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Re: [PATCH 1/1] tests/tcg/aarch64: Add bti mmap smoke test
From: |
Alex Bennée |
Subject: |
Re: [PATCH 1/1] tests/tcg/aarch64: Add bti mmap smoke test |
Date: |
Wed, 07 Oct 2020 16:05:59 +0100 |
User-agent: |
mu4e 1.5.5; emacs 28.0.50 |
Richard Henderson <richard.henderson@linaro.org> writes:
> This tests PROT_BTI, and also does not require special
> compiler support.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> tests/tcg/aarch64/bti-2.c | 108 ++++++++++++++++++++++++++++++
> tests/tcg/aarch64/Makefile.target | 7 +-
> 2 files changed, 113 insertions(+), 2 deletions(-)
> create mode 100644 tests/tcg/aarch64/bti-2.c
>
> diff --git a/tests/tcg/aarch64/bti-2.c b/tests/tcg/aarch64/bti-2.c
> new file mode 100644
> index 0000000000..6dc8908b5a
> --- /dev/null
> +++ b/tests/tcg/aarch64/bti-2.c
> @@ -0,0 +1,108 @@
> +/*
> + * 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"
> +
> +extern char test_begin[], test_end[];
> +
> +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 *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;
> + }
> +
> + memcpy(p, test_begin, test_end - test_begin);
> + return ((int (*)(void))p)();
> +}
> diff --git a/tests/tcg/aarch64/Makefile.target
> b/tests/tcg/aarch64/Makefile.target
> index 491683e91d..d7d33e293c 100644
> --- a/tests/tcg/aarch64/Makefile.target
> +++ b/tests/tcg/aarch64/Makefile.target
> @@ -26,11 +26,14 @@ 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-%: CFLAGS += -mbranch-protection=standard
> -bti-%: LDFLAGS += -nostdlib
> +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
LGTM
Acked-by: Alex Bennée <alex.bennee@linaro.org>
(I assume this just rolls up with your existing BTI patches).
--
Alex Bennée