1 files changed, 20 insertions, 8 deletions

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 778a2793e75b..3697772e3759 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -102,13 +102,13 @@ int __init early_init_dt_scan_opal(unsigned long node,
 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
                                    const char *uname, int depth, void *data)
 {
-        unsigned long i, size;
+        unsigned long i, psize, size;
         const __be32 *prop;
 
         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
                 return 0;
 
-        prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &size);
+        prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
 
         if (!prop)
                 return 1;
@@ -116,6 +116,23 @@ int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
         pr_debug("Found machine check recoverable ranges.\n");
 
         /*
+         * Calculate number of available entries.
+         *
+         * Each recoverable address range entry is (start address, len,
+         * recovery address), 2 cells each for start and recovery address,
+         * 1 cell for len, totalling 5 cells per entry.
+         */
+        mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
+
+        /* Sanity check */
+        if (!mc_recoverable_range_len)
+                return 1;
+
+        /* Size required to hold all the entries. */
+        size = mc_recoverable_range_len *
+                        sizeof(struct mcheck_recoverable_range);
+
+        /*
          * Allocate a buffer to hold the MC recoverable ranges. We would be
          * accessing them in real mode, hence it needs to be within
          * RMO region.
@@ -124,11 +141,7 @@ int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
                                                         ppc64_rma_size));
         memset(mc_recoverable_range, 0, size);
 
-        /*
-         * Each recoverable address entry is an (start address,len,
-         * recover address) pair, * 2 cells each, totalling 4 cells per entry.
-         */
-        for (i = 0; i < size / (sizeof(*prop) * 5); i++) {
+        for (i = 0; i < mc_recoverable_range_len; i++) {
                 mc_recoverable_range[i].start_addr =
                                         of_read_number(prop + (i * 5) + 0, 2);
                 mc_recoverable_range[i].end_addr =
@@ -142,7 +155,6 @@ int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
                                 mc_recoverable_range[i].end_addr,
                                 mc_recoverable_range[i].recover_addr);
         }
-        mc_recoverable_range_len = i;
         return 1;
 }