tests/tcg/aarch64: Add bti smoke tests

The note test requires gcc 10 for -mbranch-protection=standard.
The mmap test uses PROT_BTI and does not require special compiler support.

Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201021173749.111103-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2020-10-21 10:37:49 -07:00 committed by Peter Maydell
parent e8384b376e
commit 1d9ac91baf
5 changed files with 243 additions and 0 deletions

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@ -25,6 +25,16 @@ run-pauth-%: QEMU_OPTS += -cpu max
run-plugin-pauth-%: QEMU_OPTS += -cpu max
endif
# BTI Tests
# bti-1 tests the elf notes, so we require special compiler support.
ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_BTI),)
AARCH64_TESTS += bti-1
bti-1: CFLAGS += -mbranch-protection=standard
bti-1: LDFLAGS += -nostdlib
endif
# bti-2 tests PROT_BTI, so no special compiler support required.
AARCH64_TESTS += bti-2
# Semihosting smoke test for linux-user
AARCH64_TESTS += semihosting
run-semihosting: semihosting

62
tests/tcg/aarch64/bti-1.c Normal file
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@ -0,0 +1,62 @@
/*
* Branch target identification, basic notskip cases.
*/
#include "bti-crt.inc.c"
static void skip2_sigill(int sig, siginfo_t *info, ucontext_t *uc)
{
uc->uc_mcontext.pc += 8;
uc->uc_mcontext.pstate = 1;
}
#define NOP "nop"
#define BTI_N "hint #32"
#define BTI_C "hint #34"
#define BTI_J "hint #36"
#define BTI_JC "hint #38"
#define BTYPE_1(DEST) \
asm("mov %0,#1; adr x16, 1f; br x16; 1: " DEST "; mov %0,#0" \
: "=r"(skipped) : : "x16")
#define BTYPE_2(DEST) \
asm("mov %0,#1; adr x16, 1f; blr x16; 1: " DEST "; mov %0,#0" \
: "=r"(skipped) : : "x16", "x30")
#define BTYPE_3(DEST) \
asm("mov %0,#1; adr x15, 1f; br x15; 1: " DEST "; mov %0,#0" \
: "=r"(skipped) : : "x15")
#define TEST(WHICH, DEST, EXPECT) \
do { WHICH(DEST); fail += skipped ^ EXPECT; } while (0)
int main()
{
int fail = 0;
int skipped;
/* Signal-like with SA_SIGINFO. */
signal_info(SIGILL, skip2_sigill);
TEST(BTYPE_1, NOP, 1);
TEST(BTYPE_1, BTI_N, 1);
TEST(BTYPE_1, BTI_C, 0);
TEST(BTYPE_1, BTI_J, 0);
TEST(BTYPE_1, BTI_JC, 0);
TEST(BTYPE_2, NOP, 1);
TEST(BTYPE_2, BTI_N, 1);
TEST(BTYPE_2, BTI_C, 0);
TEST(BTYPE_2, BTI_J, 1);
TEST(BTYPE_2, BTI_JC, 0);
TEST(BTYPE_3, NOP, 1);
TEST(BTYPE_3, BTI_N, 1);
TEST(BTYPE_3, BTI_C, 1);
TEST(BTYPE_3, BTI_J, 0);
TEST(BTYPE_3, BTI_JC, 0);
return fail;
}

