From: David Brazdil <dbrazdil@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, David Brazdil <dbrazdil@google.com>
Subject: [PATCH v2 3/8] KVM: arm64: Add symbol at the beginning of each hyp section
Date: Tue, 5 Jan 2021 18:05:36 +0000 [thread overview]
Message-ID: <20210105180541.65031-4-dbrazdil@google.com> (raw)
In-Reply-To: <20210105180541.65031-1-dbrazdil@google.com>
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
+
/*
* 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
}
--
2.29.2.729.g45daf8777d-goog
next prev parent reply other threads:[~2021-01-05 18:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 18:05 [PATCH v2 0/8] arm64: Relocate absolute hyp VAs David Brazdil
2021-01-05 18:05 ` [PATCH v2 1/8] KVM: arm64: Rename .idmap.text in hyp linker script David Brazdil
2021-01-05 18:05 ` [PATCH v2 2/8] KVM: arm64: Set up .hyp.rodata ELF section David Brazdil
2021-01-05 18:05 ` David Brazdil [this message]
2021-01-23 13:30 ` [PATCH v2 3/8] KVM: arm64: Add symbol at the beginning of each hyp section Marc Zyngier
2021-01-05 18:05 ` [PATCH v2 4/8] KVM: arm64: Generate hyp relocation data David Brazdil
2021-01-29 21:43 ` Guenter Roeck
2021-01-30 12:16 ` Marc Zyngier
2021-01-30 13:44 ` Marc Zyngier
2021-01-30 16:11 ` Guenter Roeck
2021-01-30 18:10 ` Marc Zyngier
2021-02-01 10:42 ` David Brazdil
2021-02-01 12:06 ` Marc Zyngier
2021-01-05 18:05 ` [PATCH v2 5/8] KVM: arm64: Apply hyp relocations at runtime David Brazdil
2021-01-05 18:05 ` [PATCH v2 6/8] KVM: arm64: Fix constant-pool users in hyp David Brazdil
2021-01-05 18:05 ` [PATCH v2 7/8] KVM: arm64: Remove patching of fn pointers " David Brazdil
2021-01-05 18:05 ` [PATCH v2 8/8] KVM: arm64: Remove hyp_symbol_addr David Brazdil
2021-01-23 13:54 ` Marc Zyngier
2021-01-23 14:45 ` [PATCH v2 0/8] arm64: Relocate absolute hyp VAs Marc Zyngier
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