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| author | Catalin Marinas <catalin.marinas@arm.com> | 2019-12-10 14:19:15 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-09-04 14:46:07 +0300 |
| commit | af5ce95282dc99d08a27a407a02c763dde1c5558 (patch) | |
| tree | f47b4662e6307e2f9ca8d7d9126760216afadd4b /arch/arm64/include/asm/sysreg.h | |
| parent | 1c101da8b971a36695319dce7a24711dc567a0dd (diff) | |
| download | linux-af5ce95282dc99d08a27a407a02c763dde1c5558.tar.xz | |
arm64: mte: Allow user control of the generated random tags via prctl()
The IRG, ADDG and SUBG instructions insert a random tag in the resulting
address. Certain tags can be excluded via the GCR_EL1.Exclude bitmap
when, for example, the user wants a certain colour for freed buffers.
Since the GCR_EL1 register is not accessible at EL0, extend the
prctl(PR_SET_TAGGED_ADDR_CTRL) interface to include a 16-bit field in
the first argument for controlling which tags can be generated by the
above instruction (an include rather than exclude mask). Note that by
default all non-zero tags are excluded. This setting is per-thread.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/sysreg.h')
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index daf030a05de0..52eefe2f7d95 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1078,6 +1078,13 @@ write_sysreg(__scs_new, sysreg); \ } while (0) +#define sysreg_clear_set_s(sysreg, clear, set) do { \ + u64 __scs_val = read_sysreg_s(sysreg); \ + u64 __scs_new = (__scs_val & ~(u64)(clear)) | (set); \ + if (__scs_new != __scs_val) \ + write_sysreg_s(__scs_new, sysreg); \ +} while (0) + #endif #endif /* __ASM_SYSREG_H */ |