[PATCH v10 14/18] arm64: kexec: use ld script for relocation function

@@ -90,6 +90,10 @@ static inline void crash_prepare_suspend(void) {}
 static inline void crash_post_resume(void) {}
 #endif
 
+#if defined(CONFIG_KEXEC_CORE)
+extern const char arm64_relocate_new_kernel[];
+#endif
+
 /*
  * kern_reloc_arg is passed to kernel relocation function as an argument.
  * head		kimage->head, allows to traverse through relocation segments.

@@ -19,5 +19,6 @@ extern char __exittext_begin[], __exittext_end[];
 extern char __irqentry_text_start[], __irqentry_text_end[];
 extern char __mmuoff_data_start[], __mmuoff_data_end[];
 extern char __entry_tramp_text_start[], __entry_tramp_text_end[];
+extern char __relocate_new_kernel_start[], __relocate_new_kernel_end[];
 
 #endif /* __ASM_SECTIONS_H */

@@ -20,13 +20,10 @@
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
 #include <asm/page.h>
+#include <asm/sections.h>
 
 #include "cpu-reset.h"
 
-/* Global variables for the arm64_relocate_new_kernel routine. */
-extern const unsigned char arm64_relocate_new_kernel[];
-extern const unsigned long arm64_relocate_new_kernel_size;
-
 /**
  * kexec_image_info - For debugging output.
  */

@@ -78,13 +75,15 @@ int machine_kexec_post_load(struct kimage *kimage)
 {
 	void *reloc_code = page_to_virt(kimage->control_code_page);
 	struct kern_reloc_arg *kern_reloc_arg = kexec_page_alloc(kimage);
+	long func_offset, reloc_size;
 
 	if (!kern_reloc_arg)
 		return -ENOMEM;
 
-	memcpy(reloc_code, arm64_relocate_new_kernel,
-	       arm64_relocate_new_kernel_size);
-	kimage->arch.kern_reloc = __pa(reloc_code);
+	func_offset = arm64_relocate_new_kernel - __relocate_new_kernel_start;
+	reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start;
+	memcpy(reloc_code, __relocate_new_kernel_start, reloc_size);
+	kimage->arch.kern_reloc = __pa(reloc_code) + func_offset;
 	kimage->arch.kern_reloc_arg = __pa(kern_reloc_arg);
 	kern_reloc_arg->head = kimage->head;
 	kern_reloc_arg->entry_addr = kimage->start;

@@ -92,9 +91,9 @@ int machine_kexec_post_load(struct kimage *kimage)
 	kexec_image_info(kimage);
 
 	/* Flush the reloc_code in preparation for its execution. */
-	__flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size);
+	__flush_dcache_area(reloc_code, reloc_size);
 	flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code +
-			   arm64_relocate_new_kernel_size);
+			   reloc_size);
 	__flush_dcache_area(kern_reloc_arg, sizeof(struct kern_reloc_arg));
 
 	return 0;

@@ -14,6 +14,7 @@
 #include <asm/page.h>
 #include <asm/sysreg.h>
 
+.pushsection    ".kexec_relocate.text", "ax"
 /*
  * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
  *

@@ -75,16 +76,4 @@ SYM_CODE_START(arm64_relocate_new_kernel)
 	ldr	x0, [x0, #KEXEC_KRELOC_KERN_ARG0]	/* x0 = dtb address */
 	br	x4
 SYM_CODE_END(arm64_relocate_new_kernel)
-
-.align 3	/* To keep the 64-bit values below naturally aligned. */
-
-.Lcopy_end:
-.org	KEXEC_CONTROL_PAGE_SIZE
-
-/*
- * arm64_relocate_new_kernel_size - Number of bytes to copy to the
- * control_code_page.
- */
-.globl arm64_relocate_new_kernel_size
-arm64_relocate_new_kernel_size:
-	.quad	.Lcopy_end - arm64_relocate_new_kernel
+.popsection

@@ -12,6 +12,7 @@
 #include <asm/cache.h>
 #include <asm/hyp_image.h>
 #include <asm/kernel-pgtable.h>
+#include <asm/kexec.h>
 #include <asm/memory.h>
 #include <asm/page.h>
 

@@ -82,6 +83,16 @@ jiffies = jiffies_64;
 #define HIBERNATE_TEXT
 #endif
 
+#ifdef CONFIG_KEXEC_CORE
+#define KEXEC_TEXT					\
+	. = ALIGN(SZ_4K);				\
+	__relocate_new_kernel_start = .;		\
+	*(.kexec_relocate.text)				\
+	__relocate_new_kernel_end = .;
+#else
+#define KEXEC_TEXT
+#endif
+
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 #define TRAMP_TEXT					\
 	. = ALIGN(PAGE_SIZE);				\

@@ -142,6 +153,7 @@ SECTIONS
 			HYPERVISOR_TEXT
 			IDMAP_TEXT
 			HIBERNATE_TEXT
+			KEXEC_TEXT
 			TRAMP_TEXT
 			*(.fixup)
 			*(.gnu.warning)

@@ -316,3 +328,10 @@ ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE,
  * If padding is applied before .head.text, virt<->phys conversions will fail.
  */
 ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned")
+
+#ifdef CONFIG_KEXEC_CORE
+/* kexec relocation code should fit into one KEXEC_CONTROL_PAGE_SIZE */
+ASSERT(__relocate_new_kernel_end - (__relocate_new_kernel_start & ~(SZ_4K - 1))
+	<= SZ_4K, "kexec relocation code is too big or misaligned")
+ASSERT(KEXEC_CONTROL_PAGE_SIZE >= SZ_4K, "KEXEC_CONTROL_PAGE_SIZE is brokern")
+#endif