From 462c254430b49ef708c75e038d7e796764058ca1 Mon Sep 17 00:00:00 2001 From: "Edgar E. Iglesias" Date: Thu, 14 Jun 2018 15:48:16 +0200 Subject: target-microblaze: Rework NOP/zero instruction handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remove the abort on a sequence of NOP/zero instructions. Always return early and avoid decoding NOP/zero instructions. This fixes Coverity CID 1391443. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Edgar E. Iglesias --- target/microblaze/translate.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c index 6c64946..78ca265 100644 --- a/target/microblaze/translate.c +++ b/target/microblaze/translate.c @@ -90,7 +90,6 @@ typedef struct DisasContext { uint32_t jmp_pc; int abort_at_next_insn; - int nr_nops; struct TranslationBlock *tb; int singlestep_enabled; } DisasContext; @@ -1576,17 +1575,12 @@ static inline void decode(DisasContext *dc, uint32_t ir) dc->ir = ir; LOG_DIS("%8.8x\t", dc->ir); - if (dc->ir) - dc->nr_nops = 0; - else { + if (ir == 0) { trap_illegal(dc, dc->cpu->env.pvr.regs[2] & PVR2_OPCODE_0x0_ILL_MASK); - - LOG_DIS("nr_nops=%d\t", dc->nr_nops); - dc->nr_nops++; - if (dc->nr_nops > 4) { - cpu_abort(CPU(dc->cpu), "fetching nop sequence\n"); - } + /* Don't decode nop/zero instructions any further. */ + return; } + /* bit 2 seems to indicate insn type. */ dc->type_b = ir & (1 << 29); @@ -1633,7 +1627,6 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb) dc->singlestep_enabled = cs->singlestep_enabled; dc->cpustate_changed = 0; dc->abort_at_next_insn = 0; - dc->nr_nops = 0; if (pc_start & 3) { cpu_abort(cs, "Microblaze: unaligned PC=%x\n", pc_start); -- cgit v1.1