| Message ID | 20210105180541.65031-4-dbrazdil@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Relocate absolute hyp VAs | expand |
On Tue, 05 Jan 2021 18:05:36 +0000, David Brazdil <dbrazdil@google.com> wrote: > > 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> > --- > arch/arm64/include/asm/hyp_image.h | 29 +++++++++++++++++++++++++++-- > arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 4 ++-- > 2 files changed, 29 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/hyp_image.h b/arch/arm64/include/asm/hyp_image.h > index daa1a1da539e..f97b774b58f4 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) __HYP_CONCAT(a, b) > +#define __HYP_CONCAT(a, b) a ## b > + OK, this may seem like a completely pointless comment, but I have a total mental block when I see macros written upside down I'll fix that myself, no need to resend just for that. Thanks, M.
diff --git a/arch/arm64/include/asm/hyp_image.h b/arch/arm64/include/asm/hyp_image.h index daa1a1da539e..f97b774b58f4 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) __HYP_CONCAT(a, b) +#define __HYP_CONCAT(a, b) 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 diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S index cfdc59b4329b..cd119d82d8e3 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S @@ -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 }
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> --- arch/arm64/include/asm/hyp_image.h | 29 +++++++++++++++++++++++++++-- arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 4 ++-- 2 files changed, 29 insertions(+), 4 deletions(-)