Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/madvise.c b/mm/madvise.c
index 1107e99..24abc79 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -17,6 +17,8 @@
#include <linux/falloc.h>
#include <linux/fadvise.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/uio.h>
#include <linux/ksm.h>
#include <linux/fs.h>
#include <linux/file.h>
@@ -39,7 +41,7 @@
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
- * take mmap_sem for writing. Others, which simply traverse vmas, need
+ * take mmap_lock for writing. Others, which simply traverse vmas, need
* to only take it for reading.
*/
static int madvise_need_mmap_write(int behavior)
@@ -164,7 +166,7 @@
success:
/*
- * vm_flags is protected by the mmap_sem held in write mode.
+ * vm_flags is protected by the mmap_lock held in write mode.
*/
vma->vm_flags = new_flags;
@@ -223,25 +225,28 @@
unsigned long start, unsigned long end,
struct address_space *mapping)
{
- pgoff_t index;
+ XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start));
+ pgoff_t end_index = linear_page_index(vma, end + PAGE_SIZE - 1);
struct page *page;
- swp_entry_t swap;
- for (; start < end; start += PAGE_SIZE) {
- index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ rcu_read_lock();
+ xas_for_each(&xas, page, end_index) {
+ swp_entry_t swap;
- page = find_get_entry(mapping, index);
- if (!xa_is_value(page)) {
- if (page)
- put_page(page);
+ if (!xa_is_value(page))
continue;
- }
+ xas_pause(&xas);
+ rcu_read_unlock();
+
swap = radix_to_swp_entry(page);
page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
NULL, 0, false);
if (page)
put_page(page);
+
+ rcu_read_lock();
}
+ rcu_read_unlock();
lru_add_drain(); /* Push any new pages onto the LRU now */
}
@@ -254,6 +259,7 @@
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;
@@ -284,16 +290,16 @@
* Filesystem's fadvise may need to take various locks. We need to
* explicitly grab a reference because the vma (and hence the
* vma's reference to the file) can go away as soon as we drop
- * mmap_sem.
+ * mmap_lock.
*/
- *prev = NULL; /* tell sys_madvise we drop mmap_sem */
+ *prev = NULL; /* tell sys_madvise we drop mmap_lock */
get_file(file);
offset = (loff_t)(start - vma->vm_start)
+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
- up_read(¤t->mm->mmap_sem);
+ mmap_read_unlock(mm);
vfs_fadvise(file, offset, end - start, POSIX_FADV_WILLNEED);
fput(file);
- down_read(¤t->mm->mmap_sem);
+ mmap_read_lock(mm);
return 0;
}
@@ -762,15 +768,17 @@
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;
if (!userfaultfd_remove(vma, start, end)) {
- *prev = NULL; /* mmap_sem has been dropped, prev is stale */
+ *prev = NULL; /* mmap_lock has been dropped, prev is stale */
- down_read(¤t->mm->mmap_sem);
- vma = find_vma(current->mm, start);
+ mmap_read_lock(mm);
+ vma = find_vma(mm, start);
if (!vma)
return -ENOMEM;
if (start < vma->vm_start) {
@@ -790,7 +798,7 @@
if (end > vma->vm_end) {
/*
* Don't fail if end > vma->vm_end. If the old
- * vma was splitted while the mmap_sem was
+ * vma was splitted while the mmap_lock was
* released the effect of the concurrent
* operation may not cause madvise() to
* have an undefined result. There may be an
@@ -824,8 +832,9 @@
loff_t offset;
int error;
struct file *f;
+ struct mm_struct *mm = vma->vm_mm;
- *prev = NULL; /* tell sys_madvise we drop mmap_sem */
+ *prev = NULL; /* tell sys_madvise we drop mmap_lock */
if (vma->vm_flags & VM_LOCKED)
return -EINVAL;
@@ -846,18 +855,18 @@
* Filesystem's fallocate may need to take i_mutex. We need to
* explicitly grab a reference because the vma (and hence the
* vma's reference to the file) can go away as soon as we drop
- * mmap_sem.
+ * mmap_lock.
*/
get_file(f);
if (userfaultfd_remove(vma, start, end)) {
- /* mmap_sem was not released by userfaultfd_remove() */
- up_read(¤t->mm->mmap_sem);
+ /* mmap_lock was not released by userfaultfd_remove() */
+ mmap_read_unlock(mm);
}
error = vfs_fallocate(f,
FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
offset, end - start);
fput(f);
- down_read(¤t->mm->mmap_sem);
+ mmap_read_lock(mm);
return error;
}
@@ -868,16 +877,16 @@
static int madvise_inject_error(int behavior,
unsigned long start, unsigned long end)
{
- struct page *page;
struct zone *zone;
- unsigned int order;
+ unsigned long size;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- for (; start < end; start += PAGE_SIZE << order) {
+ for (; start < end; start += size) {
unsigned long pfn;
+ struct page *page;
int ret;
ret = get_user_pages_fast(start, 1, 0, &page);
@@ -888,36 +897,20 @@
/*
* When soft offlining hugepages, after migrating the page
* we dissolve it, therefore in the second loop "page" will
- * no longer be a compound page, and order will be 0.
+ * no longer be a compound page.
