From 87d7bfdba1d4a963e9a89052c38a32327fa25473 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 20 Dec 2021 18:50:06 -0800 Subject: [PATCH] linux-user/nios2: Properly emulate EXCP_TRAP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The real kernel has to load the instruction and extract the imm5 field; for qemu, modify the translator to do this. The use of R_AT for this in cpu_loop was a bug. Handle the other trap numbers as per the kernel's trap_table. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson Reviewed-by: Laurent Vivier Message-Id: <20211221025012.1057923-2-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/nios2/cpu_loop.c | 40 ++++++++++++++++++++----------------- target/nios2/cpu.h | 2 +- target/nios2/translate.c | 17 +++++++++++++++- 3 files changed, 39 insertions(+), 20 deletions(-) diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c index 34290fb3b5..5c3d01d22d 100644 --- a/linux-user/nios2/cpu_loop.c +++ b/linux-user/nios2/cpu_loop.c @@ -26,7 +26,6 @@ void cpu_loop(CPUNios2State *env) { CPUState *cs = env_cpu(env); - Nios2CPU *cpu = NIOS2_CPU(cs); target_siginfo_t info; int trapnr, ret; @@ -39,9 +38,10 @@ void cpu_loop(CPUNios2State *env) case EXCP_INTERRUPT: /* just indicate that signals should be handled asap */ break; + case EXCP_TRAP: - if (env->regs[R_AT] == 0) { - abi_long ret; + switch (env->error_code) { + case 0: qemu_log_mask(CPU_LOG_INT, "\nSyscall\n"); ret = do_syscall(env, env->regs[2], @@ -55,26 +55,30 @@ void cpu_loop(CPUNios2State *env) env->regs[2] = abs(ret); /* Return value is 0..4096 */ - env->regs[7] = (ret > 0xfffffffffffff000ULL); - env->regs[CR_ESTATUS] = env->regs[CR_STATUS]; - env->regs[CR_STATUS] &= ~0x3; - env->regs[R_EA] = env->regs[R_PC] + 4; + env->regs[7] = ret > 0xfffff000u; env->regs[R_PC] += 4; break; - } else { - qemu_log_mask(CPU_LOG_INT, "\nTrap\n"); - env->regs[CR_ESTATUS] = env->regs[CR_STATUS]; - env->regs[CR_STATUS] &= ~0x3; - env->regs[R_EA] = env->regs[R_PC] + 4; - env->regs[R_PC] = cpu->exception_addr; - - info.si_signo = TARGET_SIGTRAP; - info.si_errno = 0; - info.si_code = TARGET_TRAP_BRKPT; - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + case 1: + qemu_log_mask(CPU_LOG_INT, "\nTrap 1\n"); + force_sig_fault(TARGET_SIGUSR1, 0, env->regs[R_PC]); + break; + case 2: + qemu_log_mask(CPU_LOG_INT, "\nTrap 2\n"); + force_sig_fault(TARGET_SIGUSR2, 0, env->regs[R_PC]); + break; + case 31: + qemu_log_mask(CPU_LOG_INT, "\nTrap 31\n"); + force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[R_PC]); + break; + default: + qemu_log_mask(CPU_LOG_INT, "\nTrap %d\n", env->error_code); + force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, + env->regs[R_PC]); break; } + break; + case EXCP_DEBUG: info.si_signo = TARGET_SIGTRAP; info.si_errno = 0; diff --git a/target/nios2/cpu.h b/target/nios2/cpu.h index 1a69ed7a49..d2ba0c5bbd 100644 --- a/target/nios2/cpu.h +++ b/target/nios2/cpu.h @@ -160,9 +160,9 @@ struct CPUNios2State { #if !defined(CONFIG_USER_ONLY) Nios2MMU mmu; - uint32_t irq_pending; #endif + int error_code; }; /** diff --git a/target/nios2/translate.c b/target/nios2/translate.c index 08d7ac5398..a759877519 100644 --- a/target/nios2/translate.c +++ b/target/nios2/translate.c @@ -636,6 +636,21 @@ static void divu(DisasContext *dc, uint32_t code, uint32_t flags) tcg_temp_free(t0); } +static void trap(DisasContext *dc, uint32_t code, uint32_t flags) +{ +#ifdef CONFIG_USER_ONLY + /* + * The imm5 field is not stored anywhere on real hw; the kernel + * has to load the insn and extract the field. But we can make + * things easier for cpu_loop if we pop this into env->error_code. + */ + R_TYPE(instr, code); + tcg_gen_st_i32(tcg_constant_i32(instr.imm5), cpu_env, + offsetof(CPUNios2State, error_code)); +#endif + t_gen_helper_raise_exception(dc, EXCP_TRAP); +} + static const Nios2Instruction r_type_instructions[] = { INSTRUCTION_ILLEGAL(), INSTRUCTION(eret), /* eret */ @@ -682,7 +697,7 @@ static const Nios2Instruction r_type_instructions[] = { INSTRUCTION_ILLEGAL(), INSTRUCTION_ILLEGAL(), INSTRUCTION_ILLEGAL(), - INSTRUCTION_FLG(gen_excp, EXCP_TRAP), /* trap */ + INSTRUCTION(trap), /* trap */ INSTRUCTION(wrctl), /* wrctl */ INSTRUCTION_ILLEGAL(), INSTRUCTION_FLG(gen_cmpxx, TCG_COND_LTU), /* cmpltu */