X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Ffutex_compat.c;h=235716556bf16ed9b97c19a9578ef24dec19edb1;hb=9a1607071c293e48b08bd703733480b1d55c7b93;hp=27478948b318968a052e4b9fad9a27dd881ca67f;hpb=f0ede66fca23cfee4ee80b48298007d930f49bbe;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 2747894..2357165 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -8,6 +8,7 @@
 
 #include <linux/linkage.h>
 #include <linux/compat.h>
+#include <linux/nsproxy.h>
 #include <linux/futex.h>
 
 #include <asm/uaccess.h>
@@ -29,6 +30,15 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
 	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.
@@ -38,10 +48,14 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
 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, *pending;
-	unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
-	compat_uptr_t uentry, upending;
+	struct robust_list __user *entry, *next_entry, *pending;
+	unsigned int limit = ROBUST_LIST_LIMIT, pi, next_pi, pip;
+	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
@@ -61,25 +75,30 @@ void compat_exit_robust_list(struct task_struct *curr)
 	if (fetch_robust_entry(&upending, &pending,
 			       &head->list_op_pending, &pip))
 		return;
-	if (upending)
-		handle_futex_death((void __user *)pending + futex_offset, curr, pip);
 
-	while (compat_ptr(uentry) != &head->list) {
+	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)
-			if (handle_futex_death((void __user *)entry + futex_offset,
-						curr, pi))
-				return;
+		if (entry != pending) {
+			void __user *uaddr = futex_uaddr(entry, futex_offset);
 
-		/*
-		 * Fetch the next entry in the list:
-		 */
-		if (fetch_robust_entry(&uentry, &entry,
-				       (compat_uptr_t __user *)&entry->next, &pi))
+			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:
 		 */
@@ -88,12 +107,20 @@ void compat_exit_robust_list(struct task_struct *curr)
 
 		cond_resched();
 	}
+	if (pending) {
+		void __user *uaddr = futex_uaddr(pending, futex_offset);
+
+		handle_futex_death(uaddr, curr, pip);
+	}
 }
 
 asmlinkage long
 compat_sys_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;
 
@@ -108,6 +135,10 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 {
 	struct compat_robust_list_head __user *head;
 	unsigned long ret;
+	const struct cred *cred = current_cred(), *pcred;
+
+	if (!futex_cmpxchg_enabled)
+		return -ENOSYS;
 
 	if (!pid)
 		head = current->compat_robust_list;
@@ -116,12 +147,14 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 
 		ret = -ESRCH;
 		read_lock(&tasklist_lock);
-		p = find_task_by_pid(pid);
+		p = find_task_by_vpid(pid);
 		if (!p)
 			goto err_unlock;
 		ret = -EPERM;
-		if ((current->euid != p->euid) && (current->euid != p->uid) &&
-				!capable(CAP_SYS_PTRACE))
+		pcred = __task_cred(p);
+		if (cred->euid != pcred->euid &&
+		    cred->euid != pcred->uid &&
+		    !capable(CAP_SYS_PTRACE))
 			goto err_unlock;
 		head = p->compat_robust_list;
 		read_unlock(&tasklist_lock);
@@ -146,7 +179,9 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 	int val2 = 0;
 	int cmd = op & FUTEX_CMD_MASK;
 
-	if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) {
+	if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
+		      cmd == FUTEX_WAIT_BITSET ||
+		      cmd == FUTEX_WAIT_REQUEUE_PI)) {
 		if (get_compat_timespec(&ts, utime))
 			return -EFAULT;
 		if (!timespec_valid(&ts))
@@ -154,11 +189,11 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 
 		t = timespec_to_ktime(ts);
 		if (cmd == FUTEX_WAIT)
-			t = ktime_add(ktime_get(), t);
+			t = ktime_add_safe(ktime_get(), t);
 		tp = &t;
 	}
-	if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE
-	    || cmd == FUTEX_CMP_REQUEUE_PI)
+	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);