116
tests/tcg/aarch64/bti-2.c Normal file
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@ -0,0 +1,116 @@
/*
* Branch target identification, basic notskip cases.
*/
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#ifndef PROT_BTI
#define PROT_BTI 0x10
#endif
static void skip2_sigill(int sig, siginfo_t *info, void *vuc)
{
ucontext_t *uc = vuc;
uc->uc_mcontext.pc += 8;
uc->uc_mcontext.pstate = 1;
}
#define NOP "nop"
#define BTI_N "hint #32"
#define BTI_C "hint #34"
#define BTI_J "hint #36"
#define BTI_JC "hint #38"
#define BTYPE_1(DEST) \
"mov x1, #1\n\t" \
"adr x16, 1f\n\t" \
"br x16\n" \
"1: " DEST "\n\t" \
"mov x1, #0"
#define BTYPE_2(DEST) \
"mov x1, #1\n\t" \
"adr x16, 1f\n\t" \
"blr x16\n" \
"1: " DEST "\n\t" \
"mov x1, #0"
#define BTYPE_3(DEST) \
"mov x1, #1\n\t" \
"adr x15, 1f\n\t" \
"br x15\n" \
"1: " DEST "\n\t" \
"mov x1, #0"
#define TEST(WHICH, DEST, EXPECT) \
WHICH(DEST) "\n" \
".if " #EXPECT "\n\t" \
"eor x1, x1," #EXPECT "\n" \
".endif\n\t" \
"add x0, x0, x1\n\t"
asm("\n"
"test_begin:\n\t"
BTI_C "\n\t"
"mov x2, x30\n\t"
"mov x0, #0\n\t"
TEST(BTYPE_1, NOP, 1)
TEST(BTYPE_1, BTI_N, 1)
TEST(BTYPE_1, BTI_C, 0)
TEST(BTYPE_1, BTI_J, 0)
TEST(BTYPE_1, BTI_JC, 0)
TEST(BTYPE_2, NOP, 1)
TEST(BTYPE_2, BTI_N, 1)
TEST(BTYPE_2, BTI_C, 0)
TEST(BTYPE_2, BTI_J, 1)
TEST(BTYPE_2, BTI_JC, 0)
TEST(BTYPE_3, NOP, 1)
TEST(BTYPE_3, BTI_N, 1)
TEST(BTYPE_3, BTI_C, 1)
TEST(BTYPE_3, BTI_J, 0)
TEST(BTYPE_3, BTI_JC, 0)
"ret x2\n"
"test_end:"
);
int main()
{
struct sigaction sa;
void *tb, *te;
void *p = mmap(0, getpagesize(),
PROT_EXEC | PROT_READ | PROT_WRITE | PROT_BTI,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (p == MAP_FAILED) {
perror("mmap");
return 1;
}
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = skip2_sigill;
sa.sa_flags = SA_SIGINFO;
if (sigaction(SIGILL, &sa, NULL) < 0) {
perror("sigaction");
return 1;
}
/*
* ??? With "extern char test_begin[]", some compiler versions
* will use :got references, and some linker versions will
* resolve this reference to a static symbol incorrectly.
* Bypass this error by using a pc-relative reference directly.
*/
asm("adr %0, test_begin; adr %1, test_end" : "=r"(tb), "=r"(te));
memcpy(p, tb, te - tb);
return ((int (*)(void))p)();
}

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@ -0,0 +1,51 @@
/*
* Minimal user-environment for testing BTI.
*
* Normal libc is not (yet) built with BTI support enabled,
* and so could generate a BTI TRAP before ever reaching main.
*/
#include <stdlib.h>
#include <signal.h>
#include <ucontext.h>
#include <asm/unistd.h>
int main(void);
void _start(void)
{
exit(main());
}
void exit(int ret)
{
register int x0 __asm__("x0") = ret;
register int x8 __asm__("x8") = __NR_exit;
asm volatile("svc #0" : : "r"(x0), "r"(x8));
__builtin_unreachable();
}
/*
* Irritatingly, the user API struct sigaction does not match the
* kernel API struct sigaction. So for simplicity, isolate the
* kernel ABI here, and make this act like signal.
*/
void signal_info(int sig, void (*fn)(int, siginfo_t *, ucontext_t *))
{
struct kernel_sigaction {
void (*handler)(int, siginfo_t *, ucontext_t *);
unsigned long flags;
unsigned long restorer;
unsigned long mask;
} sa = { fn, SA_SIGINFO, 0, 0 };
register int x0 __asm__("x0") = sig;
register void *x1 __asm__("x1") = &sa;
register void *x2 __asm__("x2") = 0;
register int x3 __asm__("x3") = sizeof(unsigned long);
register int x8 __asm__("x8") = __NR_rt_sigaction;
asm volatile("svc #0"
: : "r"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x8) : "memory");
}

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@ -240,6 +240,10 @@ for target in $target_list; do
-march=armv8.3-a -o $TMPE $TMPC; then
echo "CROSS_CC_HAS_ARMV8_3=y" >> $config_target_mak
fi
if do_compiler "$target_compiler" $target_compiler_cflags \
-mbranch-protection=standard -o $TMPE $TMPC; then
echo "CROSS_CC_HAS_ARMV8_BTI=y" >> $config_target_mak
fi
;;
esac