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authorWill Deacon <will@kernel.org>2020-05-28 18:00:51 +0100
committerWill Deacon <will@kernel.org>2020-05-28 18:00:51 +0100
commitd27865279f12035c730818aa1a0280fada866a37 (patch)
tree5c4462885c2a6d7453b34ceb51d39b390030a2a6 /Documentation/arm64
parent342403bcb4dfe41324a0f6f4cb5a8d324f31c725 (diff)
parenta4eb355a3fdad85d16e4b098e8d56bb28b812ce0 (diff)
downloadlinux-d27865279f12035c730818aa1a0280fada866a37.tar.gz
Merge branch 'for-next/bti' into for-next/core
Support for Branch Target Identification (BTI) in user and kernel
(Mark Brown and others)
* for-next/bti: (39 commits)
  arm64: vdso: Fix CFI directives in sigreturn trampoline
  arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
  arm64: bti: Fix support for userspace only BTI
  arm64: kconfig: Update and comment GCC version check for kernel BTI
  arm64: vdso: Map the vDSO text with guarded pages when built for BTI
  arm64: vdso: Force the vDSO to be linked as BTI when built for BTI
  arm64: vdso: Annotate for BTI
  arm64: asm: Provide a mechanism for generating ELF note for BTI
  arm64: bti: Provide Kconfig for kernel mode BTI
  arm64: mm: Mark executable text as guarded pages
  arm64: bpf: Annotate JITed code for BTI
  arm64: Set GP bit in kernel page tables to enable BTI for the kernel
  arm64: asm: Override SYM_FUNC_START when building the kernel with BTI
  arm64: bti: Support building kernel C code using BTI
  arm64: Document why we enable PAC support for leaf functions
  arm64: insn: Report PAC and BTI instructions as skippable
  arm64: insn: Don't assume unrecognized HINTs are skippable
  arm64: insn: Provide a better name for aarch64_insn_is_nop()
  arm64: insn: Add constants for new HINT instruction decode
  arm64: Disable old style assembly annotations
  ...
Diffstat (limited to 'Documentation/arm64')
-rw-r--r--Documentation/arm64/cpu-feature-registers.rst2
-rw-r--r--Documentation/arm64/elf_hwcaps.rst5
2 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst
index 41937a8091aa..314fa5bc2655 100644
--- a/Documentation/arm64/cpu-feature-registers.rst
+++ b/Documentation/arm64/cpu-feature-registers.rst
@@ -176,6 +176,8 @@ infrastructure:
      +------------------------------+---------+---------+
      | SSBS                         | [7-4]   |    y    |
      +------------------------------+---------+---------+
+     | BT                           | [3-0]   |    y    |
+     +------------------------------+---------+---------+
 
 
   4) MIDR_EL1 - Main ID Register
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index 7dfb97dfe416..84a9fd2d41b4 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -236,6 +236,11 @@ HWCAP2_RNG
 
     Functionality implied by ID_AA64ISAR0_EL1.RNDR == 0b0001.
 
+HWCAP2_BTI
+
+    Functionality implied by ID_AA64PFR0_EL1.BT == 0b0001.
+
+
 4. Unused AT_HWCAP bits
 -----------------------