From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45922) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aFTvr-0004DW-Cx for qemu-devel@nongnu.org; Sat, 02 Jan 2016 16:41:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aFTvo-0006sO-5y for qemu-devel@nongnu.org; Sat, 02 Jan 2016 16:41:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37737) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aFTvo-0006sK-0R for qemu-devel@nongnu.org; Sat, 02 Jan 2016 16:41:48 -0500 Date: Sat, 2 Jan 2016 23:41:44 +0200 From: "Michael S. Tsirkin" Message-ID: <20160102233905-mutt-send-email-mst@redhat.com> References: <1451721740-6151-1-git-send-email-caoj.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1451721740-6151-1-git-send-email-caoj.fnst@cn.fujitsu.com> Subject: Re: [Qemu-devel] [PATCH v3] bugfix: passing reference instead of value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cao jin Cc: pbonzini@redhat.com, qemu-devel@nongnu.org, stefano.stabellini@eu.citrix.com On Sat, Jan 02, 2016 at 04:02:20PM +0800, Cao jin wrote: > Fix the bug introduced by 595a4f07: function host_pci_config_read() should be > pass-by-reference, not value. > > Signed-off-by: Cao jin > --- > v3 changelog: > 1. Remove cpu_to_le32() since the code only runs on X86. It really should be le32_to_cpu and a separate patch, but I think it's preferable to have it there since people tend to copy code around. But in any case, before merging any patches in this function I'd like to hear a response from someone explaining why is this function necessary at all, since it provably never did anything useful. > > hw/pci-host/piix.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c > index 715208b..924f0fa 100644 > --- a/hw/pci-host/piix.c > +++ b/hw/pci-host/piix.c > @@ -761,7 +761,7 @@ static const IGDHostInfo igd_host_bridge_infos[] = { > {0xa8, 4}, /* SNB: base of GTT stolen memory */ > }; > > -static int host_pci_config_read(int pos, int len, uint32_t val) > +static int host_pci_config_read(int pos, int len, uint32_t *val) > { > char path[PATH_MAX]; > int config_fd; > @@ -784,12 +784,14 @@ static int host_pci_config_read(int pos, int len, uint32_t val) > ret = -errno; > goto out; > } > + > do { > - rc = read(config_fd, (uint8_t *)&val, len); > + rc = read(config_fd, (uint8_t *)val, len); > } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); > if (rc != len) { > ret = -errno; > } > + > out: > close(config_fd); > return ret; > @@ -805,7 +807,7 @@ static int igd_pt_i440fx_initfn(struct PCIDevice *pci_dev) > for (i = 0; i < num; i++) { > pos = igd_host_bridge_infos[i].offset; > len = igd_host_bridge_infos[i].len; > - rc = host_pci_config_read(pos, len, val); > + rc = host_pci_config_read(pos, len, &val); > if (rc) { > return -ENODEV; > } > -- > 2.1.0 > >