[OpenBIOS] [PATCH 2/2] Don't map the page 0 to make NULL-dereferencing more obvious
Artyom Tarasenko
atar4qemu at gmail.com
Sat Apr 6 03:57:53 CEST 2013
Signed-off-by: Artyom Tarasenko <atar4qemu at gmail.com>
---
arch/sparc32/lib.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/arch/sparc32/lib.c b/arch/sparc32/lib.c
index 483069c..215ddcc 100644
--- a/arch/sparc32/lib.c
+++ b/arch/sparc32/lib.c
@@ -19,6 +19,8 @@
#define NCTX_SWIFT 0x100
#define LOWMEMSZ 32 * 1024 * 1024
+/* Avoid mapping the first page to make NULL-dereferencing more obvious */
+#define LOWMEM_START PAGE_SIZE
#ifdef CONFIG_DEBUG_MEM
#define DPRINTF(fmt, args...) \
@@ -403,7 +405,8 @@ init_mmu_swift(void)
ofmem_arch_map_pages(pa, va, size, ofmem_arch_default_translation_mode(pa));
// 1:1 mapping for RAM
- ofmem_arch_map_pages(0, 0, LOWMEMSZ, ofmem_arch_default_translation_mode(0));
+ ofmem_arch_map_pages(LOWMEM_START, LOWMEM_START, LOWMEMSZ,
+ ofmem_arch_default_translation_mode(LOWMEM_START));
/*
* Flush cache
--
1.7.1
More information about the OpenBIOS
mailing list