[RFC PATCH v2 12/16] x86/kexec: Mark relocate_kernel page as ROX instead of RWX
From: David Woodhouse
Date: Fri Nov 22 2024 - 17:48:50 EST
From: David Woodhouse <dwmw@xxxxxxxxxxxx>
All writes to the page now happen before it gets marked as executable
(or after it's already switched to the identmap page tables where it's
OK to be RWX).
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
arch/x86/kernel/machine_kexec_64.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index c653c2c22d63..2a294daeeb1a 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -319,7 +319,7 @@ int machine_kexec_prepare(struct kimage *image)
__memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start);
- set_memory_x((unsigned long)control_page, 1);
+ set_memory_rox((unsigned long)control_page, 1);
return 0;
}
@@ -329,6 +329,7 @@ void machine_kexec_cleanup(struct kimage *image)
void *control_page = page_address(image->control_code_page) + PAGE_SIZE;
set_memory_nx((unsigned long)control_page, 1);
+ set_memory_rw((unsigned long)control_page, 1);
free_transition_pgtable(image);
}
--
2.47.0