From 81993e81a994504f4c8b97d3410c9a052cdbcc9d Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Sat, 1 Feb 2014 18:54:11 -0800 Subject: [PATCH 1/2] compat: Get rid of (get|put)_compat_time(val|spec) We have two APIs for compatiblity timespec/val, with confusingly similar names. compat_(get|put)_time(val|spec) *do* handle the case where COMPAT_USE_64BIT_TIME is set, whereas (get|put)_compat_time(val|spec) do not. This is an accident waiting to happen. Clean it up by favoring the full-service version; the limited version is replaced with double-underscore versions static to kernel/compat.c. A common pattern is to convert a struct timespec to kernel format in an allocation on the user stack. Unfortunately it is open-coded in several places. Since this allocation isn't actually needed if COMPAT_USE_64BIT_TIME is true (since user format == kernel format) encapsulate that whole pattern into the function compat_convert_timespec(). An equivalent function should be written for struct timeval if it is needed in the future. Finally, get rid of compat_(get|put)_timeval_convert(): each was only used once, and the latter was not even doing what the function said (no conversion actually was being done.) Moving the conversion into compat_sys_settimeofday() itself makes the code much more similar to sys_settimeofday() itself. v3: Remove unused compat_convert_timeval(). v2: Drop bogus "const" in the destination argument for compat_convert_time*(). Cc: Mauro Carvalho Chehab Cc: Alexander Viro Cc: Hans Verkuil Cc: Andrew Morton Cc: Heiko Carstens Cc: Manfred Spraul Cc: Mateusz Guzik Cc: Rafael Aquini Cc: Davidlohr Bueso Cc: Stephen Rothwell Cc: Dan Carpenter Cc: Arnd Bergmann Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Linus Torvalds Cc: Catalin Marinas Cc: Will Deacon Tested-by: H.J. Lu Signed-off-by: H. Peter Anvin --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 2 +- fs/compat.c | 6 +- include/linux/compat.h | 23 ++-- ipc/compat.c | 12 +- ipc/compat_mq.c | 19 +-- kernel/compat.c | 108 +++++++++--------- kernel/futex_compat.c | 2 +- 7 files changed, 75 insertions(+), 97 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 8f7a6a454a4c..6191968db8fa 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -733,7 +733,7 @@ static int put_v4l2_event32(struct v4l2_event *kp, struct v4l2_event32 __user *u copy_to_user(&up->u, &kp->u, sizeof(kp->u)) || put_user(kp->pending, &up->pending) || put_user(kp->sequence, &up->sequence) || - put_compat_timespec(&kp->timestamp, &up->timestamp) || + compat_put_timespec(&kp->timestamp, &up->timestamp) || put_user(kp->id, &up->id) || copy_to_user(up->reserved, kp->reserved, 8 * sizeof(__u32))) return -EFAULT; diff --git a/fs/compat.c b/fs/compat.c index 6af20de2c1a3..62092f433759 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -92,8 +92,8 @@ asmlinkage long compat_sys_utimensat(unsigned int dfd, const char __user *filena struct timespec tv[2]; if (t) { - if (get_compat_timespec(&tv[0], &t[0]) || - get_compat_timespec(&tv[1], &t[1])) + if (compat_get_timespec(&tv[0], &t[0]) || + compat_get_timespec(&tv[1], &t[1])) return -EFAULT; if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT) @@ -512,7 +512,7 @@ compat_sys_io_getevents(aio_context_t ctx_id, nr * sizeof(struct io_event)))) goto out; if (timeout) { - if (get_compat_timespec(&t, timeout)) + if (compat_get_timespec(&t, timeout)) goto out; ut = compat_alloc_user_space(sizeof(*ut)); diff --git a/include/linux/compat.h b/include/linux/compat.h index 3f448c65511b..f7d5bc0a239f 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -140,27 +140,24 @@ struct compat_sigaction { compat_sigset_t sa_mask __packed; }; -/* - * These functions operate strictly on struct compat_time* - */ -extern int get_compat_timespec(struct timespec *, - const struct compat_timespec __user *); -extern int put_compat_timespec(const struct timespec *, - struct compat_timespec __user *); -extern int get_compat_timeval(struct timeval *, - const struct compat_timeval __user *); -extern int put_compat_timeval(const struct timeval *, - struct compat_timeval __user *); /* * These functions operate on 32- or 64-bit specs depending on - * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments and the - * naming as compat_get/put_ rather than get/put_compat_. + * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments. */ extern int compat_get_timespec(struct timespec *, const void __user *); extern int compat_put_timespec(const struct timespec *, void __user *); extern int compat_get_timeval(struct timeval *, const void __user *); extern int compat_put_timeval(const struct timeval *, void __user *); +/* + * This function convert a timespec if necessary and returns a *user + * space* pointer. If no conversion is necessary, it returns the + * initial pointer. NULL is a legitimate argument and will always + * output NULL. + */ +extern int compat_convert_timespec(struct timespec __user **, + const void __user *); + struct compat_iovec { compat_uptr_t iov_base; compat_size_t iov_len; diff --git a/ipc/compat.c b/ipc/compat.c index f486b0096a67..1048522479e5 100644 --- a/ipc/compat.c +++ b/ipc/compat.c @@ -752,14 +752,8 @@ long compat_sys_shmctl(int first, int second, void __user *uptr) long compat_sys_semtimedop(int semid, struct sembuf __user *tsems, unsigned nsops, const struct compat_timespec __user *timeout) { - struct timespec __user *ts64 = NULL; - if (timeout) { - struct timespec ts; - ts64 = compat_alloc_user_space(sizeof(*ts64)); - if (get_compat_timespec(&ts, timeout)) - return -EFAULT; - if (copy_to_user(ts64, &ts, sizeof(ts))) - return -EFAULT; - } + struct timespec __user *ts64; + if (compat_convert_timespec(&ts64, timeout)) + return -EFAULT; return sys_semtimedop(semid, tsems, nsops, ts64); } diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c index 63d7c6de335b..a9cf16378d7a 100644 --- a/ipc/compat_mq.c +++ b/ipc/compat_mq.c @@ -64,20 +64,6 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name, return sys_mq_open(u_name, oflag, mode, p); } -static int compat_prepare_timeout(struct timespec __user **p, - const struct compat_timespec __user *u) -{ - struct timespec ts; - if (!u) { - *p = NULL; - return 0; - } - *p = compat_alloc_user_space(sizeof(ts)); - if (get_compat_timespec(&ts, u) || copy_to_user(*p, &ts, sizeof(ts))) - return -EFAULT; - return 0; -} - asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, size_t msg_len, unsigned int msg_prio, @@ -85,7 +71,7 @@ asmlinkage long compat_sys_mq_timedsend(mqd_t mqdes, { struct timespec __user *u_ts; - if (compat_prepare_timeout(&u_ts, u_abs_timeout)) + if (compat_convert_timespec(&u_ts, u_abs_timeout)) return -EFAULT; return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len, @@ -98,7 +84,8 @@ asmlinkage ssize_t compat_sys_mq_timedreceive(mqd_t mqdes, const struct compat_timespec __user *u_abs_timeout) { struct timespec __user *u_ts; - if (compat_prepare_timeout(&u_ts, u_abs_timeout)) + + if (compat_convert_timespec(&u_ts, u_abs_timeout)) return -EFAULT; return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len, diff --git a/kernel/compat.c b/kernel/compat.c index 0a09e481b70b..3afc524a57ad 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -30,28 +30,6 @@ #include -/* - * Get/set struct timeval with struct timespec on the native side - */ -static int compat_get_timeval_convert(struct timespec *o, - struct compat_timeval __user *i) -{ - long usec; - - if (get_user(o->tv_sec, &i->tv_sec) || - get_user(usec, &i->tv_usec)) - return -EFAULT; - o->tv_nsec = usec * 1000; - return 0; -} - -static int compat_put_timeval_convert(struct compat_timeval __user *o, - struct timeval *i) -{ - return (put_user(i->tv_sec, &o->tv_sec) || - put_user(i->tv_usec, &o->tv_usec)) ? -EFAULT : 0; -} - static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp) { memset(txc, 0, sizeof(struct timex)); @@ -116,7 +94,7 @@ asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv, if (tv) { struct timeval ktv; do_gettimeofday(&ktv); - if (compat_put_timeval_convert(tv, &ktv)) + if (compat_put_timeval(&ktv, tv)) return -EFAULT; } if (tz) { @@ -130,59 +108,58 @@ asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv, asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv, struct timezone __user *tz) { - struct timespec kts; - struct timezone ktz; + struct timeval user_tv; + struct timespec new_ts; + struct timezone new_tz; if (tv) { - if (compat_get_timeval_convert(&kts, tv)) + if (compat_get_timeval(&user_tv, tv)) return -EFAULT; + new_ts.tv_sec = user_tv.tv_sec; + new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; } if (tz) { - if (copy_from_user(&ktz, tz, sizeof(ktz))) + if (copy_from_user(&new_tz, tz, sizeof(*tz))) return -EFAULT; } - return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL); + return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); } -int get_compat_timeval(struct timeval *tv, const struct compat_timeval __user *ctv) +static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv) { return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) || __get_user(tv->tv_sec, &ctv->tv_sec) || __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; } -EXPORT_SYMBOL_GPL(get_compat_timeval); -int put_compat_timeval(const struct timeval *tv, struct compat_timeval __user *ctv) +static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv) { return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) || __put_user(tv->tv_sec, &ctv->tv_sec) || __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; } -EXPORT_SYMBOL_GPL(put_compat_timeval); -int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts) +static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts) { return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) || __get_user(ts->tv_sec, &cts->tv_sec) || __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; } -EXPORT_SYMBOL_GPL(get_compat_timespec); -int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts) +static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts) { return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) || __put_user(ts->tv_sec, &cts->tv_sec) || __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; } -EXPORT_SYMBOL_GPL(put_compat_timespec); int compat_get_timeval(struct timeval *tv, const void __user *utv) { if (COMPAT_USE_64BIT_TIME) return copy_from_user(tv, utv, sizeof *tv) ? -EFAULT : 0; else - return get_compat_timeval(tv, utv); + return __compat_get_timeval(tv, utv); } EXPORT_SYMBOL_GPL(compat_get_timeval); @@ -191,7 +168,7 @@ int compat_put_timeval(const struct timeval *tv, void __user *utv) if (COMPAT_USE_64BIT_TIME) return copy_to_user(utv, tv, sizeof *tv) ? -EFAULT : 0; else - return put_compat_timeval(tv, utv); + return __compat_put_timeval(tv, utv); } EXPORT_SYMBOL_GPL(compat_put_timeval); @@ -200,7 +177,7 @@ int compat_get_timespec(struct timespec *ts, const void __user *uts) if (COMPAT_USE_64BIT_TIME) return copy_from_user(ts, uts, sizeof *ts) ? -EFAULT : 0; else - return get_compat_timespec(ts, uts); + return __compat_get_timespec(ts, uts); } EXPORT_SYMBOL_GPL(compat_get_timespec); @@ -209,10 +186,33 @@ int compat_put_timespec(const struct timespec *ts, void __user *uts) if (COMPAT_USE_64BIT_TIME) return copy_to_user(uts, ts, sizeof *ts) ? -EFAULT : 0; else - return put_compat_timespec(ts, uts); + return __compat_put_timespec(ts, uts); } EXPORT_SYMBOL_GPL(compat_put_timespec); +int compat_convert_timespec(struct timespec __user **kts, + const void __user *cts) +{ + struct timespec ts; + struct timespec __user *uts; + + if (!cts || COMPAT_USE_64BIT_TIME) { + *kts = (struct timespec __user *)cts; + return 0; + } + + uts = compat_alloc_user_space(sizeof(ts)); + if (!uts) + return -EFAULT; + if (compat_get_timespec(&ts, cts)) + return -EFAULT; + if (copy_to_user(uts, &ts, sizeof(ts))) + return -EFAULT; + + *kts = uts; + return 0; +} + static long compat_nanosleep_restart(struct restart_block *restart) { struct compat_timespec __user *rmtp; @@ -229,7 +229,7 @@ static long compat_nanosleep_restart(struct restart_block *restart) if (ret) { rmtp = restart->nanosleep.compat_rmtp; - if (rmtp && put_compat_timespec(&rmt, rmtp)) + if (rmtp && compat_put_timespec(&rmt, rmtp)) return -EFAULT; } @@ -243,7 +243,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, mm_segment_t oldfs; long ret; - if (get_compat_timespec(&tu, rqtp)) + if (compat_get_timespec(&tu, rqtp)) return -EFAULT; if (!timespec_valid(&tu)) @@ -263,7 +263,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, restart->fn = compat_nanosleep_restart; restart->nanosleep.compat_rmtp = rmtp; - if (rmtp && put_compat_timespec(&rmt, rmtp)) + if (rmtp && compat_put_timespec(&rmt, rmtp)) return -EFAULT; } @@ -647,8 +647,8 @@ asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len, int get_compat_itimerspec(struct itimerspec *dst, const struct compat_itimerspec __user *src) { - if (get_compat_timespec(&dst->it_interval, &src->it_interval) || - get_compat_timespec(&dst->it_value, &src->it_value)) + if (__compat_get_timespec(&dst->it_interval, &src->it_interval) || + __compat_get_timespec(&dst->it_value, &src->it_value)) return -EFAULT; return 0; } @@ -656,8 +656,8 @@ int get_compat_itimerspec(struct itimerspec *dst, int put_compat_itimerspec(struct compat_itimerspec __user *dst, const struct itimerspec *src) { - if (put_compat_timespec(&src->it_interval, &dst->it_interval) || - put_compat_timespec(&src->it_value, &dst->it_value)) + if (__compat_put_timespec(&src->it_interval, &dst->it_interval) || + __compat_put_timespec(&src->it_value, &dst->it_value)) return -EFAULT; return 0; } @@ -727,7 +727,7 @@ long compat_sys_clock_settime(clockid_t which_clock, mm_segment_t oldfs; struct timespec ts; - if (get_compat_timespec(&ts, tp)) + if (compat_get_timespec(&ts, tp)) return -EFAULT; oldfs = get_fs(); set_fs(KERNEL_DS); @@ -749,7 +749,7 @@ long compat_sys_clock_gettime(clockid_t which_clock, err = sys_clock_gettime(which_clock, (struct timespec __user *) &ts); set_fs(oldfs); - if (!err && put_compat_timespec(&ts, tp)) + if (!err && compat_put_timespec(&ts, tp)) return -EFAULT; return err; } @@ -789,7 +789,7 @@ long compat_sys_clock_getres(clockid_t which_clock, err = sys_clock_getres(which_clock, (struct timespec __user *) &ts); set_fs(oldfs); - if (!err && tp && put_compat_timespec(&ts, tp)) + if (!err && tp && compat_put_timespec(&ts, tp)) return -EFAULT; return err; } @@ -808,7 +808,7 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart) set_fs(oldfs); if ((err == -ERESTART_RESTARTBLOCK) && rmtp && - put_compat_timespec(&tu, rmtp)) + compat_put_timespec(&tu, rmtp)) return -EFAULT; if (err == -ERESTART_RESTARTBLOCK) { @@ -827,7 +827,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags, struct timespec in, out; struct restart_block *restart; - if (get_compat_timespec(&in, rqtp)) + if (compat_get_timespec(&in, rqtp)) return -EFAULT; oldfs = get_fs(); @@ -838,7 +838,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags, set_fs(oldfs); if ((err == -ERESTART_RESTARTBLOCK) && rmtp && - put_compat_timespec(&out, rmtp)) + compat_put_timespec(&out, rmtp)) return -EFAULT; if (err == -ERESTART_RESTARTBLOCK) { @@ -1130,7 +1130,7 @@ COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval, set_fs(KERNEL_DS); ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t); set_fs(old_fs); - if (put_compat_timespec(&t, interval)) + if (compat_put_timespec(&t, interval)) return -EFAULT; return ret; } diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index f9f44fd4d34d..55c8c9349cfe 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -183,7 +183,7 @@ COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI || cmd == FUTEX_WAIT_BITSET || cmd == FUTEX_WAIT_REQUEUE_PI)) { - if (get_compat_timespec(&ts, utime)) + if (compat_get_timespec(&ts, utime)) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; From dce44e03b0a3448ad11ac6c6e0cbe299e0400791 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Sun, 2 Feb 2014 17:57:28 -0800 Subject: [PATCH 2/2] compat: Fix sparse address space warnings In compat_sys_old_getrlimit() we pass a kernel pointer to sys_old_getrlimit() inside a set_fs() bracket. This is okay, so we can safely cast the affected pointer to __user. In compat_clock_nanosleep_restart(), the variable "rmtp" holds a user pointer. Annotate it as such. Both of these warnings are ancient, but were reported by Fengguang Wu's test system due to other changes. Signed-off-by: H. Peter Anvin Cc: Toyo Abe Link: http://lkml.kernel.org/n/tip-507h7cq5e45eg6ygtykon3bf@git.kernel.org --- kernel/compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/compat.c b/kernel/compat.c index 3afc524a57ad..7076b57fa52e 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -451,7 +451,7 @@ asmlinkage long compat_sys_old_getrlimit(unsigned int resource, mm_segment_t old_fs = get_fs(); set_fs(KERNEL_DS); - ret = sys_old_getrlimit(resource, &r); + ret = sys_old_getrlimit(resource, (struct rlimit __user *)&r); set_fs(old_fs); if (!ret) { @@ -799,7 +799,7 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart) long err; mm_segment_t oldfs; struct timespec tu; - struct compat_timespec *rmtp = restart->nanosleep.compat_rmtp; + struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp; restart->nanosleep.rmtp = (struct timespec __user *) &tu; oldfs = get_fs();