tests/tcg/aarch64: Adjust pauth tests for FEAT_FPAC

With FEAT_FPAC, AUT* instructions that fail authentication
do not produce an error value but instead fault.

For pauth-2, install a signal handler and verify it gets called.

For pauth-4 and pauth-5, we are explicitly testing the error value,
so there's nothing to test with FEAT_FPAC, so exit early.
Adjust the makefile to use -cpu neoverse-v1, which has FEAT_EPAC
but not FEAT_FPAC.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230829232335.965414-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2023-08-29 16:23:24 -07:00 committed by Peter Maydell
parent 03a3a62fbd
commit 871a7f6a9a
5 changed files with 98 additions and 13 deletions

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@ -42,7 +42,11 @@ endif
ifneq ($(CROSS_CC_HAS_ARMV8_3),)
AARCH64_TESTS += pauth-1 pauth-2 pauth-4 pauth-5
pauth-%: CFLAGS += -march=armv8.3-a
run-pauth-%: QEMU_OPTS += -cpu max
run-pauth-1: QEMU_OPTS += -cpu max
run-pauth-2: QEMU_OPTS += -cpu max
# Choose a cpu with FEAT_Pauth but without FEAT_FPAC for pauth-[45].
run-pauth-4: QEMU_OPTS += -cpu neoverse-v1
run-pauth-5: QEMU_OPTS += -cpu neoverse-v1
endif
# BTI Tests

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@ -1,5 +1,22 @@
#include <stdint.h>
#include <signal.h>
#include <stdlib.h>
#include <assert.h>
#include "pauth.h"
static void sigill(int sig, siginfo_t *info, void *vuc)
{
ucontext_t *uc = vuc;
uint64_t test;
/* There is only one insn below that is allowed to fault. */
asm volatile("adr %0, auth2_insn" : "=r"(test));
assert(test == uc->uc_mcontext.pc);
exit(0);
}
static int pac_feature;
void do_test(uint64_t value)
{
@ -27,31 +44,52 @@ void do_test(uint64_t value)
* An invalid salt usually fails authorization, but again there
* is a chance of choosing another salt that works.
* Iterate until we find another salt which does fail.
*
* With FEAT_FPAC, this will SIGILL instead of producing a result.
*/
for (salt2 = salt1 + 1; ; salt2++) {
asm volatile("autda %0, %2" : "=r"(decode) : "0"(encode), "r"(salt2));
asm volatile("auth2_insn: autda %0, %2"
: "=r"(decode) : "0"(encode), "r"(salt2));
if (decode != value) {
break;
}
}
assert(pac_feature < 4); /* No FEAT_FPAC */
/* The VA bits, bit 55, and the TBI bits, should be unchanged. */
assert(((decode ^ value) & 0xff80ffffffffffffull) == 0);
/*
* Bits [54:53] are an error indicator based on the key used;
* the DA key above is keynumber 0, so error == 0b01. Otherwise
* bit 55 of the original is sign-extended into the rest of the auth.
* Without FEAT_Pauth2, bits [54:53] are an error indicator based on
* the key used; the DA key above is keynumber 0, so error == 0b01.
* Otherwise, bit 55 of the original is sign-extended into the rest
* of the auth.
*/
if ((value >> 55) & 1) {
assert(((decode >> 48) & 0xff) == 0b10111111);
} else {
assert(((decode >> 48) & 0xff) == 0b00100000);
if (pac_feature < 3) {
if ((value >> 55) & 1) {
assert(((decode >> 48) & 0xff) == 0b10111111);
} else {
assert(((decode >> 48) & 0xff) == 0b00100000);
}
}
}
int main()
{
static const struct sigaction sa = {
.sa_sigaction = sigill,
.sa_flags = SA_SIGINFO
};
pac_feature = get_pac_feature();
assert(pac_feature != 0);
if (pac_feature >= 4) {
/* FEAT_FPAC */
sigaction(SIGILL, &sa, NULL);
}
do_test(0);
do_test(0xda004acedeadbeefull);
return 0;

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@ -2,14 +2,24 @@
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "pauth.h"
#define TESTS 1000
int main()
{
char base[TESTS];
int i, count = 0;
float perc;
void *base = malloc(TESTS);
int pac_feature = get_pac_feature();
/*
* Exit if no PAuth or FEAT_FPAC, which will SIGILL on AUTIA failure
* rather than return an error for us to check below.
*/
if (pac_feature == 0 || pac_feature >= 4) {
return 0;
}
for (i = 0; i < TESTS; i++) {
uintptr_t in, x, y;
@ -17,7 +27,7 @@ int main()
in = i + (uintptr_t) base;
asm("mov %0, %[in]\n\t"
"pacia %0, sp\n\t" /* sigill if pauth not supported */
"pacia %0, sp\n\t"
"eor %0, %0, #4\n\t" /* corrupt single bit */
"mov %1, %0\n\t"
"autia %1, sp\n\t" /* validate corrupted pointer */
@ -36,10 +46,10 @@ int main()
if (x != y) {
count++;
}
}
perc = (float) count / (float) TESTS;
printf("Checks Passed: %0.2f%%", perc * 100.0);
printf("Checks Passed: %0.2f%%\n", perc * 100.0);
assert(perc > 0.95);
return 0;
}

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@ -1,4 +1,5 @@
#include <assert.h>
#include "pauth.h"
static int x;
@ -6,6 +7,15 @@ int main()
{
int *p0 = &x, *p1, *p2, *p3;
unsigned long salt = 0;
int pac_feature = get_pac_feature();
/*
* Exit if no PAuth or FEAT_FPAC, which will SIGILL on AUTDA failure
* rather than return an error for us to check below.
*/
if (pac_feature == 0 || pac_feature >= 4) {
return 0;
}
/*
* With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so

23
tests/tcg/aarch64/pauth.h Normal file
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@ -0,0 +1,23 @@
/*
* Helper for pauth test case
*
* Copyright (c) 2023 Linaro Ltd
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include <assert.h>
#include <sys/auxv.h>
static int get_pac_feature(void)
{
unsigned long isar1, isar2;
assert(getauxval(AT_HWCAP) & HWCAP_CPUID);
asm("mrs %0, id_aa64isar1_el1" : "=r"(isar1));
asm("mrs %0, S3_0_C0_C6_2" : "=r"(isar2)); /* id_aa64isar2_el1 */
return ((isar1 >> 4) & 0xf) /* APA */
| ((isar1 >> 8) & 0xf) /* API */
| ((isar2 >> 12) & 0xf); /* APA3 */
}