From patchwork Sat Apr 4 09:40:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474137 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3656581 for ; Sat, 4 Apr 2020 09:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14ABB2076C for ; Sat, 4 Apr 2020 09:41:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TW+1Nsxw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726373AbgDDJl3 (ORCPT ); Sat, 4 Apr 2020 05:41:29 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37324 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgDDJl1 (ORCPT ); Sat, 4 Apr 2020 05:41:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=NRX1JUyAqjf5wXlVipKJFb3msvliCBG3tEKEYgkCtZI=; b=TW+1Nsxw9TeWcVrte9M7Y2RiZf bttXuw1z5zLfVK1WKBJ9jQEQf7bg2g3Fg3SjKMFlkWjKtQf8eBs6sAShzs50QzEkhEYuRgGo2cqLw sxqzKiUVJKsJNq94JciRHqm24H9d1DSNhAh8AnNZ3OTE4Y7KycDq66CAvr1+dyt8vwvIB3/6gRN4f FYCwLQouLYxTM39n5sny6lvKNNYBzZtJ9WiPRttH/ULLC29LcNQ7B4wmHhVkg3k8AWnWyJrXfPzLy MA3LbNhEicLxFqAFS+ffkTacJUVr8MK6eq027yBMz9st5HO3pb93uX7KfVLnvtMdvHW+H2Qgc+bx9 R7AvViAg==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIZ-0002cr-En; Sat, 04 Apr 2020 09:41:08 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/6] amdgpu: a NULL ->mm does not mean a thread is a kthread Date: Sat, 4 Apr 2020 11:40:56 +0200 Message-Id: <20200404094101.672954-2-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Use the proper API instead. Fixes: 70539bd795002 ("drm/amd: Update MEC HQD loading code for KFD") Signed-off-by: Christoph Hellwig Reviewed-by: Felix Kuehling --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index 13feb313e9b3..4db143c19dcc 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -190,7 +190,7 @@ uint8_t amdgpu_amdkfd_get_xgmi_hops_count(struct kgd_dev *dst, struct kgd_dev *s pagefault_disable(); \ if ((mmptr) == current->mm) { \ valid = !get_user((dst), (wptr)); \ - } else if (current->mm == NULL) { \ + } else if (current->flags & PF_KTHREAD) { \ use_mm(mmptr); \ valid = !get_user((dst), (wptr)); \ unuse_mm(mmptr); \ From patchwork Sat Apr 4 09:40:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474147 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 51E48912 for ; Sat, 4 Apr 2020 09:41:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26F3620739 for ; Sat, 4 Apr 2020 09:41:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="E5rDDKMw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726246AbgDDJlW (ORCPT ); Sat, 4 Apr 2020 05:41:22 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37216 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgDDJlV (ORCPT ); Sat, 4 Apr 2020 05:41:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=FjP6zoayZ1fjLTQ5J40k73xEcDLUAFsLpp9ITbvNuIc=; b=E5rDDKMwWfrap1JfG6yNklw4O2 GNgNgDdFmbxfo1fUVp5J1gaGFscM2Apu4SX2zjRhB1+YnuUkrq4wHrSoK6KStx9kPDNIH/ANmeneN wQ02zm0tKQ1R6ebfTq6wzZkFEMzwXBcqrmfyGf8xA5tZRYW83fb+mtQ8J+8dagGuRpquxFp/Q68nq FW1kAC2RNliuc7Tp/7ADj02HUyYGYkHXUO6rqnrjgGwA1crPkLp/2s+nq7pS6OYTuy64eguvFMaLD xOAvUjLwiu/DrMQZbyP3jl7d3qekyjoqtsaLSBWrrQVdwUV+JywA4azyO0oEnsF6xvSa20P+kDcLL Ntn9iIgQ==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIc-0002d1-GL; Sat, 04 Apr 2020 09:41:11 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/6] i915/gvt/kvm: a NULL ->mm does not mean a thread is a kthread Date: Sat, 4 Apr 2020 11:40:57 +0200 Message-Id: <20200404094101.672954-3-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Use the proper API instead. Fixes: f440c8a572d7 ("drm/i915/gvt/kvmgt: read/write GPA via KVM API") Signed-off-by: Christoph Hellwig --- drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 074c4efb58eb..5848400620b4 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -2037,7 +2037,7 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa, struct kvmgt_guest_info *info; struct kvm *kvm; int idx, ret; - bool kthread = current->mm == NULL; + bool kthread = (current->flags & PF_KTHREAD); if (!handle_valid(handle)) return -ESRCH; From patchwork Sat Apr 4 09:40:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474151 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 05D3E81 for ; Sat, 4 Apr 2020 09:41:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF2C42076E for ; Sat, 4 Apr 2020 09:41:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="CThSaAil" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726437AbgDDJlp (ORCPT ); Sat, 4 Apr 2020 05:41:45 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37224 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbgDDJlV (ORCPT ); Sat, 4 Apr 2020 05:41:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=/tDvMcpQEBI9S68wHOZLUB3dDI6IS68bO71B9/9EwUE=; b=CThSaAilR3ovdk8YHEBYWt5Ywb +Ig6dXA4SCkBKlwyH+dnd9gAgLYDklih2fs3Sb/j0+a+tRF+2om4l+ZEMhYbZmkdlBtdFVjiOQh6i rsAU0NmW5zgW+9jcbnYb4/kuzcl5lzPPmnD2sruNcp/WjLsPVH8LEVgHKSxKPKtGQYFGDWE4qpe1/ DN2i1aQV0nYWQyrfC3Q3YeHvjhe4lq6+1lGucDhrbtE0PvUI/PauoxgjTggfvH5eWTsh+88FTmiYE czENSm+bnFheaetCcE3kGE4wi0mZP4UK4qBRnn/gHR5USuqGiVuvVJn8j4hTaI6SxpNERUEcH8AUT 3r99EnWQ==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIf-0002dK-G0; Sat, 04 Apr 2020 09:41:14 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 3/6] i915/gvt: remove unused xen bits Date: Sat, 4 Apr 2020 11:40:58 +0200 Message-Id: <20200404094101.672954-4-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org No Xen support anywhere here. Remove a dead declaration and an unused include. Signed-off-by: Christoph Hellwig Acked-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/gvt.c | 1 - drivers/gpu/drm/i915/gvt/hypercall.h | 2 -- 2 files changed, 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c index 9e1787867894..c7c561237883 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.c +++ b/drivers/gpu/drm/i915/gvt/gvt.c @@ -31,7 +31,6 @@ */ #include -#include #include #include "i915_drv.h" diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h index b17c4a1599cd..b79da5124f83 100644 --- a/drivers/gpu/drm/i915/gvt/hypercall.h +++ b/drivers/gpu/drm/i915/gvt/hypercall.h @@ -79,6 +79,4 @@ struct intel_gvt_mpt { bool (*is_valid_gfn)(unsigned long handle, unsigned long gfn); }; -extern struct intel_gvt_mpt xengt_mpt; - #endif /* _GVT_HYPERCALL_H_ */ From patchwork Sat Apr 4 09:40:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474143 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 30FB4912 for ; Sat, 4 Apr 2020 09:41:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0486820737 for ; Sat, 4 Apr 2020 09:41:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EnjlznyT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726332AbgDDJl3 (ORCPT ); Sat, 4 Apr 2020 05:41:29 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37296 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726300AbgDDJlZ (ORCPT ); Sat, 4 Apr 2020 05:41:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=L4k367lz9ZR25gN2kYKg7ydUq9PF8rtgOzuec3oaq5I=; b=EnjlznyTr2/l7nAuHqFMHvK6b7 lhW300pxY46mKuXToj3sSXy93SRwkRJAzgCtA3in7pHlkHNRWNrbFehEUFfpCVp5TaSg+87JjNiCP X+zQul7TSmArDjIkfnRfHTcpN3yRK6v0go7vmhFahU8SiMXoMm1xLOpS5cl5AmBPzvFPh8fDKqUOY H9BcMacgvVQ/8RovB/LosctguYeHd4yLfPm1ITO5uiTEAzQDmaA1t89x7sxn2mcDaIi+MaLZgGypt /ylCvvzHmQ1Lrdo4WeKU/3/nyKkSg2b1zbBfUmyKBBLRCONJVhkXDooUUhoLfcIfSxE8rY56cNm3I 3FN27cxA==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIi-0002db-De; Sat, 04 Apr 2020 09:41:17 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 4/6] kernel: move use_mm/unuse_mm to kthread.c Date: Sat, 4 Apr 2020 11:40:59 +0200 Message-Id: <20200404094101.672954-5-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org These helpers are only for use with kernel threads, and I will tie them more into the kthread infrastructure going forward. Also move the prototypes to kthread.h - mmu_context.h was a little weird to start with as it otherwise contains very low-level MM bits. Signed-off-by: Christoph Hellwig Acked-by: Felix Kuehling --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 + .../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 1 - .