From 4ff5ef9e911c670ca10cdd36dd27c5395ec2c753 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Tue, 17 Dec 2019 15:08:57 +0000 Subject: target/arm: only update pc after semihosting completes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Before we introduce blocking semihosting calls we need to ensure we can restart the system on semi hosting exception. To be able to do this the EXCP_SEMIHOST operation should be idempotent until it finally completes. Practically this means ensureing we only update the pc after the semihosting call has completed. Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Reviewed-by: Keith Packard Tested-by: Keith Packard --- target/arm/helper.c | 2 ++ target/arm/m_helper.c | 1 + target/arm/translate-a64.c | 2 +- target/arm/translate.c | 6 +++--- 4 files changed, 7 insertions(+), 4 deletions(-) (limited to 'target/arm') diff --git a/target/arm/helper.c b/target/arm/helper.c index da22c19800..19a57a17da 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8614,11 +8614,13 @@ static void handle_semihosting(CPUState *cs) "...handling as semihosting call 0x%" PRIx64 "\n", env->xregs[0]); env->xregs[0] = do_arm_semihosting(env); + env->pc += 4; } else { qemu_log_mask(CPU_LOG_INT, "...handling as semihosting call 0x%x\n", env->regs[0]); env->regs[0] = do_arm_semihosting(env); + env->regs[15] += env->thumb ? 2 : 4; } } #endif diff --git a/target/arm/m_helper.c b/target/arm/m_helper.c index 76de317e6a..33d414a684 100644 --- a/target/arm/m_helper.c +++ b/target/arm/m_helper.c @@ -2185,6 +2185,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) "...handling as semihosting call 0x%x\n", env->regs[0]); env->regs[0] = do_arm_semihosting(env); + env->regs[15] += env->thumb ? 2 : 4; return; case EXCP_BKPT: armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG, false); diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index d4bebbe629..972c28c3c9 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1937,7 +1937,7 @@ static void disas_exc(DisasContext *s, uint32_t insn) break; } #endif - gen_exception_internal_insn(s, s->base.pc_next, EXCP_SEMIHOST); + gen_exception_internal_insn(s, s->pc_curr, EXCP_SEMIHOST); } else { unsupported_encoding(s, insn); } diff --git a/target/arm/translate.c b/target/arm/translate.c index 2b6c1f91bf..5185e08641 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -1124,7 +1124,7 @@ static inline void gen_hlt(DisasContext *s, int imm) s->current_el != 0 && #endif (imm == (s->thumb ? 0x3c : 0xf000))) { - gen_exception_internal_insn(s, s->base.pc_next, EXCP_SEMIHOST); + gen_exception_internal_insn(s, s->pc_curr, EXCP_SEMIHOST); return; } @@ -8457,7 +8457,7 @@ static bool trans_BKPT(DisasContext *s, arg_BKPT *a) !IS_USER(s) && #endif (a->imm == 0xab)) { - gen_exception_internal_insn(s, s->base.pc_next, EXCP_SEMIHOST); + gen_exception_internal_insn(s, s->pc_curr, EXCP_SEMIHOST); } else { gen_exception_bkpt_insn(s, syn_aa32_bkpt(a->imm, false)); } @@ -10266,7 +10266,7 @@ static bool trans_SVC(DisasContext *s, arg_SVC *a) !IS_USER(s) && #endif (a->imm == semihost_imm)) { - gen_exception_internal_insn(s, s->base.pc_next, EXCP_SEMIHOST); + gen_exception_internal_insn(s, s->pc_curr, EXCP_SEMIHOST); } else { gen_set_pc_im(s, s->base.pc_next); s->svc_imm = a->imm; -- cgit v1.2.3