From patchwork Mon Feb 18 14:30:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1044098 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="ZQQnQhB5"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4436fY1bF2z9s3x for ; Tue, 19 Feb 2019 02:07:17 +1100 (AEDT) Received: from localhost ([127.0.0.1]:60143 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvkVn-0000zY-2s for incoming@patchwork.ozlabs.org; Mon, 18 Feb 2019 10:07:15 -0500 Received: from eggs.gnu.org ([209.51.188.92]:38801) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvjwz-0005h5-Dx for qemu-devel@nongnu.org; Mon, 18 Feb 2019 09:31:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gvjwq-0002ec-8V for qemu-devel@nongnu.org; Mon, 18 Feb 2019 09:31:15 -0500 Received: from ozlabs.org ([203.11.71.1]:49475) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gvjwp-0002bX-EY; Mon, 18 Feb 2019 09:31:08 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4435rg2sT9z9sQm; Tue, 19 Feb 2019 01:30:58 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1550500259; bh=E+JxlrJ/pDFyS5PHraRA/utYy+hjrBoU1vKR/rjy2sY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZQQnQhB5UVAMVePcFnZ9aUzxz0j0frIQg8bnQeiY5/9Zmlgb/sgrCsJw542RMGv3I yRutQIRvjKcKttDV4IfFWLyR18Ju3lI/IWfKrbssd4jdVx074TLI0ARyYU8PRANkrg sgsXbN9m+GhZtnD5GTp++B2NQecCQMogv+hoks3A= From: David Gibson To: peter.maydell@linaro.org Date: Tue, 19 Feb 2019 01:30:16 +1100 Message-Id: <20190218143049.17142-11-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218143049.17142-1-david@gibson.dropbear.id.au> References: <20190218143049.17142-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 203.11.71.1 Subject: [Qemu-devel] [PULL 10/43] ppc: fix crash during branch stepping X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Roman Kapl , groug@kaod.org, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, clg@kaod.org, David Gibson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Roman Kapl The PPC BRANCH exception could bubble up, but this is an QEMU internal exception and QEMU then crased. Instead it should trigger TRACE exception, according to PPC 2.07 book. It could happen only when using branch stepping, which is not commonly used. Change gen_prep_dbgex do do trigger TRACE. The excp, argument is now removed, since the type of exception can be inferred from the singlestep_enabled flags. removed the guards around gen_exception, since they are unnecessary. Fixes: 0e3bf48909 ("ppc: add DBCR based debugging"). Signed-off-by: Roman Kapl Message-Id: <20190212121255.2279-1-rka@sysgo.com> Signed-off-by: David Gibson --- target/ppc/translate.c | 37 +++++++++++++++---------------------- 1 file changed, 15 insertions(+), 22 deletions(-) diff --git a/target/ppc/translate.c b/target/ppc/translate.c index 5429ceb1ab..d5f29d3536 100644 --- a/target/ppc/translate.c +++ b/target/ppc/translate.c @@ -287,26 +287,22 @@ static void gen_exception_nip(DisasContext *ctx, uint32_t excp, ctx->exception = (excp); } -/* Translates the EXCP_TRACE/BRANCH exceptions used on most PowerPCs to - * EXCP_DEBUG, if we are running on cores using the debug enable bit (e.g. - * BookE). +/* + * Tells the caller what is the appropriate exception to generate and prepares + * SPR registers for this exception. + * + * The exception can be either POWERPC_EXCP_TRACE (on most PowerPCs) or + * POWERPC_EXCP_DEBUG (on BookE). */ -static uint32_t gen_prep_dbgex(DisasContext *ctx, uint32_t excp) +static uint32_t gen_prep_dbgex(DisasContext *ctx) { - if ((ctx->singlestep_enabled & CPU_SINGLE_STEP) - && (excp == POWERPC_EXCP_BRANCH)) { - /* Trace excpt. has priority */ - excp = POWERPC_EXCP_TRACE; - } if (ctx->flags & POWERPC_FLAG_DE) { target_ulong dbsr = 0; - switch (excp) { - case POWERPC_EXCP_TRACE: + if (ctx->singlestep_enabled & CPU_SINGLE_STEP) { dbsr = DBCR0_ICMP; - break; - case POWERPC_EXCP_BRANCH: + } else { + /* Must have been branch */ dbsr = DBCR0_BRT; - break; } TCGv t0 = tcg_temp_new(); gen_load_spr(t0, SPR_BOOKE_DBSR); @@ -315,7 +311,7 @@ static uint32_t gen_prep_dbgex(DisasContext *ctx, uint32_t excp) tcg_temp_free(t0); return POWERPC_EXCP_DEBUG; } else { - return excp; + return POWERPC_EXCP_TRACE; } } @@ -3652,10 +3648,8 @@ static void gen_lookup_and_goto_ptr(DisasContext *ctx) if (sse & GDBSTUB_SINGLE_STEP) { gen_debug_exception(ctx); } else if (sse & (CPU_SINGLE_STEP | CPU_BRANCH_STEP)) { - uint32_t excp = gen_prep_dbgex(ctx, POWERPC_EXCP_BRANCH); - if (excp != POWERPC_EXCP_NONE) { - gen_exception(ctx, excp); - } + uint32_t excp = gen_prep_dbgex(ctx); + gen_exception(ctx, excp); } tcg_gen_exit_tb(NULL, 0); } else { @@ -7790,9 +7784,8 @@ static void ppc_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs) ctx->exception != POWERPC_SYSCALL && ctx->exception != POWERPC_EXCP_TRAP && ctx->exception != POWERPC_EXCP_BRANCH)) { - uint32_t excp = gen_prep_dbgex(ctx, POWERPC_EXCP_TRACE); - if (excp != POWERPC_EXCP_NONE) - gen_exception_nip(ctx, excp, ctx->base.pc_next); + uint32_t excp = gen_prep_dbgex(ctx); + gen_exception_nip(ctx, excp, ctx->base.pc_next); } if (tcg_check_temp_count()) {