-rt/lib/sanitizer_common/sanitizer_errno_codes.h @@ -24,6 +24,7 @@ namespace __sanitizer { #define errno_ENOMEM 12 #define errno_EBUSY 16 #define errno_EINVAL 22 +#define errno_ENAMETOOLONG 36 // Those might not present or their value differ on different platforms. extern const int errno_EOWNERDEAD;