From nobody Tue Dec 16 04:27:41 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14471C32771 for ; Mon, 26 Sep 2022 11:38:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238014AbiIZLi3 (ORCPT ); Mon, 26 Sep 2022 07:38:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236400AbiIZLhp (ORCPT ); Mon, 26 Sep 2022 07:37:45 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B54416EF1C; Mon, 26 Sep 2022 03:44:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6885CB80976; Mon, 26 Sep 2022 10:44:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A75BAC433C1; Mon, 26 Sep 2022 10:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664189051; bh=YJBYjcC2WRnCGvMzno/Zx1BeXA5cT/QGzX6nrE2Afjk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HHlaLs1DiuXAcZbuGKiaBp3dOd6Mpkwd0K6VcomYHs6KYv4Nr3iBmA87VustPscNm MJuYEJ1AA1ex1FxuTZ6NJS7yV3G262uYBpGkkRnt4xB9l3hTqOmtyPxpnQC78OJm5u xhOZMZTm7ll370O3OIhlJMWls2gFo176+TJfn8NE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Janes , Chris Wilson , Andi Shyti , Janusz Krzysztofik , Tvrtko Ursulin , Rodrigo Vivi Subject: [PATCH 5.19 057/207] drm/i915/gem: Really move i915_gem_context.link under ref protection Date: Mon, 26 Sep 2022 12:10:46 +0200 Message-Id: <20220926100809.164998197@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220926100806.522017616@linuxfoundation.org> References: <20220926100806.522017616@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Chris Wilson commit d119888b09bd567e07c6b93a07f175df88857e02 upstream. i915_perf assumes that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration. However, this requires that we do not remove the context from the list until after we drop the final reference and release the struct. If, as currently, we remove the context from the list during context_close(), the link.next pointer may be poisoned while we are holding the context reference and cause a GPF: [ 4070.573157] i915 0000:00:02.0: [drm:i915_perf_open_ioctl [i915]] filteri= ng on ctx_id=3D0x1fffff ctx_id_mask=3D0x1fffff [ 4070.574881] general protection fault, probably for non-canonical address= 0xdead000000000100: 0000 [#1] PREEMPT SMP [ 4070.574897] CPU: 1 PID: 284392 Comm: amd_performance Tainted: G = E 5.17.9 #180 [ 4070.574903] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS B= NKBL357.86A.0052.2017.0918.1346 09/18/2017 [ 4070.574907] RIP: 0010:oa_configure_all_contexts.isra.0+0x222/0x350 [i915] [ 4070.574982] Code: 08 e8 32 6e 10 e1 4d 8b 6d 50 b8 ff ff ff ff 49 83 ed = 50 f0 41 0f c1 04 24 83 f8 01 0f 84 e3 00 00 00 85 c0 0f 8e fa 00 00 00 <49= > 8b 45 50 48 8d 70 b0 49 8d 45 50 48 39 44 24 10 0f 85 34 fe ff [ 4070.574990] RSP: 0018:ffffc90002077b78 EFLAGS: 00010202 [ 4070.574995] RAX: 0000000000000002 RBX: 0000000000000002 RCX: 00000000000= 00000 [ 4070.575000] RDX: 0000000000000001 RSI: ffffc90002077b20 RDI: ffff88810dd= c7c68 [ 4070.575004] RBP: 0000000000000001 R08: ffff888103242648 R09: fffffffffff= ffffc [ 4070.575008] R10: ffffffff82c50bc0 R11: 0000000000025c80 R12: ffff888101b= f1860 [ 4070.575012] R13: dead0000000000b0 R14: ffffc90002077c04 R15: ffff88810be= 5cabc [ 4070.575016] FS: 00007f1ed50c0780(0000) GS:ffff88885ec80000(0000) knlGS:= 0000000000000000 [ 4070.575021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4070.575025] CR2: 00007f1ed5590280 CR3: 000000010ef6f005 CR4: 00000000003= 706e0 [ 4070.575029] Call Trace: [ 4070.575033] [ 