diff options
Diffstat (limited to 'arch/x86/mm/pageattr.c')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index dd38bfbefd1f..1d4eb93d333c 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -279,6 +279,22 @@ 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) + /* + * 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 (kernel_set_to_readonly && + 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; @@ -1069,12 +1085,18 @@ EXPORT_SYMBOL(set_memory_array_wb); int set_memory_x(unsigned long addr, int numpages) { + if (!(__supported_pte_mask & _PAGE_NX)) + return 0; + return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0); } EXPORT_SYMBOL(set_memory_x); int set_memory_nx(unsigned long addr, int numpages) { + if (!(__supported_pte_mask & _PAGE_NX)) + return 0; + return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0); } EXPORT_SYMBOL(set_memory_nx); |