[RFC 5/6] memtrack: Add memtrack accounting for forked processes.
Ruchi Kandoi
kandoiruchi at google.com
Tue Oct 11 23:50:09 UTC 2016
When a process is forked, all the buffers are shared with the forked
process too. Adds the functionality to add memtrack accounting for the
forked processes.
Forked process gets a copy of the mapped pages of the parent process.
This patch makes sure that the new mapped pages are attributed to the
child process instead of the parent.
Signed-off-by: Ruchi Kandoi <kandoiruchi at google.com>
---
drivers/misc/memtrack.c | 45 +++++++++++++++++++++++++++++++++++----
drivers/staging/android/ion/ion.c | 45 +++++++++++++++++++++++++++++++++++++--
include/linux/memtrack.h | 19 +++++++++++------
include/linux/mm.h | 3 +++
kernel/fork.c | 19 +++++++++++++++--
5 files changed, 117 insertions(+), 14 deletions(-)
diff --git a/drivers/misc/memtrack.c b/drivers/misc/memtrack.c
index 4b2d17f..fa2601a 100644
--- a/drivers/misc/memtrack.c
+++ b/drivers/misc/memtrack.c
@@ -204,12 +204,13 @@ EXPORT_SYMBOL(memtrack_buffer_uninstall);
* @buffer: the buffer's memtrack entry
*
* @vma: vma being opened
+ * @task: task which mapped the pages
*/
void memtrack_buffer_vm_open(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma)
+ const struct vm_area_struct *vma, struct task_struct *task)
{
unsigned long flags;
- struct task_struct *leader = current->group_leader;
+ struct task_struct *leader = task->group_leader;
struct memtrack_vma_list *vma_list;
vma_list = kmalloc(sizeof(*vma_list), GFP_KERNEL);
@@ -228,12 +229,13 @@ EXPORT_SYMBOL(memtrack_buffer_vm_open);
*
* @buffer: the buffer's memtrack entry
* @vma: the vma being closed
+ * @task: task that mmaped the pages
*/
void memtrack_buffer_vm_close(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma)
+ const struct vm_area_struct *vma, struct task_struct *task)
{
unsigned long flags;
- struct task_struct *leader = current->group_leader;
+ struct task_struct *leader = task->group_leader;
write_lock_irqsave(&leader->memtrack_lock, flags);
memtrack_buffer_vm_close_locked(&leader->memtrack_rb, buffer, vma);
@@ -241,6 +243,41 @@ void memtrack_buffer_vm_close(struct memtrack_buffer *buffer,
}
EXPORT_SYMBOL(memtrack_buffer_vm_close);
+/**
+ * memtrack_buffer_install_fork - Install all parent's handles into
+ * child.
+ *
+ * @parent: parent task
+ * @child: child task
+ */
+void memtrack_buffer_install_fork(struct task_struct *parent,
+ struct task_struct *child)
+{
+ struct task_struct *leader, *leader_child;
+ struct rb_root *root;
+ struct rb_node *node;
+ unsigned long flags;
+
+ if (!child || !parent)
+ return;
+
+ leader = parent->group_leader;
+ leader_child = child->group_leader;
+ write_lock_irqsave(&leader->memtrack_lock, flags);
+ root = &leader->memtrack_rb;
+ node = rb_first(root);
+ while (node) {
+ struct memtrack_handle *handle;
+
+ handle = rb_entry(node, struct memtrack_handle, node);
+ memtrack_buffer_install_locked(&leader_child->memtrack_rb,
+ handle->buffer);
+ node = rb_next(node);
+ }
+ write_unlock_irqrestore(&leader->memtrack_lock, flags);
+}
+EXPORT_SYMBOL(memtrack_buffer_install_fork);
+
static int memtrack_id_alloc(struct memtrack_buffer *buffer)
{
int ret;
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index c32d520..451aa0f 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -906,7 +906,7 @@ static void ion_vm_open(struct vm_area_struct *vma)
list_add(&vma_list->list, &buffer->vmas);
mutex_unlock(&buffer->lock);
pr_debug("%s: adding %p\n", __func__, vma);
- memtrack_buffer_vm_open(&buffer->memtrack_buffer, vma);
+ memtrack_buffer_vm_open(&buffer->memtrack_buffer, vma, current);
}
static void ion_vm_close(struct vm_area_struct *vma)
@@ -925,13 +925,51 @@ static void ion_vm_close(struct vm_area_struct *vma)
break;
}
mutex_unlock(&buffer->lock);
- memtrack_buffer_vm_close(&buffer->memtrack_buffer, vma);
+ memtrack_buffer_vm_close(&buffer->memtrack_buffer, vma, current);
+}
+
+void vm_track(struct vm_area_struct *vma, struct task_struct *task)
+{
+ struct ion_buffer *buffer = vma->vm_private_data;
+
+ memtrack_buffer_vm_open(&buffer->memtrack_buffer, vma, task);
+}
+
+void vm_untrack(struct vm_area_struct *vma, struct task_struct *task)
+{
+ struct ion_buffer *buffer = vma->vm_private_data;
+
+ memtrack_buffer_vm_close(&buffer->memtrack_buffer, vma, task);
}
static const struct vm_operations_struct ion_vma_ops = {
.open = ion_vm_open,
.close = ion_vm_close,
.fault = ion_vm_fault,
+ .track = vm_track,
+ .untrack = vm_untrack,
+};
+
+static void memtrack_vm_close(struct vm_area_struct *vma)
+{
+ struct ion_buffer *buffer = vma->vm_private_data;
+
+ memtrack_buffer_vm_close(&buffer->memtrack_buffer, vma, current);
+}
+
+static void memtrack_vm_open(struct vm_area_struct *vma)
