linux-kernel - Re: [patch v2 2/4] x86, ptrace: regset extensions to support xstate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100210141836.GA23861@redhat.com>
Date:	Wed, 10 Feb 2010 15:18:36 +0100
From:	Oleg Nesterov <oleg@...hat.com>
To:	Suresh Siddha <suresh.b.siddha@...el.com>
Cc:	Roland McGrath <roland@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>,
	LKML <linux-kernel@...r.kernel.org>, hjl.tools@...il.com
Subject: Re: [patch v2 2/4] x86, ptrace: regset extensions to support xstate

static inline int user_regset_copyout(unsigned int *pos, unsigned int *count,
				      void **kbuf,
				      void __user **ubuf, const void *data,
				      const int start_pos, const int end_pos)
{
	if (*count == 0)
		return 0;
	BUG_ON(*pos < start_pos);
	if (end_pos < 0 || *pos < end_pos) {
		unsigned int copy = (end_pos < 0 ? *count
				     : min(*count, end_pos - *pos));
		data += *pos - start_pos;
                            ^^^
Is it correct? Shouldn't it be

		data += *pos + start_pos;

?

Currently this doesn't matter, start_pos == 0 always. In fact I don't
understand why do we need this arg. In unlikely case the caller wants
to copy the part of *data, it can adjust data/end_pos itself.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/