diff options
| -rw-r--r-- | target/arm/pauth_helper.c | 6 | ||||
| -rw-r--r-- | tests/tcg/aarch64/Makefile.target | 2 | ||||
| -rw-r--r-- | tests/tcg/aarch64/pauth-5.c | 33 |
3 files changed, 39 insertions, 2 deletions
diff --git a/target/arm/pauth_helper.c b/target/arm/pauth_helper.c index b909630..6dbab03 100644 --- a/target/arm/pauth_helper.c +++ b/target/arm/pauth_helper.c @@ -300,7 +300,11 @@ static uint64_t pauth_addpac(CPUARMState *env, uint64_t ptr, uint64_t modifier, */ test = sextract64(ptr, bot_bit, top_bit - bot_bit); if (test != 0 && test != -1) { - pac ^= MAKE_64BIT_MASK(top_bit - 1, 1); + /* + * Note that our top_bit is one greater than the pseudocode's + * version, hence "- 2" here. + */ + pac ^= MAKE_64BIT_MASK(top_bit - 2, 1); } /* diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target index b617f2a..e724991 100644 --- a/tests/tcg/aarch64/Makefile.target +++ b/tests/tcg/aarch64/Makefile.target @@ -19,7 +19,7 @@ run-fcvt: fcvt # Pauth Tests ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_3),) -AARCH64_TESTS += pauth-1 pauth-2 pauth-4 +AARCH64_TESTS += pauth-1 pauth-2 pauth-4 pauth-5 pauth-%: CFLAGS += -march=armv8.3-a run-pauth-%: QEMU_OPTS += -cpu max run-plugin-pauth-%: QEMU_OPTS += -cpu max diff --git a/tests/tcg/aarch64/pauth-5.c b/tests/tcg/aarch64/pauth-5.c new file mode 100644 index 0000000..67c2579 --- /dev/null +++ b/tests/tcg/aarch64/pauth-5.c @@ -0,0 +1,33 @@ +#include <assert.h> + +static int x; + +int main() +{ + int *p0 = &x, *p1, *p2, *p3; + unsigned long salt = 0; + + /* + * With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so + * a 1/128 chance of auth = pac(ptr,key,salt) producing zero. + * Find a salt that creates auth != 0. + */ + do { + salt++; + asm("pacda %0, %1" : "=r"(p1) : "r"(salt), "0"(p0)); + } while (p0 == p1); + + /* + * This pac must fail, because the input pointer bears an encryption, + * and so is not properly extended within bits [55:47]. This will + * toggle bit 54 in the output... + */ + asm("pacda %0, %1" : "=r"(p2) : "r"(salt), "0"(p1)); + + /* ... so that the aut must fail, setting bit 53 in the output ... */ + asm("autda %0, %1" : "=r"(p3) : "r"(salt), "0"(p2)); + + /* ... which means this equality must not hold. */ + assert(p3 != p0); + return 0; +} |