1 files changed, 58 insertions, 20 deletions

diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 14735d5ede52..9c7f7811af70 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -188,6 +188,63 @@ static inline void __init reserve_crashkernel(void)
 {}
 #endif
 
+static void __init check_for_initrd(void)
+{
+#ifdef CONFIG_BLK_DEV_INITRD
+        unsigned long start, end;
+
+        /*
+         * Check for the rare cases where boot loaders adhere to the boot
+         * ABI.
+         */
+        if (!LOADER_TYPE || !INITRD_START || !INITRD_SIZE)
+                goto disable;
+
+        start = INITRD_START + __MEMORY_START;
+        end = start + INITRD_SIZE;
+
+        if (unlikely(end <= start))
+                goto disable;
+        if (unlikely(start & ~PAGE_MASK)) {
+                pr_err("initrd must be page aligned\n");
+                goto disable;
+        }
+
+        if (unlikely(start < PAGE_OFFSET)) {
+                pr_err("initrd start < PAGE_OFFSET\n");
+                goto disable;
+        }
+
+        if (unlikely(end > lmb_end_of_DRAM())) {
+                pr_err("initrd extends beyond end of memory "
+                       "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
+                       end, (unsigned long)lmb_end_of_DRAM());
+                goto disable;
+        }
+
+        /*
+         * If we got this far inspite of the boot loader's best efforts
+         * to the contrary, assume we actually have a valid initrd and
+         * fix up the root dev.
+         */
+        ROOT_DEV = Root_RAM0;
+
+        /*
+         * Address sanitization
+         */
+        initrd_start = (unsigned long)__va(__pa(start));
+        initrd_end = initrd_start + INITRD_SIZE;
+
+        reserve_bootmem(__pa(initrd_start), INITRD_SIZE, BOOTMEM_DEFAULT);
+
+        return;
+
+disable:
+        pr_info("initrd disabled\n");
+        initrd_start = initrd_end = 0;
+#endif
+}
+
 void __cpuinit calibrate_delay(void)
 {
         struct clk *clk = clk_get(NULL, "cpu_clk");
@@ -277,26 +334,7 @@ void __init setup_bootmem_allocator(unsigned long free_pfn)
 
         sparse_memory_present_with_active_regions(0);
 
-#ifdef CONFIG_BLK_DEV_INITRD
-        ROOT_DEV = Root_RAM0;
-
-        if (LOADER_TYPE && INITRD_START) {
-                unsigned long initrd_start_phys = INITRD_START + __MEMORY_START;
-
-                if (initrd_start_phys + INITRD_SIZE <= PFN_PHYS(max_low_pfn)) {
-                        reserve_bootmem(initrd_start_phys, INITRD_SIZE,
-                                        BOOTMEM_DEFAULT);
-                        initrd_start = (unsigned long)__va(initrd_start_phys);
-                        initrd_end = initrd_start + INITRD_SIZE;
-                } else {
-                        printk("initrd extends beyond end of memory "
-                               "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
-                               initrd_start_phys + INITRD_SIZE,
-                               (unsigned long)PFN_PHYS(max_low_pfn));
-                        initrd_start = 0;
-                }
-        }
-#endif
+        check_for_initrd();
 
         reserve_crashkernel();
 }