summaryrefslogtreecommitdiff
path: root/arch/arm64/mm
diff options
context:
space:
mode:
authorJeremy Linton <jeremy.linton@arm.com>2016-02-19 20:50:32 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2016-02-26 18:08:04 +0300
commit2f39b5f91eb4bccd786d194e70db1dccad784755 (patch)
tree726713a839445a87a77fa05fb369cd0107e60346 /arch/arm64/mm
parentb7dc8d16e76c25409d93ff3aceda42fc386efc4e (diff)
downloadlinux-2f39b5f91eb4bccd786d194e70db1dccad784755.tar.xz
arm64: mm: Mark .rodata as RO
Currently the .rodata section is actually still executable when DEBUG_RODATA is enabled. This changes that so the .rodata is actually read only, no execute. It also adds the .rodata section to the mem_init banner. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> [catalin.marinas@arm.com: added vm_struct vmlinux_rodata in map_kernel()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm')
-rw-r--r--arch/arm64/mm/init.c4
-rw-r--r--arch/arm64/mm/mmu.c19
2 files changed, 16 insertions, 7 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 80c8bdeeb41a..b938de23dc77 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -363,6 +363,7 @@ void __init mem_init(void)
" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
" .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
" .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n"
" .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
@@ -377,7 +378,8 @@ void __init mem_init(void)
MLM(MODULES_VADDR, MODULES_END),
MLG(VMALLOC_START, VMALLOC_END),
MLK_ROUNDUP(__init_begin, __init_end),
- MLK_ROUNDUP(_text, _etext),
+ MLK_ROUNDUP(_text, __start_rodata),
+ MLK_ROUNDUP(__start_rodata, _etext),
MLK_ROUNDUP(_sdata, _edata),
#ifdef CONFIG_SPARSEMEM_VMEMMAP
MLG((unsigned long)vmemmap,
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 00d166465ff4..d2d8b8c2e17f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -449,12 +449,18 @@ static void __init map_mem(pgd_t *pgd)
void mark_rodata_ro(void)
{
- if (!IS_ENABLED(CONFIG_DEBUG_RODATA))
- return;
+ unsigned long section_size;
+ section_size = (unsigned long)__start_rodata - (unsigned long)_stext;
create_mapping_late(__pa(_stext), (unsigned long)_stext,
- (unsigned long)_etext - (unsigned long)_stext,
- PAGE_KERNEL_ROX);
+ section_size, PAGE_KERNEL_ROX);
+ /*
+ * mark .rodata as read only. Use _etext rather than __end_rodata to
+ * cover NOTES and EXCEPTION_TABLE.
+ */
+ section_size = (unsigned long)_etext - (unsigned long)__start_rodata;
+ create_mapping_late(__pa(__start_rodata), (unsigned long)__start_rodata,
+ section_size, PAGE_KERNEL_RO);
}
void fixup_init(void)
@@ -493,9 +499,10 @@ static void __init map_kernel_chunk(pgd_t *pgd, void *va_start, void *va_end,
*/
static void __init map_kernel(pgd_t *pgd)
{
- static struct vm_struct vmlinux_text, vmlinux_init, vmlinux_data;
+ static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_init, vmlinux_data;
- map_kernel_chunk(pgd, _stext, _etext, PAGE_KERNEL_EXEC, &vmlinux_text);
+ map_kernel_chunk(pgd, _stext, __start_rodata, PAGE_KERNEL_EXEC, &vmlinux_text);
+ map_kernel_chunk(pgd, __start_rodata, _etext, PAGE_KERNEL, &vmlinux_rodata);
map_kernel_chunk(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC,
&vmlinux_init);
map_kernel_chunk(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data);