leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: arm64: Add symbol at the beginning of each hyp section

Browse Source 
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
This commit is contained in:
David Brazdil 2021-01-05 18:05:36 +00:00 committed by Marc Zyngier
parent 16174eea2e
commit f7a4825d95
2 changed files with 29 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
arch/arm64/include/asm/hyp_image.h
View File

@ -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

4
arch/arm64/kvm/hyp/nvhe/hyp.lds.S
View File

@ -22,7 +22,7 @@ SECTIONS {
* alignment for when linking into vmlinux.
*/
. = ALIGN(PAGE_SIZE);
HYP_SECTION_NAME(.data..percpu) : {
BEGIN_HYP_SECTION(.data..percpu)
PERCPU_INPUT(L1_CACHE_BYTES)
}
END_HYP_SECTION
}