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| author | Catalin Marinas <catalin.marinas@arm.com> | 2019-11-27 13:30:15 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-09-04 14:46:07 +0300 |
| commit | 1c101da8b971a36695319dce7a24711dc567a0dd (patch) | |
| tree | c791523a3008b05b4c47267da585568bd3622b3f /arch/arm64/include/asm/processor.h | |
| parent | 51b0bff2f703f7ecfeb228eaa3d8f6090c18c9c1 (diff) | |
| download | linux-1c101da8b971a36695319dce7a24711dc567a0dd.tar.xz | |
arm64: mte: Allow user control of the tag check mode via prctl()
By default, even if PROT_MTE is set on a memory range, there is no tag
check fault reporting (SIGSEGV). Introduce a set of option to the
exiting prctl(PR_SET_TAGGED_ADDR_CTRL) to allow user control of the tag
check fault mode:
PR_MTE_TCF_NONE - no reporting (default)
PR_MTE_TCF_SYNC - synchronous tag check fault reporting
PR_MTE_TCF_ASYNC - asynchronous tag check fault reporting
These options translate into the corresponding SCTLR_EL1.TCF0 bitfield,
context-switched by the kernel. Note that the kernel accesses to the
user address space (e.g. read() system call) are not checked if the user
thread tag checking mode is PR_MTE_TCF_NONE or PR_MTE_TCF_ASYNC. If the
tag checking mode is PR_MTE_TCF_SYNC, the kernel makes a best effort to
check its user address accesses, however it cannot always guarantee it.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/processor.h')
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 240fe5e5b720..80e7f0573309 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -151,6 +151,9 @@ struct thread_struct { struct ptrauth_keys_user keys_user; struct ptrauth_keys_kernel keys_kernel; #endif +#ifdef CONFIG_ARM64_MTE + u64 sctlr_tcf0; +#endif }; static inline void arch_thread_struct_whitelist(unsigned long *offset, |