linux-user: Fix shmdt

If the shm region is not mapped at shmaddr, EINVAL.
Do not unmap the region until the syscall succeeds.
Use mmap_reserve_or_unmap to preserve reserved_va semantics.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-08-20 12:38:49 -07:00
parent 69fa2708a2
commit ceda5688b6

View file

@ -1102,14 +1102,25 @@ abi_long target_shmdt(abi_ulong shmaddr)
/* shmdt pointers are always untagged */
WITH_MMAP_LOCK_GUARD() {
for (int i = 0; i < N_SHM_REGIONS; ++i) {
int i;
for (i = 0; i < N_SHM_REGIONS; ++i) {
if (shm_regions[i].in_use && shm_regions[i].start == shmaddr) {
shm_regions[i].in_use = false;
page_set_flags(shmaddr, shmaddr + shm_regions[i].size - 1, 0);
break;
}
}
if (i == N_SHM_REGIONS) {
return -TARGET_EINVAL;
}
rv = get_errno(shmdt(g2h_untagged(shmaddr)));
if (rv == 0) {
abi_ulong size = shm_regions[i].size;
shm_regions[i].in_use = false;
page_set_flags(shmaddr, shmaddr + size - 1, 0);
mmap_reserve_or_unmap(shmaddr, size);
}
}
return rv;
}