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authorBernd Schmidt <bernds_cb1@t-online.de>2008-04-24 03:06:15 +0800
committerBryan Wu <cooloney@kernel.org>2008-04-24 03:06:15 +0800
commitd5adb029efad3c51db376d620319abe65d1efc21 (patch)
tree660caff4c28e904f00a040c0ed4a17d5010c6f20
parent1ebc723cf04b55e7aeeec2e758293575d29a9c2b (diff)
[Blackfin] arch: This allows XIP to work with FD-PIC.
Previously, init failed to do anything meaningful; it turns out that the reason is that FD-PIC has a readonly data section which can be located in the XIP filesystem, and various address checks in the kernel reject such addresses for syscall arguments. Hence, init's execve ("/bin/sh", ...) failed with error code EFAULT. There's room for improvement here: in case people want to have filesystems on flash rather than in main memory, _access_ok should be modified to allow this. This bug fix is also dedicated to Michael Hennerich. Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de> Signed-off-by: Bryan Wu <cooloney@kernel.org>
-rw-r--r--arch/blackfin/kernel/process.c6
-rw-r--r--include/asm-blackfin/processor.h5
2 files changed, 9 insertions, 2 deletions
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index fb94cbeafad..be9fdd00d7c 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -324,6 +324,12 @@ int _access_ok(unsigned long addr, unsigned long size)
return 1;
if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
return 1;
+
+#ifdef CONFIG_ROMFS_MTD_FS
+ /* For XIP, allow user space to use pointers within the ROMFS. */
+ if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
+ return 1;
+#endif
#else
if (addr >= memory_start && (addr + size) <= physical_mem_end)
return 1;
diff --git a/include/asm-blackfin/processor.h b/include/asm-blackfin/processor.h
index 1033e5c7601..1c004072461 100644
--- a/include/asm-blackfin/processor.h
+++ b/include/asm-blackfin/processor.h
@@ -26,9 +26,10 @@ static inline void wrusp(unsigned long usp)
/*
* User space process size: 1st byte beyond user address space.
+ * Fairly meaningless on nommu. Parts of user programs can be scattered
+ * in a lot of places, so just disable this by setting it to 0xFFFFFFFF.
*/
-extern unsigned long memory_end;
-#define TASK_SIZE (memory_end)
+#define TASK_SIZE 0xFFFFFFFF
#ifdef __KERNEL__
#define STACK_TOP TASK_SIZE