diff options
Diffstat (limited to 'Documentation/arm64')
| -rw-r--r-- | Documentation/arm64/booting.rst | 10 | ||||
| -rw-r--r-- | Documentation/arm64/memory-tagging-extension.rst | 28 | ||||
| -rw-r--r-- | Documentation/arm64/silicon-errata.rst | 2 |
3 files changed, 32 insertions, 8 deletions
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst index 52d060caf8bb..29884b261aa9 100644 --- a/Documentation/arm64/booting.rst +++ b/Documentation/arm64/booting.rst @@ -10,9 +10,9 @@ This document is based on the ARM booting document by Russell King and is relevant to all public releases of the AArch64 Linux kernel. The AArch64 exception model is made up of a number of exception levels -(EL0 - EL3), with EL0 and EL1 having a secure and a non-secure -counterpart. EL2 is the hypervisor level and exists only in non-secure -mode. EL3 is the highest priority level and exists only in secure mode. +(EL0 - EL3), with EL0, EL1 and EL2 having a secure and a non-secure +counterpart. EL2 is the hypervisor level, EL3 is the highest priority +level and exists only in secure mode. Both are architecturally optional. For the purposes of this document, we will use the term `boot loader` simply to define all software that executes on the CPU(s) before control @@ -167,8 +167,8 @@ Before jumping into the kernel, the following conditions must be met: All forms of interrupts must be masked in PSTATE.DAIF (Debug, SError, IRQ and FIQ). - The CPU must be in either EL2 (RECOMMENDED in order to have access to - the virtualisation extensions) or non-secure EL1. + The CPU must be in non-secure state, either in EL2 (RECOMMENDED in order + to have access to the virtualisation extensions), or in EL1. - Caches, MMUs diff --git a/Documentation/arm64/memory-tagging-extension.rst b/Documentation/arm64/memory-tagging-extension.rst index 7e812a51e506..dd27f78d7608 100644 --- a/Documentation/arm64/memory-tagging-extension.rst +++ b/Documentation/arm64/memory-tagging-extension.rst @@ -94,8 +94,9 @@ mode is specified, the program will run in that mode. If multiple modes are specified, the mode is selected as described in the "Per-CPU preferred tag checking modes" section below. -The current tag check fault mode can be read using the -``prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0)`` system call. +The current tag check fault configuration can be read using the +``prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0)`` system call. If +multiple modes were requested then all will be reported. Tag checking can also be disabled for a user thread by setting the ``PSTATE.TCO`` bit with ``MSR TCO, #1``. @@ -223,6 +224,29 @@ address ABI control and MTE configuration of a process as per the Documentation/arm64/tagged-address-abi.rst and above. The corresponding ``regset`` is 1 element of 8 bytes (``sizeof(long))``). +Core dump support +----------------- + +The allocation tags for user memory mapped with ``PROT_MTE`` are dumped +in the core file as additional ``PT_ARM_MEMTAG_MTE`` segments. The +program header for such segment is defined as: + +:``p_type``: ``PT_ARM_MEMTAG_MTE`` +:``p_flags``: 0 +:``p_offset``: segment file offset +:``p_vaddr``: segment virtual address, same as the corresponding + ``PT_LOAD`` segment +:``p_paddr``: 0 +:``p_filesz``: segment size in file, calculated as ``p_mem_sz / 32`` + (two 4-bit tags cover 32 bytes of memory) +:``p_memsz``: segment size in memory, same as the corresponding + ``PT_LOAD`` segment +:``p_align``: 0 + +The tags are stored in the core file at ``p_offset`` as two 4-bit tags +in a byte. With the tag granule of 16 bytes, a 4K page requires 128 +bytes in the core file. + Example of correct usage ======================== diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index ea281dd75517..466cb9e89047 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -136,7 +136,7 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | Cavium | ThunderX ITS | #23144 | CAVIUM_ERRATUM_23144 | +----------------+-----------------+-----------------+-----------------------------+ -| Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 | +| Cavium | ThunderX GICv3 | #23154,38545 | CAVIUM_ERRATUM_23154 | +----------------+-----------------+-----------------+-----------------------------+ | Cavium | ThunderX GICv3 | #38539 | N/A | +----------------+-----------------+-----------------+-----------------------------+ |