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| author |   Heiko Carstens <heiko.carstens@de.ibm.com> | 2016-06-07 12:20:51 +0200 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-06-13 15:58:22 +0200 |
| commit | 32fb2fc5c357fb99616bbe100dbcb27bc7f5d045 (patch) | |
| tree | 81e8a21e7687debcaf46d1af635f64c863262aeb /include/asm-generic | |
| parent | s390/mm: simplify the TLB flushing code (diff) | |
| download | linux-dev-32fb2fc5c357fb99616bbe100dbcb27bc7f5d045.tar.xz linux-dev-32fb2fc5c357fb99616bbe100dbcb27bc7f5d045.zip | |
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>
Diffstat (limited to 'include/asm-generic')
| -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 6a67ab94b553..c4436d072d37 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -250,6 +250,14 @@ VMLINUX_SYMBOL(__end_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) \ @@ -257,7 +265,7 @@ .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) = .; \ |