On Wed, May 26, 2021 at 5:22 AM Laurent Vivier <laur...@vivier.eu> wrote:
>
> Le 24/05/2021 à 06:54, YAMAMOTO Takashi a écrit :
> > Used by runc.
> >
> > Signed-off-by: YAMAMOTO Takashi <yamam...@midokura.com>
> > ---
> > linux-user/syscall.c | 23 +++++++++++++++++++++++
> > 1 file changed, 23 insertions(+)
> >
> > diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> > index 2947e79dc0..e739921e86 100644
> > --- a/linux-user/syscall.c
> > +++ b/linux-user/syscall.c
> > @@ -35,6 +35,7 @@
> > #include <sys/prctl.h>
> > #include <sys/resource.h>
> > #include <sys/swap.h>
> > +#include <sys/syscall.h>
>
> we don't need that include, see below
>
> > #include <linux/capability.h>
> > #include <sched.h>
> > #include <sys/timex.h>
> > @@ -8254,6 +8255,11 @@ static int host_to_target_cpu_mask(const unsigned
> > long *host_mask,
> > return 0;
> > }
> >
> > +static int pivot_root(const char *new_root, const char *put_old)
> > +{
> > + return syscall(SYS_pivot_root, new_root, put_old);
> > +}
>
> Better to use:
>
> #if defined(TARGET_NR_pivot_root) && defined(__NR_pivot_root)
> _syscall2(int, pivot_root, const char *, new_root, const char *, put_old)
> #endif
ok. i haven't noticed the _syscall2 macro in this file. thank you.
>
> > +
> > /* This is an internal helper for do_syscall so that it is easier
> > * to have a single return point, so that actions, such as logging
> > * of syscall results, can be performed.
> > @@ -13222,6 +13228,23 @@ static abi_long do_syscall1(void *cpu_env, int
> > num, abi_long arg1,
> > return ret;
> > #endif
> >
> > +#if defined(TARGET_NR_pivot_root)
> > + case TARGET_NR_pivot_root:
> > + {
> > + void *p2;
> > + p = lock_user_string(arg1); /* new_root */
> > + p2 = lock_user_string(arg2); /* put_old */
> > + if (!p || !p2) {
> > + ret = -TARGET_EFAULT;
> > + } else {
> > + ret = get_errno(pivot_root(p, p2));
> > + }
> > + unlock_user(p2, arg2, 0);
> > + unlock_user(p, arg1, 0);
> > + }
> > + return ret;
> > +#endif
> > +
> > default:
> > qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
> > return -TARGET_ENOSYS;
> >
>
> Thanks,
> Laurent
>
