diff options
| -rw-r--r-- | linux-user/syscall.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 6182a272ec..ee82a2da4e 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8631,7 +8631,20 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, #ifdef TARGET_NR_set_robust_list case TARGET_NR_set_robust_list: - goto unimplemented_nowarn; + case TARGET_NR_get_robust_list: + /* The ABI for supporting robust futexes has userspace pass + * the kernel a pointer to a linked list which is updated by + * userspace after the syscall; the list is walked by the kernel + * when the thread exits. Since the linked list in QEMU guest + * memory isn't a valid linked list for the host and we have + * no way to reliably intercept the thread-death event, we can't + * support these. Silently return ENOSYS so that guest userspace + * falls back to a non-robust futex implementation (which should + * be OK except in the corner case of the guest crashing while + * holding a mutex that is shared with another process via + * shared memory). + */ + goto unimplemented_nowarn; #endif #if defined(TARGET_NR_utimensat) && defined(__NR_utimensat) |