On 10/11/25 15:03, Matthew Lugg wrote:
This typo meant that calls to `mremap` which shrink a mapping by some N
bytes would, when the virtual address space was pre-reserved (e.g.
32-bit guest on 64-bit host), unmap the N bytes following the *original*
mapping.
Signed-off-by: Matthew Lugg <[email protected]>
---
linux-user/mmap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 847092a28a..ec8392b35b 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -1164,7 +1164,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong
old_size,
errno = ENOMEM;
host_addr = MAP_FAILED;
} else if (reserved_va && old_size > new_size) {
- mmap_reserve_or_unmap(old_addr + old_size,
+ /* Re-reserve pages we just shrunk out of the mapping */
+ mmap_reserve_or_unmap(old_addr + new_size,
old_size - new_size);
}
}
Reviewed-by: Richard Henderson <[email protected]>
r~
