From d4881da9b39df183f976349f223231ac1d81087b Mon Sep 17 00:00:00 2001 From: Bastian Koppelmann Date: Wed, 21 Aug 2019 11:15:10 +0200 Subject: target/tricore: Fix tricore_tr_translate_insn we now fetch 2 bytes first, check whether we have a 32 bit insn, and only then fetch another 2 bytes. We also make sure that a 16 bit insn that still fits into the current page does not end up in the next page. Reviewed-by: Richard Henderson Signed-off-by: Bastian Koppelmann --- target/tricore/translate.c | 47 +++++++++++++++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 13 deletions(-) (limited to 'target/tricore') diff --git a/target/tricore/translate.c b/target/tricore/translate.c index 88b2840..4f10407 100644 --- a/target/tricore/translate.c +++ b/target/tricore/translate.c @@ -8781,17 +8781,9 @@ static void decode_32Bit_opc(DisasContext *ctx) } } -static void decode_opc(DisasContext *ctx) +static bool tricore_insn_is_16bit(uint32_t insn) { - /* 16-Bit Instruction */ - if ((ctx->opcode & 0x1) == 0) { - ctx->pc_succ_insn = ctx->base.pc_next + 2; - decode_16Bit_opc(ctx); - /* 32-Bit Instruction */ - } else { - ctx->pc_succ_insn = ctx->base.pc_next + 4; - decode_32Bit_opc(ctx); - } + return (insn & 0x1) == 0; } static void tricore_tr_init_disas_context(DisasContextBase *dcbase, @@ -8829,20 +8821,49 @@ static bool tricore_tr_breakpoint_check(DisasContextBase *dcbase, CPUState *cpu, return true; } +static bool insn_crosses_page(CPUTriCoreState *env, DisasContext *ctx) +{ + /* + * Return true if the insn at ctx->base.pc_next might cross a page boundary. + * (False positives are OK, false negatives are not.) + * Our caller ensures we are only called if dc->base.pc_next is less than + * 4 bytes from the page boundary, so we cross the page if the first + * 16 bits indicate that this is a 32 bit insn. + */ + uint16_t insn = cpu_lduw_code(env, ctx->base.pc_next); + + return !tricore_insn_is_16bit(insn); +} + + static void tricore_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) { DisasContext *ctx = container_of(dcbase, DisasContext, base); CPUTriCoreState *env = cpu->env_ptr; + uint16_t insn_lo; + bool is_16bit; - ctx->opcode = cpu_ldl_code(env, ctx->base.pc_next); - decode_opc(ctx); + insn_lo = cpu_lduw_code(env, ctx->base.pc_next); + is_16bit = tricore_insn_is_16bit(insn_lo); + if (is_16bit) { + ctx->opcode = insn_lo; + ctx->pc_succ_insn = ctx->base.pc_next + 2; + decode_16Bit_opc(ctx); + } else { + uint32_t insn_hi = cpu_lduw_code(env, ctx->base.pc_next + 2); + ctx->opcode = insn_hi << 16 | insn_lo; + ctx->pc_succ_insn = ctx->base.pc_next + 4; + decode_32Bit_opc(ctx); + } ctx->base.pc_next = ctx->pc_succ_insn; if (ctx->base.is_jmp == DISAS_NEXT) { target_ulong page_start; page_start = ctx->base.pc_first & TARGET_PAGE_MASK; - if (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE) { + if (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE + || (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE - 3 + && insn_crosses_page(env, ctx))) { ctx->base.is_jmp = DISAS_TOO_MANY; } } -- cgit v1.1