[PARISC] Add CONFIG_DEBUG_RODATA to protect read-only data

Add the parisc version of the "mark rodata section read only" patches.
Based on code from and Signed-off-by Arjan van de Ven
<arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@muc.de>,
Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

2 files changed, 7 insertions, 1 deletions

diff --git a/include/asm-parisc/cacheflush.h b/include/asm-parisc/cacheflush.h
index 1bc3c83ee74b..c53af9ff41b5 100644
--- a/include/asm-parisc/cacheflush.h
+++ b/include/asm-parisc/cacheflush.h
@@ -183,4 +183,10 @@ flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long
                 __flush_cache_page(vma, vmaddr);
 
 }
+
+#ifdef CONFIG_DEBUG_RODATA
+void mark_rodata_ro(void);
 #endif
+
+#endif /* _PARISC_CACHEFLUSH_H */
+
diff --git a/include/asm-parisc/pgtable.h b/include/asm-parisc/pgtable.h
index b4554711c3e7..4e34c6b44059 100644
--- a/include/asm-parisc/pgtable.h
+++ b/include/asm-parisc/pgtable.h
@@ -213,7 +213,7 @@ extern  void *vmalloc_start;
 #define PAGE_COPY       PAGE_EXECREAD
 #define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC |_PAGE_ACCESSED)
 #define PAGE_KERNEL     __pgprot(_PAGE_KERNEL)
-#define PAGE_KERNEL_RO  __pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_KERNEL_RO  __pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
 #define PAGE_KERNEL_UNC __pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
 #define PAGE_FLUSH      __pgprot(_PAGE_FLUSH)