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c | 1 - .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c | 2 - .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c | 2 - .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c | 2 - drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +- drivers/usb/gadget/function/f_fs.c | 2 +- drivers/usb/gadget/legacy/inode.c | 2 +- drivers/vhost/vhost.c | 1 - fs/aio.c | 1 - fs/io-wq.c | 1 - fs/io_uring.c | 1 - include/linux/kthread.h | 5 ++ include/linux/mmu_context.h | 5 -- kernel/kthread.c | 56 ++++++++++++++++ mm/Makefile | 2 +- mm/mmu_context.c | 64 ------------------- 18 files changed, 66 insertions(+), 85 deletions(-) delete mode 100644 mm/mmu_context.c diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index 4db143c19dcc..bce5e93fefc8 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -27,6 +27,7 @@ #include #include +#include #include #include #include diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c index 6529caca88fe..35d4a5ab0228 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include "amdgpu.h" #include "amdgpu_amdkfd.h" diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c index 4ec6d0c03201..b1655054b919 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c @@ -19,7 +19,6 @@ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ -#include #include "amdgpu.h" #include "amdgpu_amdkfd.h" #include "gc/gc_10_1_0_offset.h" diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c index 0b7e78748540..7d01420c0c85 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c @@ -20,8 +20,6 @@ * OTHER DEALINGS IN THE SOFTWARE. */ -#include - #include "amdgpu.h" #include "amdgpu_amdkfd.h" #include "cikd.h" diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c index ccd635b812b5..635cd1a26bed 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c @@ -20,8 +20,6 @@ * OTHER DEALINGS IN THE SOFTWARE. */ -#include - #include "amdgpu.h" #include "amdgpu_amdkfd.h" #include "gfx_v8_0.h" diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c index df841c2ac5e7..c7fd0c47b254 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c @@ -19,8 +19,6 @@ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ -#include - #include "amdgpu.h" #include "amdgpu_amdkfd.h" #include "gc/gc_9_0_offset.h" diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 5848400620b4..dee01c371bf5 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -31,7 +31,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c81023b195c3..c57b1b2507c6 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -32,7 +32,7 @@ #include #include -#include +#include #include #include diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index aa0de9e35afa..8b5233888bf8 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -21,7 +21,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index f44340b41494..4e9ce54869af 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include diff --git a/fs/aio.c b/fs/aio.c index 5f3d3d814928..328829f0343b 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include #include diff --git a/fs/io-wq.c b/fs/io-wq.c index cc5cf2209fb0..c49c2bdbafb5 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -10,7 +10,6 @@ #include #include #include -#include #include #include #include diff --git a/fs/io_uring.c b/fs/io_uring.c index 358f97be9c7b..27a4ecb724ca 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -55,7 +55,6 @@ #include #include #include -#include #include #include #include diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 8bbcaad7ef0f..c2d40c9672d6 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -5,6 +5,8 @@ #include #include +struct mm_struct; + __printf(4, 5) struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), void *data, @@ -198,6 +200,9 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); void