Commit 32fb2fc5 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

vmlinux.lds.h: allow arch specific handling of ro_after_init data section

commit c74ba8b3

 ("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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 64f31d58
...@@ -249,6 +249,14 @@ ...@@ -249,6 +249,14 @@
*(.data..init_task) \ *(.data..init_task) \
VMLINUX_SYMBOL(__end_init_task) = .; 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 * Read only Data
*/ */
...@@ -257,7 +265,7 @@ ...@@ -257,7 +265,7 @@
.rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \ .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_rodata) = .; \ VMLINUX_SYMBOL(__start_rodata) = .; \
*(.rodata) *(.rodata.*) \ *(.rodata) *(.rodata.*) \
*(.data..ro_after_init) /* Read only after init */ \ RO_AFTER_INIT_DATA /* Read only after init */ \
*(__vermagic) /* Kernel version magic */ \ *(__vermagic) /* Kernel version magic */ \
. = ALIGN(8); \ . = ALIGN(8); \
VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .; \ VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .; \
......
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