From ed1182dc004dbcc7cfe64fb0e8ac520b25431715 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Fri, 27 Nov 2020 18:17:26 +0100 Subject: xdp: Handle MEM_TYPE_XSK_BUFF_POOL correctly in xdp_return_buff() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It turns out that it does exist a path where xdp_return_buff() is being passed an XDP buffer of type MEM_TYPE_XSK_BUFF_POOL. This path is when AF_XDP zero-copy mode is enabled, and a buffer is redirected to a DEVMAP with an attached XDP program that drops the buffer. This change simply puts the handling of MEM_TYPE_XSK_BUFF_POOL back into xdp_return_buff(). Fixes: 82c41671ca4f ("xdp: Simplify xdp_return_{frame, frame_rx_napi, buff}") Reported-by: Maxim Mikityanskiy Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Acked-by: Maxim Mikityanskiy Link: https://lore.kernel.org/bpf/20201127171726.123627-1-bjorn.topel@gmail.com --- net/core/xdp.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/core/xdp.c b/net/core/xdp.c index 48aba933a5a8..491ad569a79c 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -335,11 +335,10 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); * scenarios (e.g. queue full), it is possible to return the xdp_frame * while still leveraging this protection. The @napi_direct boolean * is used for those calls sites. Thus, allowing for faster recycling - * of xdp_frames/pages in those cases. This path is never used by the - * MEM_TYPE_XSK_BUFF_POOL memory type, so it's explicitly not part of - * the switch-statement. + * of xdp_frames/pages in those cases. */ -static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) +static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, + struct xdp_buff *xdp) { struct xdp_mem_allocator *xa; struct page *page; @@ -361,6 +360,10 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) page = virt_to_page(data); /* Assumes order0 page*/ put_page(page); break; + case MEM_TYPE_XSK_BUFF_POOL: + /* NB! Only valid from an xdp_buff! */ + xsk_buff_free(xdp); + break; default: /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ WARN(1, "Incorrect XDP memory type (%d) usage", mem->type); @@ -370,19 +373,19 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) void xdp_return_frame(struct xdp_frame *xdpf) { - __xdp_return(xdpf->data, &xdpf->mem, false); + __xdp_return(xdpf->data, &xdpf->mem, false, NULL); } EXPORT_SYMBOL_GPL(xdp_return_frame); void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) { - __xdp_return(xdpf->data, &xdpf->mem, true); + __xdp_return(xdpf->data, &xdpf->mem, true, NULL); } EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); void xdp_return_buff(struct xdp_buff *xdp) { - __xdp_return(xdp->data, &xdp->rxq->mem, true); + __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp); } /* Only called for MEM_TYPE_PAGE_POOL see xdp.h */ -- cgit v1.2.3