diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/init_64.c | 14 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr.c | 14 |
2 files changed, 27 insertions, 1 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 7dafd4159ad6..0ed09fad6aa1 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -727,9 +727,13 @@ void set_kernel_text_ro(void) void mark_rodata_ro(void) { - unsigned long start = PFN_ALIGN(_text), end = PFN_ALIGN(__end_rodata); + unsigned long start = PFN_ALIGN(_text); unsigned long rodata_start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; + unsigned long end = (unsigned long) &__end_rodata_hpage_align; + unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); + unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); + unsigned long data_start = (unsigned long) &_sdata; printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", (end - start) >> 10); @@ -752,6 +756,14 @@ void mark_rodata_ro(void) printk(KERN_INFO "Testing CPA: again\n"); set_memory_ro(start, (end-start) >> PAGE_SHIFT); #endif + + free_init_pages("unused kernel memory", + (unsigned long) page_address(virt_to_page(text_end)), + (unsigned long) + page_address(virt_to_page(rodata_start))); + free_init_pages("unused kernel memory", + (unsigned long) page_address(virt_to_page(rodata_end)), + (unsigned long) page_address(virt_to_page(data_start))); } #endif diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index dd38bfbefd1f..b494fc4a986e 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -279,6 +279,20 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, __pa((unsigned long)__end_rodata) >> PAGE_SHIFT)) pgprot_val(forbidden) |= _PAGE_RW; +#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) + /* + * 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. + * + * This will preserve the large page mappings for kernel text/data + * at no extra cost. + */ + if (within(address, (unsigned long)_text, + (unsigned long)__end_rodata_hpage_align)) + pgprot_val(forbidden) |= _PAGE_RW; +#endif + prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden)); return prot; |