Revision 32ffa4f71e10009498ae6b54da65ab316db967bd authored by Axel Rasmussen on 19 May 2021, 20:03:33 UTC, committed by Paolo Bonzini on 27 May 2021, 11:45:55 UTC
This is a preparatory commit needed before we can use different kinds of backing pages for guest memory. Previously, we used perf_test_args.host_page_size, which is the host's native page size (commonly 4K). For VM_MEM_SRC_ANONYMOUS this turns out to be okay, but in a follow-up commit we want to allow using different kinds of backing memory. Take VM_MEM_SRC_ANONYMOUS_HUGETLB for example. Without this change, if we used that backing page type, when we issued a UFFDIO_COPY ioctl we'd only do so with 4K, rather than the full 2M of a backing hugepage. In this case, UFFDIO_COPY returns -EINVAL (__mcopy_atomic_hugetlb checks the size). Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Message-Id: <20210519200339.829146-5-axelrasmussen@google.com> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 25408e5
tty_mutex.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/semaphore.h>
#include <linux/sched.h>
#include "tty.h"
/* Legacy tty mutex glue */
/*
* Getting the big tty mutex.
*/
void tty_lock(struct tty_struct *tty)
{
if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return;
tty_kref_get(tty);
mutex_lock(&tty->legacy_mutex);
}
EXPORT_SYMBOL(tty_lock);
int tty_lock_interruptible(struct tty_struct *tty)
{
int ret;
if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return -EIO;
tty_kref_get(tty);
ret = mutex_lock_interruptible(&tty->legacy_mutex);
if (ret)
tty_kref_put(tty);
return ret;
}
void tty_unlock(struct tty_struct *tty)
{
if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
return;
mutex_unlock(&tty->legacy_mutex);
tty_kref_put(tty);
}
EXPORT_SYMBOL(tty_unlock);
void tty_lock_slave(struct tty_struct *tty)
{
if (tty && tty != tty->link)
tty_lock(tty);
}
void tty_unlock_slave(struct tty_struct *tty)
{
if (tty && tty != tty->link)
tty_unlock(tty);
}
void tty_set_lock_subclass(struct tty_struct *tty)
{
lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
}
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