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Date: Wed, 1 Dec 2010 21:17:26 +0000
Message-ID: <AANLkTimWMRmMCHj9qFwhkFjHBGcAHwuAhiAFYECT7dJH@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH] Convert fprintf() to error_request():
	virtio-9p
From: Stefan Hajnoczi <stefanha@gmail.com>
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To: "Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>
Cc: Sanchit Garg <sancgarg@linux.vnet.ibm.com>, qemu-devel@nongnu.org

On Wed, Dec 1, 2010 at 6:01 PM, Venkateswararao Jujjuri (JV)
<jvrao@linux.vnet.ibm.com> wrote:
> On 12/1/2010 1:35 AM, Stefan Hajnoczi wrote:
>> On Tue, Nov 30, 2010 at 9:52 AM, Sanchit Garg
>> <sancgarg@linux.vnet.ibm.com> wrote:
>>> @@ -3707,19 +3708,19 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, =
V9fsConf *conf)
>>> =A0 =A0 =A0 =A0 s->ctx.fs_sm =3D SM_NONE;
>>> =A0 =A0 =A0 =A0 s->ctx.xops =3D none_xattr_ops;
>>> =A0 =A0 } else {
>>> - =A0 =A0 =A0 =A0fprintf(stderr, "Default to security_model=3Dnone. You=
 may want"
>>> + =A0 =A0 =A0 =A0error_report("Default to security_model=3Dnone. You ma=
y want"
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 " enable advanced security model using =
"
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 "security option:\n\t security_model=3D=
passthrough \n\t "
>>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0"security_model=3Dmapped\n");
>>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0"security_model=3Dmapped");
>>> =A0 =A0 =A0 =A0 s->ctx.fs_sm =3D SM_NONE;
>>> =A0 =A0 =A0 =A0 s->ctx.xops =3D none_xattr_ops;
>>> =A0 =A0 }
>>
>> It would be safer to avoid embedded \n\t. =A0Although I can't find
>> anything prohibiting it in the source, no other place does this.
>> Program output is easier to handle when constrained to one message per
>> line. =A0Security issues arise when unfiltered inputs are logged *and*
>> linebreaks are allowed because malicious input can inject fake log
>> lines. =A0Let's avoid getting into the habit.
>
> Embedded breaks were introduced to give more readable and formatted outpu=
t.
> Stafan do you suggest to print the entire message in one line?

Yes, exactly.

Stefan