diff options
| -rw-r--r-- | arch/x86/include/asm/cacheflush.h | 1 | ||||
| -rw-r--r-- | arch/x86/mm/init_32.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/init_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr.c | 10 |
4 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index b54f6afe7ec4..eebb2cd2b9bf 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/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/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index f64d0d5e0f89..c973f8e2a6cf 100644 --- a/arch/x86/mm/init_32.c +++ b/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/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0ed09fad6aa1..4b507c089402 100644 --- a/arch/x86/mm/init_64.c +++ b/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/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 78d3168b3c64..8d1e8d95ea45 100644 --- a/arch/x86/mm/pageattr.c +++ b/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 |