diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2023-02-27 11:33:26 -1000 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2023-03-06 14:08:11 +0000 |
commit | e995d5cce4a022afc4624471cafd2e4eb72962e6 (patch) | |
tree | 608192b3e8f286b980878e528dee54b270dadd48 /target/arm | |
parent | abf1f1b03aad07d9b7aa4bb5b06ac5a2c7b134d1 (diff) |
target/arm: Implement gdbstub pauth extension
The extension is primarily defined by the Linux kernel NT_ARM_PAC_MASK
ptrace register set.
The original gdb feature consists of two masks, data and code, which are
used to mask out the authentication code within a pointer. Following
discussion with Luis Machado, add two more masks in order to support
pointers within the high half of the address space (i.e. TTBR1 vs TTBR0).
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1105
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230227213329.793795-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm')
-rw-r--r-- | target/arm/gdbstub.c | 5 | ||||
-rw-r--r-- | target/arm/gdbstub64.c | 34 | ||||
-rw-r--r-- | target/arm/internals.h | 2 |
3 files changed, 41 insertions, 0 deletions
diff --git a/target/arm/gdbstub.c b/target/arm/gdbstub.c index bf8aff7824..062c8d447a 100644 --- a/target/arm/gdbstub.c +++ b/target/arm/gdbstub.c @@ -355,6 +355,11 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu) aarch64_gdb_set_fpu_reg, 34, "aarch64-fpu.xml", 0); } + if (isar_feature_aa64_pauth(&cpu->isar)) { + gdb_register_coprocessor(cs, aarch64_gdb_get_pauth_reg, + aarch64_gdb_set_pauth_reg, + 4, "aarch64-pauth.xml", 0); + } #endif } else { if (arm_feature(env, ARM_FEATURE_NEON)) { diff --git a/target/arm/gdbstub64.c b/target/arm/gdbstub64.c index 3d9e9e97c8..3bee892fb7 100644 --- a/target/arm/gdbstub64.c +++ b/target/arm/gdbstub64.c @@ -210,6 +210,40 @@ int aarch64_gdb_set_sve_reg(CPUARMState *env, uint8_t *buf, int reg) return 0; } +int aarch64_gdb_get_pauth_reg(CPUARMState *env, GByteArray *buf, int reg) +{ + switch (reg) { + case 0: /* pauth_dmask */ + case 1: /* pauth_cmask */ + case 2: /* pauth_dmask_high */ + case 3: /* pauth_cmask_high */ + /* + * Note that older versions of this feature only contained + * pauth_{d,c}mask, for use with Linux user processes, and + * thus exclusively in the low half of the address space. + * + * To support system mode, and to debug kernels, two new regs + * were added to cover the high half of the address space. + * For the purpose of pauth_ptr_mask, we can use any well-formed + * address within the address space half -- here, 0 and -1. + */ + { + bool is_data = !(reg & 1); + bool is_high = reg & 2; + uint64_t mask = pauth_ptr_mask(env, -is_high, is_data); + return gdb_get_reg64(buf, mask); + } + default: + return 0; + } +} + +int aarch64_gdb_set_pauth_reg(CPUARMState *env, uint8_t *buf, int reg) +{ + /* All pseudo registers are read-only. */ + return 0; +} + static void output_vector_union_type(GString *s, int reg_width, const char *name) { diff --git a/target/arm/internals.h b/target/arm/internals.h index c891c7a383..dda89aa5df 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -1349,6 +1349,8 @@ int aarch64_gdb_get_sve_reg(CPUARMState *env, GByteArray *buf, int reg); int aarch64_gdb_set_sve_reg(CPUARMState *env, uint8_t *buf, int reg); int aarch64_gdb_get_fpu_reg(CPUARMState *env, GByteArray *buf, int reg); int aarch64_gdb_set_fpu_reg(CPUARMState *env, uint8_t *buf, int reg); +int aarch64_gdb_get_pauth_reg(CPUARMState *env, GByteArray *buf, int reg); +int aarch64_gdb_set_pauth_reg(CPUARMState *env, uint8_t *buf, int reg); void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp); void arm_cpu_sme_finalize(ARMCPU *cpu, Error **errp); void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp); |