kthread_destroy_worker(struct kthread_worker *worker); +void use_mm(struct mm_struct *mm); +void unuse_mm(struct mm_struct *mm); + struct cgroup_subsys_state; #ifdef CONFIG_BLK_CGROUP diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h index d9a543a9e1cc..c51a84132d7c 100644 --- a/include/linux/mmu_context.h +++ b/include/linux/mmu_context.h @@ -4,11 +4,6 @@ #include -struct mm_struct; - -void use_mm(struct mm_struct *mm); -void unuse_mm(struct mm_struct *mm); - /* Architectures that care about IRQ state in switch_mm can override this. */ #ifndef switch_mm_irqs_off # define switch_mm_irqs_off switch_mm diff --git a/kernel/kthread.c b/kernel/kthread.c index bfbfa481be3a..ce4610316377 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1,13 +1,17 @@ // SPDX-License-Identifier: GPL-2.0-only /* Kernel thread helper functions. * Copyright (C) 2004 IBM Corporation, Rusty Russell. + * Copyright (C) 2009 Red Hat, Inc. * * Creation is done via kthreadd, so that we get a clean environment * even if we're invoked from userspace (think modprobe, hotplug cpu, * etc.). */ #include +#include +#include #include +#include #include #include #include @@ -25,6 +29,7 @@ #include #include + static DEFINE_SPINLOCK(kthread_create_lock); static LIST_HEAD(kthread_create_list); struct task_struct *kthreadd_task; @@ -1203,6 +1208,57 @@ void kthread_destroy_worker(struct kthread_worker *worker) } EXPORT_SYMBOL(kthread_destroy_worker); +/* + * use_mm + * Makes the calling kernel thread take on the specified + * mm context. + * (Note: this routine is intended to be called only + * from a kernel thread context) + */ +void use_mm(struct mm_struct *mm) +{ + struct mm_struct *active_mm; + struct task_struct *tsk = current; + + task_lock(tsk); + active_mm = tsk->active_mm; + if (active_mm != mm) { + mmgrab(mm); + tsk->active_mm = mm; + } + tsk->mm = mm; + switch_mm(active_mm, mm, tsk); + task_unlock(tsk); +#ifdef finish_arch_post_lock_switch + finish_arch_post_lock_switch(); +#endif + + if (active_mm != mm) + mmdrop(active_mm); +} +EXPORT_SYMBOL_GPL(use_mm); + +/* + * unuse_mm + * Reverses the effect of use_mm, i.e. releases the + * specified mm context which was earlier taken on + * by the calling kernel thread + * (Note: this routine is intended to be called only + * from a kernel thread context) + */ +void unuse_mm(struct mm_struct *mm) +{ + struct task_struct *tsk = current; + + task_lock(tsk); + sync_mm_rss(mm); + tsk->mm = NULL; + /* active_mm is still 'mm' */ + enter_lazy_tlb(mm, tsk); + task_unlock(tsk); +} +EXPORT_SYMBOL_GPL(unuse_mm); + #ifdef CONFIG_BLK_CGROUP /** * kthread_associate_blkcg - associate blkcg to current kthread diff --git a/mm/Makefile b/mm/Makefile index dbc8346d16ca..0af4ee81aed2 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -41,7 +41,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ maccess.o page-writeback.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ util.o mmzone.o vmstat.o backing-dev.o \ - mm_init.o mmu_context.o percpu.o slab_common.o \ + mm_init.o percpu.o slab_common.o \ compaction.o vmacache.o \ interval_tree.o list_lru.o workingset.o \ debug.o gup.o $(mmu-y) diff --git a/mm/mmu_context.c b/mm/mmu_context.c deleted file mode 100644 index 3e612ae748e9..000000000000 --- a/mm/mmu_context.c +++ /dev/null @@ -1,64 +0,0 @@ -/* Copyright (C) 2009 Red Hat, Inc. - * - * See ../COPYING for licensing terms. - */ - -#include -#include -#include -#include -#include -#include - -#include - -/* - * use_mm - * Makes the calling kernel thread take on the specified - * mm context. - * (Note: this routine is intended to be called only - * from a kernel thread context) - */ -void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - if (active_mm != mm) { - mmgrab(mm); - tsk->active_mm = mm; - } - tsk->mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); -#ifdef finish_arch_post_lock_switch - finish_arch_post_lock_switch(); -#endif - - if (active_mm != mm) - mmdrop(active_mm); -} -EXPORT_SYMBOL_GPL(use_mm); - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thread context) - */ -void unuse_mm(struct mm_struct *mm) -{ - struct task_struct *tsk = current; - - task_lock(tsk); - sync_mm_rss(mm); - tsk->mm = NULL; - /* active_mm is still 'mm' */ - enter_lazy_tlb(mm, tsk); - task_unlock(tsk); -} -EXPORT_SYMBOL_GPL(unuse_mm); From patchwork Sat Apr 4 09:41:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474111 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D18A981 for ; Sat, 4 Apr 2020 09:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CB7B20752 for ; Sat, 4 Apr 2020 09:41:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="r5h07XmT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726302AbgDDJlZ (ORCPT ); Sat, 4 Apr 2020 05:41:25 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37262 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgDDJlX (ORCPT ); Sat, 4 Apr 2020 05:41:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=yiF0lZnKKv5ku7aLqgztTZhdcRHfig0kbM0LbrrrVUs=; b=r5h07XmTUWMIn1VNnYBovE9lNf xZ4CnmUBMqRf+9UeWNFMQo+mo9ZhaQ/Co7wR7SUBEGTJxM0pTeKhip4AxCLvSXHjjz5eh0/gAStU5 KIX3zjjTe5O60momreJHkws8KltSYQL9Ge/hWtyewr9K9WmMKpJeG2lXgQpp9UfvWuelEuXkdj/GD HgXp3FYx4GRy1fU2zRSuJfyspAui1jOY3yE2FoHG5tBMDp+gCayf+ZVqqvSNmSNxHnJ6Z7khVB0FA sjzUa+e1ldZt9D7pfySqoMzGeChxJOCmNYlrzUFGHdo/7d5vWUDXaCmOmA4XlGrfhvK5tnLIx899w VbIF+6AA==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIl-0002du-Da; Sat, 04 Apr 2020 09:41:19 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 5/6] kernel: better document the use_mm/unuse_mm API contract Date: Sat, 4 Apr 2020 11:41:00 +0200 Message-Id: <20200404094101.672954-6-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Switch the function documentation to kerneldoc comments, and add WARN_ON_ONCE asserts that the calling thread is a kernel thread and does not have ->mm set (or has ->mm set in the case of unuse_mm). Also give the functions a kthread_ prefix to better document the use case. Signed-off-by: Christoph Hellwig Acked-by: Felix Kuehling --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 4 +-- drivers/gpu/drm/i915/gvt/kvmgt.c | 4 +-- drivers/usb/gadget/function/f_fs.c | 4 +-- drivers/usb/gadget/legacy/inode.c | 4 +-- drivers/vhost/vhost.c | 4 +-- fs/io-wq.c | 6 ++-- fs/io_uring.c | 6 ++-- include/linux/kthread.h | 4 +-- kernel/kthread.c | 33 +++++++++++----------- mm/oom_kill.c | 6 ++-- mm/vmacache.c | 4 +-- 11 files changed, 39 insertions(+), 40 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index bce5e93fefc8..63db84e09408 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -192,9 +192,9 @@ uint8_t amdgpu_amdkfd_get_xgmi_hops_count(struct kgd_dev *dst, struct kgd_dev *s if ((mmptr) == current->mm) { \ valid = !get_user((dst), (wptr)); \ } else if (current->flags & PF_KTHREAD) { \ - use_mm(mmptr); \ + kthread_use_mm(mmptr); \ valid = !get_user((dst), (wptr)); \ - unuse_mm(mmptr); \ + kthread_unuse_mm(mmptr); \ } \ pagefault_enable(); \ } \ diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index dee01c371bf5..92e9b340dbc2 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -2048,7 +2048,7 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa, if (kthread) { if (!mmget_not_zero(kvm->mm)) return -EFAULT; - use_mm(kvm->mm); + kthread_use_mm(kvm->mm); } idx = srcu_read_lock(&kvm->srcu); @@ -2057,7 +2057,7 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa, srcu_read_unlock(&kvm->srcu, idx); if (kthread) { - unuse_mm(kvm->mm); + kthread_unuse_mm(kvm->mm); mmput(kvm->mm); } diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c57b1b2507c6..d9e48bd7c692 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -827,9 +827,9 @@ static void ffs_user_copy_worker(struct work_struct *work) mm_segment_t oldfs = get_fs(); set_fs(USER_DS); - use_mm(io_data->mm); + kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); - unuse_mm(io_data->mm); + kthread_unuse_mm(io_data->mm); set_fs(oldfs); } diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index 8b5233888bf8..a05552bc2ff8 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -462,9 +462,9 @@ static void ep_user_copy_worker(struct work_struct *work) struct kiocb *iocb = priv->iocb; size_t ret; - use_mm(mm); + kthread_use_mm(mm); ret = copy_to_iter(priv->buf, priv->actual, &priv->to); - unuse_mm(mm); + kthread_unuse_mm(mm); if (!ret) ret = -EFAULT; diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 4e9ce54869af..1787d426a956 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -336,7 +336,7 @@ static int vhost_worker(void *data) mm_segment_t oldfs = get_fs(); set_fs(USER_DS); - use_mm(dev->mm); + kthread_use_mm(dev->mm); for (;;) { /* mb paired w/ kthread_stop */ @@ -364,7 +364,7 @@ static int vhost_worker(void *data) schedule(); } } - unuse_mm(dev->mm); + kthread_unuse_mm(dev->mm); set_fs(oldfs); return 0; } diff --git a/fs/io-wq.c b/fs/io-wq.c index c49c2bdbafb5..83c2868eff2a 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -169,7 +169,7 @@ static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker) } __set_current_state(TASK_RUNNING); set_fs(KERNEL_DS); - unuse_mm(worker->mm); + kthread_unuse_mm(worker->mm); mmput(worker->mm); worker->mm = NULL; } @@ -416,7 +416,7 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe) static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work) { if (worker->mm) { - unuse_mm(worker->mm); + kthread_unuse_mm(worker->mm); mmput(worker->mm); worker->mm = NULL; } @@ -425,7 +425,7 @@ static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work) return; } if (mmget_not_zero(work->mm)) { - use_mm(work->mm); + kthread_use_mm(work->mm); if (!worker->mm) set_fs(USER_DS); worker->mm = work->mm; diff --git a/fs/io_uring.c b/fs/io_uring.c index 27a4ecb724ca..367406381044 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5839,7 +5839,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, err = -EFAULT; goto fail_req; } - use_mm(ctx->sqo_mm); + kthread_use_mm(ctx->sqo_mm); *mm = ctx->sqo_mm; } @@ -5911,7 +5911,7 @@ static int io_sq_thread(void *data) * may sleep. */ if (cur_mm) { - unuse_mm(cur_mm); + kthread_unuse_mm(cur_mm); mmput(cur_mm); cur_mm = NULL; } @@ -5987,7 +5987,7 @@ static int io_sq_thread(void *data) set_fs(old_fs); if (cur_mm) { - unuse_mm(cur_mm); + kthread_unuse_mm(cur_mm); mmput(cur_mm); } revert_creds(old_cred); diff --git a/include/linux/kthread.h b/include/linux/kthread.h index c2d40c9672d6..12258ea077cf 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -200,8 +200,8 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); void kthread_destroy_worker(struct kthread_worker *worker); -void use_mm(struct mm_struct *mm); -void unuse_mm(struct mm_struct *mm); +void kthread_use_mm(struct mm_struct *mm); +void kthread_unuse_mm(struct mm_struct *mm); struct cgroup_subsys_state; diff --git a/kernel/kthread.c b/kernel/kthread.c index ce4610316377..316db17f6b4f 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1208,18 +1208,18 @@ void kthread_destroy_worker(struct kthread_worker *worker) } EXPORT_SYMBOL(kthread_destroy_worker); -/* - * use_mm - * Makes the calling kernel thread take on the specified - * mm context. - * (Note: this routine is intended to be called only - * from a kernel thread context) +/** + * kthread_use_mm - make the calling kthread operate on an address space + * @mm: address space to operate on */ -void use_mm(struct mm_struct *mm) +void kthread_use_mm(struct mm_struct *mm) { struct mm_struct *active_mm; struct task_struct *tsk = current; + WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); + WARN_ON_ONCE(tsk->mm); + task_lock(tsk); active_mm = tsk->active_mm; if (active_mm != mm) { @@ -1236,20 +1236,19 @@ void use_mm(struct mm_struct *mm) if (active_mm != mm) mmdrop(active_mm); } -EXPORT_SYMBOL_GPL(use_mm); +EXPORT_SYMBOL_GPL(kthread_use_mm); -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thread context) +/** + * kthread_use_mm - reverse the effect of kthread_use_mm() + * @mm: address space to operate on */ -void unuse_mm(struct mm_struct *mm) +void kthread_unuse_mm(struct mm_struct *mm) { struct task_struct *tsk = current; + WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); + WARN_ON_ONCE(!tsk->mm); + task_lock(tsk); sync_mm_rss(mm); tsk->mm = NULL; @@ -1257,7 +1256,7 @@ void unuse_mm(struct mm_struct *mm) enter_lazy_tlb(mm, tsk); task_unlock(tsk); } -EXPORT_SYMBOL_GPL(unuse_mm); +EXPORT_SYMBOL_GPL(kthread_unuse_mm); #ifdef CONFIG_BLK_CGROUP /** diff --git a/mm/oom_kill.c b/mm/oom_kill.c index dfc357614e56..958d2972313f 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -126,7 +126,7 @@ static bool oom_cpuset_eligible(struct task_struct *tsk, struct oom_control *oc) /* * The process p may have detached its own ->mm while exiting or through - * use_mm(), but one or more of its subthreads may still have a valid + * kthread_use_mm(), but one or more of its subthreads may still have a valid * pointer. Return p, or any of its subthreads with a valid ->mm, with * task_lock() held. */ @@ -919,8 +919,8 @@ static void __oom_kill_process(struct task_struct *victim, const char *message) continue; } /* - * No use_mm() user needs to read from the userspace so we are - * ok to reap it. + * No kthead_use_mm() user needs to read from the userspace so + * we are ok to reap it. */ if (unlikely(p->flags & PF_KTHREAD)) continue; diff --git a/mm/vmacache.c b/mm/vmacache.c index cdc32a3b02fa..ceedbab82106 100644 --- a/mm/vmacache.c +++ b/mm/vmacache.c @@ -25,8 +25,8 @@ * task's vmacache pertains to a different mm (ie, its own). There is * nothing we can do here. * - * Also handle the case where a kernel thread has adopted this mm via use_mm(). - * That kernel thread's vmacache is not applicable to this mm. + * Also handle the case where a kernel thread has adopted this mm via + * kthread_use_mm(). That kernel thread's vmacache is not applicable to this mm. */ static inline bool vmacache_valid_mm(struct mm_struct *mm) { From patchwork Sat Apr 4 09:41:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11474131 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7DF8B81 for ; Sat, 4 Apr 2020 09:41:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 51ABC20719 for ; Sat, 4 Apr 2020 09:41:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="V91+pfIB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726397AbgDDJlb (ORCPT ); Sat, 4 Apr 2020 05:41:31 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:37356 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726387AbgDDJla (ORCPT ); Sat, 4 Apr 2020 05:41:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=AqMtuIfKhyb9qBOeLF2ngCbDbTkgWPlfw5hjLkqb7k0=; b=V91+pfIB+e0EjxYrdGBz6mZLeU b6sl/kba8YztMoKxFixyGrWr2+p6+TfA0D2AjbbjkY2bZIGjyOrkiEGXkydG/usWfjQAgQeph03/p IWY4AL97ClQJOz6TWS+xW7Q5iK9baeejsY4mWXxok+AnXwWf653d3wli0gWSTPPlZ6KaOgRSwSOl5 ZU06lYY6VKTEueQ24UaKOf1HYDEX1xNZgSOexOSURxirYAwMPmyD5kygFhpOgyfR/W1FL0cGLBzUE 0gBw5EZWuSLQPZ/XjtACPARRjtV8sgcPjEmiku93dzKae7Y9qUh6wCDy895raR0m7+CLsUAZ0uQnk j8K7x5+A==; Received: from [2001:4bb8:180:7914:2ca6:9476:bbfa:a4d0] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jKfIo-0002e8-4W; Sat, 04 Apr 2020 09:41:22 +0000 From: Christoph Hellwig To: Linus Torvalds , Andrew Morton Cc: Al Viro , Felix Kuehling , Alex Deucher , Zhenyu Wang , Zhi Wang , Felipe Balbi , "Michael S. Tsirkin" , Jason Wang , Jens Axboe , linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 6/6] kernel: set USER_DS in kthread_use_mm Date: Sat, 4 Apr 2020 11:41:01 +0200 Message-Id: <20200404094101.672954-7-hch@lst.