+{
+ struct ion_buffer *buffer = vma->vm_private_data;
+
+ memtrack_buffer_vm_open(&buffer->memtrack_buffer, vma, current);
+}
+
+static struct vm_operations_struct memtrack_vma_ops = {
+ .open = memtrack_vm_open,
+ .close = memtrack_vm_close,
+ .fault = NULL,
+ .track = vm_track,
+ .untrack = vm_untrack,
};
static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
@@ -952,6 +990,9 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
vma->vm_ops = &ion_vma_ops;
ion_vm_open(vma);
return 0;
+ } else {
+ vma->vm_private_data = buffer;
+ vma->vm_ops = &memtrack_vma_ops;
}
if (!(buffer->flags & ION_FLAG_CACHED))
diff --git a/include/linux/memtrack.h b/include/linux/memtrack.h
index 5a4c7ea..4595fb0 100644
--- a/include/linux/memtrack.h
+++ b/include/linux/memtrack.h
@@ -41,10 +41,12 @@ void memtrack_buffer_install(struct memtrack_buffer *buffer,
struct task_struct *tsk);
void memtrack_buffer_uninstall(struct memtrack_buffer *buffer,
struct task_struct *tsk);
+void memtrack_buffer_install_fork(struct task_struct *parent,
+ struct task_struct *child);
void memtrack_buffer_vm_open(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma);
+ const struct vm_area_struct *vma, struct task_struct *task);
void memtrack_buffer_vm_close(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma);
+ const struct vm_area_struct *vma, struct task_struct *task);
/**
* memtrack_buffer_set_tag - add a descriptive tag to a memtrack entry
@@ -90,6 +92,11 @@ static inline void memtrack_buffer_uninstall(struct memtrack_buffer *buffer,
{
}
+static inline void memtrack_buffer_install_fork(struct task_struct *parent,
+ struct task_struct *child)
+{
+}
+
static inline int memtrack_buffer_set_tag(struct memtrack_buffer *buffer,
const char *tag)
{
@@ -97,12 +104,12 @@ static inline int memtrack_buffer_set_tag(struct memtrack_buffer *buffer,
}
static inline void memtrack_buffer_vm_open(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma)
+ const struct vm_area_struct *vma, struct task_struct *task)
{
}
static inline void memtrack_buffer_vm_close(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma)
+ const struct vm_area_struct *vma, struct task_struct *task)
{
}
#endif /* CONFIG_MEMTRACK */
@@ -115,9 +122,9 @@ static inline void memtrack_buffer_vm_close(struct memtrack_buffer *buffer,
* @vma: the vma passed to mmap()
*/
static inline void memtrack_buffer_mmap(struct memtrack_buffer *buffer,
- const struct vm_area_struct *vma)
+ struct vm_area_struct *vma)
{
- memtrack_buffer_vm_open(buffer, vma);
+ memtrack_buffer_vm_open(buffer, vma, current);
}
#endif /* _MEMTRACK_ */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e9caec6..619ea7f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -402,6 +402,9 @@ struct vm_operations_struct {
*/
struct page *(*find_special_page)(struct vm_area_struct *vma,
unsigned long addr);
+
+ void (*track)(struct vm_area_struct *vma, struct task_struct *task);
+ void (*untrack)(struct vm_area_struct *vma, struct task_struct *task);
};
struct mmu_gather;
diff --git a/kernel/fork.c b/kernel/fork.c
index da8537a..43a2e73 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -76,6 +76,7 @@
#include <linux/compiler.h>
#include <linux/sysctl.h>
#include <linux/kcov.h>
+#include <linux/memtrack.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -547,7 +548,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
}
#ifdef CONFIG_MMU
-static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
+static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm,
+ struct task_struct *tsk)
{
struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
struct rb_node **rb_link, *rb_parent;
@@ -660,6 +662,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (tmp->vm_ops && tmp->vm_ops->open)
tmp->vm_ops->open(tmp);
+ if (tmp->vm_ops && tmp->vm_ops->track && tmp->vm_ops->untrack) {
+ tmp->vm_ops->untrack(tmp, current);
+ tmp->vm_ops->track(tmp, tsk);
+ }
+
if (retval)
goto out;
}
@@ -1125,7 +1132,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
if (!mm_init(mm, tsk))
goto fail_nomem;
- err = dup_mmap(mm, oldmm);
+ err = dup_mmap(mm, oldmm, tsk);
if (err)
goto free_pt;
@@ -1235,6 +1242,12 @@ static int copy_files(unsigned long clone_flags, struct task_struct *tsk)
tsk->files = newf;
error = 0;
+#ifdef CONFIG_MEMTRACK
+ if (!(clone_flags & CLONE_THREAD)) {
+ tsk->group_leader = tsk;
+ memtrack_buffer_install_fork(current, tsk);
+ }
+#endif
out:
return error;
}
@@ -2153,6 +2166,8 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
*new_fdp = dup_fd(fd, &error);
if (!*new_fdp)
return error;
+
+ memtrack_buffer_install_fork(current->parent, current);
}
return 0;
--
2.8.0.rc3.226.g39d4020
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