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Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c128
1 files changed, 33 insertions, 95 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index e646661f6282..83404124b77b 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -32,30 +32,13 @@
* "But they come in a choice of three flavours!"
*/
#include <linux/compat.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/fs.h>
-#include <linux/file.h>
#include <linux/jhash.h>
-#include <linux/init.h>
-#include <linux/futex.h>
-#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/syscalls.h>
-#include <linux/signal.h>
-#include <linux/export.h>
-#include <linux/magic.h>
-#include <linux/pid.h>
-#include <linux/nsproxy.h>
-#include <linux/ptrace.h>
-#include <linux/sched/rt.h>
-#include <linux/sched/wake_q.h>
-#include <linux/sched/mm.h>
#include <linux/hugetlb.h>
#include <linux/freezer.h>
#include <linux/memblock.h>
#include <linux/fault-inject.h>
-#include <linux/refcount.h>
#include <asm/futex.h>
@@ -476,7 +459,7 @@ static u64 get_inode_sequence_number(struct inode *inode)
/**
* get_futex_key() - Get parameters which are the keys for a futex
* @uaddr: virtual address of the futex
- * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @fshared: false for a PROCESS_PRIVATE futex, true for PROCESS_SHARED
* @key: address where result is stored.
* @rw: mapping needs to be read/write (values: FUTEX_READ,
* FUTEX_WRITE)
@@ -500,8 +483,8 @@ static u64 get_inode_sequence_number(struct inode *inode)
*
* lock_page() might sleep, the caller should not hold a spinlock.
*/
-static int
-get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_access rw)
+static int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,
+ enum futex_access rw)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
@@ -538,7 +521,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_a
again:
/* Ignore any VERIFY_READ mapping (futex common case) */
- if (unlikely(should_fail_futex(fshared)))
+ if (unlikely(should_fail_futex(true)))
return -EFAULT;
err = get_user_pages_fast(address, 1, FOLL_WRITE, &page);
@@ -626,7 +609,7 @@ again:
* A RO anonymous page will never change and thus doesn't make
* sense for futex operations.
*/
- if (unlikely(should_fail_futex(fshared)) || ro) {
+ if (unlikely(should_fail_futex(true)) || ro) {
err = -EFAULT;
goto out;
}
@@ -677,10 +660,6 @@ out:
return err;
}
-static inline void put_futex_key(union futex_key *key)
-{
-}
-
/**
* fault_in_user_writeable() - Fault in user address and verify RW access
* @uaddr: pointer to faulting user space address
@@ -1326,7 +1305,7 @@ static int lookup_pi_state(u32 __user *uaddr, u32 uval,
static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval)
{
int err;
- u32 uninitialized_var(curval);
+ u32 curval;
if (unlikely(should_fail_futex(true)))
return -EFAULT;
@@ -1496,7 +1475,7 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q)
*/
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state)
{
- u32 uninitialized_var(curval), newval;
+ u32 curval, newval;
struct task_struct *new_owner;
bool postunlock = false;
DEFINE_WAKE_Q(wake_q);
@@ -1611,13 +1590,13 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_READ);
if (unlikely(ret != 0))
- goto out;
+ return ret;
hb = hash_futex(&key);
/* Make sure we really have tasks to wakeup */
if (!hb_waiters_pending(hb))
- goto out_put_key;
+ return ret;
spin_lock(&hb->lock);
@@ -1640,9 +1619,6 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
spin_unlock(&hb->lock);
wake_up_q(&wake_q);
-out_put_key:
- put_futex_key(&key);
-out:
return ret;
}
@@ -1709,10 +1685,10 @@ futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
retry:
ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
if (unlikely(ret != 0))
- goto out;
+ return ret;
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
if (unlikely(ret != 0))
- goto out_put_key1;
+ return ret;
hb1 = hash_futex(&key1);
hb2 = hash_futex(&key2);
@@ -1730,13 +1706,13 @@ retry_private:
* an MMU, but we might get them from range checking
*/
ret = op_ret;
- goto out_put_keys;
+ return ret;
}
if (op_ret == -EFAULT) {
ret = fault_in_user_writeable(uaddr2);
if (ret)
- goto out_put_keys;
+ return ret;
}
if (!(flags & FLAGS_SHARED)) {
@@ -1744,8 +1720,6 @@ retry_private:
goto retry_private;
}
- put_futex_key(&key2);
- put_futex_key(&key1);
cond_resched();
goto retry;
}
@@ -1781,11 +1755,6 @@ retry_private:
out_unlock:
double_unlock_hb(hb1, hb2);
wake_up_q(&wake_q);
-out_put_keys:
- put_futex_key(&key2);
-out_put_key1:
- put_futex_key(&key1);
-out:
return ret;
}
@@ -1992,20 +1961,18 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
retry:
ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
if (unlikely(ret != 0))
- goto out;
+ return ret;
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2,
requeue_pi ? FUTEX_WRITE : FUTEX_READ);
if (unlikely(ret != 0))
- goto out_put_key1;
+ return ret;
/*
* The check above which compares uaddrs is not sufficient for
* shared futexes. We need to compare the keys:
*/
- if (requeue_pi && match_futex(&key1, &key2)) {
- ret = -EINVAL;
- goto out_put_keys;
