diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | kernel/power/hibernate.c | 3 | ||||
| -rw-r--r-- | kernel/power/power.h | 7 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 42 |
4 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c958d1c..07960c24642d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3594,6 +3594,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. present during boot. nocompress Don't compress/decompress hibernation images. no Disable hibernation and resume. + protect_image Turn on image protection during restoration + (that will set all pages holding image data + during restoration read-only). retain_initrd [RAM] Keep initrd memory after extraction diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index b00f270d328e..51441d87f0b6 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -1126,6 +1126,9 @@ static int __init hibernate_setup(char *str) } else if (!strncmp(str, "no", 2)) { noresume = 1; nohibernate = 1; + } else if (IS_ENABLED(CONFIG_DEBUG_RODATA) + && !strncmp(str, "protect_image", 13)) { + enable_restore_image_protection(); } return 1; } diff --git a/kernel/power/power.h b/kernel/power/power.h index 51f02ecaf125..064963e89194 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -59,6 +59,13 @@ extern int hibernation_snapshot(int platform_mode); extern int hibernation_restore(int platform_mode); extern int hibernation_platform_enter(void); +#ifdef CONFIG_DEBUG_RODATA +/* kernel/power/snapshot.c */ +extern void enable_restore_image_protection(void); +#else +static inline void enable_restore_image_protection(void) {} +#endif /* CONFIG_DEBUG_RODATA */ + #else /* !CONFIG_HIBERNATION */ static inline void hibernate_reserved_size_init(void) {} diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index d64d5d0efa79..d90df926b59f 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -38,6 +38,43 @@ #include "power.h" +#ifdef CONFIG_DEBUG_RODATA +static bool hibernate_restore_protection; +static bool hibernate_restore_protection_active; + +void enable_restore_image_protection(void) +{ + hibernate_restore_protection = true; +} + +static inline void hibernate_restore_protection_begin(void) +{ + hibernate_restore_protection_active = hibernate_restore_protection; +} + +static inline void hibernate_restore_protection_end(void) +{ + hibernate_restore_protection_active = false; +} + +static inline void hibernate_restore_protect_page(void *page_address) +{ + if (hibernate_restore_protection_active) + set_memory_ro((unsigned long)page_address, 1); +} + +static inline void hibernate_restore_unprotect_page(void *page_address) +{ + if (hibernate_restore_protection_active) + set_memory_rw((unsigned long)page_address, 1); +} +#else +static inline void hibernate_restore_protection_begin(void) {} +static inline void hibernate_restore_protection_end(void) {} +static inline void hibernate_restore_protect_page(void *page_address) {} +static inline void hibernate_restore_unprotect_page(void *page_address) {} +#endif /* CONFIG_DEBUG_RODATA */ + static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); @@ -1414,6 +1451,7 @@ loop: memory_bm_clear_current(forbidden_pages_map); memory_bm_clear_current(free_pages_map); + hibernate_restore_unprotect_page(page_address(page)); __free_page(page); goto loop; } @@ -1425,6 +1463,7 @@ out: buffer = NULL; alloc_normal = 0; alloc_highmem = 0; + hibernate_restore_protection_end(); } /* Helper functions used for the shrinking of memory. */ @@ -2548,6 +2587,7 @@ int snapshot_write_next(struct snapshot_handle *handle) if (error) return error; + hibernate_restore_protection_begin(); } else if (handle->cur <= nr_meta_pages + 1) { error = unpack_orig_pfns(buffer, ©_bm); if (error) @@ -2570,6 +2610,7 @@ int snapshot_write_next(struct snapshot_handle *handle) copy_last_highmem_page(); /* Restore page key for data page (s390 only). */ page_key_write(handle->buffer); + hibernate_restore_protect_page(handle->buffer); handle->buffer = get_buffer(&orig_bm, &ca); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); @@ -2594,6 +2635,7 @@ void snapshot_write_finalize(struct snapshot_handle *handle) /* Restore page key for data page (s390 only). */ page_key_write(handle->buffer); page_key_free(); + hibernate_restore_protect_page(handle->buffer); /* Do that only if we have loaded the image entirely */ if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) { memory_bm_recycle(&orig_bm); |