Author: hselasky
Date: Fri Mar 17 10:30:06 2017
New Revision: 315443
URL: https://svnweb.freebsd.org/changeset/base/315443
Log:
Implement minimalistic memory mapping structure, struct mm_struct, and
some associated helper functions in the LinuxKPI. Let the existing
linux_alloc_current() function allocate and initialize the new
structure and let linux_free_current() drop the refcount on the memory
mapping structure. When the mm_struct's refcount reaches zero, the
structure is freed.
Obtained from: kmacy @
MFC after: 1 week
Sponsored by: Mellanox Technologies
Added:
head/sys/compat/linuxkpi/common/include/linux/mm_types.h (contents, props
changed)
Modified:
head/sys/compat/linuxkpi/common/include/linux/mm.h
head/sys/compat/linuxkpi/common/include/linux/sched.h
head/sys/compat/linuxkpi/common/src/linux_current.c
Modified: head/sys/compat/linuxkpi/common/include/linux/mm.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/linux/mm.h Fri Mar 17 08:02:46
2017 (r315442)
+++ head/sys/compat/linuxkpi/common/include/linux/mm.h Fri Mar 17 10:30:06
2017 (r315443)
@@ -36,6 +36,7 @@
#include <linux/spinlock.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
+#include <linux/mm_types.h>
#define PAGE_ALIGN(x) ALIGN(x, PAGE_SIZE)
Added: head/sys/compat/linuxkpi/common/include/linux/mm_types.h
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/compat/linuxkpi/common/include/linux/mm_types.h Fri Mar 17
10:30:06 2017 (r315443)
@@ -0,0 +1,71 @@
+/*-
+ * Copyright (c) 2017 Mellanox Technologies, Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice unmodified, this list of conditions, and the following
+ * disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LINUX_MM_TYPES_H_
+#define _LINUX_MM_TYPES_H_
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/page.h>
+#include <linux/rwsem.h>
+
+#include <asm/atomic.h>
+
+struct vm_area_struct;
+struct task_struct;
+struct vmspace;
+
+struct mm_struct {
+ struct vm_area_struct *mmap;
+ struct vmspace *vmspace;
+ atomic_t mm_count;
+ atomic_t mm_users;
+ size_t pinned_vm;
+ struct rw_semaphore mmap_sem;
+};
+
+extern void linux_mm_dtor(struct mm_struct *mm);
+
+static inline void
+mmdrop(struct mm_struct *mm)
+{
+ if (__predict_false(atomic_dec_and_test(&mm->mm_count)))
+ linux_mm_dtor(mm);
+}
+
+static inline void
+mmput(struct mm_struct *mm)
+{
+ if (__predict_false(atomic_dec_and_test(&mm->mm_users)))
+ mmdrop(mm);
+}
+
+extern struct mm_struct *linux_get_task_mm(struct task_struct *);
+#define get_task_mm(task) linux_get_task_mm(task)
+
+#endif /* _LINUX_MM_TYPES_H_ */
Modified: head/sys/compat/linuxkpi/common/include/linux/sched.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/linux/sched.h Fri Mar 17
08:02:46 2017 (r315442)
+++ head/sys/compat/linuxkpi/common/include/linux/sched.h Fri Mar 17
10:30:06 2017 (r315443)
@@ -40,6 +40,7 @@
#include <linux/types.h>
#include <linux/completion.h>
#include <linux/slab.h>
+#include <linux/mm_types.h>
#include <asm/atomic.h>
@@ -54,6 +55,7 @@
struct task_struct {
struct thread *task_thread;
+ struct mm_struct *mm;
linux_task_fn_t *task_fn;
void *task_data;
int task_ret;
Modified: head/sys/compat/linuxkpi/common/src/linux_current.c
==============================================================================
--- head/sys/compat/linuxkpi/common/src/linux_current.c Fri Mar 17 08:02:46
2017 (r315442)
+++ head/sys/compat/linuxkpi/common/src/linux_current.c Fri Mar 17 10:30:06
2017 (r315443)
@@ -43,6 +43,7 @@ int
linux_alloc_current(struct thread *td, int flags)
{
struct task_struct *ts;
+ struct mm_struct *mm;
MPASS(td->td_lkpi_task == NULL);
@@ -50,18 +51,55 @@ linux_alloc_current(struct thread *td, i
if (ts == NULL)
return (ENOMEM);
+ mm = malloc(sizeof(*mm), M_LINUX_CURRENT, flags | M_ZERO);
+ if (mm == NULL) {
+ free(ts, M_LINUX_CURRENT);
+ return (ENOMEM);
+ }
+
atomic_set(&ts->kthread_flags, 0);
ts->task_thread = td;
ts->comm = td->td_name;
ts->pid = td->td_tid;
+ ts->mm = mm;
ts->state = TASK_RUNNING;
+
+ /* setup mm_struct */
+ init_rwsem(&mm->mmap_sem);
+ atomic_set(&mm->mm_count, 1);
+ atomic_set(&mm->mm_users, 1);
+ mm->vmspace = vmspace_acquire_ref(td->td_proc);
+
+ /* store pointer to task struct */
td->td_lkpi_task = ts;
return (0);
}
+struct mm_struct *
+linux_get_task_mm(struct task_struct *task)
+{
+ struct mm_struct *mm;
+
+ mm = task->mm;
+ if (mm != NULL && mm->vmspace != NULL) {
+ atomic_inc(&mm->mm_users);
+ return (mm);
+ }
+ return (NULL);
+}
+
+void
+linux_mm_dtor(struct mm_struct *mm)
+{
+ if (mm->vmspace != NULL)
+ vmspace_free(mm->vmspace);
+ free(mm, M_LINUX_CURRENT);
+}
+
void
linux_free_current(struct task_struct *ts)
{
+ mmput(ts->mm);
free(ts, M_LINUX_CURRENT);
}
@@ -75,7 +113,7 @@ linuxkpi_thread_dtor(void *arg __unused,
return;
td->td_lkpi_task = NULL;
- free(ts, M_LINUX_CURRENT);
+ linux_free_current(ts);
}
static void
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