Re: [PATCH v15 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation
From: Matthew Wilcox <willy@infradead.org>
Date: 2021-01-21 01:02:28
Also in:
linux-api, linux-arch, linux-arm-kernel, linux-fsdevel, linux-kselftest, linux-riscv, lkml, nvdimm
On Wed, Jan 20, 2021 at 08:06:08PM +0200, Mike Rapoport wrote:
+static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp)
{
+ unsigned long nr_pages = (1 << PMD_PAGE_ORDER);
+ struct gen_pool *pool = ctx->pool;
+ unsigned long addr;
+ struct page *page;
+ int err;
+
+ page = cma_alloc(secretmem_cma, nr_pages, PMD_SIZE, gfp & __GFP_NOWARN);
+ if (!page)
+ return -ENOMEM;Does cma_alloc() zero the pages it allocates? If not, where do we avoid leaking kernel memory to userspace?