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Revision ac34ebb3a67e699edcb5ac72f19d31679369dfaa authored by Christopher Yeoh on 31 May 2012, 23:26:42 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:32 UTC 
aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
 
A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.

Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to.  This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent ee62c6b
Raw File
smpboot.c 
/*
 * Common SMP CPU bringup/teardown functions
 */
#include <linux/err.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/percpu.h>

#include "smpboot.h"

#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
/*
 * For the hotplug case we keep the task structs around and reuse
 * them.
 */
static DEFINE_PER_CPU(struct task_struct *, idle_threads);

struct task_struct * __cpuinit idle_thread_get(unsigned int cpu)
{
	struct task_struct *tsk = per_cpu(idle_threads, cpu);

	if (!tsk)
		return ERR_PTR(-ENOMEM);
	init_idle(tsk, cpu);
	return tsk;
}

void __init idle_thread_set_boot_cpu(void)
{
	per_cpu(idle_threads, smp_processor_id()) = current;
}

static inline void idle_init(unsigned int cpu)
{
	struct task_struct *tsk = per_cpu(idle_threads, cpu);

	if (!tsk) {
		tsk = fork_idle(cpu);
		if (IS_ERR(tsk))
			pr_err("SMP: fork_idle() failed for CPU %u\n", cpu);
		else
			per_cpu(idle_threads, cpu) = tsk;
	}
}

/**
 * idle_thread_init - Initialize the idle thread for a cpu
 * @cpu:	The cpu for which the idle thread should be initialized
 *
 * Creates the thread if it does not exist.
 */
void __init idle_threads_init(void)
{
	unsigned int cpu;

	for_each_possible_cpu(cpu) {
		if (cpu != smp_processor_id())
			idle_init(cpu);
	}
}
#endif
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