diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2016-06-07 12:20:51 +0200 |
|---|---|---|
| committer | Sami Tolvanen <samitolvanen@google.com> | 2016-09-23 10:04:42 -0700 |
| commit | 609abcd0c940b2fa0b7a548c58665bfb5c02d22b (patch) | |
| tree | 9ec155cba2b86a61b08798250509533c3a9a3883 | |
| parent | 3cfedbe672ad7fbd73cb5a073ee6a6f60f8130fa (diff) | |
UPSTREAM: vmlinux.lds.h: allow arch specific handling of ro_after_init data section
commit c74ba8b3480d ("arch: Introduce post-init read-only memory")
introduced the __ro_after_init attribute which allows to add variables
to the ro_after_init data section.
This new section was added to rodata, even though it contains writable
data. This in turn causes problems on architectures which mark the
page table entries read-only that point to rodata very early.
This patch allows architectures to implement an own handling of the
.data..ro_after_init section.
Usually that would be:
- mark the rodata section read-only very early
- mark the ro_after_init section read-only within mark_rodata_ro
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Bug: 31660652
Change-Id: If68cb4d86f88678c9bac8c47072775ab85ef5770
(cherry picked from commit 32fb2fc5c357fb99616bbe100dbcb27bc7f5d045)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 772c784ba763..33eb2fe23071 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -249,6 +249,14 @@ *(.data..init_task) /* + * Allow architectures to handle ro_after_init data on their + * own by defining an empty RO_AFTER_INIT_DATA. + */ +#ifndef RO_AFTER_INIT_DATA +#define RO_AFTER_INIT_DATA *(.data..ro_after_init) +#endif + +/* * Read only Data */ #define RO_DATA_SECTION(align) \ @@ -256,7 +264,7 @@ .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start_rodata) = .; \ *(.rodata) *(.rodata.*) \ - *(.data..ro_after_init) /* Read only after init */ \ + RO_AFTER_INIT_DATA /* Read only after init */ \ *(__vermagic) /* Kernel version magic */ \ . = ALIGN(8); \ VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .; \ |