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@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;