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| author | Richard Henderson | 2021-02-12 19:48:51 +0100 |
|---|---|---|
| committer | Peter Maydell | 2021-02-16 14:06:16 +0100 |
| commit | 0e0c030c681730f3ec55ba3b223b608a8f3e8282 (patch) | |
| tree | b787487c814a2833973d96d3ef135cd784d5f46a /target/arm | |
| parent | linux-user: Handle tags in lock_user/unlock_user (diff) | |
| download | qemu-0e0c030c681730f3ec55ba3b223b608a8f3e8282.tar.gz qemu-0e0c030c681730f3ec55ba3b223b608a8f3e8282.tar.xz qemu-0e0c030c681730f3ec55ba3b223b608a8f3e8282.zip | |
linux-user/aarch64: Implement PR_TAGGED_ADDR_ENABLE
This is the prctl bit that controls whether syscalls accept tagged
addresses. See Documentation/arm64/tagged-address-abi.rst in the
linux kernel.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm')
| -rw-r--r-- | target/arm/cpu-param.h | 3 | ||||
| -rw-r--r-- | target/arm/cpu.h | 31 |
2 files changed, 34 insertions, 0 deletions
diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h index 00e7d9e937..7f38d33b8e 100644 --- a/target/arm/cpu-param.h +++ b/target/arm/cpu-param.h @@ -20,6 +20,9 @@ #ifdef CONFIG_USER_ONLY #define TARGET_PAGE_BITS 12 +# ifdef TARGET_AARCH64 +# define TARGET_TAGGED_ADDRESSES +# endif #else /* * ARMv7 and later CPUs have 4K pages minimum, but ARMv5 and v6 diff --git a/target/arm/cpu.h b/target/arm/cpu.h index f240275407..72a0819eb8 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -721,6 +721,11 @@ typedef struct CPUARMState { const struct arm_boot_info *boot_info; /* Store GICv3CPUState to access from this struct */ void *gicv3state; + +#ifdef TARGET_TAGGED_ADDRESSES + /* Linux syscall tagged address support */ + bool tagged_addr_enable; +#endif } CPUARMState; static inline void set_feature(CPUARMState *env, int feature) @@ -3604,6 +3609,32 @@ static inline MemTxAttrs *typecheck_memtxattrs(MemTxAttrs *x) */ #define PAGE_BTI PAGE_TARGET_1 +#ifdef TARGET_TAGGED_ADDRESSES +/** + * cpu_untagged_addr: + * @cs: CPU context + * @x: tagged address + * + * Remove any address tag from @x. This is explicitly related to the + * linux syscall TIF_TAGGED_ADDR setting, not TBI in general. + * + * There should be a better place to put this, but we need this in + * include/exec/cpu_ldst.h, and not some place linux-user specific. + */ +static inline target_ulong cpu_untagged_addr(CPUState *cs, target_ulong x) +{ + ARMCPU *cpu = ARM_CPU(cs); + if (cpu->env.tagged_addr_enable) { + /* + * TBI is enabled for userspace but not kernelspace addresses. + * Only clear the tag if bit 55 is clear. + */ + x &= sextract64(x, 0, 56); + } + return x; +} +#endif + /* * Naming convention for isar_feature functions: * Functions which test 32-bit ID registers should have _aa32_ in |