summaryrefslogtreecommitdiff
path: root/fs/proc
diff options
context:
space:
mode:
authorAndrew Morton <akpm@linux-foundation.org>2023-08-22 00:26:20 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-08-22 00:26:20 +0300
commit5994eabf3bbbea550166ae90de0c854fc984c95d (patch)
tree6b242a70d3254c408c68157a5f5b2fa7eb9f6a4b /fs/proc
parente45a2e947dfa6da2d73e2cf91ed6399c12522d4f (diff)
parent6867c7a3320669cbe44b905a3eb35db725c6d470 (diff)
downloadlinux-5994eabf3bbbea550166ae90de0c854fc984c95d.tar.xz
merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/kcore.c30
-rw-r--r--fs/proc/task_mmu.c8
2 files changed, 33 insertions, 5 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 9cb32e1a78a0..23fc24d16b31 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -309,6 +309,8 @@ static void append_kcore_note(char *notes, size_t *i, const char *name,
static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
{
+ struct file *file = iocb->ki_filp;
+ char *buf = file->private_data;
loff_t *fpos = &iocb->ki_pos;
size_t phdrs_offset, notes_offset, data_offset;
size_t page_offline_frozen = 1;
@@ -555,10 +557,21 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
case KCORE_VMEMMAP:
case KCORE_TEXT:
/*
- * We use _copy_to_iter() to bypass usermode hardening
- * which would otherwise prevent this operation.
+ * Sadly we must use a bounce buffer here to be able to
+ * make use of copy_from_kernel_nofault(), as these
+ * memory regions might not always be mapped on all
+ * architectures.
*/
- if (_copy_to_iter((char *)start, tsz, iter) != tsz) {
+ if (copy_from_kernel_nofault(buf, (void *)start, tsz)) {
+ if (iov_iter_zero(tsz, iter) != tsz) {
+ ret = -EFAULT;
+ goto out;
+ }
+ /*
+ * We know the bounce buffer is safe to copy from, so
+ * use _copy_to_iter() directly.
+ */
+ } else if (_copy_to_iter(buf, tsz, iter) != tsz) {
ret = -EFAULT;
goto out;
}
@@ -595,6 +608,10 @@ static int open_kcore(struct inode *inode, struct file *filp)
if (ret)
return ret;
+ filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!filp->private_data)
+ return -ENOMEM;
+
if (kcore_need_update)
kcore_update_ram();
if (i_size_read(inode) != proc_root_kcore->size) {
@@ -605,9 +622,16 @@ static int open_kcore(struct inode *inode, struct file *filp)
return 0;
}
+static int release_kcore(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+ return 0;
+}
+
static const struct proc_ops kcore_proc_ops = {
.proc_read_iter = read_kcore_iter,
.proc_open = open_kcore,
+ .proc_release = release_kcore,
.proc_lseek = default_llseek,
};
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 74cbb00422ea..15ddf4653a19 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -571,8 +571,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
bool migration = false;
if (pmd_present(*pmd)) {
- /* FOLL_DUMP will return -EFAULT on huge zero page */
- page = follow_trans_huge_pmd(vma, addr, pmd, FOLL_DUMP);
+ page = vm_normal_page_pmd(vma, addr, *pmd);
} else if (unlikely(thp_migration_supported() && is_swap_pmd(*pmd))) {
swp_entry_t entry = pmd_to_swp_entry(*pmd);
@@ -742,12 +741,14 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
static const struct mm_walk_ops smaps_walk_ops = {
.pmd_entry = smaps_pte_range,
.hugetlb_entry = smaps_hugetlb_range,
+ .walk_lock = PGWALK_RDLOCK,
};
static const struct mm_walk_ops smaps_shmem_walk_ops = {
.pmd_entry = smaps_pte_range,
.hugetlb_entry = smaps_hugetlb_range,
.pte_hole = smaps_pte_hole,
+ .walk_lock = PGWALK_RDLOCK,
};
/*
@@ -1229,6 +1230,7 @@ static int clear_refs_test_walk(unsigned long start, unsigned long end,
static const struct mm_walk_ops clear_refs_walk_ops = {
.pmd_entry = clear_refs_pte_range,
.test_walk = clear_refs_test_walk,
+ .walk_lock = PGWALK_WRLOCK,
};
static ssize_t clear_refs_write(struct file *file, const char __user *buf,
@@ -1606,6 +1608,7 @@ static const struct mm_walk_ops pagemap_ops = {
.pmd_entry = pagemap_pmd_range,
.pte_hole = pagemap_pte_hole,
.hugetlb_entry = pagemap_hugetlb_range,
+ .walk_lock = PGWALK_RDLOCK,
};
/*
@@ -1919,6 +1922,7 @@ static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
static const struct mm_walk_ops show_numa_ops = {
.hugetlb_entry = gather_hugetlb_stats,
.pmd_entry = gather_pte_stats,
+ .walk_lock = PGWALK_RDLOCK,
};
/*