bsd-user: Implement shmat(2) and shmdt(2)
Use `WITH_MMAP_LOCK_GUARD` instead of mmap_lock() and mmap_unlock(),
to match linux-user implementation, according to the following commits:
69fa2708a216df715ba5102a0f98468b540a464e linux-user: Use WITH_MMAP_LOCK_GUARD in target_{shmat,shmdt}
ceda5688b650646248f269a992c06b11148c5759 linux-user: Fix shmdt
Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Message-Id: <20230925182709.4834-23-kariem.taha2.7@gmail.com>
diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h
index b82f3ea..c512a4e 100644
--- a/bsd-user/bsd-mem.h
+++ b/bsd-user/bsd-mem.h
@@ -344,4 +344,91 @@
return ret;
}
+/* shmat(2) */
+static inline abi_long do_bsd_shmat(int shmid, abi_ulong shmaddr, int shmflg)
+{
+ abi_ulong raddr;
+ abi_long ret;
+ struct shmid_ds shm_info;
+
+ /* Find out the length of the shared memory segment. */
+ ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info));
+ if (is_error(ret)) {
+ /* Can't get the length */
+ return ret;
+ }
+
+ if (!guest_range_valid_untagged(shmaddr, shm_info.shm_segsz)) {
+ return -TARGET_EINVAL;
+ }
+
+ WITH_MMAP_LOCK_GUARD() {
+ void *host_raddr;
+
+ if (shmaddr) {
+ host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
+ } else {
+ abi_ulong mmap_start;
+
+ mmap_start = mmap_find_vma(0, shm_info.shm_segsz);
+
+ if (mmap_start == -1) {
+ return -TARGET_ENOMEM;
+ }
+ host_raddr = shmat(shmid, g2h_untagged(mmap_start),
+ shmflg | SHM_REMAP);
+ }
+
+ if (host_raddr == (void *)-1) {
+ return get_errno(-1);
+ }
+ raddr = h2g(host_raddr);
+
+ page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
+ PAGE_VALID | PAGE_RESET | PAGE_READ |
+ (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
+
+ for (int i = 0; i < N_BSD_SHM_REGIONS; i++) {
+ if (bsd_shm_regions[i].start == 0) {
+ bsd_shm_regions[i].start = raddr;
+ bsd_shm_regions[i].size = shm_info.shm_segsz;
+ break;
+ }
+ }
+ }
+
+ return raddr;
+}
+
+/* shmdt(2) */
+static inline abi_long do_bsd_shmdt(abi_ulong shmaddr)
+{
+ abi_long ret;
+
+ WITH_MMAP_LOCK_GUARD() {
+ int i;
+
+ for (i = 0; i < N_BSD_SHM_REGIONS; ++i) {
+ if (bsd_shm_regions[i].start == shmaddr) {
+ break;
+ }
+ }
+
+ if (i == N_BSD_SHM_REGIONS) {
+ return -TARGET_EINVAL;
+ }
+
+ ret = get_errno(shmdt(g2h_untagged(shmaddr)));
+ if (ret == 0) {
+ abi_ulong size = bsd_shm_regions[i].size;
+
+ bsd_shm_regions[i].start = 0;
+ page_set_flags(shmaddr, shmaddr + size - 1, 0);
+ mmap_reserve(shmaddr, size);
+ }
+ }
+
+ return ret;
+}
+
#endif /* BSD_USER_BSD_MEM_H */
