On Thu, Feb 5, 2026 at 6:44 PM Richard Henderson <
[email protected]> wrote:

> On 2/6/26 03:26, Warner Losh wrote:
> > From: Stacey Son <[email protected]>
> >
> > Add target_to_host_semarray() to convert target semaphore array to host
> > format for semctl(2) SETALL operations.
> >
> > Signed-off-by: Stacey Son <[email protected]>
> > Signed-off-by: Warner Losh <[email protected]>
> > ---
> >   bsd-user/bsd-misc.c | 35 +++++++++++++++++++++++++++++++++++
> >   1 file changed, 35 insertions(+)
> >
> > diff --git a/bsd-user/bsd-misc.c b/bsd-user/bsd-misc.c
> > index d2107b2f85..07d8bf1304 100644
> > --- a/bsd-user/bsd-misc.c
> > +++ b/bsd-user/bsd-misc.c
> > @@ -18,6 +18,11 @@
> >    */
> >   #include "qemu/osdep.h"
> >
> > +#define _WANT_SEMUN
> > +#include <sys/types.h>
> > +#include <sys/ipc.h>
> > +#include <sys/msg.h>
> > +#include <sys/sem.h>
> >   #include <sys/uuid.h>
> >
> >   #include "qemu.h"
> > @@ -44,3 +49,33 @@ abi_long host_to_target_uuid(abi_ulong target_addr,
> struct uuid *host_uuid)
> >       unlock_user_struct(target_uuid, target_addr, 1);
> >       return 0;
> >   }
> > +
> > +abi_long target_to_host_semarray(int semid, unsigned short **host_array,
> > +        abi_ulong target_addr)
> > +{
> > +    abi_long ret;
> > +    int nsems, i;
> > +    unsigned short *array;
> > +    union semun semun;
> > +    struct semid_ds semid_ds;
> > +
> > +    semun.buf = &semid_ds;
> > +    ret = semctl(semid, 0, IPC_STAT, semun);
> > +    if (ret == -1) {
> > +        return get_errno(ret);
> > +    }
> > +    nsems = semid_ds.sem_nsems;
> > +    *host_array = (unsigned short *)malloc(nsems * sizeof(unsigned
> short));
>
> g_malloc, or test for allocation failure and return -TARGET_ENOMEM.
>

Oh, right. It's slowly coming back to me to look for things like this.


> > +    array = lock_user(VERIFY_READ, target_addr,
> > +        nsems * sizeof(unsigned short), 1);
> > +    if (array == NULL) {
> > +        free(*host_array);
> > +        return -TARGET_EFAULT;
> > +    }
> > +    for (i = 0; i < nsems; i++) {
> > +        (*host_array)[i] = array[i];
>
> __get_user, for endianness issues.
>

Good call. You'll find several of these...

Warner


>
> r~
>
>

Reply via email to