From 4a2696c0d4d80e14a192b28148c6167bc5056f94 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 8 Feb 2020 12:58:10 +0000 Subject: target/arm: Set PAN bit as required on exception entry The PAN bit is preserved, or set as per SCTLR_ELx.SPAN, plus several other conditions listed in the ARM ARM. Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell Message-id: 20200208125816.14954-15-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/helper.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 50 insertions(+), 3 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 178757d271..de16ce79ad 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8763,8 +8763,12 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode, uint32_t mask, uint32_t offset, uint32_t newpc) { + int new_el; + /* Change the CPU state so as to actually take the exception. */ switch_mode(env, new_mode); + new_el = arm_current_el(env); + /* * For exceptions taken to AArch32 we must clear the SS bit in both * PSTATE and in the old-state value we save to SPSR_, so zero it now. @@ -8777,7 +8781,7 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode, env->uncached_cpsr = (env->uncached_cpsr & ~CPSR_M) | new_mode; /* Set new mode endianness */ env->uncached_cpsr &= ~CPSR_E; - if (env->cp15.sctlr_el[arm_current_el(env)] & SCTLR_EE) { + if (env->cp15.sctlr_el[new_el] & SCTLR_EE) { env->uncached_cpsr |= CPSR_E; } /* J and IL must always be cleared for exception entry */ @@ -8788,6 +8792,25 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode, env->thumb = (env->cp15.sctlr_el[2] & SCTLR_TE) != 0; env->elr_el[2] = env->regs[15]; } else { + /* CPSR.PAN is normally preserved preserved unless... */ + if (cpu_isar_feature(aa64_pan, env_archcpu(env))) { + switch (new_el) { + case 3: + if (!arm_is_secure_below_el3(env)) { + /* ... the target is EL3, from non-secure state. */ + env->uncached_cpsr &= ~CPSR_PAN; + break; + } + /* ... the target is EL3, from secure state ... */ + /* fall through */ + case 1: + /* ... the target is EL1 and SCTLR.SPAN is 0. */ + if (!(env->cp15.sctlr_el[new_el] & SCTLR_SPAN)) { + env->uncached_cpsr |= CPSR_PAN; + } + break; + } + } /* * this is a lie, as there was no c1_sys on V4T/V5, but who cares * and we should just guard the thumb mode on V4 @@ -9050,6 +9073,7 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs) unsigned int new_el = env->exception.target_el; target_ulong addr = env->cp15.vbar_el[new_el]; unsigned int new_mode = aarch64_pstate_mode(new_el, true); + unsigned int old_mode; unsigned int cur_el = arm_current_el(env); /* @@ -9129,20 +9153,43 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs) } if (is_a64(env)) { - env->banked_spsr[aarch64_banked_spsr_index(new_el)] = pstate_read(env); + old_mode = pstate_read(env); aarch64_save_sp(env, arm_current_el(env)); env->elr_el[new_el] = env->pc; } else { - env->banked_spsr[aarch64_banked_spsr_index(new_el)] = cpsr_read(env); + old_mode = cpsr_read(env); env->elr_el[new_el] = env->regs[15]; aarch64_sync_32_to_64(env); env->condexec_bits = 0; } + env->banked_spsr[aarch64_banked_spsr_index(new_el)] = old_mode; + qemu_log_mask(CPU_LOG_INT, "...with ELR 0x%" PRIx64 "\n", env->elr_el[new_el]); + if (cpu_isar_feature(aa64_pan, cpu)) { + /* The value of PSTATE.PAN is normally preserved, except when ... */ + new_mode |= old_mode & PSTATE_PAN; + switch (new_el) { + case 2: + /* ... the target is EL2 with HCR_EL2.{E2H,TGE} == '11' ... */ + if ((arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) + != (HCR_E2H | HCR_TGE)) { + break; + } + /* fall through */ + case 1: + /* ... the target is EL1 ... */ + /* ... and SCTLR_ELx.SPAN == 0, then set to 1. */ + if ((env->cp15.sctlr_el[new_el] & SCTLR_SPAN) == 0) { + new_mode |= PSTATE_PAN; + } + break; + } + } + pstate_write(env, PSTATE_DAIF | new_mode); env->aarch64 = 1; aarch64_restore_sp(env, new_el); -- cgit v1.2.3