From ba9c5de5f2d33d468a07a8794121472ea031a0b5 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 28 Jun 2014 13:06:19 -0700 Subject: [PATCH] target-alpha: Set PC correctly for floating-point exceptions PC should be one past the faulting insn. Add better commentary for the machine-check exception path. Reported-by: Al Viro Signed-off-by: Richard Henderson --- target-alpha/helper.c | 2 ++ target-alpha/mem_helper.c | 9 ++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/target-alpha/helper.c b/target-alpha/helper.c index a8aa782a2a..e202fee659 100644 --- a/target-alpha/helper.c +++ b/target-alpha/helper.c @@ -571,6 +571,8 @@ void QEMU_NORETURN dynamic_excp(CPUAlphaState *env, uintptr_t retaddr, env->error_code = error; if (retaddr) { cpu_restore_state(cs, retaddr); + /* Floating-point exceptions (our only users) point to the next PC. */ + env->pc += 4; } cpu_loop_exit(cs); } diff --git a/target-alpha/mem_helper.c b/target-alpha/mem_helper.c index fc4f57a644..7b5e30ddb7 100644 --- a/target-alpha/mem_helper.c +++ b/target-alpha/mem_helper.c @@ -128,7 +128,14 @@ void alpha_cpu_unassigned_access(CPUState *cs, hwaddr addr, env->trap_arg0 = addr; env->trap_arg1 = is_write ? 1 : 0; - dynamic_excp(env, 0, EXCP_MCHK, 0); + cs->exception_index = EXCP_MCHK; + env->error_code = 0; + + /* ??? We should cpu_restore_state to the faulting insn, but this hook + does not have access to the retaddr value from the orignal helper. + It's all moot until the QEMU PALcode grows an MCHK handler. */ + + cpu_loop_exit(cs); } /* try to fill the TLB and return an exception if error. If retaddr is