[PATCH] powerpc/pmem: Fix kernel crash due to wrong range value usage in flush_dcache_range

[Aneesh Kumar K.V]

This patch fix the below kernel crash.

 BUG: Unable to handle kernel data access on read at 0xc000000380000000
 Faulting instruction address: 0xc00000000008b6f0
cpu 0x5: Vector: 300 (Data Access) at [c0000000d8587790]
    pc: c00000000008b6f0: arch_remove_memory+0x150/0x210
    lr: c00000000008b720: arch_remove_memory+0x180/0x210
    sp: c0000000d8587a20
   msr: 800000000280b033
   dar: c000000380000000
 dsisr: 40000000
  current = 0xc0000000d8558600
  paca    = 0xc00000000fff8f00   irqmask: 0x03   irq_happened: 0x01
    pid   = 1220, comm = ndctl
enter ? for help
 memunmap_pages+0x33c/0x410
 devm_action_release+0x30/0x50
 release_nodes+0x30c/0x3a0
 device_release_driver_internal+0x178/0x240
 unbind_store+0x74/0x190
 drv_attr_store+0x44/0x60
 sysfs_kf_write+0x74/0xa0
 kernfs_fop_write+0x1b0/0x260
 __vfs_write+0x3c/0x70
 vfs_write+0xe4/0x200
 ksys_write+0x7c/0x140
 system_call+0x5c/0x68

Fixes: 076265907cf9 ("powerpc: Chunk calls to flush_dcache_range in arch_*_memory")
Reported-by: Sachin Sant <sachinp at linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
 arch/powerpc/mm/mem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index ad299e72ec30..9488b63dfc87 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -121,7 +121,7 @@ static void flush_dcache_range_chunked(unsigned long start, unsigned long stop,
 	unsigned long i;
 
 	for (i = start; i < stop; i += chunk) {
-		flush_dcache_range(i, min(stop, start + chunk));
+		flush_dcache_range(i, min(stop, i + chunk));
 		cond_resched();
 	}
 }
-- 
2.23.0