---

yaml --- r: 173041 b: refs/heads/master c: 502f660 h: refs/heads/master i: 173039: 2570f09 v: v3
git-mirror · Nov 2, 2009 · 0954575 · 0954575
1 parent 96e9af0
commit 0954575
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Showing 5 changed files with 10 additions and 7 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 883242dd0e5faaba041528a9a99f483f2a656c83
+refs/heads/master: 502f660466ba7a66711ffdf414b1f7f1131dcbf7
diff --git a/trunk/arch/x86/include/asm/cacheflush.h b/trunk/arch/x86/include/asm/cacheflush.h
@@ -176,6 +176,7 @@ void clflush_cache_range(void *addr, unsigned int size);
 #ifdef CONFIG_DEBUG_RODATA
 void mark_rodata_ro(void);
 extern const int rodata_test_data;
+extern int kernel_set_to_readonly;
 void set_kernel_text_rw(void);
 void set_kernel_text_ro(void);
 #else

diff --git a/trunk/arch/x86/mm/init_32.c b/trunk/arch/x86/mm/init_32.c
@@ -997,7 +997,7 @@ static noinline int do_test_wp_bit(void)
 const int rodata_test_data = 0xC3;
 EXPORT_SYMBOL_GPL(rodata_test_data);
 
-static int kernel_set_to_readonly;
+int kernel_set_to_readonly __read_mostly;
 
 void set_kernel_text_rw(void)
 {

diff --git a/trunk/arch/x86/mm/init_64.c b/trunk/arch/x86/mm/init_64.c
@@ -695,7 +695,7 @@ void __init mem_init(void)
 const int rodata_test_data = 0xC3;
 EXPORT_SYMBOL_GPL(rodata_test_data);
 
-static int kernel_set_to_readonly;
+int kernel_set_to_readonly;
 
 void set_kernel_text_rw(void)
 {

diff --git a/trunk/arch/x86/mm/pageattr.c b/trunk/arch/x86/mm/pageattr.c
@@ -282,14 +282,16 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
 #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) && \
 	!defined(CONFIG_DYNAMIC_FTRACE)
 	/*
-	 * Kernel text mappings for the large page aligned .rodata section
-	 * will be read-only. For the kernel identity mappings covering
-	 * the holes caused by this alignment can be anything.
+	 * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
+	 * kernel text mappings for the large page aligned text, rodata sections
+	 * will be always read-only. For the kernel identity mappings covering
+	 * the holes caused by this alignment can be anything that user asks.
 	 *
 	 * This will preserve the large page mappings for kernel text/data
 	 * at no extra cost.
 	 */
-	if (within(address, (unsigned long)_text,
+	if (kernel_set_to_readonly &&
+	    within(address, (unsigned long)_text,
 		   (unsigned long)__end_rodata_hpage_align))
 		pgprot_val(forbidden) |= _PAGE_RW;
 #endif