[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>
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index fb94cbe..be9fdd0 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -324,6 +324,12 @@
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;