kernel/arch/arm64/include/asm/asm-uaccess.h, branch linux-6.2.y

arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

2022-06-28T11:11:47Z

Currnetly, the extable type used by __arch_copy_from/to_user() is EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful EX_TYPE_UACCESS_*. Suggested-by: Mark Rutland Signed-off-by: Tong Tiangen Link: https://lore.kernel.org/r/20220621072638.1273594-5-tongtiangen@huawei.com Signed-off-by: Will Deacon

arm64: extable: consolidate definitions

2021-10-21T09:45:22Z

In subsequent patches we'll alter the structure and usage of struct exception_table_entry. For inline assembly, we create these using the `_ASM_EXTABLE()` CPP macro defined in , and for plain assembly code we use the `_asm_extable()` GAS macro defined in , which are largely identical save for different escaping and stringification requirements. This patch moves the common definitions to a new header, so that it's easier to keep the two in-sync, and to remove the implication that these are only used for uaccess helpers (as e.g. load_unaligned_zeropad() is only used on kernel memory, and depends upon `_ASM_EXTABLE()`. At the same time, a few minor modifications are made for clarity and in preparation for subsequent patches: * The structure creation is factored out into an `__ASM_EXTABLE_RAW()` macro. This will make it easier to support different fixup variants in subsequent patches without needing to update all users of `_ASM_EXTABLE()`, and makes it easier to see tha the CPP and GAS variants of the macros are structurally identical. For the CPP macro, the stringification of fields is left to the wrapper macro, `_ASM_EXTABLE()`, as in subsequent patches it will be necessary to stringify fields in wrapper macros to safely concatenate strings which cannot be token-pasted together in CPP. * The fields of the structure are created separately on their own lines. This will make it easier to add/remove/modify individual fields clearly. * Additional parentheses are added around the use of macro arguments in field definitions to avoid any potential problems with evaluation due to operator precedence, and to make errors upon misuse clearer. * USER() is moved into , as it is not required by all assembly code, and is already refered to by comments in that file. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Reviewed-by: Ard Biesheuvel Cc: Catalin Marinas Cc: James Morse Cc: Robin Murphy Cc: Will Deacon Link: https://lore.kernel.org/r/20211019160219.5202-8-mark.rutland@arm.com Signed-off-by: Will Deacon

arm64: vmlinux.ld.S: add assertion for reserved_pg_dir offset

2021-02-03T20:43:45Z

Add RESERVED_SWAPPER_OFFSET and use that instead of hardcoding the offset between swapper_pg_dir and reserved_pg_dir. Then use RESERVED_SWAPPER_OFFSET to assert that the offset is correct at link time. Signed-off-by: Joey Gouly Reviewed-by: Mark Rutland Tested-by: Mark Rutland Link: https://lore.kernel.org/r/20210202123658.22308-2-joey.gouly@arm.com Signed-off-by: Will Deacon

Merge branch 'for-next/misc' into for-next/core

2020-12-09T18:04:48Z

* for-next/misc: : Miscellaneous patches arm64: vmlinux.lds.S: Drop redundant *.init.rodata.* kasan: arm64: set TCR_EL1.TBID1 when enabled arm64: mte: optimize asynchronous tag check fault flag check arm64/mm: add fallback option to allocate virtually contiguous memory arm64/smp: Drop the macro S(x,s) arm64: consistently use reserved_pg_dir arm64: kprobes: Remove redundant kprobe_step_ctx # Conflicts: # arch/arm64/kernel/vmlinux.lds.S

arm64: uaccess cleanup macro naming

2020-12-02T19:49:11Z

Now the uaccess primitives use LDTR/STTR unconditionally, the uao_{ldp,stp,user_alternative} asm macros are misnamed, and have a redundant argument. Let's remove the redundant argument and rename these to user_{ldp,stp,ldst} respectively to clean this up. Signed-off-by: Mark Rutland Reviewed-by: Robin Murohy Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: uaccess: split user/kernel routines

2020-12-02T19:49:11Z

This patch separates arm64's user and kernel memory access primitives into distinct routines, adding new __{get,put}_kernel_nofault() helpers to access kernel memory, upon which core code builds larger copy routines. The kernel access routines (using LDR/STR) are not affected by PAN (when legitimately accessing kernel memory), nor are they affected by UAO. Switching to KERNEL_DS may set UAO, but this does not adversely affect the kernel access routines. The user access routines (using LDTR/STTR) are not affected by PAN (when legitimately accessing user memory), but are affected by UAO. As these are only legitimate to use under USER_DS with UAO clear, this should not be problematic. Routines performing atomics to user memory (futex and deprecated instruction emulation) still need to transiently clear PAN, and these are left as-is. These are never used on kernel memory. Subsequent patches will refactor the uaccess helpers to remove redundant code, and will also remove the redundant PAN/UAO manipulation. Signed-off-by: Mark Rutland Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-8-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: consistently use reserved_pg_dir

