Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
 "Another round of small ARM fixes.

  restore_user_regs early stack deallocation is buggy in the presence of
  FIQs which switch to SVC mode, and could lead to corrupted registers
  being returned to a user process given an inopportune FIQ event.

  Another bug was spotted in the ARM perf code where it could lose track
  of perf counter overflows, leading to incorrect perf results.

  Lastly, a bug in arm_add_memory() was spotted where the memory sizes
  aren't properly rounded.  As most people pass properly rounded sizes,
  this hasn't been noticed"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8292/1: mm: fix size rounding-down of arm_add_memory() function
  ARM: 8255/1: perf: Prevent wraparound during overflow
  ARM: 8266/1: Remove early stack deallocation from restore_user_regs

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 715ae19bc7c8..e55408e96559 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -657,10 +657,13 @@ int __init arm_add_memory(u64 start, u64 size)
 
 	/*
 	 * Ensure that start/size are aligned to a page boundary.
-	 * Size is appropriately rounded down, start is rounded up.
+	 * Size is rounded down, start is rounded up.
 	 */
-	size -= start & ~PAGE_MASK;
 	aligned_start = PAGE_ALIGN(start);
+	if (aligned_start > start + size)
+		size = 0;
+	else
+		size -= aligned_start - start;
 
 #ifndef CONFIG_ARCH_PHYS_ADDR_T_64BIT
 	if (aligned_start > ULONG_MAX) {