From: yuanzhichang <yuanzhich...@hisilicon.com>
In the patch whose title is "add better page protections to arm64"
(commit da141706aea52c1a9fbd28cb8d289b78819f5436), The direct mapping
page table entries for HEAD_TEXT segment were configured as PAGE_KERNEL,
without the executable attribute. But when the secondary CPUs are booting
based on spin-table mechanism, some functions in head.S are needed to run.
Only PAGE_KERNEL dosen't work for this case.
This patch will configure the page attributes as PAGE_KERNEL_EXEC for
HEAD_TEXT segment.
Signed-off-by: Zhichang Yuan <yuanzhich...@hisilicon.com>
---
arch/arm64/mm/mmu.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index c6daaf6..ad08dfd 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -305,8 +305,8 @@ static void __init __map_memblock(phys_addr_t start,
phys_addr_t end)
* for now. This will get more fine grained later once all memory
* is mapped
*/
- unsigned long kernel_x_start = round_down(__pa(_stext), SECTION_SIZE);
- unsigned long kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
+ phys_addr_t kernel_x_start = round_down(__pa(_text), SECTION_SIZE);
+ phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
if (end < kernel_x_start) {
create_mapping(start, __phys_to_virt(start),
@@ -315,6 +315,18 @@ static void __init __map_memblock(phys_addr_t start,
phys_addr_t end)
create_mapping(start, __phys_to_virt(start),
end - start, PAGE_KERNEL);
} else {
+ /*
+ * At this moment, the text segment must reside in valid physical
+ * memory section range to make sure the text are totally mapped.
+ * If mapping from non-section aligned address is support, then
+ * _text can be used here directly in replace to kernel_x_start.
+ */
+ phys_addr_t max_left, min_right;
+
+ max_left = max(kernel_x_start, start);
+ min_right = min(kernel_x_end, end);
+ BUG_ON(max_left != kernel_x_start || min_right != kernel_x_end);
+
if (start < kernel_x_start)
create_mapping(start, __phys_to_virt(start),
kernel_x_start - start,
@@ -394,12 +406,12 @@ void __init fixup_executable(void)
{
#ifdef CONFIG_DEBUG_RODATA
/* now that we are actually fully mapped, make the start/end more fine
grained */
- if (!IS_ALIGNED((unsigned long)_stext, SECTION_SIZE)) {
- unsigned long aligned_start = round_down(__pa(_stext),
+ if (!IS_ALIGNED((unsigned long)_text, SECTION_SIZE)) {
+ unsigned long aligned_start = round_down(__pa(_text),
SECTION_SIZE);
create_mapping(aligned_start, __phys_to_virt(aligned_start),
- __pa(_stext) - aligned_start,
+ __pa(_text) - aligned_start,
PAGE_KERNEL);
}
@@ -418,7 +430,7 @@ void mark_rodata_ro(void)
{
create_mapping_late(__pa(_stext), (unsigned long)_stext,
(unsigned long)_etext - (unsigned long)_stext,
- PAGE_KERNEL_EXEC | PTE_RDONLY);
+ (PAGE_KERNEL_EXEC | PTE_RDONLY) & ~PTE_WRITE);
}
#endif
--
1.9.1
--
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