2020-11-10T17:30:40Z

Depending on configuration options and specific code paths, we either use the empty_zero_page or the configuration-dependent reserved_ttbr0 as a reserved value for TTBR{0,1}_EL1. To simplify this code, let's always allocate and use the same reserved_pg_dir, replacing reserved_ttbr0. Note that this is allocated (and hence pre-zeroed), and is also marked as read-only in the kernel Image mapping. Keeping this separate from the empty_zero_page potentially helps with robustness as the empty_zero_page is used in a number of cases where a failure to map it read-only could allow it to become corrupted. The (presently unused) swapper_pg_end symbol is also removed, and comments are added wherever we rely on the offsets between the pre-allocated pg_dirs to keep these cases easily identifiable. Signed-off-by: Mark Rutland Cc: Will Deacon Link: https://lore.kernel.org/r/20201103102229.8542-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: alternatives: Split up alternative.h

2020-11-09T21:49:34Z

asm/alternative.h contains both the macros needed to use alternatives, as well the type definitions and function prototypes for applying them. Split the header in two, so that alternatives can be used from core header files such as linux/compiler.h without the risk of circular includes Acked-by: Peter Zijlstra (Intel) Acked-by: Mark Rutland Signed-off-by: Will Deacon

arm64: uaccess: move uao_* alternatives to asm-uaccess.h

2020-11-09T21:49:34Z

The uao_* alternative asm macros are only used by the uaccess assembly routines in arch/arm64/lib/, where they are included indirectly via asm-uaccess.h. Since they're specific to the uaccess assembly (and will lose the alternatives in subsequent patches), let's move them into asm-uaccess.h. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon [will: update #include in mte.S to pull in uao asm macros] Signed-off-by: Will Deacon

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2019-11-25T23:39:19Z

Pull arm64 updates from Catalin Marinas: "Apart from the arm64-specific bits (core arch and perf, new arm64 selftests), it touches the generic cow_user_page() (reviewed by Kirill) together with a macro for x86 to preserve the existing behaviour on this architecture. Summary: - On ARMv8 CPUs without hardware updates of the access flag, avoid failing cow_user_page() on PFN mappings if the pte is old. The patches introduce an arch_faults_on_old_pte() macro, defined as false on x86. When true, cow_user_page() makes the pte young before attempting __copy_from_user_inatomic(). - Covert the synchronous exception handling paths in arch/arm64/kernel/entry.S to C. - FTRACE_WITH_REGS support for arm64. - ZONE_DMA re-introduced on arm64 to support Raspberry Pi 4 - Several kselftest cases specific to arm64, together with a MAINTAINERS update for these files (moved to the ARM64 PORT entry). - Workaround for a Neoverse-N1 erratum where the CPU may fetch stale instructions under certain conditions. - Workaround for Cortex-A57 and A72 errata where the CPU may speculatively execute an AT instruction and associate a VMID with the wrong guest page tables (corrupting the TLB). - Perf updates for arm64: additional PMU topologies on HiSilicon platforms, support for CCN-512 interconnect, AXI ID filtering in the IMX8 DDR PMU, support for the CCPI2 uncore PMU in ThunderX2. - GICv3 optimisation to avoid a heavy barrier when accessing the ICC_PMR_EL1 register. - ELF HWCAP documentation updates and clean-up. - SMC calling convention conduit code clean-up. - KASLR diagnostics printed during boot - NVIDIA Carmel CPU added to the KPTI whitelist - Some arm64 mm clean-ups: use generic free_initrd_mem(), remove stale macro, simplify calculation in __create_pgd_mapping(), typos. - Kconfig clean-ups: CMDLINE_FORCE to depend on CMDLINE, choice for endinanness to help with allmodconfig" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits) arm64: Kconfig: add a choice for endianness kselftest: arm64: fix spelling mistake "contiguos" -> "contiguous" arm64: Kconfig: make CMDLINE_FORCE depend on CMDLINE MAINTAINERS: Add arm64 selftests to the ARM64 PORT entry arm64: kaslr: Check command line before looking for a seed arm64: kaslr: Announce KASLR status on boot kselftest: arm64: fake_sigreturn_misaligned_sp kselftest: arm64: fake_sigreturn_bad_size kselftest: arm64: fake_sigreturn_duplicated_fpsimd kselftest: arm64: fake_sigreturn_missing_fpsimd kselftest: arm64: fake_sigreturn_bad_size_for_magic0 kselftest: arm64: fake_sigreturn_bad_magic kselftest: arm64: add helper get_current_context kselftest: arm64: extend test_init functionalities kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht] kselftest: arm64: mangle_pstate_invalid_daif_bits kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils kselftest: arm64: extend toplevel skeleton Makefile drivers/perf: hisi: update the sccl_id/ccl_id for certain HiSilicon platform arm64: mm: reserve CMA and crashkernel in ZONE_DMA32 ...