From e995d5cce4a022afc4624471cafd2e4eb72962e6 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 27 Feb 2023 11:33:26 -1000 Subject: [PATCH] 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 Signed-off-by: Richard Henderson Message-id: 20230227213329.793795-12-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- configs/targets/aarch64-linux-user.mak | 2 +- configs/targets/aarch64-softmmu.mak | 2 +- configs/targets/aarch64_be-linux-user.mak | 2 +- gdb-xml/aarch64-pauth.xml | 15 ++++++++++ target/arm/gdbstub.c | 5 ++++ target/arm/gdbstub64.c | 34 +++++++++++++++++++++++ target/arm/internals.h | 2 ++ 7 files changed, 59 insertions(+), 3 deletions(-) create mode 100644 gdb-xml/aarch64-pauth.xml diff --git a/configs/targets/aarch64-linux-user.mak b/configs/targets/aarch64-linux-user.mak index db552f1839..ba8bc5fe3f 100644 --- a/configs/targets/aarch64-linux-user.mak +++ b/configs/targets/aarch64-linux-user.mak @@ -1,6 +1,6 @@ TARGET_ARCH=aarch64 TARGET_BASE_ARCH=arm -TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml +TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/aarch64-pauth.xml TARGET_HAS_BFLT=y CONFIG_SEMIHOSTING=y CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y diff --git a/configs/targets/aarch64-softmmu.mak b/configs/targets/aarch64-softmmu.mak index d489e6da83..b4338e9568 100644 --- a/configs/targets/aarch64-softmmu.mak +++ b/configs/targets/aarch64-softmmu.mak @@ -1,5 +1,5 @@ TARGET_ARCH=aarch64 TARGET_BASE_ARCH=arm TARGET_SUPPORTS_MTTCG=y -TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml gdb-xml/arm-m-profile-mve.xml +TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml gdb-xml/arm-m-profile-mve.xml gdb-xml/aarch64-pauth.xml TARGET_NEED_FDT=y diff --git a/configs/targets/aarch64_be-linux-user.mak b/configs/targets/aarch64_be-linux-user.mak index dc78044fb1..acb5620cdb 100644 --- a/configs/targets/aarch64_be-linux-user.mak +++ b/configs/targets/aarch64_be-linux-user.mak @@ -1,7 +1,7 @@ TARGET_ARCH=aarch64 TARGET_BASE_ARCH=arm TARGET_BIG_ENDIAN=y -TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml +TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/aarch64-pauth.xml TARGET_HAS_BFLT=y CONFIG_SEMIHOSTING=y CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y diff --git a/gdb-xml/aarch64-pauth.xml b/gdb-xml/aarch64-pauth.xml new file mode 100644 index 0000000000..24af5f903c --- /dev/null +++ b/gdb-xml/aarch64-pauth.xml @@ -0,0 +1,15 @@ + + + + + + + + + + + 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);