From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/mm/process_vm_access.c | 129 +++++++++---------------------------------
1 files changed, 29 insertions(+), 100 deletions(-)
diff --git a/kernel/mm/process_vm_access.c b/kernel/mm/process_vm_access.c
index a447092..c90d722 100644
--- a/kernel/mm/process_vm_access.c
+++ b/kernel/mm/process_vm_access.c
@@ -1,26 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* linux/mm/process_vm_access.c
*
* Copyright (C) 2010-2011 Christopher Yeoh <cyeoh@au1.ibm.com>, IBM Corp.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*/
+#include <linux/compat.h>
#include <linux/mm.h>
#include <linux/uio.h>
#include <linux/sched.h>
+#include <linux/compat.h>
#include <linux/sched/mm.h>
#include <linux/highmem.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
-
-#ifdef CONFIG_COMPAT
-#include <linux/compat.h>
-#endif
/**
* process_vm_rw_pages - read/write pages from task specified
@@ -46,12 +40,11 @@
if (copy > len)
copy = len;
- if (vm_write) {
+ if (vm_write)
copied = copy_page_from_iter(page, offset, copy, iter);
- set_page_dirty_lock(page);
- } else {
+ else
copied = copy_page_to_iter(page, offset, copy, iter);
- }
+
len -= copied;
if (copied < copy && iov_iter_count(iter))
return -EFAULT;
@@ -100,7 +93,7 @@
flags |= FOLL_WRITE;
while (!rc && nr_pages && iov_iter_count(iter)) {
- int pages = min(nr_pages, max_pages_per_loop);
+ int pinned_pages = min(nr_pages, max_pages_per_loop);
int locked = 1;
size_t bytes;
@@ -109,15 +102,16 @@
* access remotely because task/mm might not
* current/current->mm
*/
- down_read(&mm->mmap_sem);
- pages = get_user_pages_remote(task, mm, pa, pages, flags,
- process_pages, NULL, &locked);
+ mmap_read_lock(mm);
+ pinned_pages = pin_user_pages_remote(mm, pa, pinned_pages,
+ flags, process_pages,
+ NULL, &locked);
if (locked)
- up_read(&mm->mmap_sem);
- if (pages <= 0)
+ mmap_read_unlock(mm);
+ if (pinned_pages <= 0)
return -EFAULT;
- bytes = pages * PAGE_SIZE - start_offset;
+ bytes = pinned_pages * PAGE_SIZE - start_offset;
if (bytes > len)
bytes = len;
@@ -126,10 +120,12 @@
vm_write);
len -= bytes;
start_offset = 0;
- nr_pages -= pages;
- pa += pages * PAGE_SIZE;
- while (pages)
- put_page(process_pages[--pages]);
+ nr_pages -= pinned_pages;
+ pa += pinned_pages * PAGE_SIZE;
+
+ /* If vm_write is set, the pages need to be made dirty: */
+ unpin_user_pages_dirty_lock(process_pages, pinned_pages,
+ vm_write);
}
return rc;
@@ -208,7 +204,7 @@
if (!mm || IS_ERR(mm)) {
rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
/*
- * Explicitly map EACCES to EPERM as EPERM is a more a
+ * Explicitly map EACCES to EPERM as EPERM is a more
* appropriate error code for process_vw_readv/writev
*/
if (rc == -EACCES)
@@ -278,20 +274,18 @@
if (rc < 0)
return rc;
if (!iov_iter_count(&iter))
- goto free_iovecs;
-
- rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
- iovstack_r, &iov_r);
- if (rc <= 0)
- goto free_iovecs;
-
+ goto free_iov_l;
+ iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r,
+ in_compat_syscall());
+ if (IS_ERR(iov_r)) {
+ rc = PTR_ERR(iov_r);
+ goto free_iov_l;
+ }
rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
-
-free_iovecs:
if (iov_r != iovstack_r)
kfree(iov_r);
+free_iov_l:
kfree(iov_l);
-
return rc;
}
@@ -309,68 +303,3 @@
{
return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1);
}
-
-#ifdef CONFIG_COMPAT
-
-static ssize_t
-compat_process_vm_rw(compat_pid_t pid,
- const struct compat_iovec __user *lvec,
- unsigned long liovcnt,
- const struct compat_iovec __user *rvec,
- unsigned long riovcnt,
- unsigned long flags, int vm_write)
-{
- struct iovec iovstack_l[UIO_FASTIOV];
- struct iovec iovstack_r[UIO_FASTIOV];
- struct iovec *iov_l = iovstack_l;
- struct iovec *iov_r = iovstack_r;
- struct iov_iter iter;
- ssize_t rc = -EFAULT;
- int dir = vm_write ? WRITE : READ;
-
- if (flags != 0)
- return -EINVAL;
-
- rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
- if (rc < 0)
- return rc;
- if (!iov_iter_count(&iter))
- goto free_iovecs;
- rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
- UIO_FASTIOV, iovstack_r,
- &iov_r);
- if (rc <= 0)
- goto free_iovecs;
-
- rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
-
-free_iovecs:
- if (iov_r != iovstack_r)
- kfree(iov_r);
- kfree(iov_l);
- return rc;
-}
-
-COMPAT_SYSCALL_DEFINE6(process_vm_readv, compat_pid_t, pid,
- const struct compat_iovec __user *, lvec,
- compat_ulong_t, liovcnt,
- const struct compat_iovec __user *, rvec,
- compat_ulong_t, riovcnt,
- compat_ulong_t, flags)
-{
- return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
- riovcnt, flags, 0);
-}
-
-COMPAT_SYSCALL_DEFINE6(process_vm_writev, compat_pid_t, pid,
- const struct compat_iovec __user *, lvec,
- compat_ulong_t, liovcnt,
- const struct compat_iovec __user *, rvec,
- compat_ulong_t, riovcnt,
- compat_ulong_t, flags)
-{
- return compat_process_vm_rw(pid, lvec, liovcnt, rvec,
- riovcnt, flags, 1);
-}
-
-#endif
--
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