From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:59846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtF9E-00020I-Rx for qemu-devel@nongnu.org; Mon, 11 Feb 2019 12:13:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gtExk-0000tk-8o for qemu-devel@nongnu.org; Mon, 11 Feb 2019 12:01:47 -0500 Received: from mail-pl1-x62d.google.com ([2607:f8b0:4864:20::62d]:43702) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gtExi-0000s1-AA for qemu-devel@nongnu.org; Mon, 11 Feb 2019 12:01:42 -0500 Received: by mail-pl1-x62d.google.com with SMTP id f90so5336280plb.10 for ; Mon, 11 Feb 2019 09:01:41 -0800 (PST) From: Richard Henderson Date: Mon, 11 Feb 2019 09:01:33 -0800 Message-Id: <20190211170136.18680-2-richard.henderson@linaro.org> In-Reply-To: <20190211170136.18680-1-richard.henderson@linaro.org> References: <20190211170136.18680-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PULL 1/4] tcg: Diagnose referenced labels that have not been emitted List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org Currently, a jump to a label that is not defined anywhere will be emitted not be relocated. This results in a jump to a random jump target. With tcg debugging, print a diagnostic to the -d op file and abort. This could help debug or detect errors like c2d9644e6d ("target/arm: Fix crash on conditional instruction in an IT block") Reported-by: Roman Kapl Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- tcg/tcg-op.h | 1 + tcg/tcg.h | 12 +++++++++--- tcg/tcg.c | 23 +++++++++++++++++++++++ 3 files changed, 33 insertions(+), 3 deletions(-) diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h index 2d98868d8f..d3e51b15af 100644 --- a/tcg/tcg-op.h +++ b/tcg/tcg-op.h @@ -255,6 +255,7 @@ static inline void tcg_gen_op6ii_i64(TCGOpcode opc, TCGv_i64 a1, TCGv_i64 a2, static inline void gen_set_label(TCGLabel *l) { + l->present = 1; tcg_gen_op1(INDEX_op_set_label, label_arg(l)); } diff --git a/tcg/tcg.h b/tcg/tcg.h index 045c24a357..32b7cf3489 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -244,16 +244,21 @@ typedef struct TCGRelocation { intptr_t addend; } TCGRelocation; -typedef struct TCGLabel { +typedef struct TCGLabel TCGLabel; +struct TCGLabel { + unsigned present : 1; unsigned has_value : 1; - unsigned id : 15; + unsigned id : 14; unsigned refs : 16; union { uintptr_t value; tcg_insn_unit *value_ptr; TCGRelocation *first_reloc; } u; -} TCGLabel; +#ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_ENTRY(TCGLabel) next; +#endif +}; typedef struct TCGPool { struct TCGPool *next; @@ -685,6 +690,7 @@ struct TCGContext { #endif #ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_HEAD(, TCGLabel) labels; int temps_in_use; int goto_tb_issue_mask; #endif diff --git a/tcg/tcg.c b/tcg/tcg.c index 20a5d8f315..9b2bf7f439 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -305,6 +305,9 @@ TCGLabel *gen_new_label(void) *l = (TCGLabel){ .id = s->nb_labels++ }; +#ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_INSERT_TAIL(&s->labels, l, next); +#endif return l; } @@ -1092,6 +1095,9 @@ void tcg_func_start(TCGContext *s) QTAILQ_INIT(&s->ops); QTAILQ_INIT(&s->free_ops); +#ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_INIT(&s->labels); +#endif } static inline TCGTemp *tcg_temp_alloc(TCGContext *s) @@ -3841,6 +3847,23 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) } #endif +#ifdef CONFIG_DEBUG_TCG + /* Ensure all labels referenced have been emitted. */ + { + TCGLabel *l; + bool error = false; + + QSIMPLEQ_FOREACH(l, &s->labels, next) { + if (unlikely(!l->present) && l->refs) { + qemu_log_mask(CPU_LOG_TB_OP, + "$L%d referenced but not present.\n", l->id); + error = true; + } + } + assert(!error); + } +#endif + #ifdef CONFIG_PROFILER atomic_set(&prof->opt_time, prof->opt_time - profile_getclock()); #endif -- 2.17.2