From 95e39f60bea1db5c733aec280ad8dc6aee046cc8 Mon Sep 17 00:00:00 2001 From: Jeff Kubascik Date: Sat, 21 Mar 2020 12:07:02 -0400 Subject: [PATCH] target/arm: adjust program counter for wfi exception in AArch32 The wfi instruction can be configured to be trapped by a higher exception level, such as the EL2 hypervisor. When the instruction is trapped, the program counter should contain the address of the wfi instruction that caused the exception. The program counter is adjusted for this in the wfi op helper function. However, this correction is done to env->pc, which only applies to AArch64 mode. For AArch32, the program counter is stored in env->regs[15]. This adds an if-else statement to modify the correct program counter location based on the the current CPU mode. Backports commit 855532912b0e1bf803ae393e5b0c7e80948cd6a4 from qemu --- qemu/target/arm/op_helper.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/qemu/target/arm/op_helper.c b/qemu/target/arm/op_helper.c index 07d88b49..c4be91dd 100644 --- a/qemu/target/arm/op_helper.c +++ b/qemu/target/arm/op_helper.c @@ -297,7 +297,12 @@ void HELPER(wfi)(CPUARMState *env, uint32_t insn_len) } if (target_el) { - env->pc -= insn_len; + if (env->aarch64) { + env->pc -= insn_len; + } else { + env->regs[15] -= insn_len; + } + raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0, insn_len == 2), target_el); }