Le 14/09/2016 à 22:19, Aleksandar Markovic a écrit :
> From: Aleksandar Markovic <[email protected]>
>
> This patch implements Qemu user mode ustat() syscall support.
>
> Syscall ustat() returns information about a mounted filesystem.
>
> The implementation is similar to the implementations of statfs(),
> fstatfs() and other related syscalls. It is based on invocation of
> host's ustat(), and its key part is in the correspondent case segment
> of the main switch statement of the function do_syscall(), in file
> linux-user/syscalls.c. All necessary conversions of data structures
> from target to host and from host to target are covered. Sufficient
> support for "-strace" option for this syscall is already present,
> and this patch does not change it.
>
> This patch also fixes failures of LTP tests ustat01, and ustat02, if
> executed on Qemu-emulated systems.
>
> Signed-off-by: Aleksandar Markovic <[email protected]>
> ---
> linux-user/syscall.c | 25 ++++++++++++++++++++++++-
> 1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 3436ee6..7f8ae41 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -48,6 +48,7 @@ int __clone2(int (*fn)(void *), void *child_stack_base,
> #include <sys/shm.h>
> #include <sys/sem.h>
> #include <sys/statfs.h>
> +#include <ustat.h>
> #include <utime.h>
> #include <sys/sysinfo.h>
> #include <sys/signalfd.h>
> @@ -8098,7 +8099,29 @@ abi_long do_syscall(void *cpu_env, int num, abi_long
> arg1,
> break;
> #ifdef TARGET_NR_ustat
> case TARGET_NR_ustat:
> - goto unimplemented;
> + {
> + struct ustat ust;
> + int cnt;
> + ret = get_errno(ustat(arg1, &ust));
> +
> + if (!is_error(ret)) {
> + struct ustat *target_ust;
You must define your own "struct target_ustat" as __kernel_daddr_t and
__kernel_ino_t are long (or int).
> +
> + if (!lock_user_struct(VERIFY_WRITE, target_ust, arg2, 0)) {
> + goto efault;
> + }
> +
> + __put_user(ust.f_tfree, &target_ust->f_tfree);
> + __put_user(ust.f_tinode, &target_ust->f_tinode);
> +
> + for (cnt = 0; cnt < 6; cnt++) {
> + __put_user(ust.f_fname[cnt], &target_ust->f_fname[cnt]);
> + __put_user(ust.f_fpack[cnt], &target_ust->f_fpack[cnt]);
> + }
As the structure is locked and they are "char", you can do memcpy().
> + unlock_user_struct(target_ust, arg2, 1);
> + }
> + break;
> + }
> #endif
> #ifdef TARGET_NR_dup2
> case TARGET_NR_dup2:
>
Laurent
