From d67ebada159148bfdfde84871338738e4465e985 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 9 Jun 2019 15:22:49 -0700 Subject: target/arm: Fix output of PAuth Auth The ARM pseudocode installs the error_code into the original pointer, not the encrypted pointer. The difference applies within the 7 bits of pac data; the result should be the sign extension of bit 55. Add a testcase to that effect. Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- tests/tcg/aarch64/Makefile.target | 2 +- tests/tcg/aarch64/pauth-2.c | 61 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+), 1 deletion(-) create mode 100644 tests/tcg/aarch64/pauth-2.c (limited to 'tests/tcg') diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target index 2bb914975b..31ba9cfcaa 100644 --- a/tests/tcg/aarch64/Makefile.target +++ b/tests/tcg/aarch64/Makefile.target @@ -15,7 +15,7 @@ run-fcvt: fcvt $(call run-test,$<,$(QEMU) $<, "$< on $(TARGET_NAME)") $(call diff-out,$<,$(AARCH64_SRC)/fcvt.ref) -AARCH64_TESTS += pauth-1 +AARCH64_TESTS += pauth-1 pauth-2 run-pauth-%: QEMU += -cpu max TESTS:=$(AARCH64_TESTS) diff --git a/tests/tcg/aarch64/pauth-2.c b/tests/tcg/aarch64/pauth-2.c new file mode 100644 index 0000000000..2fe030ba3d --- /dev/null +++ b/tests/tcg/aarch64/pauth-2.c @@ -0,0 +1,61 @@ +#include +#include + +asm(".arch armv8.4-a"); + +void do_test(uint64_t value) +{ + uint64_t salt1, salt2; + uint64_t encode, decode; + + /* + * With TBI enabled and a 48-bit VA, there are 7 bits of auth, + * and so a 1/128 chance of encode = pac(value,key,salt) producing + * an auth for which leaves value unchanged. + * Iterate until we find a salt for which encode != value. + */ + for (salt1 = 1; ; salt1++) { + asm volatile("pacda %0, %2" : "=r"(encode) : "0"(value), "r"(salt1)); + if (encode != value) { + break; + } + } + + /* A valid salt must produce a valid authorization. */ + asm volatile("autda %0, %2" : "=r"(decode) : "0"(encode), "r"(salt1)); + assert(decode == 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. + */ + for (salt2 = salt1 + 1; ; salt2++) { + asm volatile("autda %0, %2" : "=r"(decode) : "0"(encode), "r"(salt2)); + if (decode != value) { + break; + } + } + + /* 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. + */ + if ((value >> 55) & 1) { + assert(((decode >> 48) & 0xff) == 0b10111111); + } else { + assert(((decode >> 48) & 0xff) == 0b00100000); + } +} + +int main() +{ + do_test(0); + do_test(-1); + do_test(0xda004acedeadbeefull); + return 0; +} -- cgit v1.2.3