On 8/19/23 02:48, Karim Taha wrote:
From: Stacey Son <s...@freebsd.org>
Signed-off-by: Stacey Son <s...@freebsd.org>
Signed-off-by: Karim Taha <kariem.taha...@gmail.com>
---
bsd-user/bsd-mem.h | 72 +++++++++++++++++++++++++++++++++++
bsd-user/freebsd/os-syscall.c | 8 ++++
2 files changed, 80 insertions(+)
diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h
index 221ad76d8c..f737b94885 100644
--- a/bsd-user/bsd-mem.h
+++ b/bsd-user/bsd-mem.h
@@ -335,4 +335,76 @@ static inline abi_long do_bsd_shmctl(abi_long shmid,
abi_long cmd,
return ret;
}
+/* shmat(2) */
+static inline abi_long do_bsd_shmat(int shmid, abi_ulong shmaddr, int shmflg)
+{
+ abi_ulong raddr;
+ abi_long ret;
+ void *host_raddr;
+ struct shmid_ds shm_info;
+ int i;
+
+ /* 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;
+ }
+
+ mmap_lock();
+
+ if (shmaddr) {
+ host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
Missing
if (!guest_range_valid_untagged(shmaddr, shm_info.shm_segsz)) {
return -TARGET_EINVAL;
}
+ } else {
+ abi_ulong mmap_start;
+
+ mmap_start = mmap_find_vma(0, shm_info.shm_segsz);
+
+ if (mmap_start == -1) {
+ errno = ENOMEM;
+ host_raddr = (void *)-1;
+ } else {
+ host_raddr = shmat(shmid, g2h_untagged(mmap_start),
+ shmflg); /* | SHM_REMAP XXX WHY? */
With reserved_va, the entire guest address space is mapped PROT_NONE so that it is
reserved, so that the kernel does not use it for something else. You need the SHM_REMAP
to replace the reservation mapping.
+/* shmdt(2) */
+static inline abi_long do_bsd_shmdt(abi_ulong shmaddr)
+{
+ int i;
+
+ for (i = 0; i < N_BSD_SHM_REGIONS; ++i) {
+ if (bsd_shm_regions[i].start == shmaddr) {
+ bsd_shm_regions[i].start = 0;
+ page_set_flags(shmaddr,
+ shmaddr + bsd_shm_regions[i].size, 0);
+ break;
+ }
+ }
+
+ return get_errno(shmdt(g2h_untagged(shmaddr)));
+}
Hmm, bug with linux-user as well, because here we should re-establish the reserved_va
reservation.
Also, we should not be using a fixed sized array. Nothing good happens when the array
fills up.
r~
