Merge tag 'v3.4-rc3' into staging/for_v3.5

* tag 'v3.4-rc3': (3755 commits)
  Linux 3.4-rc3
  x86-32: fix up strncpy_from_user() sign error
  ARM: 7386/1: jump_label: fixup for rename to static_key
  ARM: 7384/1: ThumbEE: Disable userspace TEEHBR access for !CONFIG_ARM_THUMBEE
  ARM: 7382/1: mm: truncate memory banks to fit in 4GB space for classic MMU
  ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus
  PCI: Fix regression in pci_restore_state(), v3
  SCSI: Fix error handling when no ULD is attached
  ARM: OMAP: clock: cleanup CPUfreq leftovers, fix build errors
  ARM: dts: remove blank interrupt-parent properties
  ARM: EXYNOS: Fix Kconfig dependencies for device tree enabled machine files
  do not export kernel's NULL #define to userspace
  ARM: EXYNOS: Remove broken config values for touchscren for NURI board
  ARM: EXYNOS: set fix xusbxti clock for NURI and Universal210 boards
  ARM: EXYNOS: fix regulator name for NURI board
  ARM: SAMSUNG: make SAMSUNG_PM_DEBUG select DEBUG_LL
  cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS
  sparc64: Eliminate obsolete __handle_softirq() function
  sparc64: Fix bootup crash on sun4v.
  ARM: msm: Fix section mismatches in proc_comm.c
  ...

1 files changed, 15 insertions, 23 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 72efa1e4359a..e2b0fb9a0b3b 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);