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authorDavid Brazdil <dbrazdil@google.com>2021-01-05 21:05:36 +0300
committerMarc Zyngier <maz@kernel.org>2021-01-23 17:00:57 +0300
commitf7a4825d9569593b9a81f0768313b86175691ef1 (patch)
tree647829cea26b049d455582c771e07a4ada12fb05 /arch/arm64/include/asm/hyp_image.h
parent16174eea2e4fe8247e04c17da682f2034fec0369 (diff)
downloadlinux-f7a4825d9569593b9a81f0768313b86175691ef1.tar.xz
KVM: arm64: Add symbol at the beginning of each hyp section
Generating hyp relocations will require referencing positions at a given offset from the beginning of hyp sections. Since the final layout will not be determined until the linking of `vmlinux`, modify the hyp linker script to insert a symbol at the first byte of each hyp section to use as an anchor. The linker of `vmlinux` will place the symbols together with the sections. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210105180541.65031-4-dbrazdil@google.com
Diffstat (limited to 'arch/arm64/include/asm/hyp_image.h')
-rw-r--r--arch/arm64/include/asm/hyp_image.h29
1 files changed, 27 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/hyp_image.h b/arch/arm64/include/asm/hyp_image.h
index daa1a1da539e..737ded6b6d0d 100644
--- a/arch/arm64/include/asm/hyp_image.h
+++ b/arch/arm64/include/asm/hyp_image.h
@@ -7,6 +7,9 @@
#ifndef __ARM64_HYP_IMAGE_H__
#define __ARM64_HYP_IMAGE_H__
+#define __HYP_CONCAT(a, b) a ## b
+#define HYP_CONCAT(a, b) __HYP_CONCAT(a, b)
+
/*
* KVM nVHE code has its own symbol namespace prefixed with __kvm_nvhe_,
* to separate it from the kernel proper.
@@ -21,9 +24,31 @@
*/
#define HYP_SECTION_NAME(NAME) .hyp##NAME
+/* Symbol defined at the beginning of each hyp section. */
+#define HYP_SECTION_SYMBOL_NAME(NAME) \
+ HYP_CONCAT(__hyp_section_, HYP_SECTION_NAME(NAME))
+
+/*
+ * Helper to generate linker script statements starting a hyp section.
+ *
+ * A symbol with a well-known name is defined at the first byte. This
+ * is used as a base for hyp relocations (see gen-hyprel.c). It must
+ * be defined inside the section so the linker of `vmlinux` cannot
+ * separate it from the section data.
+ */
+#define BEGIN_HYP_SECTION(NAME) \
+ HYP_SECTION_NAME(NAME) : { \
+ HYP_SECTION_SYMBOL_NAME(NAME) = .;
+
+/* Helper to generate linker script statements ending a hyp section. */
+#define END_HYP_SECTION \
+ }
+
/* Defines an ELF hyp section from input section @NAME and its subsections. */
-#define HYP_SECTION(NAME) \
- HYP_SECTION_NAME(NAME) : { *(NAME NAME##.*) }
+#define HYP_SECTION(NAME) \
+ BEGIN_HYP_SECTION(NAME) \
+ *(NAME NAME##.*) \
+ END_HYP_SECTION
/*
* Defines a linker script alias of a kernel-proper symbol referenced by