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authorDavid Hildenbrand <david@redhat.com>2022-09-27 13:01:19 +0200
committerAndrew Morton <akpm@linux-foundation.org>2022-11-08 17:37:15 -0800
commitc77369b437f983a862bb6741814670d4ad38478c (patch)
treee11a0e49d999f6622a13ce5fcd3e4846b3b8cbd5 /mm/gup_test.c
parente487ebbd12986facc7f77129d3ca80de84841170 (diff)
mm/gup_test: start/stop/read functionality for PIN LONGTERM test
We want an easy way to take a R/O or R/W longterm pin on a range and be able to observe the content of the pinned pages, so we can properly test how longterm puns interact with our COW logic. [david@redhat.com: silence a warning on 32-bit] Link: https://lkml.kernel.org/r/74adbb51-6e33-f636-8a9c-2ad87bd9007e@redhat.com [yang.lee@linux.alibaba.com: ./mm/gup_test.c:281:2-3: Unneeded semicolon] Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2455 Link: https://lkml.kernel.org/r/20221020024035.113619-1-yang.lee@linux.alibaba.com Link: https://lkml.kernel.org/r/20220927110120.106906-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph von Recklinghausen <crecklin@redhat.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/gup_test.c')
-rw-r--r--mm/gup_test.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/mm/gup_test.c b/mm/gup_test.c
index 12b0a91767d3..0d76d9b4bb5a 100644
--- a/mm/gup_test.c
+++ b/mm/gup_test.c
@@ -203,6 +203,135 @@ free_pages:
return ret;
}
+static DEFINE_MUTEX(pin_longterm_test_mutex);
+static struct page **pin_longterm_test_pages;
+static unsigned long pin_longterm_test_nr_pages;
+
+static inline void pin_longterm_test_stop(void)
+{
+ if (pin_longterm_test_pages) {
+ if (pin_longterm_test_nr_pages)
+ unpin_user_pages(pin_longterm_test_pages,
+ pin_longterm_test_nr_pages);
+ kfree(pin_longterm_test_pages);
+ pin_longterm_test_pages = NULL;
+ pin_longterm_test_nr_pages = 0;
+ }
+}
+
+static inline int pin_longterm_test_start(unsigned long arg)
+{
+ long nr_pages, cur_pages, addr, remaining_pages;
+ int gup_flags = FOLL_LONGTERM;
+ struct pin_longterm_test args;
+ struct page **pages;
+ int ret = 0;
+ bool fast;
+
+ if (pin_longterm_test_pages)
+ return -EINVAL;
+
+ if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
+ return -EFAULT;
+
+ if (args.flags &
+ ~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST))
+ return -EINVAL;
+ if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE))
+ return -EINVAL;
+ if (args.size > LONG_MAX)
+ return -EINVAL;
+ nr_pages = args.size / PAGE_SIZE;
+ if (!nr_pages)
+ return -EINVAL;
+
+ pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+ if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE)
+ gup_flags |= FOLL_WRITE;
+ fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST);
+
+ if (!fast && mmap_read_lock_killable(current->mm)) {
+ kfree(pages);
+ return -EINTR;
+ }
+
+ pin_longterm_test_pages = pages;
+ pin_longterm_test_nr_pages = 0;
+
+ while (nr_pages - pin_longterm_test_nr_pages) {
+ remaining_pages = nr_pages - pin_longterm_test_nr_pages;
+ addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE;
+
+ if (fast)
+ cur_pages = pin_user_pages_fast(addr, remaining_pages,
+ gup_flags, pages);
+ else
+ cur_pages = pin_user_pages(addr, remaining_pages,
+ gup_flags, pages, NULL);
+ if (cur_pages < 0) {
+ pin_longterm_test_stop();
+ ret = cur_pages;
+ break;
+ }
+ pin_longterm_test_nr_pages += cur_pages;
+ pages += cur_pages;
+ }
+
+ if (!fast)
+ mmap_read_unlock(current->mm);
+ return ret;
+}
+
+static inline int pin_longterm_test_read(unsigned long arg)
+{
+ __u64 user_addr;
+ unsigned long i;
+
+ if (!pin_longterm_test_pages)
+ return -EINVAL;
+
+ if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr)))
+ return -EFAULT;
+
+ for (i = 0; i < pin_longterm_test_nr_pages; i++) {
+ void *addr = page_to_virt(pin_longterm_test_pages[i]);
+
+ if (copy_to_user((void __user *)(unsigned long)user_addr, addr,
+ PAGE_SIZE))
+ return -EFAULT;
+ user_addr += PAGE_SIZE;
+ }
+ return 0;
+}
+
+static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = -EINVAL;
+
+ if (mutex_lock_killable(&pin_longterm_test_mutex))
+ return -EINTR;
+
+ switch (cmd) {
+ case PIN_LONGTERM_TEST_START:
+ ret = pin_longterm_test_start(arg);
+ break;
+ case PIN_LONGTERM_TEST_STOP:
+ pin_longterm_test_stop();
+ ret = 0;
+ break;
+ case PIN_LONGTERM_TEST_READ:
+ ret = pin_longterm_test_read(arg);
+ break;
+ }
+
+ mutex_unlock(&pin_longterm_test_mutex);
+ return ret;
+}
+
static long gup_test_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
@@ -217,6 +346,10 @@ static long gup_test_ioctl(struct file *filep, unsigned int cmd,
case PIN_BASIC_TEST:
case DUMP_USER_PAGES_TEST:
break;
+ case PIN_LONGTERM_TEST_START:
+ case PIN_LONGTERM_TEST_STOP:
+ case PIN_LONGTERM_TEST_READ:
+ return pin_longterm_test_ioctl(filep, cmd, arg);
default:
return -EINVAL;
}
@@ -234,9 +367,17 @@ static long gup_test_ioctl(struct file *filep, unsigned int cmd,
return 0;
}
+static int gup_test_release(struct inode *inode, struct file *file)
+{
+ pin_longterm_test_stop();
+
+ return 0;
+}
+
static const struct file_operations gup_test_fops = {
.open = nonseekable_open,
.unlocked_ioctl = gup_test_ioctl,
+ .release = gup_test_release,
};
static int __init gup_test_init(void)