From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D13AC433EF for ; Wed, 6 Oct 2021 05:03:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56A446113E for ; Wed, 6 Oct 2021 05:03:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229956AbhJFFEw (ORCPT ); Wed, 6 Oct 2021 01:04:52 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:43723 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229554AbhJFFEw (ORCPT ); Wed, 6 Oct 2021 01:04:52 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HPMlm06Vlz9sVL; Wed, 6 Oct 2021 07:03:00 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xAEXDdeBPiZG; Wed, 6 Oct 2021 07:02:59 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4HPMll6CBfz9sVK; Wed, 6 Oct 2021 07:02:59 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id BA32B8B765; Wed, 6 Oct 2021 07:02:59 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id QtB9uTetnFVH; Wed, 6 Oct 2021 07:02:59 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.204.229]) by messagerie.si.c-s.fr (Postfix) with ESMTP id F09138B763; Wed, 6 Oct 2021 07:02:58 +0200 (CEST) Subject: Re: [PATCH v2 10/10] powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000 To: "Naveen N. Rao" , Michael Ellerman , Nicholas Piggin , Jordan Niethe , Daniel Borkmann , Alexei Starovoitov , Johan Almbladh , Song Liu Cc: bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <7135360a0cdf70adedbccf9863128b8daef18764.1633464148.git.naveen.n.rao@linux.vnet.ibm.com> From: Christophe Leroy Message-ID: Date: Wed, 6 Oct 2021 07:02:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <7135360a0cdf70adedbccf9863128b8daef18764.1633464148.git.naveen.n.rao@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr-FR Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Le 05/10/2021 à 22:25, Naveen N. Rao a écrit : > Special case handling of the smallest 32-bit negative number for BPF_SUB. > > Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") > Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy > --- > arch/powerpc/net/bpf_jit_comp32.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c > index 68dc8a8231de04..0da31d41d41310 100644 > --- a/arch/powerpc/net/bpf_jit_comp32.c > +++ b/arch/powerpc/net/bpf_jit_comp32.c > @@ -357,7 +357,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * > PPC_LI32(_R0, imm); > EMIT(PPC_RAW_ADDC(dst_reg, dst_reg, _R0)); > } > - if (imm >= 0) > + if (imm >= 0 || (BPF_OP(code) == BPF_SUB && imm == 0x80000000)) > EMIT(PPC_RAW_ADDZE(dst_reg_h, dst_reg_h)); > else > EMIT(PPC_RAW_ADDME(dst_reg_h, dst_reg_h)); >