long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3);
-extern int
-handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
-
/*
* Futexes are matched on equal values of this key.
* The key type depends on whether it's a shared or private mapping.
#ifdef CONFIG_FUTEX
extern void exit_robust_list(struct task_struct *curr);
-#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
-#define futex_cmpxchg_enabled 1
-#else
-extern int futex_cmpxchg_enabled;
-#endif
#else
static inline void exit_robust_list(struct task_struct *curr)
{
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/
obj-$(CONFIG_FUTEX) += futex.o
-ifeq ($(CONFIG_COMPAT),y)
-obj-$(CONFIG_FUTEX) += futex_compat.o
-endif
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
ifneq ($(CONFIG_SMP),y)
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/compat.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fs.h>
* double_lock_hb() and double_unlock_hb(), respectively.
*/
-#ifndef CONFIG_HAVE_FUTEX_CMPXCHG
-int __read_mostly futex_cmpxchg_enabled;
+#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
+#define futex_cmpxchg_enabled 1
+#else
+static int __read_mostly futex_cmpxchg_enabled;
#endif
/*
* Process a futex-list entry, check whether it's owned by the
* dying task, and do notification if so:
*/
-int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi)
+static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi)
{
u32 uval, uninitialized_var(nval), mval;
int err;
return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
}
+#ifdef CONFIG_COMPAT
+/*
+ * Fetch a robust-list pointer. Bit 0 signals PI futexes:
+ */
+static inline int
+compat_fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
+ compat_uptr_t __user *head, unsigned int *pi)
+{
+ if (get_user(*uentry, head))
+ return -EFAULT;
+
+ *entry = compat_ptr((*uentry) & ~1);
+ *pi = (unsigned int)(*uentry) & 1;
+
+ return 0;
+}
+
+static void __user *futex_uaddr(struct robust_list __user *entry,
+ compat_long_t futex_offset)
+{
+ compat_uptr_t base = ptr_to_compat(entry);
+ void __user *uaddr = compat_ptr(base + futex_offset);
+
+ return uaddr;
+}
+
+/*
+ * Walk curr->robust_list (very carefully, it's a userspace list!)
+ * and mark any locks found there dead, and notify any waiters.
+ *
+ * We silently return on any sign of list-walking problem.
+ */
+void compat_exit_robust_list(struct task_struct *curr)
+{
+ struct compat_robust_list_head __user *head = curr->compat_robust_list;
+ struct robust_list __user *entry, *next_entry, *pending;
+ unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
+ unsigned int uninitialized_var(next_pi);
+ compat_uptr_t uentry, next_uentry, upending;
+ compat_long_t futex_offset;
+ int rc;
+
+ if (!futex_cmpxchg_enabled)
+ return;
+
+ /*
+ * Fetch the list head (which was registered earlier, via
+ * sys_set_robust_list()):
+ */
+ if (compat_fetch_robust_entry(&uentry, &entry, &head->list.next, &pi))
+ return;
+ /*
+ * Fetch the relative futex offset:
+ */
+ if (get_user(futex_offset, &head->futex_offset))
+ return;
+ /*
+ * Fetch any possibly pending lock-add first, and handle it
+ * if it exists:
+ */
+ if (compat_fetch_robust_entry(&upending, &pending,
+ &head->list_op_pending, &pip))
+ return;
+
+ next_entry = NULL; /* avoid warning with gcc */
+ while (entry != (struct robust_list __user *) &head->list) {
+ /*
+ * Fetch the next entry in the list before calling
+ * handle_futex_death:
+ */
+ rc = compat_fetch_robust_entry(&next_uentry, &next_entry,
+ (compat_uptr_t __user *)&entry->next, &next_pi);
+ /*
