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[Qemu-arm] [PATCH v1 4/4] tests/tcg/aarch64: userspace system register t
From: |
Alex Bennée |
Subject: |
[Qemu-arm] [PATCH v1 4/4] tests/tcg/aarch64: userspace system register test |
Date: |
Mon, 28 Jan 2019 17:39:40 +0000 |
This tests a bunch of registers that the kernel allows userspace to
read including the CPUID registers.
Signed-off-by: Alex Bennée <address@hidden>
---
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;
+}
--
2.17.1