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Diffstat (limited to 'tests/tcg/aarch64/sysregs.c')
| -rw-r--r-- | tests/tcg/aarch64/sysregs.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/tests/tcg/aarch64/sysregs.c b/tests/tcg/aarch64/sysregs.c new file mode 100644 index 0000000000..40cf8d2877 --- /dev/null +++ b/tests/tcg/aarch64/sysregs.c @@ -0,0 +1,172 @@ +/* + * Check emulated system register access for linux-user mode. + * + * See: https://www.kernel.org/doc/Documentation/arm64/cpu-feature-registers.txt + * + * Copyright (c) 2019 Linaro + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include <asm/hwcap.h> +#include <stdio.h> +#include <sys/auxv.h> +#include <signal.h> +#include <string.h> +#include <stdbool.h> + +#ifndef HWCAP_CPUID +#define HWCAP_CPUID (1 << 11) +#endif + +int failed_bit_count; + +/* Read and print system register `id' value */ +#define get_cpu_reg(id) ({ \ + unsigned long __val = 0xdeadbeef; \ + asm("mrs %0, "#id : "=r" (__val)); \ + printf("%-20s: 0x%016lx\n", #id, __val); \ + __val; \ + }) + +/* As above but also check no bits outside of `mask' are set*/ +#define get_cpu_reg_check_mask(id, mask) ({ \ + unsigned long __cval = get_cpu_reg(id); \ + unsigned long __extra = __cval & ~mask; \ + if (__extra) { \ + printf("%-20s: 0x%016lx\n", " !!extra bits!!", __extra); \ + failed_bit_count++; \ + } \ +}) + +/* As above but check RAZ */ +#define get_cpu_reg_check_zero(id) ({ \ + unsigned long __val = 0xdeadbeef; \ + asm("mrs %0, "#id : "=r" (__val)); \ + if (__val) { \ + printf("%-20s: 0x%016lx (not RAZ!)\n", #id, __val); \ + failed_bit_count++; \ + } \ +}) + +/* Chunk up mask into 63:48, 47:32, 31:16, 15:0 to ease counting */ +#define _m(a, b, c, d) (0x ## a ## b ## c ## d ##ULL) + +bool should_fail; +int should_fail_count; +int should_not_fail_count; +uintptr_t failed_pc[10]; + +void sigill_handler(int signo, siginfo_t *si, void *data) +{ + ucontext_t *uc = (ucontext_t *)data; + + if (should_fail) { + should_fail_count++; + } else { + uintptr_t pc = (uintptr_t) uc->uc_mcontext.pc; + failed_pc[should_not_fail_count++] = pc; + } + uc->uc_mcontext.pc += 4; +} + +int main(void) +{ + struct sigaction sa; + + /* Hook in a SIGILL handler */ + memset(&sa, 0, sizeof(struct sigaction)); + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = &sigill_handler; + sigemptyset(&sa.sa_mask); + + if (sigaction(SIGILL, &sa, 0) != 0) { + perror("sigaction"); + return 1; + } + + /* Counter values have been exposed since Linux 4.12 */ + printf("Checking Counter registers\n"); + + get_cpu_reg(ctr_el0); + get_cpu_reg(cntvct_el0); + get_cpu_reg(cntfrq_el0); + + /* HWCAP_CPUID indicates we can read feature registers, since Linux 4.11 */ + if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) { + printf("CPUID registers unavailable\n"); + return 1; + } else { + printf("Checking CPUID registers\n"); + } + + /* + * Some registers only expose some bits to user-space. Anything + * that is IMPDEF is exported as 0 to user-space. The _mask checks + * assert no extra bits are set. + * + * This check is *not* comprehensive as some fields are set to + * minimum valid fields - for the purposes of this check allowed + * to have non-zero values. + */ + get_cpu_reg_check_mask(id_aa64isar0_el1, _m(00ff,ffff,f0ff,fff0)); + get_cpu_reg_check_mask(id_aa64isar1_el1, _m(0000,00f0,ffff,ffff)); + /* TGran4 & TGran64 as pegged to -1 */ + get_cpu_reg_check_mask(id_aa64mmfr0_el1, _m(0000,0000,ff00,0000)); + get_cpu_reg_check_zero(id_aa64mmfr1_el1); + /* EL1/EL0 reported as AA64 only */ + get_cpu_reg_check_mask(id_aa64pfr0_el1, _m(000f,000f,00ff,0011)); + get_cpu_reg_check_mask(id_aa64pfr1_el1, _m(0000,0000,0000,00f0)); + /* all hidden, DebugVer fixed to 0x6 (ARMv8 debug architecture) */ + get_cpu_reg_check_mask(id_aa64dfr0_el1, _m(0000,0000,0000,0006)); + get_cpu_reg_check_zero(id_aa64dfr1_el1); + get_cpu_reg_check_zero(id_aa64zfr0_el1); + + get_cpu_reg_check_zero(id_aa64afr0_el1); + get_cpu_reg_check_zero(id_aa64afr1_el1); + + get_cpu_reg_check_mask(midr_el1, _m(0000,0000,ffff,ffff)); + /* mpidr sets bit 31, everything else hidden */ + get_cpu_reg_check_mask(mpidr_el1, _m(0000,0000,8000,0000)); + /* REVIDR is all IMPDEF so should be all zeros to user-space */ + get_cpu_reg_check_zero(revidr_el1); + + /* + * There are a block of more registers that are RAZ in the rest of + * the Op0=3, Op1=0, CRn=0, CRm=0,4,5,6,7 space. However for + * brevity we don't check stuff that is currently un-allocated + * here. Feel free to add them ;-) + */ + + printf("Remaining registers should fail\n"); + should_fail = true; + + /* Unexposed register access causes SIGILL */ + get_cpu_reg(id_mmfr0_el1); + get_cpu_reg(id_mmfr1_el1); + get_cpu_reg(id_mmfr2_el1); + get_cpu_reg(id_mmfr3_el1); + + get_cpu_reg(mvfr0_el1); + get_cpu_reg(mvfr1_el1); + + if (should_not_fail_count > 0) { + int i; + for (i = 0; i < should_not_fail_count; i++) { + uintptr_t pc = failed_pc[i]; + uint32_t insn = *(uint32_t *) pc; + printf("insn %#x @ %#lx unexpected FAIL\n", insn, pc); + } + return 1; + } + + if (failed_bit_count > 0) { + printf("Extra information leaked to user-space!\n"); + return 1; + } + + return should_fail_count == 6 ? 0 : 1; +} |