firmware/br-ext-chip-allwinner/board/v83x/kernel/patches/00000-kernel_sys.c.patch

diff -drupN a/kernel/sys.c b/kernel/sys.c
--- a/kernel/sys.c	2018-08-06 17:23:04.000000000 +0300
+++ b/kernel/sys.c	2022-06-12 05:28:14.000000000 +0300
@@ -41,6 +41,8 @@
 #include <linux/syscore_ops.h>
 #include <linux/version.h>
 #include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/mempolicy.h>
 
 #include <linux/compat.h>
 #include <linux/syscalls.h>
@@ -2075,6 +2077,153 @@ static int prctl_get_tid_address(struct
 }
 #endif
 
+#ifdef CONFIG_MMU
+static int prctl_update_vma_anon_name(struct vm_area_struct *vma,
+		struct vm_area_struct **prev,
+		unsigned long start, unsigned long end,
+		const char __user *name_addr)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	int error = 0;
+	pgoff_t pgoff;
+
+	if (name_addr == vma_get_anon_name(vma)) {
+		*prev = vma;
+		goto out;
+	}
+
+	pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+	*prev = vma_merge(mm, *prev, start, end, vma->vm_flags, vma->anon_vma,
+				vma->vm_file, pgoff, vma_policy(vma),
+				vma->vm_userfaultfd_ctx, name_addr);
+	if (*prev) {
+		vma = *prev;
+		goto success;
+	}
+
+	*prev = vma;
+
+	if (start != vma->vm_start) {
+		error = split_vma(mm, vma, start, 1);
+		if (error)
+			goto out;
+	}
+
+	if (end != vma->vm_end) {
+		error = split_vma(mm, vma, end, 0);
+		if (error)
+			goto out;
+	}
+
+success:
+	if (!vma->vm_file)
+		vma->anon_name = name_addr;
+
+out:
+	if (error == -ENOMEM)
+		error = -EAGAIN;
+	return error;
+}
+
+static int prctl_set_vma_anon_name(unsigned long start, unsigned long end,
+			unsigned long arg)
+{
+	unsigned long tmp;
+	struct vm_area_struct *vma, *prev;
+	int unmapped_error = 0;
+	int error = -EINVAL;
+
+	/*
+	 * If the interval [start,end) covers some unmapped address
+	 * ranges, just ignore them, but return -ENOMEM at the end.
+	 * - this matches the handling in madvise.
+	 */
+	vma = find_vma_prev(current->mm, start, &prev);
+	if (vma && start > vma->vm_start)
+		prev = vma;
+
+	for (;;) {
+		/* Still start < end. */
+		error = -ENOMEM;
+		if (!vma)
+			return error;
+
+		/* Here start < (end|vma->vm_end). */
+		if (start < vma->vm_start) {
+			unmapped_error = -ENOMEM;
+			start = vma->vm_start;
+			if (start >= end)
+				return error;
+		}
+
+		/* Here vma->vm_start <= start < (end|vma->vm_end) */
+		tmp = vma->vm_end;
+		if (end < tmp)
+			tmp = end;
+
+		/* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */
+		error = prctl_update_vma_anon_name(vma, &prev, start, tmp,
+				(const char __user *)arg);
+		if (error)
+			return error;
+		start = tmp;
+		if (prev && start < prev->vm_end)
+			start = prev->vm_end;
+		error = unmapped_error;
+		if (start >= end)
+			return error;
+		if (prev)
+			vma = prev->vm_next;
+		else	/* madvise_remove dropped mmap_sem */
+			vma = find_vma(current->mm, start);
+	}
+}
+
+static int prctl_set_vma(unsigned long opt, unsigned long start,
+		unsigned long len_in, unsigned long arg)
+{
+	struct mm_struct *mm = current->mm;
+	int error;
+	unsigned long len;
+	unsigned long end;
+
+	if (start & ~PAGE_MASK)
+		return -EINVAL;
+	len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+
+	/* Check to see whether len was rounded up from small -ve to zero */
+	if (len_in && !len)
+		return -EINVAL;
+
+	end = start + len;
+	if (end < start)
+		return -EINVAL;
+
+	if (end == start)
+		return 0;
+
+	down_write(&mm->mmap_sem);
+
+	switch (opt) {
+	case PR_SET_VMA_ANON_NAME:
+		error = prctl_set_vma_anon_name(start, end, arg);
+		break;
+	default:
+		error = -EINVAL;
+	}
+
+	up_write(&mm->mmap_sem);
+
+	return error;
+}
+#else /* CONFIG_MMU */
+static int prctl_set_vma(unsigned long opt, unsigned long start,
+		unsigned long len_in, unsigned long arg)
+{
+	return -EINVAL;
+}
+#endif
+
 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
 {
 	return -EINVAL;
@@ -2294,6 +2443,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsi
 			return -EINVAL;
 		error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
 		break;
+	case PR_SET_VMA:
+		error = prctl_set_vma(arg2, arg3, arg4, arg5);
+		break;
 	default:
 		error = -EINVAL;
 		break;