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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 15:18:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 15:18:27 -0700
commit533b220f7be4e461a5222a223d169b42856741ef (patch)
tree3684fae5a676b31a4a75e275a0ee5519f0d3c6d9 /Documentation
parent3ee3723b40d55f473b8c82c60ed0e67f1f9ec6b9 (diff)
parent082af5ec5080b028f7d0846a6c27cbb87f288205 (diff)
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon: "A sizeable pile of arm64 updates for 5.8. Summary below, but the big two features are support for Branch Target Identification and Clang's Shadow Call stack. The latter is currently arm64-only, but the high-level parts are all in core code so it could easily be adopted by other architectures pending toolchain support Branch Target Identification (BTI): - Support for ARMv8.5-BTI in both user- and kernel-space. This allows branch targets to limit the types of branch from which they can be called and additionally prevents branching to arbitrary code, although kernel support requires a very recent toolchain. - Function annotation via SYM_FUNC_START() so that assembly functions are wrapped with the relevant "landing pad" instructions. - BPF and vDSO updates to use the new instructions. - Addition of a new HWCAP and exposure of BTI capability to userspace via ID register emulation, along with ELF loader support for the BTI feature in .note.gnu.property. - Non-critical fixes to CFI unwind annotations in the sigreturn trampoline. Shadow Call Stack (SCS): - Support for Clang's Shadow Call Stack feature, which reserves platform register x18 to point at a separate stack for each task that holds only return addresses. This protects function return control flow from buffer overruns on the main stack. - Save/restore of x18 across problematic boundaries (user-mode, hypervisor, EFI, suspend, etc). - Core support for SCS, should other architectures want to use it too. - SCS overflow checking on context-switch as part of the existing stack limit check if CONFIG_SCHED_STACK_END_CHECK=y. CPU feature detection: - Removed numerous "SANITY CHECK" errors when running on a system with mismatched AArch32 support at EL1. This is primarily a concern for KVM, which disabled support for 32-bit guests on such a system. - Addition of new ID registers and fields as the architecture has been extended. Perf and PMU drivers: - Minor fixes and cleanups to system PMU drivers. Hardware errata: - Unify KVM workarounds for VHE and nVHE configurations. - Sort vendor errata entries in Kconfig. Secure Monitor Call Calling Convention (SMCCC): - Update to the latest specification from Arm (v1.2). - Allow PSCI code to query the SMCCC version. Software Delegated Exception Interface (SDEI): - Unexport a bunch of unused symbols. - Minor fixes to handling of firmware data. Pointer authentication: - Add support for dumping the kernel PAC mask in vmcoreinfo so that the stack can be unwound by tools such as kdump. - Simplification of key initialisation during CPU bringup. BPF backend: - Improve immediate generation for logical and add/sub instructions. vDSO: - Minor fixes to the linker flags for consistency with other architectures and support for LLVM's unwinder. - Clean up logic to initialise and map the vDSO into userspace. ACPI: - Work around for an ambiguity in the IORT specification relating to the "num_ids" field. - Support _DMA method for all named components rather than only PCIe root complexes. - Minor other IORT-related fixes. Miscellaneous: - Initialise debug traps early for KGDB and fix KDB cacheflushing deadlock. - Minor tweaks to early boot state (documentation update, set TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections). - Refactoring and cleanup" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits) KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h KVM: arm64: Check advertised Stage-2 page size capability arm64/cpufeature: Add get_arm64_ftr_reg_nowarn() ACPI/IORT: Remove the unused __get_pci_rid() arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register arm64/cpufeature: Add remaining feature bits in ID_PFR0 register arm64/cpufeature: Introduce ID_MMFR5 CPU register arm64/cpufeature: Introduce ID_DFR1 CPU register arm64/cpufeature: Introduce ID_PFR2 CPU register arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0 arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register arm64: mm: Add asid_gen_match() helper firmware: smccc: Fix missing prototype warning for arm_smccc_version_init arm64: vdso: Fix CFI directives in sigreturn trampoline arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kdump/vmcoreinfo.rst6
-rw-r--r--Documentation/arm64/booting.rst3
-rw-r--r--Documentation/arm64/cpu-feature-registers.rst2
-rw-r--r--Documentation/arm64/elf_hwcaps.rst5
-rw-r--r--Documentation/arm64/silicon-errata.rst8
-rw-r--r--Documentation/filesystems/proc.rst1
6 files changed, 20 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 007a6b86e0ee..e4ee8b2db604 100644
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
@@ -393,6 +393,12 @@ KERNELOFFSET
The kernel randomization offset. Used to compute the page offset. If
KASLR is disabled, this value is zero.
+KERNELPACMASK
+-------------
+
+The mask to extract the Pointer Authentication Code from a kernel virtual
+address.
+
arm
===
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index a3f1a47b6f1c..d063c05d5fb0 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -173,7 +173,8 @@ Before jumping into the kernel, the following conditions must be met:
- Caches, MMUs
The MMU must be off.
- Instruction cache may be on or off.
+ The instruction cache may be on or off, and must not hold any stale
+ entries corresponding to the loaded kernel image.
The address range corresponding to the loaded kernel image must be
cleaned to the PoC. In the presence of a system cache or other
coherent masters with caches enabled, this will typically require
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
-----------------------
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index 2c08c628febd..936cf2a59ca4 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -64,6 +64,10 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A53 | #843419 | ARM64_ERRATUM_843419 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-A55 | #1530923 | ARM64_ERRATUM_1530923 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A57 | #832075 | ARM64_ERRATUM_832075 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A57 | #852523 | N/A |
@@ -78,8 +82,6 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 |
+----------------+-----------------+-----------------+-----------------------------+
-| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
-+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A76 | #1188873,1418040| ARM64_ERRATUM_1418040 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A76 | #1165522 | ARM64_ERRATUM_1165522 |
@@ -88,8 +90,6 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 |
+----------------+-----------------+-----------------+-----------------------------+
-| ARM | Cortex-A55 | #1530923 | ARM64_ERRATUM_1530923 |
-+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1349291 | N/A |
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 38b606991065..9969bf4c0c44 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -543,6 +543,7 @@ encoded manner. The codes are the following:
hg huge page advise flag
nh no huge page advise flag
mg mergable advise flag
+ bt - arm64 BTI guarded page
== =======================================
Note that there is no guarantee that every flag and associated mnemonic will