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-rw-r--r--Documentation/kernel-parameters.txt3
-rw-r--r--kernel/power/hibernate.c3
-rw-r--r--kernel/power/power.h7
-rw-r--r--kernel/power/snapshot.c42
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, &copy_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);