From: David Brazdil <dbrazdil@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kernel-team@android.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
Marc Zyngier <maz@kernel.org>,
David Brazdil <dbrazdil@google.com>,
Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH 4/9] KVM: arm64: Add symbol at the beginning of each hyp section
Date: Wed, 9 Dec 2020 13:17:41 +0000 [thread overview]
Message-ID: <20201209131746.85622-5-dbrazdil@google.com> (raw)
In-Reply-To: <20201209131746.85622-1-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..65e8008da932 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
}
--
2.29.2.576.ga3fc446d84-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-12-09 13:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-09 13:17 [PATCH 0/9] KVM: arm64: Relocate absolute hyp VAs David Brazdil
2020-12-09 13:17 ` [PATCH 1/9] KVM: arm64: Correctly align nVHE percpu data David Brazdil
2020-12-09 13:17 ` [PATCH 2/9] KVM: arm64: Rename .idmap.text in hyp linker script David Brazdil
2020-12-09 13:17 ` [PATCH 3/9] KVM: arm64: Set up .hyp.rodata ELF section David Brazdil
2020-12-09 13:17 ` David Brazdil [this message]
2020-12-09 13:17 ` [PATCH 5/9] KVM: arm64: Generate hyp relocation data David Brazdil
2020-12-09 13:17 ` [PATCH 6/9] KVM: arm64: Apply hyp relocations at runtime David Brazdil
2020-12-09 13:17 ` [PATCH 7/9] KVM: arm64: Fix constant-pool users in hyp David Brazdil
2020-12-09 13:17 ` [PATCH 8/9] KVM: arm64: Remove patching of fn pointers " David Brazdil
2020-12-09 13:17 ` [PATCH 9/9] KVM: arm64: Remove hyp_symbol_addr David Brazdil
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201209131746.85622-5-dbrazdil@google.com \
--to=dbrazdil@google.com \
--cc=ardb@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=julien.thierry.kdev@gmail.com \
--cc=kernel-team@android.com \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).