diff options
| -rw-r--r-- | accel/tcg/translate-all.c | 38 | ||||
| -rw-r--r-- | tcg/tcg.c | 4 |
2 files changed, 36 insertions, 6 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 39532fd44c..20b59f93f4 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1722,6 +1722,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu, tb->cflags = cflags; tb->trace_vcpu_dstate = *cpu->trace_dstate; tcg_ctx->tb_cflags = cflags; + tb_overflow: #ifdef CONFIG_PROFILER /* includes aborted translations because of exceptions */ @@ -1755,14 +1756,39 @@ TranslationBlock *tb_gen_code(CPUState *cpu, ti = profile_getclock(); #endif - /* ??? Overflow could be handled better here. In particular, we - don't need to re-do gen_intermediate_code, nor should we re-do - the tcg optimization currently hidden inside tcg_gen_code. All - that should be required is to flush the TBs, allocate a new TB, - re-initialize it per above, and re-do the actual code generation. */ gen_code_size = tcg_gen_code(tcg_ctx, tb); if (unlikely(gen_code_size < 0)) { - goto buffer_overflow; + switch (gen_code_size) { + case -1: + /* + * Overflow of code_gen_buffer, or the current slice of it. + * + * TODO: We don't need to re-do gen_intermediate_code, nor + * should we re-do the tcg optimization currently hidden + * inside tcg_gen_code. All that should be required is to + * flush the TBs, allocate a new TB, re-initialize it per + * above, and re-do the actual code generation. + */ + goto buffer_overflow; + + case -2: + /* + * The code generated for the TranslationBlock is too large. + * The maximum size allowed by the unwind info is 64k. + * There may be stricter constraints from relocations + * in the tcg backend. + * + * Try again with half as many insns as we attempted this time. + * If a single insn overflows, there's a bug somewhere... + */ + max_insns = tb->icount; + assert(max_insns > 1); + max_insns /= 2; + goto tb_overflow; + + default: + g_assert_not_reached(); + } } search_size = encode_search(tb, (void *)gen_code_buf + gen_code_size); if (unlikely(search_size < 0)) { @@ -3996,6 +3996,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) if (unlikely((void *)s->code_ptr > s->code_gen_highwater)) { return -1; } + /* Test for TB overflow, as seen by gen_insn_end_off. */ + if (unlikely(tcg_current_code_size(s) > UINT16_MAX)) { + return -2; + } } tcg_debug_assert(num_insns >= 0); s->gen_insn_end_off[num_insns] = tcg_current_code_size(s); |