+ * A pending lock might already be on the list, so
+ * dont process it twice:
+ */
+ if (entry != pending) {
+ void __user *uaddr = futex_uaddr(entry, futex_offset);
+
+ if (handle_futex_death(uaddr, curr, pi))
+ return;
+ }
+ if (rc)
+ return;
+ uentry = next_uentry;
+ entry = next_entry;
+ pi = next_pi;
+ /*
+ * Avoid excessively long or circular lists:
+ */
+ if (!--limit)
+ break;
+
+ cond_resched();
+ }
+ if (pending) {
+ void __user *uaddr = futex_uaddr(pending, futex_offset);
+
+ handle_futex_death(uaddr, curr, pip);
+ }
+}
+
+COMPAT_SYSCALL_DEFINE2(set_robust_list,
+ struct compat_robust_list_head __user *, head,
+ compat_size_t, len)
+{
+ if (!futex_cmpxchg_enabled)
+ return -ENOSYS;
+
+ if (unlikely(len != sizeof(*head)))
+ return -EINVAL;
+
+ current->compat_robust_list = head;
+
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
+ compat_uptr_t __user *, head_ptr,
+ compat_size_t __user *, len_ptr)
+{
+ struct compat_robust_list_head __user *head;
+ unsigned long ret;
+ struct task_struct *p;
+
+ if (!futex_cmpxchg_enabled)
+ return -ENOSYS;
+
+ rcu_read_lock();
+
+ ret = -ESRCH;
+ if (!pid)
+ p = current;
+ else {
+ p = find_task_by_vpid(pid);
+ if (!p)
+ goto err_unlock;
+ }
+
+ ret = -EPERM;
+ if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS))
+ goto err_unlock;
+
+ head = p->compat_robust_list;
+ rcu_read_unlock();
+
+ if (put_user(sizeof(*head), len_ptr))
+ return -EFAULT;
+ return put_user(ptr_to_compat(head), head_ptr);
+
+err_unlock:
+ rcu_read_unlock();
+
+ return ret;
+}
+
+COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
+ struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+ u32, val3)
+{
+ struct timespec ts;
+ ktime_t t, *tp = NULL;
+ int val2 = 0;
+ int cmd = op & FUTEX_CMD_MASK;
+
+ if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
+ cmd == FUTEX_WAIT_BITSET ||
+ cmd == FUTEX_WAIT_REQUEUE_PI)) {
+ if (compat_get_timespec(&ts, utime))
+ return -EFAULT;
+ if (!timespec_valid(&ts))
+ return -EINVAL;
+
+ t = timespec_to_ktime(ts);
+ if (cmd == FUTEX_WAIT)
+ t = ktime_add_safe(ktime_get(), t);
+ tp = &t;
+ }
+ if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
+ cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
+ val2 = (int) (unsigned long) utime;
+
+ return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
+}
+#endif /* CONFIG_COMPAT */
+
static void __init futex_detect_cmpxchg(void)
{
#ifndef CONFIG_HAVE_FUTEX_CMPXCHG
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/kernel/futex_compat.c
- *
- * Futex compatibililty routines.
- *
- * Copyright 2006, Red Hat, Inc., Ingo Molnar
- */
-
-#include <linux/linkage.h>
-#include <linux/compat.h>
-#include <linux/nsproxy.h>
-#include <linux/futex.h>
-#include <linux/ptrace.h>
-#include <linux/syscalls.h>
-
-#include <linux/uaccess.h>
-
-
-/*
- * Fetch a robust-list pointer. Bit 0 signals PI futexes:
- */
-static inline int
-fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
- compat_uptr_t __user *head, unsigned int *pi)
-{
- if (get_user(*uentry, head))
- return -EFAULT;
-
- *entry = compat_ptr((*uentry) & ~1);
- *pi = (unsigned int)(*uentry) & 1;
-
- return 0;
-}
-
-static void __user *futex_uaddr(struct robust_list __user *entry,
- compat_long_t futex_offset)
-{
- compat_uptr_t base = ptr_to_compat(entry);
- void __user *uaddr = compat_ptr(base + futex_offset);
-
- return uaddr;
-}
-
-/*
- * Walk curr->robust_list (very carefully, it's a userspace list!)
- * and mark any locks found there dead, and notify any waiters.
- *
- * We silently return on any sign of list-walking problem.
