diff options
| -rw-r--r-- | src/wayland-os.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/wayland-os.c b/src/wayland-os.c index 27c6035..a9066ca 100644 --- a/src/wayland-os.c +++ b/src/wayland-os.c @@ -231,21 +231,22 @@ wl_os_mremap_maymove(int fd, void *old_data, ssize_t *old_size, ssize_t new_size, int prot, int flags) { void *result; - /* - * We could try mapping a new block immediately after the current one + + /* Make sure any pending write is flushed. */ + if (msync(old_data, *old_size, MS_SYNC) != 0) + return MAP_FAILED; + + /* We could try mapping a new block immediately after the current one * with MAP_FIXED, however that is not guaranteed to work and breaks * on CHERI-enabled architectures since the data pointer will still - * have the bounds of the previous allocation. As this is not a - * performance-critical path, we always map a new region and copy the - * old data to the new region. + * have the bounds of the previous allocation. */ result = mmap(NULL, new_size, prot, flags, fd, 0); - if (result != MAP_FAILED) { - /* Copy the data over and unmap the old mapping. */ - memcpy(result, old_data, *old_size); - if (munmap(old_data, *old_size) == 0) { - *old_size = 0; /* successfully unmapped old data. */ - } - } + if (result == MAP_FAILED) + return MAP_FAILED; + + if (munmap(old_data, *old_size) == 0) + *old_size = 0; + return result; } |