- }
+ if (requeue_pi && match_futex(&key1, &key2))
+ return -EINVAL;
hb1 = hash_futex(&key1);
hb2 = hash_futex(&key2);
@@ -2025,13 +1992,11 @@ retry_private:
ret = get_user(curval, uaddr1);
if (ret)
- goto out_put_keys;
+ return ret;
if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(&key2);
- put_futex_key(&key1);
goto retry;
}
if (curval != *cmpval) {
@@ -2090,12 +2055,10 @@ retry_private:
case -EFAULT:
double_unlock_hb(hb1, hb2);
hb_waiters_dec(hb2);
- put_futex_key(&key2);
- put_futex_key(&key1);
ret = fault_in_user_writeable(uaddr2);
if (!ret)
goto retry;
- goto out;
+ return ret;
case -EBUSY:
case -EAGAIN:
/*
@@ -2106,8 +2069,6 @@ retry_private:
*/
double_unlock_hb(hb1, hb2);
hb_waiters_dec(hb2);
- put_futex_key(&key2);
- put_futex_key(&key1);
/*
* Handle the case where the owner is in the middle of
* exiting. Wait for the exit to complete otherwise
@@ -2216,12 +2177,6 @@ out_unlock:
double_unlock_hb(hb1, hb2);
wake_up_q(&wake_q);
hb_waiters_dec(hb2);
-
-out_put_keys:
- put_futex_key(&key2);
-out_put_key1:
- put_futex_key(&key1);
-out:
return ret ? ret : task_count;
}
@@ -2370,7 +2325,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
struct task_struct *argowner)
{
struct futex_pi_state *pi_state = q->pi_state;
- u32 uval, uninitialized_var(curval), newval;
+ u32 uval, curval, newval;
struct task_struct *oldowner, *newowner;
u32 newtid;
int ret, err = 0;
@@ -2567,7 +2522,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
*/
if (q->pi_state->owner != current)
ret = fixup_pi_state_owner(uaddr, q, current);
- goto out;
+ return ret ? ret : locked;
}
/*
@@ -2580,7 +2535,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
*/
if (q->pi_state->owner == current) {
ret = fixup_pi_state_owner(uaddr, q, NULL);
- goto out;
+ return ret;
}
/*
@@ -2594,8 +2549,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
q->pi_state->owner);
}
-out:
- return ret ? ret : locked;
+ return ret;
}
/**
@@ -2692,12 +2646,11 @@ retry_private:
ret = get_user(uval, uaddr);
if (ret)
- goto out;
+ return ret;
if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(&q->key);
goto retry;
}
@@ -2706,9 +2659,6 @@ retry_private:
ret = -EWOULDBLOCK;
}
-out:
- if (ret)
- put_futex_key(&q->key);
return ret;
}
@@ -2853,7 +2803,6 @@ retry_private:
* - EAGAIN: The user space value changed.
*/
queue_unlock(hb);
- put_futex_key(&q.key);
/*
* Handle the case where the owner is in the middle of
* exiting. Wait for the exit to complete otherwise
@@ -2961,13 +2910,11 @@ no_block:
put_pi_state(pi_state);
}
- goto out_put_key;
+ goto out;
out_unlock_put_key:
queue_unlock(hb);
-out_put_key:
- put_futex_key(&q.key);
out:
if (to) {
hrtimer_cancel(&to->timer);
@@ -2980,12 +2927,11 @@ uaddr_faulted:
ret = fault_in_user_writeable(uaddr);
if (ret)
- goto out_put_key;
+ goto out;
if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(&q.key);
goto retry;
}
@@ -2996,7 +2942,7 @@ uaddr_faulted:
*/
static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
{
- u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current);
+ u32 curval, uval, vpid = task_pid_vnr(current);
union futex_key key = FUTEX_KEY_INIT;
struct futex_hash_bucket *hb;
struct futex_q *top_waiter;
@@ -3114,16 +3060,13 @@ retry:
out_unlock:
spin_unlock(&hb->lock);
out_putkey:
- put_futex_key(&key);
return ret;
pi_retry:
- put_futex_key(&key);
cond_resched();
goto retry;
pi_faulted:
- put_futex_key(&key);
ret = fault_in_user_writeable(uaddr);
if (!ret)
@@ -3265,7 +3208,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
*/
ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
if (ret)
- goto out_key2;
+ goto out;
/*
* The check above which compares uaddrs is not sufficient for
@@ -3274,7 +3217,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
if (match_futex(&q.key, &key2)) {
queue_unlock(hb);
ret = -EINVAL;
- goto out_put_keys;
+ goto out;
}
/* Queue the futex_q, drop the hb lock, wait for wakeup. */
@@ -3284,7 +3227,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
spin_unlock(&hb->lock);
if (ret)
- goto out_put_keys;
+ goto out;
/*
* In order for us to be here, we know our q.key == key2, and since
@@ -3374,11 +3317,6 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
ret = -EWOULDBLOCK;
}
-out_put_keys:
- put_futex_key(&q.key);
-out_key2:
- put_futex_key(&key2);
-
out:
if (to) {
hrtimer_cancel(&to->timer);
@@ -3479,7 +3417,7 @@ err_unlock:
static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr,
bool pi, bool pending_op)
{
- u32 uval, uninitialized_var(nval), mval;
+ u32 uval, nval, mval;
int err;
/* Futex address must be 32bit aligned */
@@ -3609,7 +3547,7 @@ static void exit_robust_list(struct task_struct *curr)
struct robust_list_head __user *head = curr->robust_list;
struct robust_list __user *entry, *next_entry, *pending;
unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
- unsigned int uninitialized_var(next_pi);
+ unsigned int next_pi;
unsigned long futex_offset;
int rc;
@@ -3909,7 +3847,7 @@ static 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);
+ unsigned int next_pi;
compat_uptr_t uentry, next_uentry, upending;
compat_long_t futex_offset;
int rc;