From be0e3d7a1e148180fe1b89c7f93720db0607614e Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 1 Jun 2018 16:55:52 -0700 Subject: [PATCH] target/sh4: Fix translator.c assertion failure for gUSA MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The translator loop does not allow the tb_start hook to set dc->base.is_jmp; the only hook allowed to do that is translate_insn. Split the work between init_disas_context where we validate the gUSA parameters, and translate_insn where we emit code. Tested-by: Alex Bennée Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- target/sh4/translate.c | 81 +++++++++++++++++++++++++++----------------------- 1 file changed, 44 insertions(+), 37 deletions(-) diff --git a/target/sh4/translate.c b/target/sh4/translate.c index c716b74a0f..1b9a201d6d 100644 --- a/target/sh4/translate.c +++ b/target/sh4/translate.c @@ -1895,35 +1895,18 @@ static void decode_opc(DisasContext * ctx) any sequence via cpu_exec_step_atomic, we can recognize the "normal" sequences and transform them into atomic operations as seen by the host. */ -static int decode_gusa(DisasContext *ctx, CPUSH4State *env, int *pmax_insns) +static void decode_gusa(DisasContext *ctx, CPUSH4State *env) { uint16_t insns[5]; int ld_adr, ld_dst, ld_mop; int op_dst, op_src, op_opc; int mv_src, mt_dst, st_src, st_mop; TCGv op_arg; - uint32_t pc = ctx->base.pc_next; uint32_t pc_end = ctx->base.tb->cs_base; - int backup = sextract32(ctx->tbflags, GUSA_SHIFT, 8); int max_insns = (pc_end - pc) / 2; int i; - if (pc != pc_end + backup || max_insns < 2) { - /* This is a malformed gUSA region. Don't do anything special, - since the interpreter is likely to get confused. */ - ctx->envflags &= ~GUSA_MASK; - return 0; - } - - if (ctx->tbflags & GUSA_EXCLUSIVE) { - /* Regardless of single-stepping or the end of the page, - we must complete execution of the gUSA region while - holding the exclusive lock. */ - *pmax_insns = max_insns; - return 0; - } - /* The state machine below will consume only a few insns. If there are more than that in a region, fail now. */ if (max_insns > ARRAY_SIZE(insns)) { @@ -2140,7 +2123,6 @@ static int decode_gusa(DisasContext *ctx, CPUSH4State *env, int *pmax_insns) /* * Emit the operation. */ - tcg_gen_insn_start(pc, ctx->envflags); switch (op_opc) { case -1: /* No operation found. Look for exchange pattern. */ @@ -2235,7 +2217,8 @@ static int decode_gusa(DisasContext *ctx, CPUSH4State *env, int *pmax_insns) /* The entire region has been translated. */ ctx->envflags &= ~GUSA_MASK; ctx->base.pc_next = pc_end; - return max_insns; + ctx->base.num_insns += max_insns - 1; + return; fail: qemu_log_mask(LOG_UNIMP, "Unrecognized gUSA sequence %08x-%08x\n", @@ -2243,7 +2226,6 @@ static int decode_gusa(DisasContext *ctx, CPUSH4State *env, int *pmax_insns) /* Restart with the EXCLUSIVE bit set, within a TB run via cpu_exec_step_atomic holding the exclusive lock. */ - tcg_gen_insn_start(pc, ctx->envflags); ctx->envflags |= GUSA_EXCLUSIVE; gen_save_cpu_state(ctx, false); gen_helper_exclusive(cpu_env); @@ -2254,7 +2236,7 @@ static int decode_gusa(DisasContext *ctx, CPUSH4State *env, int *pmax_insns) entire region consumed via ctx->base.pc_next so that it's immediately available in the disassembly dump. */ ctx->base.pc_next = pc_end; - return 1; + ctx->base.num_insns += max_insns - 1; } #endif @@ -2262,19 +2244,39 @@ static void sh4_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) { DisasContext *ctx = container_of(dcbase, DisasContext, base); CPUSH4State *env = cs->env_ptr; + uint32_t tbflags; int bound; - ctx->tbflags = (uint32_t)ctx->base.tb->flags; - ctx->envflags = ctx->base.tb->flags & TB_FLAG_ENVFLAGS_MASK; - ctx->memidx = (ctx->tbflags & (1u << SR_MD)) == 0 ? 1 : 0; + ctx->tbflags = tbflags = ctx->base.tb->flags; + ctx->envflags = tbflags & TB_FLAG_ENVFLAGS_MASK; + ctx->memidx = (tbflags & (1u << SR_MD)) == 0 ? 1 : 0; /* We don't know if the delayed pc came from a dynamic or static branch, so assume it is a dynamic branch. */ ctx->delayed_pc = -1; /* use delayed pc from env pointer */ ctx->features = env->features; - ctx->has_movcal = (ctx->tbflags & TB_FLAG_PENDING_MOVCA); - ctx->gbank = ((ctx->tbflags & (1 << SR_MD)) && - (ctx->tbflags & (1 << SR_RB))) * 0x10; - ctx->fbank = ctx->tbflags & FPSCR_FR ? 0x10 : 0; + ctx->has_movcal = (tbflags & TB_FLAG_PENDING_MOVCA); + ctx->gbank = ((tbflags & (1 << SR_MD)) && + (tbflags & (1 << SR_RB))) * 0x10; + ctx->fbank = tbflags & FPSCR_FR ? 0x10 : 0; + + if (tbflags & GUSA_MASK) { + uint32_t pc = ctx->base.pc_next; + uint32_t pc_end = ctx->base.tb->cs_base; + int backup = sextract32(ctx->tbflags, GUSA_SHIFT, 8); + int max_insns = (pc_end - pc) / 2; + + if (pc != pc_end + backup || max_insns < 2) { + /* This is a malformed gUSA region. Don't do anything special, + since the interpreter is likely to get confused. */ + ctx->envflags &= ~GUSA_MASK; + } else if (tbflags & GUSA_EXCLUSIVE) { + /* Regardless of single-stepping or the end of the page, + we must complete execution of the gUSA region while + holding the exclusive lock. */ + ctx->base.max_insns = max_insns; + return; + } + } /* Since the ISA is fixed-width, we can bound by the number of instructions remaining on the page. */ @@ -2284,14 +2286,6 @@ static void sh4_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) static void sh4_tr_tb_start(DisasContextBase *dcbase, CPUState *cs) { -#ifdef CONFIG_USER_ONLY - DisasContext *ctx = container_of(dcbase, DisasContext, base); - CPUSH4State *env = cs->env_ptr; - - if (ctx->tbflags & GUSA_MASK) { - ctx->base.num_insns = decode_gusa(ctx, env, &ctx->base.max_insns); - } -#endif } static void sh4_tr_insn_start(DisasContextBase *dcbase, CPUState *cs) @@ -2323,6 +2317,19 @@ static void sh4_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs) CPUSH4State *env = cs->env_ptr; DisasContext *ctx = container_of(dcbase, DisasContext, base); +#ifdef CONFIG_USER_ONLY + if (unlikely(ctx->envflags & GUSA_MASK) + && !(ctx->envflags & GUSA_EXCLUSIVE)) { + /* We're in an gUSA region, and we have not already fallen + back on using an exclusive region. Attempt to parse the + region into a single supported atomic operation. Failure + is handled within the parser by raising an exception to + retry using an exclusive region. */ + decode_gusa(ctx, env); + return; + } +#endif + ctx->opcode = cpu_lduw_code(env, ctx->base.pc_next); decode_opc(ctx); ctx->base.pc_next += 2; -- 2.11.0