*/
- order = compound_order(compound_head(page));
-
- if (PageHWPoison(page)) {
- put_page(page);
- continue;
- }
+ size = page_size(compound_head(page));
if (behavior == MADV_SOFT_OFFLINE) {
pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
- pfn, start);
-
- ret = soft_offline_page(page, MF_COUNT_INCREASED);
- if (ret)
- return ret;
- continue;
+ pfn, start);
+ ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
+ } else {
+ pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n",
+ pfn, start);
+ ret = memory_failure(pfn, MF_COUNT_INCREASED);
}
- pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n",
- pfn, start);
-
- /*
- * Drop the page reference taken by get_user_pages_fast(). In
- * the absence of MF_COUNT_INCREASED the memory_failure()
- * routine is responsible for pinning the page to prevent it
- * from being released back to the page allocator.
- */
- put_page(page);
- ret = memory_failure(pfn, 0);
if (ret)
return ret;
}
@@ -989,6 +982,18 @@
}
}
+static bool
+process_madvise_behavior_valid(int behavior)
+{
+ switch (behavior) {
+ case MADV_COLD:
+ case MADV_PAGEOUT:
+ return true;
+ default:
+ return false;
+ }
+}
+
/*
* The madvise(2) system call.
*
@@ -1036,6 +1041,11 @@
* MADV_DONTDUMP - the application wants to prevent pages in the given range
* from being included in its core dump.
* MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump.
+ * MADV_COLD - the application is not expected to use this memory soon,
+ * deactivate pages in this range so that they can be reclaimed
+ * easily if memory pressure hanppens.
+ * MADV_PAGEOUT - the application is not expected to use this memory soon,
+ * page out the pages in this range immediately.
*
* return values:
* zero - success
@@ -1050,7 +1060,7 @@
* -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 mm_struct *mm, unsigned long start, size_t len_in, int behavior)
{
unsigned long end, tmp;
struct vm_area_struct *vma, *prev;
@@ -1065,9 +1075,9 @@
if (!madvise_behavior_valid(behavior))
return error;
- if (start & ~PAGE_MASK)
+ if (!PAGE_ALIGNED(start))
return error;
- len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+ len = PAGE_ALIGN(len_in);
/* Check to see whether len was rounded up from small -ve to zero */
if (len_in && !len)
@@ -1088,10 +1098,10 @@
write = madvise_need_mmap_write(behavior);
if (write) {
- if (down_write_killable(¤t->mm->mmap_sem))
+ if (mmap_write_lock_killable(mm))
return -EINTR;
} else {
- down_read(¤t->mm->mmap_sem);
+ mmap_read_lock(mm);
}
/*
@@ -1099,7 +1109,7 @@
* 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;
@@ -1135,15 +1145,101 @@
goto out;
if (prev)
vma = prev->vm_next;
- else /* madvise_remove dropped mmap_sem */
- vma = find_vma(current->mm, start);
+ else /* madvise_remove dropped mmap_lock */
+ vma = find_vma(mm, start);
}
out:
blk_finish_plug(&plug);
if (write)
- up_write(¤t->mm->mmap_sem);
+ mmap_write_unlock(mm);
else
- up_read(¤t->mm->mmap_sem);
+ mmap_read_unlock(mm);
return error;
}
+
+SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
+{
+ return do_madvise(current->mm, start, len_in, behavior);
+}
+
+SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
+ size_t, vlen, int, behavior, unsigned int, flags)
+{
+ ssize_t ret;
+ struct iovec iovstack[UIO_FASTIOV], iovec;
+ struct iovec *iov = iovstack;
+ struct iov_iter iter;
+ struct pid *pid;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ size_t total_len;
+ unsigned int f_flags;
+
+ if (flags != 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
+ if (ret < 0)
+ goto out;
+
+ pid = pidfd_get_pid(pidfd, &f_flags);
+ if (IS_ERR(pid)) {
+ ret = PTR_ERR(pid);
+ goto free_iov;
+ }
+
+ task = get_pid_task(pid, PIDTYPE_PID);
+ if (!task) {
+ ret = -ESRCH;
+ goto put_pid;
+ }
+
+ if (!process_madvise_behavior_valid(behavior)) {
+ ret = -EINVAL;
+ goto release_task;
+ }
+
+ /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */
+ mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
+ if (IS_ERR_OR_NULL(mm)) {
+ ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
+ goto release_task;
+ }
+
+ /*
+ * Require CAP_SYS_NICE for influencing process performance. Note that
+ * only non-destructive hints are currently supported.
+ */
+ if (!capable(CAP_SYS_NICE)) {
+ ret = -EPERM;
+ goto release_mm;
+ }
+
+ total_len = iov_iter_count(&iter);
+
+ while (iov_iter_count(&iter)) {
+ iovec = iov_iter_iovec(&iter);
+ ret = do_madvise(mm, (unsigned long)iovec.iov_base,
+ iovec.iov_len, behavior);
+ if (ret < 0)
+ break;
+ iov_iter_advance(&iter, iovec.iov_len);
+ }
+
+ if (ret == 0)
+ ret = total_len - iov_iter_count(&iter);
+
+release_mm:
+ mmput(mm);
+release_task:
+ put_task_struct(task);
+put_pid:
+ put_pid(pid);
+free_iov:
+ kfree(iov);
+out:
+ return ret;
+}