Merge tag 'powerpc-5.6-2' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix an existing bug in our user access handling, exposed by one of
   the bug fixes we merged this cycle.

 - A fix for a boot hang on 32-bit with CONFIG_TRACE_IRQFLAGS and the
   recently added CONFIG_VMAP_STACK.

Thanks to: Christophe Leroy, Guenter Roeck.

* tag 'powerpc-5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Fix CONFIG_TRACE_IRQFLAGS with CONFIG_VMAP_STACK
  powerpc/futex: Fix incorrect user access blocking

arch/powerpc/include/asm/futex.h

@@ -35,7 +35,7 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
 {
 	int oldval = 0, ret;
 
-	allow_write_to_user(uaddr, sizeof(*uaddr));
+	allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
 	pagefault_disable();
 
 	switch (op) {
@@ -62,7 +62,7 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
 
 	*oval = oldval;
 
-	prevent_write_to_user(uaddr, sizeof(*uaddr));
+	prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
 	return ret;
 }
 
@@ -76,7 +76,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	if (!access_ok(uaddr, sizeof(u32)))
 		return -EFAULT;
 
-	allow_write_to_user(uaddr, sizeof(*uaddr));
+	allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
+
         __asm__ __volatile__ (
         PPC_ATOMIC_ENTRY_BARRIER
 "1:     lwarx   %1,0,%3         # futex_atomic_cmpxchg_inatomic\n\
@@ -97,7 +98,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
         : "cc", "memory");
 
 	*uval = prev;
-	prevent_write_to_user(uaddr, sizeof(*uaddr));
+	prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
+
         return ret;
 }
 

arch/powerpc/kernel/entry_32.S

@@ -214,7 +214,7 @@ transfer_to_handler_cont:
 	 * To speed up the syscall path where interrupts stay on, let's check
 	 * first if we are changing the MSR value at all.
 	 */
-	tophys(r12, r1)
+	tophys_novmstack r12, r1
 	lwz	r12,_MSR(r12)
 	andi.	r12,r12,MSR_EE
 	bne	1f