Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 38 insertions, 51 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 1614be20173..e2b0fb9a0b3 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -59,6 +59,7 @@
 #include <linux/magic.h>
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
+#include <linux/ptrace.h>
 
 #include <asm/futex.h>
 
@@ -2443,40 +2444,31 @@ SYSCALL_DEFINE3(get_robust_list, int, pid,
 {
 	struct robust_list_head __user *head;
 	unsigned long ret;
-	const struct cred *cred = current_cred(), *pcred;
+	struct task_struct *p;
 
 	if (!futex_cmpxchg_enabled)
 		return -ENOSYS;
 
+	WARN_ONCE(1, "deprecated: get_robust_list will be deleted in 2013.\n");
+
+	rcu_read_lock();
+
+	ret = -ESRCH;
 	if (!pid)
-		head = current->robust_list;
+		p = current;
 	else {
-		struct task_struct *p;
-
-		ret = -ESRCH;
-		rcu_read_lock();
 		p = find_task_by_vpid(pid);
 		if (!p)
 			goto err_unlock;
-		ret = -EPERM;
-		pcred = __task_cred(p);
-		/* If victim is in different user_ns, then uids are not
-		   comparable, so we must have CAP_SYS_PTRACE */
-		if (cred->user->user_ns != pcred->user->user_ns) {
-			if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
-				goto err_unlock;
-			goto ok;
-		}
-		/* If victim is in same user_ns, then uids are comparable */
-		if (cred->euid != pcred->euid &&
-		    cred->euid != pcred->uid &&
-		    !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
-			goto err_unlock;
-ok:
-		head = p->robust_list;
-		rcu_read_unlock();
 	}
 
+	ret = -EPERM;
+	if (!ptrace_may_access(p, PTRACE_MODE_READ))
+		goto err_unlock;
+
+	head = p->robust_list;
+	rcu_read_unlock();
+
 	if (put_user(sizeof(*head), len_ptr))
 		return -EFAULT;
 	return put_user(head, head_ptr);
@@ -2628,7 +2620,7 @@ void exit_robust_list(struct task_struct *curr)
 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
 		u32 __user *uaddr2, u32 val2, u32 val3)
 {
-	int ret = -ENOSYS, cmd = op & FUTEX_CMD_MASK;
+	int cmd = op & FUTEX_CMD_MASK;
 	unsigned int flags = 0;
 
 	if (!(op & FUTEX_PRIVATE_FLAG))
@@ -2641,49 +2633,44 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
 	}
 
 	switch (cmd) {
+	case FUTEX_LOCK_PI:
+	case FUTEX_UNLOCK_PI:
+	case FUTEX_TRYLOCK_PI:
+	case FUTEX_WAIT_REQUEUE_PI:
+	case FUTEX_CMP_REQUEUE_PI:
+		if (!futex_cmpxchg_enabled)
+			return -ENOSYS;
+	}
+
+	switch (cmd) {
 	case FUTEX_WAIT:
 		val3 = FUTEX_BITSET_MATCH_ANY;
 	case FUTEX_WAIT_BITSET:
-		ret = futex_wait(uaddr, flags, val, timeout, val3);
-		break;
+		return futex_wait(uaddr, flags, val, timeout, val3);
 	case FUTEX_WAKE:
 		val3 = FUTEX_BITSET_MATCH_ANY;
 	case FUTEX_WAKE_BITSET:
-		ret = futex_wake(uaddr, flags, val, val3);
-		break;
+		return futex_wake(uaddr, flags, val, val3);
 	case FUTEX_REQUEUE:
-		ret = futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
-		break;
+		return futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
 	case FUTEX_CMP_REQUEUE:
-		ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
-		break;
+		return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
 	case FUTEX_WAKE_OP:
-		ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
-		break;
+		return futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
 	case FUTEX_LOCK_PI:
-		if (futex_cmpxchg_enabled)
-			ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
-		break;
+		return futex_lock_pi(uaddr, flags, val, timeout, 0);
 	case FUTEX_UNLOCK_PI:
-		if (futex_cmpxchg_enabled)
-			ret = futex_unlock_pi(uaddr, flags);
-		break;
+		return futex_unlock_pi(uaddr, flags);
 	case FUTEX_TRYLOCK_PI:
-		if (futex_cmpxchg_enabled)
-			ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
-		break;
+		return futex_lock_pi(uaddr, flags, 0, timeout, 1);
 	case FUTEX_WAIT_REQUEUE_PI:
 		val3 = FUTEX_BITSET_MATCH_ANY;
-		ret = futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
-					    uaddr2);
-		break;
+		return futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
+					     uaddr2);
 	case FUTEX_CMP_REQUEUE_PI:
-		ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
-		break;
-	default:
-		ret = -ENOSYS;
+		return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
 	}
-	return ret;
+	return -ENOSYS;
 }