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200404094101.672954-1-hch@lst.de> References: <20200404094101.672954-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Some architectures like arm64 and s390 require USER_DS to be set for kernel threads to access user address space, which is the whole purpose of kthread_use_mm, but other like x86 don't. That has lead to a huge mess where some callers are fixed up once they are tested on said architectures, while others linger around and yet other like io_uring try to do "clever" optimizations for what usually is just a trivial asignment to a member in the thread_struct for most architectures. Make kthread_use_mm set USER_DS, and kthread_unuse_mm restore to the previous value instead. Signed-off-by: Christoph Hellwig Acked-by: Michael S. Tsirkin --- drivers/usb/gadget/function/f_fs.c | 4 ---- drivers/vhost/vhost.c | 3 --- fs/io-wq.c | 8 ++------ fs/io_uring.c | 4 ---- kernel/kthread.c | 6 ++++++ 5 files changed, 8 insertions(+), 17 deletions(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index d9e48bd7c692..a1198f4c527c 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -824,13 +824,9 @@ static void ffs_user_copy_worker(struct work_struct *work) bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; if (io_data->read && ret > 0) { - mm_segment_t oldfs = get_fs(); - - set_fs(USER_DS); kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); kthread_unuse_mm(io_data->mm); - set_fs(oldfs); } io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 1787d426a956..b5229ae01d3b 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -333,9 +333,7 @@ static int vhost_worker(void *data) struct vhost_dev *dev = data; struct vhost_work *work, *work_next; struct llist_node *node; - mm_segment_t oldfs = get_fs(); - set_fs(USER_DS); kthread_use_mm(dev->mm); for (;;) { @@ -365,7 +363,6 @@ static int vhost_worker(void *data) } } kthread_unuse_mm(dev->mm); - set_fs(oldfs); return 0; } diff --git a/fs/io-wq.c b/fs/io-wq.c index 83c2868eff2a..75cc2f31816d 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -168,7 +168,6 @@ static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker) dropped_lock = true; } __set_current_state(TASK_RUNNING); - set_fs(KERNEL_DS); kthread_unuse_mm(worker->mm); mmput(worker->mm); worker->mm = NULL; @@ -420,14 +419,11 @@ static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work) mmput(worker->mm); worker->mm = NULL; } - if (!work->mm) { - set_fs(KERNEL_DS); + if (!work->mm) return; - } + if (mmget_not_zero(work->mm)) { kthread_use_mm(work->mm); - if (!worker->mm) - set_fs(USER_DS); worker->mm = work->mm; /* hang on to this mm */ work->mm = NULL; diff --git a/fs/io_uring.c b/fs/io_uring.c index 367406381044..c332a34e8b34 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5871,15 +5871,12 @@ static int io_sq_thread(void *data) struct io_ring_ctx *ctx = data; struct mm_struct *cur_mm = NULL; const struct cred *old_cred; - mm_segment_t old_fs; DEFINE_WAIT(wait); unsigned long timeout; int ret = 0; complete(&ctx->completions[1]); - old_fs = get_fs(); - set_fs(USER_DS); old_cred = override_creds(ctx->creds); timeout = jiffies + ctx->sq_thread_idle; @@ -5985,7 +5982,6 @@ static int io_sq_thread(void *data) if (current->task_works) task_work_run(); - set_fs(old_fs); if (cur_mm) { kthread_unuse_mm(cur_mm); mmput(cur_mm); diff --git a/kernel/kthread.c b/kernel/kthread.c index 316db17f6b4f..9e27d01b6d78 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -52,6 +52,7 @@ struct kthread { unsigned long flags; unsigned int cpu; void *data; + mm_segment_t oldfs; struct completion parked; struct completion exited; #ifdef CONFIG_BLK_CGROUP @@ -1235,6 +1236,9 @@ void kthread_use_mm(struct mm_struct *mm) if (active_mm != mm) mmdrop(active_mm); + + to_kthread(tsk)->oldfs = get_fs(); + set_fs(USER_DS); } EXPORT_SYMBOL_GPL(kthread_use_mm); @@ -1249,6 +1253,8 @@ void kthread_unuse_mm(struct mm_struct *mm) WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); WARN_ON_ONCE(!tsk->mm); + set_fs(to_kthread(tsk)->oldfs); + task_lock(tsk); sync_mm_rss(mm); tsk->mm = NULL;