linux-kernel - linux/kernel/sched.c: context

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-next>] [day] [month] [year] [list]

Message-Id: <201009081508.30490.fabio@metanix.org>
Date:	Wed, 8 Sep 2010 15:08:29 +0200
From:	fabio de francesco <fabio@...anix.org>
To:	LKML <linux-kernel@...r.kernel.org>
Subject: linux/kernel/sched.c: context_switch().

There must be something I am missing in sched.c at context_switch() function 
definition. 

There I can read the following code:

static inline void
context_switch(struct rq *rq, struct task_struct *prev,
               struct task_struct *next)
{
	...
	struct mm_struct *mm;
	mm = next->mm;
	if (likely(!mm)) {
                next->active_mm = oldmm;
                atomic_inc(&oldmm->mm_count);
                enter_lazy_tlb(oldmm, next);
        } else
                switch_mm(oldmm, mm, next);
	...
}

May someone please explain why the mm pointer is likely supposed to be NULL?

Thanks in advance.

fabio
--
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/