MIPS: Malta: Improve system memory detection for '{e, }memsize' >= 2G

Using kstrtol to parse the "{e,}memsize" variables was wrong because this
parses signed long numbers. In case of '{e,}memsize' >= 2G, the top bit
is set, resulting to -ERANGE errors and possibly random system memory
boundaries. We fix this by replacing "kstrtol" with "kstrtoul".
We also improve the code to check the kstrtoul return value and
print a warning if an error was returned.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7543/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 10 insertions, 4 deletions

diff --git a/arch/mips/mti-malta/malta-memory.c b/arch/mips/mti-malta/malta-memory.c
index 0c35dee0a215..8fddd2cdbff7 100644
--- a/arch/mips/mti-malta/malta-memory.c
+++ b/arch/mips/mti-malta/malta-memory.c
@@ -35,13 +35,19 @@ fw_memblock_t * __init fw_getmdesc(int eva)
         /* otherwise look in the environment */
 
         memsize_str = fw_getenv("memsize");
-        if (memsize_str)
-                tmp = kstrtol(memsize_str, 0, &memsize);
+        if (memsize_str) {
+                tmp = kstrtoul(memsize_str, 0, &memsize);
+                if (tmp)
+                        pr_warn("Failed to read the 'memsize' env variable.\n");
+        }
         if (eva) {
         /* Look for ememsize for EVA */
                 ememsize_str = fw_getenv("ememsize");
-                if (ememsize_str)
-                        tmp = kstrtol(ememsize_str, 0, &ememsize);
+                if (ememsize_str) {
+                        tmp = kstrtoul(ememsize_str, 0, &ememsize);
+                        if (tmp)
+                                pr_warn("Failed to read the 'ememsize' env variable.\n");
+                }
         }
         if (!memsize && !ememsize) {
                 pr_warn("memsize not set in YAMON, set to default (32Mb)\n");