Alex Bennée <alex.ben...@linaro.org> writes:
> This tests a bunch of registers that the kernel allows userspace to > read including the CPUID registers. > > Signed-off-by: Alex Bennée <alex.ben...@linaro.org> I'll also merge the following fix: modified tests/tcg/aarch64/sysregs.c @@ -11,6 +11,10 @@ #include <string.h> #include <stdbool.h> +#ifndef HWCAP_CPUID +#define HWCAP_CPUID (1 << 11) +#endif + int failed_mask_count; #define get_cpu_reg(id) ({ \ > > --- > v4 > - also test for extra bits that shouldn't be exposed > --- > tests/tcg/aarch64/Makefile.target | 2 +- > tests/tcg/aarch64/sysregs.c | 120 ++++++++++++++++++++++++++++++ > 2 files changed, 121 insertions(+), 1 deletion(-) > create mode 100644 tests/tcg/aarch64/sysregs.c > > diff --git a/tests/tcg/aarch64/Makefile.target > b/tests/tcg/aarch64/Makefile.target > index 08c45b8470..cc1a7eb486 100644 > --- a/tests/tcg/aarch64/Makefile.target > +++ b/tests/tcg/aarch64/Makefile.target > @@ -7,7 +7,7 @@ VPATH += $(AARCH64_SRC) > > # we don't build any of the ARM tests > AARCH64_TESTS=$(filter-out $(ARM_TESTS), $(TESTS)) > -AARCH64_TESTS+=fcvt > +AARCH64_TESTS+=fcvt sysregs > TESTS:=$(AARCH64_TESTS) > > fcvt: LDFLAGS+=-lm > diff --git a/tests/tcg/aarch64/sysregs.c b/tests/tcg/aarch64/sysregs.c > new file mode 100644 > index 0000000000..8e11288ee3 > --- /dev/null > +++ b/tests/tcg/aarch64/sysregs.c > @@ -0,0 +1,120 @@ > +/* > + * Check emulated system register access for linux-user mode. > + * > + * See: > https://www.kernel.org/doc/Documentation/arm64/cpu-feature-registers.txt > + */ > + > +#include <asm/hwcap.h> > +#include <stdio.h> > +#include <sys/auxv.h> > +#include <signal.h> > +#include <string.h> > +#include <stdbool.h> > + > +int failed_mask_count; > + > +#define get_cpu_reg(id) ({ \ > + unsigned long __val = 0xdeadbeef; \ > + asm("mrs %0, "#id : "=r" (__val)); \ > + printf("%-20s: 0x%016lx\n", #id, __val); \ > + __val; \ > + }) > + > +#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_mask_count++; \ > + } \ > +}) > + > +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; > + } > + > + /* since 4.12 */ > + printf("Checking CNT registers\n"); > + > + get_cpu_reg(ctr_el0); > + get_cpu_reg(cntvct_el0); > + get_cpu_reg(cntfrq_el0); > + > + /* when (getauxval(AT_HWCAP) & HWCAP_CPUID), since 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 IMDEF is exported as 0 to user-space. > + */ > + get_cpu_reg_check_mask(id_aa64isar0_el1, 0x000fffffff0ffff0ULL); > + get_cpu_reg_check_mask(id_aa64isar1_el1, 0x00000000ffffffffULL); > + get_cpu_reg(id_aa64mmfr0_el1); > + get_cpu_reg(id_aa64mmfr1_el1); > + get_cpu_reg_check_mask(id_aa64pfr0_el1, 0x000f000f0ff0000ULL); > + get_cpu_reg(id_aa64pfr1_el1); > + get_cpu_reg(id_aa64dfr0_el1); > + get_cpu_reg(id_aa64dfr1_el1); > + > + get_cpu_reg_check_mask(midr_el1, 0x00000000ffffffffULL); > + get_cpu_reg(mpidr_el1); > + /* REVIDR is all IMPDEF so should be all zeros to user-space */ > + get_cpu_reg_check_mask(revidr_el1, 0x0); > + > + printf("Remaining registers should fail\n"); > + should_fail = true; > + > + /* Unexposed register access causes SIGILL */ > + get_cpu_reg(id_mmfr0_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_mask_count > 0) { > + printf("Extra information leaked to user-space!\n"); > + return 1; > + } > + > + return should_fail_count == 1 ? 0 : 1; > +} -- Alex Bennée