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Re: [Qemu-devel] [PATCH v2 3/3] linux-user: Use safe_syscall wrapper for
From: |
Laurent Vivier |
Subject: |
Re: [Qemu-devel] [PATCH v2 3/3] linux-user: Use safe_syscall wrapper for fcntl |
Date: |
Thu, 9 Jun 2016 21:28:06 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 |
Le 09/06/2016 à 16:09, Peter Maydell a écrit :
> Use the safe_syscall wrapper for fcntl. This is straightforward now
> that we always use 'struct fcntl64' on the host, as we don't need
> to select whether to call the host's fcntl64 or fcntl syscall
> (a detail that the libc previously hid for us).
>
> Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Laurent Vivier <address@hidden>
> ---
> linux-user/syscall.c | 34 +++++++++++++++++++++++-----------
> 1 file changed, 23 insertions(+), 11 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 78c36dd..121b89f 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -784,6 +784,16 @@ safe_syscall5(int, mq_timedreceive, int, mqdes, char *,
> msg_ptr,
> * the libc function.
> */
> #define safe_ioctl(...) safe_syscall(__NR_ioctl, __VA_ARGS__)
> +/* Similarly for fcntl. Note that callers must always:
> + * pass the F_GETLK64 etc constants rather than the unsuffixed F_GETLK
> + * use the flock64 struct rather than unsuffixed flock
> + * This will then work and use a 64-bit offset for both 32-bit and 64-bit
> hosts.
> + */
> +#ifdef __NR_fcntl64
> +#define safe_fcntl(...) safe_syscall(__NR_fcntl64, __VA_ARGS__)
> +#else
> +#define safe_fcntl(...) safe_syscall(__NR_fcntl, __VA_ARGS__)
> +#endif
>
> static inline int host_to_target_sock_type(int host_type)
> {
> @@ -5741,7 +5751,7 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
> if (ret) {
> return ret;
> }
> - ret = get_errno(fcntl(fd, host_cmd, &fl64));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fl64));
> if (ret == 0) {
> ret = copy_to_user_flock(arg, &fl64);
> }
> @@ -5753,7 +5763,7 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
> if (ret) {
> return ret;
> }
> - ret = get_errno(fcntl(fd, host_cmd, &fl64));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fl64));
> break;
>
> case TARGET_F_GETLK64:
> @@ -5761,7 +5771,7 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
> if (ret) {
> return ret;
> }
> - ret = get_errno(fcntl(fd, host_cmd, &fl64));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fl64));
> if (ret == 0) {
> ret = copy_to_user_flock64(arg, &fl64);
> }
> @@ -5772,23 +5782,25 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong
> arg)
> if (ret) {
> return ret;
> }
> - ret = get_errno(fcntl(fd, host_cmd, &fl64));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fl64));
> break;
>
> case TARGET_F_GETFL:
> - ret = get_errno(fcntl(fd, host_cmd, arg));
> + ret = get_errno(safe_fcntl(fd, host_cmd, arg));
> if (ret >= 0) {
> ret = host_to_target_bitmask(ret, fcntl_flags_tbl);
> }
> break;
>
> case TARGET_F_SETFL:
> - ret = get_errno(fcntl(fd, host_cmd, target_to_host_bitmask(arg,
> fcntl_flags_tbl)));
> + ret = get_errno(safe_fcntl(fd, host_cmd,
> + target_to_host_bitmask(arg,
> + fcntl_flags_tbl)));
> break;
>
> #ifdef F_GETOWN_EX
> case TARGET_F_GETOWN_EX:
> - ret = get_errno(fcntl(fd, host_cmd, &fox));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fox));
> if (ret >= 0) {
> if (!lock_user_struct(VERIFY_WRITE, target_fox, arg, 0))
> return -TARGET_EFAULT;
> @@ -5806,7 +5818,7 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
> fox.type = tswap32(target_fox->type);
> fox.pid = tswap32(target_fox->pid);
> unlock_user_struct(target_fox, arg, 0);
> - ret = get_errno(fcntl(fd, host_cmd, &fox));
> + ret = get_errno(safe_fcntl(fd, host_cmd, &fox));
> break;
> #endif
>
> @@ -5816,11 +5828,11 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong
> arg)
> case TARGET_F_GETSIG:
> case TARGET_F_SETLEASE:
> case TARGET_F_GETLEASE:
> - ret = get_errno(fcntl(fd, host_cmd, arg));
> + ret = get_errno(safe_fcntl(fd, host_cmd, arg));
> break;
>
> default:
> - ret = get_errno(fcntl(fd, cmd, arg));
> + ret = get_errno(safe_fcntl(fd, cmd, arg));
> break;
> }
> return ret;
> @@ -10253,7 +10265,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long
> arg1,
> if (ret) {
> break;
> }
> - ret = get_errno(fcntl(arg1, cmd, &fl));
> + ret = get_errno(safe_fcntl(arg1, cmd, &fl));
> break;
> default:
> ret = do_fcntl(arg1, arg2, arg3);
>