From: David Woodhouse <dwmw@xxxxxxxxxxxx>
There's no need for this to wait until the actual machine_kexec() invocation;
a subsequent change will mark the control page ROX so all writes should be
completed earlier.
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
arch/x86/kernel/machine_kexec_64.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 123e9544506b..60632a5a2a13 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -297,6 +297,8 @@ static void load_segments(void)
int machine_kexec_prepare(struct kimage *image)
{
void *control_page = page_address(image->control_code_page) + PAGE_SIZE;
+ unsigned long reloc_start = (unsigned long)__relocate_kernel_start;
+ unsigned long reloc_end = (unsigned long)__relocate_kernel_end;
unsigned long start_pgtable;
int result;
@@ -308,6 +310,8 @@ int machine_kexec_prepare(struct kimage *image)
if (result)
return result;
+ __memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start);
+
set_memory_x((unsigned long)control_page, 1);
return 0;
@@ -334,7 +338,6 @@ void machine_kexec(struct kimage *image)
unsigned int preserve_context,
unsigned int host_mem_enc_active);
unsigned long reloc_start = (unsigned long)__relocate_kernel_start;
- unsigned long reloc_end = (unsigned long)__relocate_kernel_end;
unsigned long page_list[PAGES_NR];
unsigned int host_mem_enc_active;
int save_ftrace_enabled;
@@ -372,7 +375,6 @@ void machine_kexec(struct kimage *image)
}
control_page = page_address(image->control_code_page) + PAGE_SIZE;
- __memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start);
page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
--
2.47.0
