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-rw-r--r--arch/x86/include/asm/kexec.h12
-rw-r--r--arch/x86/kernel/machine_kexec_64.c22
-rw-r--r--arch/x86/kernel/relocate_kernel_64.S25
3 files changed, 38 insertions, 21 deletions
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index f2ad77929d6e..12cebbcdb6c8 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -13,6 +13,15 @@
# define KEXEC_DEBUG_EXC_HANDLER_SIZE 6 /* PUSHI, PUSHI, 2-byte JMP */
#endif
+#ifdef CONFIG_X86_64
+
+#include <linux/bits.h>
+
+#define RELOC_KERNEL_PRESERVE_CONTEXT BIT(0)
+#define RELOC_KERNEL_HOST_MEM_ENC_ACTIVE BIT(1)
+
+#endif
+
# define KEXEC_CONTROL_PAGE_SIZE 4096
# define KEXEC_CONTROL_CODE_MAX_SIZE 2048
@@ -121,8 +130,7 @@ typedef unsigned long
relocate_kernel_fn(unsigned long indirection_page,
unsigned long pa_control_page,
unsigned long start_address,
- unsigned int preserve_context,
- unsigned int host_mem_enc_active);
+ unsigned int flags);
#endif
extern relocate_kernel_fn relocate_kernel;
#define ARCH_HAS_KIMAGE_ARCH
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 697fb99406e6..5cda8d8d8b13 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -384,16 +384,10 @@ void __nocfi machine_kexec(struct kimage *image)
{
unsigned long reloc_start = (unsigned long)__relocate_kernel_start;
relocate_kernel_fn *relocate_kernel_ptr;
- unsigned int host_mem_enc_active;
+ unsigned int relocate_kernel_flags;
int save_ftrace_enabled;
void *control_page;
- /*
- * This must be done before load_segments() since if call depth tracking
- * is used then GS must be valid to make any function calls.
- */
- host_mem_enc_active = cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT);
-
#ifdef CONFIG_KEXEC_JUMP
if (image->preserve_context)
save_processor_state();
@@ -427,6 +421,17 @@ void __nocfi machine_kexec(struct kimage *image)
*/
relocate_kernel_ptr = control_page + (unsigned long)relocate_kernel - reloc_start;
+ relocate_kernel_flags = 0;
+ if (image->preserve_context)
+ relocate_kernel_flags |= RELOC_KERNEL_PRESERVE_CONTEXT;
+
+ /*
+ * This must be done before load_segments() since if call depth tracking
+ * is used then GS must be valid to make any function calls.
+ */
+ if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+ relocate_kernel_flags |= RELOC_KERNEL_HOST_MEM_ENC_ACTIVE;
+
/*
* The segment registers are funny things, they have both a
* visible and an invisible part. Whenever the visible part is
@@ -443,8 +448,7 @@ void __nocfi machine_kexec(struct kimage *image)
image->start = relocate_kernel_ptr((unsigned long)image->head,
virt_to_phys(control_page),
image->start,
- image->preserve_context,
- host_mem_enc_active);
+ relocate_kernel_flags);
#ifdef CONFIG_KEXEC_JUMP
if (image->preserve_context)
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index ea604f4d0b52..26e945f85d19 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -66,8 +66,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
* %rdi indirection_page
* %rsi pa_control_page
* %rdx start address
- * %rcx preserve_context
- * %r8 host_mem_enc_active
+ * %rcx flags: RELOC_KERNEL_*
*/
/* Save the CPU context, used for jumping back */
@@ -111,7 +110,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
/* save indirection list for jumping back */
movq %rdi, pa_backup_pages_map(%rip)
- /* Save the preserve_context to %r11 as swap_pages clobbers %rcx. */
+ /* Save the flags to %r11 as swap_pages clobbers %rcx. */
movq %rcx, %r11
/* setup a new stack at the end of the physical control page */
@@ -129,9 +128,8 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
/*
* %rdi indirection page
* %rdx start address
- * %r8 host_mem_enc_active
* %r9 page table page
- * %r11 preserve_context
+ * %r11 flags: RELOC_KERNEL_*
* %r13 original CR4 when relocate_kernel() was invoked
*/
@@ -204,7 +202,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
* entries that will conflict with the now unencrypted memory
* used by kexec. Flush the caches before copying the kernel.
*/
- testq %r8, %r8
+ testb $RELOC_KERNEL_HOST_MEM_ENC_ACTIVE, %r11b
jz .Lsme_off
wbinvd
.Lsme_off:
@@ -220,7 +218,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
movq %cr3, %rax
movq %rax, %cr3
- testq %r11, %r11 /* preserve_context */
+ testb $RELOC_KERNEL_PRESERVE_CONTEXT, %r11b
jnz .Lrelocate
/*
@@ -273,7 +271,13 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
ANNOTATE_NOENDBR
andq $PAGE_MASK, %r8
lea PAGE_SIZE(%r8), %rsp
- movl $1, %r11d /* Ensure preserve_context flag is set */
+ /*
+ * Ensure RELOC_KERNEL_PRESERVE_CONTEXT flag is set so that
+ * swap_pages() can swap pages correctly. Note all other
+ * RELOC_KERNEL_* flags passed to relocate_kernel() are not
+ * restored.
+ */
+ movl $RELOC_KERNEL_PRESERVE_CONTEXT, %r11d
call swap_pages
movq kexec_va_control_page(%rip), %rax
0: addq $virtual_mapped - 0b, %rax
@@ -321,7 +325,7 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
UNWIND_HINT_END_OF_STACK
/*
* %rdi indirection page
- * %r11 preserve_context
+ * %r11 flags: RELOC_KERNEL_*
*/
movq %rdi, %rcx /* Put the indirection_page in %rcx */
xorl %edi, %edi
@@ -357,7 +361,8 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
movq %rdi, %rdx /* Save destination page to %rdx */
movq %rsi, %rax /* Save source page to %rax */
- testq %r11, %r11 /* Only actually swap for ::preserve_context */
+ /* Only actually swap for ::preserve_context */
+ testb $RELOC_KERNEL_PRESERVE_CONTEXT, %r11b
jz .Lnoswap
/* copy source page to swap page */