diff options
| -rw-r--r-- | target/arm/pauth_helper.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/target/arm/pauth_helper.c b/target/arm/pauth_helper.c index fa7707e0bf..bc89dd8c11 100644 --- a/target/arm/pauth_helper.c +++ b/target/arm/pauth_helper.c @@ -35,7 +35,47 @@ static uint64_t pauth_computepac(uint64_t data, uint64_t modifier, static uint64_t pauth_addpac(CPUARMState *env, uint64_t ptr, uint64_t modifier, ARMPACKey *key, bool data) { - g_assert_not_reached(); /* FIXME */ + ARMMMUIdx mmu_idx = arm_stage1_mmu_idx(env); + ARMVAParameters param = aa64_va_parameters(env, ptr, mmu_idx, data); + uint64_t pac, ext_ptr, ext, test; + int bot_bit, top_bit; + + /* If tagged pointers are in use, use ptr<55>, otherwise ptr<63>. */ + if (param.tbi) { + ext = sextract64(ptr, 55, 1); + } else { + ext = sextract64(ptr, 63, 1); + } + + /* Build a pointer with known good extension bits. */ + top_bit = 64 - 8 * param.tbi; + bot_bit = 64 - param.tsz; + ext_ptr = deposit64(ptr, bot_bit, top_bit - bot_bit, ext); + + pac = pauth_computepac(ext_ptr, modifier, *key); + + /* + * Check if the ptr has good extension bits and corrupt the + * pointer authentication code if not. + */ + test = sextract64(ptr, bot_bit, top_bit - bot_bit); + if (test != 0 && test != -1) { + pac ^= MAKE_64BIT_MASK(top_bit - 1, 1); + } + + /* + * Preserve the determination between upper and lower at bit 55, + * and insert pointer authentication code. + */ + if (param.tbi) { + ptr &= ~MAKE_64BIT_MASK(bot_bit, 55 - bot_bit + 1); + pac &= MAKE_64BIT_MASK(bot_bit, 54 - bot_bit + 1); + } else { + ptr &= MAKE_64BIT_MASK(0, bot_bit); + pac &= ~(MAKE_64BIT_MASK(55, 1) | MAKE_64BIT_MASK(0, bot_bit)); + } + ext &= MAKE_64BIT_MASK(55, 1); + return pac | ext | ptr; } static uint64_t pauth_original_ptr(uint64_t ptr, ARMVAParameters param) |