- */
-void compat_exit_robust_list(struct task_struct *curr)
-{
- struct compat_robust_list_head __user *head = curr->compat_robust_list;
- struct robust_list __user *entry, *next_entry, *pending;
- unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
- unsigned int uninitialized_var(next_pi);
- compat_uptr_t uentry, next_uentry, upending;
- compat_long_t futex_offset;
- int rc;
-
- if (!futex_cmpxchg_enabled)
- return;
-
- /*
- * Fetch the list head (which was registered earlier, via
- * sys_set_robust_list()):
- */
- if (fetch_robust_entry(&uentry, &entry, &head->list.next, &pi))
- return;
- /*
- * Fetch the relative futex offset:
- */
- if (get_user(futex_offset, &head->futex_offset))
- return;
- /*
- * Fetch any possibly pending lock-add first, and handle it
- * if it exists:
- */
- if (fetch_robust_entry(&upending, &pending,
- &head->list_op_pending, &pip))
- return;
-
- next_entry = NULL; /* avoid warning with gcc */
- while (entry != (struct robust_list __user *) &head->list) {
- /*
- * Fetch the next entry in the list before calling
- * handle_futex_death:
- */
- rc = fetch_robust_entry(&next_uentry, &next_entry,
- (compat_uptr_t __user *)&entry->next, &next_pi);
- /*
- * A pending lock might already be on the list, so
- * dont process it twice:
- */
- if (entry != pending) {
- void __user *uaddr = futex_uaddr(entry, futex_offset);
-
- if (handle_futex_death(uaddr, curr, pi))
- return;
- }
- if (rc)
- return;
- uentry = next_uentry;
- entry = next_entry;
- pi = next_pi;
- /*
- * Avoid excessively long or circular lists:
- */
- if (!--limit)
- break;
-
- cond_resched();
- }
- if (pending) {
- void __user *uaddr = futex_uaddr(pending, futex_offset);
-
- handle_futex_death(uaddr, curr, pip);
- }
-}
-
-COMPAT_SYSCALL_DEFINE2(set_robust_list,
- struct compat_robust_list_head __user *, head,
- compat_size_t, len)
-{
- if (!futex_cmpxchg_enabled)
- return -ENOSYS;
-
- if (unlikely(len != sizeof(*head)))
- return -EINVAL;
-
- current->compat_robust_list = head;
-
- return 0;
-}
-
-COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
- compat_uptr_t __user *, head_ptr,
- compat_size_t __user *, len_ptr)
-{
- struct compat_robust_list_head __user *head;
- unsigned long ret;
- struct task_struct *p;
-
- if (!futex_cmpxchg_enabled)
- return -ENOSYS;
-
- rcu_read_lock();
-
- ret = -ESRCH;
- if (!pid)
- p = current;
- else {
- p = find_task_by_vpid(pid);
- if (!p)
- goto err_unlock;
- }
-
- ret = -EPERM;
- if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS))
- goto err_unlock;
-
- head = p->compat_robust_list;
- rcu_read_unlock();
-
- if (put_user(sizeof(*head), len_ptr))
- return -EFAULT;
- return put_user(ptr_to_compat(head), head_ptr);
-
-err_unlock:
- rcu_read_unlock();
-
- return ret;
-}
-
-COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
- struct compat_timespec __user *, utime, u32 __user *, uaddr2,
- u32, val3)
-{
- struct timespec ts;
- ktime_t t, *tp = NULL;
- int val2 = 0;
- int cmd = op & FUTEX_CMD_MASK;
-
- if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
- cmd == FUTEX_WAIT_BITSET ||
- cmd == FUTEX_WAIT_REQUEUE_PI)) {
- if (compat_get_timespec(&ts, utime))
- return -EFAULT;
- if (!timespec_valid(&ts))
- return -EINVAL;
-
- t = timespec_to_ktime(ts);
- if (cmd == FUTEX_WAIT)
- t = ktime_add_safe(ktime_get(), t);
- tp = &t;
- }
- if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
- cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
- val2 = (int) (unsigned long) utime;
-
- return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
-}
projects / mirror_ubuntu-bionic-kernel.git / commitdiff