diff options
Diffstat (limited to 'mm/process_vm_access.c')
| -rw-r--r-- | mm/process_vm_access.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 0523edab03a6..b308e96cd05a 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -53,7 +53,10 @@ static int process_vm_rw_pages(struct page **pages, } /* Maximum number of pages kmalloc'd to hold struct page's during copy */ -#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2) +#define PVM_MAX_KMALLOC_PAGES 2 + +/* Maximum number of pages that can be stored at a time */ +#define PVM_MAX_USER_PAGES (PVM_MAX_KMALLOC_PAGES * PAGE_SIZE / sizeof(struct page *)) /** * process_vm_rw_single_vec - read/write pages from task specified @@ -79,8 +82,6 @@ static int process_vm_rw_single_vec(unsigned long addr, unsigned long start_offset = addr - pa; unsigned long nr_pages; ssize_t rc = 0; - unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES - / sizeof(struct pages *); unsigned int flags = 0; /* Work out address and page range required */ @@ -92,7 +93,7 @@ static int process_vm_rw_single_vec(unsigned long addr, flags |= FOLL_WRITE; while (!rc && nr_pages && iov_iter_count(iter)) { - int pinned_pages = min(nr_pages, max_pages_per_loop); + int pinned_pages = min_t(unsigned long, nr_pages, PVM_MAX_USER_PAGES); int locked = 1; size_t bytes; @@ -171,7 +172,7 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, iov_len = rvec[i].iov_len; if (iov_len > 0) { nr_pages_iov = ((unsigned long)rvec[i].iov_base - + iov_len) + + iov_len - 1) / PAGE_SIZE - (unsigned long)rvec[i].iov_base / PAGE_SIZE + 1; nr_pages = max(nr_pages, nr_pages_iov); @@ -184,8 +185,8 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) { /* For reliability don't try to kmalloc more than 2 pages worth */ - process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES, - sizeof(struct pages *)*nr_pages), + process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES * PAGE_SIZE, + sizeof(struct page *)*nr_pages), GFP_KERNEL); if (!process_pages) |