Merge "mm/madvise: pass task and mm to do_madvise" (016b45df) · Commits · e / devices / android_kernel_fairphone_FP5

include/linux/mm.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -2350,6 +2350,8 @@ extern int __do_munmap(struct mm_struct *, unsigned long, size_t,
		struct list_head *uf, bool downgrade);
		extern int do_munmap(struct mm_struct *, unsigned long, size_t,
		struct list_head *uf);
		extern int do_madvise(struct task_struct target_task, struct mm_struct mm,
		unsigned long start, size_t len_in, int behavior);

		static inline unsigned long
		do_mmap_pgoff(struct file *file, unsigned long addr,

mm/madvise.c

+43 −14

Original line number	Diff line number	Diff line
		@@ -22,11 +22,14 @@
		#include <linux/file.h>
		#include <linux/blkdev.h>
		#include <linux/backing-dev.h>
		#include <linux/compat.h>
		#include <linux/pagewalk.h>
		#include <linux/swap.h>
		#include <linux/swapops.h>
		#include <linux/shmem_fs.h>
		#include <linux/mmu_notifier.h>
		#include <linux/sched/mm.h>
		#include <linux/uio.h>

		#include <asm/tlb.h>

		@@ -254,6 +257,7 @@ static long madvise_willneed(struct vm_area_struct *vma,
		struct vm_area_struct **prev,
		unsigned long start, unsigned long end)
		{
		struct mm_struct *mm = vma->vm_mm;
		struct file *file = vma->vm_file;
		loff_t offset;

		@@ -288,12 +292,12 @@ static long madvise_willneed(struct vm_area_struct *vma,
		*/
		prev = NULL; / tell sys_madvise we drop mmap_sem */
		get_file(file);
		up_read(&current->mm->mmap_sem);
		up_read(&mm->mmap_sem);
		offset = (loff_t)(start - vma->vm_start)
		+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
		vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED);
		fput(file);
		down_read(&current->mm->mmap_sem);
		down_read(&mm->mmap_sem);
		return 0;
		}

		@@ -682,7 +686,6 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
		if (nr_swap) {
		if (current->mm == mm)
		sync_mm_rss(mm);

		add_mm_counter(mm, MM_SWAPENTS, nr_swap);
		}
		arch_leave_lazy_mmu_mode();
		@@ -762,6 +765,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
		unsigned long start, unsigned long end,
		int behavior)
		{
		struct mm_struct *mm = vma->vm_mm;

		*prev = vma;
		if (!can_madv_lru_vma(vma))
		return -EINVAL;
		@@ -769,8 +774,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
		if (!userfaultfd_remove(vma, start, end)) {
		prev = NULL; / mmap_sem has been dropped, prev is stale */

		down_read(&current->mm->mmap_sem);
		vma = find_vma(current->mm, start);
		down_read(&mm->mmap_sem);
		vma = find_vma(mm, start);
		if (!vma)
		return -ENOMEM;
		if (start < vma->vm_start) {
		@@ -824,6 +829,7 @@ static long madvise_remove(struct vm_area_struct *vma,
		loff_t offset;
		int error;
		struct file *f;
		struct mm_struct *mm = vma->vm_mm;

		prev = NULL; / tell sys_madvise we drop mmap_sem */

		@@ -851,13 +857,13 @@ static long madvise_remove(struct vm_area_struct *vma,
		get_file(f);
		if (userfaultfd_remove(vma, start, end)) {
		/* mmap_sem was not released by userfaultfd_remove() */
		up_read(&current->mm->mmap_sem);
		up_read(&mm->mmap_sem);
		}
		error = vfs_fallocate(f,
		FALLOC_FL_PUNCH_HOLE \| FALLOC_FL_KEEP_SIZE,
		offset, end - start);
		fput(f);
		down_read(&current->mm->mmap_sem);
		down_read(&mm->mmap_sem);
		return error;
		}

		@@ -1050,7 +1056,8 @@ madvise_behavior_valid(int behavior)
		* -EBADF - map exists, but area maps something that isn't a file.
		* -EAGAIN - a kernel resource was temporarily unavailable.
		*/
		SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		int do_madvise(struct task_struct target_task, struct mm_struct mm,
		unsigned long start, size_t len_in, int behavior)
		{
		unsigned long end, tmp;
		struct vm_area_struct vma, prev;
		@@ -1088,10 +1095,27 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)

		write = madvise_need_mmap_write(behavior);
		if (write) {
		if (down_write_killable(&current->mm->mmap_sem))
		if (down_write_killable(&mm->mmap_sem))
		return -EINTR;

		/*
		* We may have stolen the mm from another process
		* that is undergoing core dumping.
		*
		* Right now that's io_ring, in the future it may
		* be remote process management and not "current"
		* at all.
		*
		* We need to fix core dumping to not do this,
		* but for now we have the mmget_still_valid()
		* model.
		*/
		if (!mmget_still_valid(mm)) {
		up_write(&mm->mmap_sem);
		return -EINTR;
		}
		} else {
		down_read(&current->mm->mmap_sem);
		down_read(&mm->mmap_sem);
		}

		/*
		@@ -1099,7 +1123,7 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		* ranges, just ignore them, but return -ENOMEM at the end.
		* - different from the way of handling in mlock etc.
		*/
		vma = find_vma_prev(current->mm, start, &prev);
		vma = find_vma_prev(mm, start, &prev);
		if (vma && start > vma->vm_start)
		prev = vma;

		@@ -1136,14 +1160,19 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		if (prev)
		vma = prev->vm_next;
		else /* madvise_remove dropped mmap_sem */
		vma = find_vma(current->mm, start);
		vma = find_vma(mm, start);
		}
		out:
		blk_finish_plug(&plug);
		if (write)
		up_write(&current->mm->mmap_sem);
		up_write(&mm->mmap_sem);
		else
		up_read(&current->mm->mmap_sem);
		up_read(&mm->mmap_sem);

		return error;
		}

		SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		{
		return do_madvise(current, current->mm, start, len_in, behavior);
		}