diff options
Diffstat (limited to 'include/linux/execmem.h')
| -rw-r--r-- | include/linux/execmem.h | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/include/linux/execmem.h b/include/linux/execmem.h index 64130ae19690..ca42d5e46ccc 100644 --- a/include/linux/execmem.h +++ b/include/linux/execmem.h @@ -4,6 +4,7 @@ #include <linux/types.h> #include <linux/moduleloader.h> +#include <linux/cleanup.h> #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ !defined(CONFIG_KASAN_VMALLOC) @@ -53,7 +54,7 @@ enum execmem_range_flags { EXECMEM_ROX_CACHE = (1 << 1), }; -#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX +#if defined(CONFIG_ARCH_HAS_EXECMEM_ROX) && defined(CONFIG_EXECMEM) /** * execmem_fill_trapping_insns - set memory to contain instructions that * will trap @@ -65,6 +66,43 @@ enum execmem_range_flags { * Architectures that use EXECMEM_ROX_CACHE must implement this. */ void execmem_fill_trapping_insns(void *ptr, size_t size, bool writable); + +/** + * execmem_make_temp_rw - temporarily remap region with read-write + * permissions + * @ptr: address of the region to remap + * @size: size of the region to remap + * + * Remaps a part of the cached large page in the ROX cache in the range + * [@ptr, @ptr + @size) as writable and not executable. The caller must + * have exclusive ownership of this range and ensure nothing will try to + * execute code in this range. + * + * Return: 0 on success or negative error code on failure. + */ +int execmem_make_temp_rw(void *ptr, size_t size); + +/** + * execmem_restore_rox - restore read-only-execute permissions + * @ptr: address of the region to remap + * @size: size of the region to remap + * + * Restores read-only-execute permissions on a range [@ptr, @ptr + @size) + * after it was temporarily remapped as writable. Relies on architecture + * implementation of set_memory_rox() to restore mapping using large pages. + * + * Return: 0 on success or negative error code on failure. + */ +int execmem_restore_rox(void *ptr, size_t size); + +/* + * Called from mark_readonly(), where the system transitions to ROX. + */ +void execmem_cache_make_ro(void); +#else +static inline int execmem_make_temp_rw(void *ptr, size_t size) { return 0; } +static inline int execmem_restore_rox(void *ptr, size_t size) { return 0; } +static inline void execmem_cache_make_ro(void) { } #endif /** @@ -139,6 +177,8 @@ void *execmem_alloc(enum execmem_type type, size_t size); */ void execmem_free(void *ptr); +DEFINE_FREE(execmem, void *, if (_T) execmem_free(_T)); + #ifdef CONFIG_MMU /** * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory |