diff options
| -rw-r--r-- | fs/select.c | 112 |
1 files changed, 64 insertions, 48 deletions
diff --git a/fs/select.c b/fs/select.c index 11d0285d46b7..7aef49552d4c 100644 --- a/fs/select.c +++ b/fs/select.c @@ -766,22 +766,38 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, * which has a pointer to the sigset_t itself followed by a size_t containing * the sigset size. */ +struct sigset_argpack { + sigset_t __user *p; + size_t size; +}; + +static inline int get_sigset_argpack(struct sigset_argpack *to, + struct sigset_argpack __user *from) +{ + // the path is hot enough for overhead of copy_from_user() to matter + if (from) { + if (!user_read_access_begin(from, sizeof(*from))) + return -EFAULT; + unsafe_get_user(to->p, &from->p, Efault); + unsafe_get_user(to->size, &from->size, Efault); + user_read_access_end(); + } + return 0; +Efault: + user_access_end(); + return -EFAULT; +} + SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp, fd_set __user *, exp, struct __kernel_timespec __user *, tsp, void __user *, sig) { - size_t sigsetsize = 0; - sigset_t __user *up = NULL; - - if (sig) { - if (!access_ok(sig, sizeof(void *)+sizeof(size_t)) - || __get_user(up, (sigset_t __user * __user *)sig) - || __get_user(sigsetsize, - (size_t __user *)(sig+sizeof(void *)))) - return -EFAULT; - } + struct sigset_argpack x = {NULL, 0}; + + if (get_sigset_argpack(&x, sig)) + return -EFAULT; - return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_TIMESPEC); + return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC); } #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) @@ -790,18 +806,12 @@ SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, fd_set __user *, exp, struct old_timespec32 __user *, tsp, void __user *, sig) { - size_t sigsetsize = 0; - sigset_t __user *up = NULL; - - if (sig) { - if (!access_ok(sig, sizeof(void *)+sizeof(size_t)) - || __get_user(up, (sigset_t __user * __user *)sig) - || __get_user(sigsetsize, - (size_t __user *)(sig+sizeof(void *)))) - return -EFAULT; - } + struct sigset_argpack x = {NULL, 0}; + + if (get_sigset_argpack(&x, sig)) + return -EFAULT; - return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_OLD_TIMESPEC); + return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC); } #endif @@ -1325,24 +1335,37 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, return poll_select_finish(&end_time, tsp, type, ret); } +struct compat_sigset_argpack { + compat_uptr_t p; + compat_size_t size; +}; +static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to, + struct compat_sigset_argpack __user *from) +{ + if (from) { + if (!user_read_access_begin(from, sizeof(*from))) + return -EFAULT; + unsafe_get_user(to->p, &from->p, Efault); + unsafe_get_user(to->size, &from->size, Efault); + user_read_access_end(); + } + return 0; +Efault: + user_access_end(); + return -EFAULT; +} + COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, struct __kernel_timespec __user *, tsp, void __user *, sig) { - compat_size_t sigsetsize = 0; - compat_uptr_t up = 0; - - if (sig) { - if (!access_ok(sig, - sizeof(compat_uptr_t)+sizeof(compat_size_t)) || - __get_user(up, (compat_uptr_t __user *)sig) || - __get_user(sigsetsize, - (compat_size_t __user *)(sig+sizeof(up)))) - return -EFAULT; - } + struct compat_sigset_argpack x = {0, 0}; + + if (get_compat_sigset_argpack(&x, sig)) + return -EFAULT; - return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up), - sigsetsize, PT_TIMESPEC); + return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), + x.size, PT_TIMESPEC); } #if defined(CONFIG_COMPAT_32BIT_TIME) @@ -1351,20 +1374,13 @@ COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, struct old_timespec32 __user *, tsp, void __user *, sig) { - compat_size_t sigsetsize = 0; - compat_uptr_t up = 0; - - if (sig) { - if (!access_ok(sig, - sizeof(compat_uptr_t)+sizeof(compat_size_t)) || - __get_user(up, (compat_uptr_t __user *)sig) || - __get_user(sigsetsize, - (compat_size_t __user *)(sig+sizeof(up)))) - return -EFAULT; - } + struct compat_sigset_argpack x = {0, 0}; + + if (get_compat_sigset_argpack(&x, sig)) + return -EFAULT; - return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up), - sigsetsize, PT_OLD_TIMESPEC); + return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), + x.size, PT_OLD_TIMESPEC); } #endif |