4070.575037] lrc_configure_all_contexts+0x13e/0x150 [i915] [ 4070.575103] gen8_enable_metric_set+0x4d/0x90 [i915] [ 4070.575164] i915_perf_open_ioctl+0xbc0/0x1500 [i915] [ 4070.575224] ? asm_common_interrupt+0x1e/0x40 [ 4070.575232] ? i915_oa_init_reg_state+0x110/0x110 [i915] [ 4070.575290] drm_ioctl_kernel+0x85/0x110 [ 4070.575296] ? update_load_avg+0x5f/0x5e0 [ 4070.575302] drm_ioctl+0x1d3/0x370 [ 4070.575307] ? i915_oa_init_reg_state+0x110/0x110 [i915] [ 4070.575382] ? gen8_gt_irq_handler+0x46/0x130 [i915] [ 4070.575445] __x64_sys_ioctl+0x3c4/0x8d0 [ 4070.575451] ? __do_softirq+0xaa/0x1d2 [ 4070.575456] do_syscall_64+0x35/0x80 [ 4070.575461] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 4070.575467] RIP: 0033:0x7f1ed5c10397 [ 4070.575471] Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff = 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48= > 3d 01 f0 ff ff 73 01 c3 48 8b 0d a9 da 0d 00 f7 d8 64 89 01 48 [ 4070.575478] RSP: 002b:00007ffd65c8d7a8 EFLAGS: 00000246 ORIG_RAX: 000000= 0000000010 [ 4070.575484] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f1ed5c= 10397 [ 4070.575488] RDX: 00007ffd65c8d7c0 RSI: 0000000040106476 RDI: 00000000000= 00006 [ 4070.575492] RBP: 00005620972f9c60 R08: 000000000000000a R09: 00000000000= 00005 [ 4070.575496] R10: 000000000000000d R11: 0000000000000246 R12: 00000000000= 0000a [ 4070.575500] R13: 000000000000000d R14: 0000000000000000 R15: 00007ffd65c= 8d7c0 [ 4070.575505] [ 4070.575507] Modules linked in: nls_ascii(E) nls_cp437(E) vfat(E) fat(E) = i915(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) crct10dif_pclmul(E) crc= 32_pclmul(E) crc32c_intel(E) aesni_intel(E) crypto_simd(E) intel_gtt(E) cry= ptd(E) ttm(E) rapl(E) intel_cstate(E) drm_kms_helper(E) cfbfillrect(E) sysc= opyarea(E) cfbimgblt(E) intel_uncore(E) sysfillrect(E) mei_me(E) sysimgblt(= E) i2c_i801(E) fb_sys_fops(E) mei(E) intel_pch_thermal(E) i2c_smbus(E) cfbc= opyarea(E) video(E) button(E) efivarfs(E) autofs4(E) [ 4070.575549] ---[ end trace 0000000000000000 ]--- v3: fix incorrect syntax of spin_lock() replacing spin_lock_irqsave() v2: irqsave not required in a worker, neither conversion to irq safe elsewhere (Tvrtko), - perf: it's safe to call gen8_configure_context() even if context has been closed, no need to check, - drop unrelated cleanup (Andi, Tvrtko) Reported-by: Mark Janes Closes: https://gitlab.freedesktop.org/drm/intel/issues/6222 Fixes: f8246cf4d9a9 ("drm/i915/gem: Drop free_work for GEM contexts") Signed-off-by: Chris Wilson Reviewed-by: Andi Shyti Signed-off-by: Janusz Krzysztofik Cc: Tvrtko Ursulin Cc: # v5.12+ Signed-off-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20220916092403.201355-3= -janusz.krzysztofik@linux.intel.com (cherry picked from commit ad3aa7c31efa5a09b0dba42e66cfdf77e0db7dc2) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -1269,6 +1269,10 @@ static void i915_gem_context_release_wor trace_i915_context_free(ctx); GEM_BUG_ON(!i915_gem_context_is_closed(ctx)); =20 + spin_lock(&ctx->i915->gem.contexts.lock); + list_del(&ctx->link); + spin_unlock(&ctx->i915->gem.contexts.lock); + if (ctx->syncobj) drm_syncobj_put(ctx->syncobj); =20 @@ -1514,10 +1518,6 @@ static void context_close(struct i915_ge =20 ctx->file_priv =3D ERR_PTR(-EBADF); =20 - spin_lock(&ctx->i915->gem.contexts.lock); - list_del(&ctx->link); - spin_unlock(&ctx->i915->gem.contexts.lock); - client =3D ctx->client; if (client) { spin_lock(&client->ctx_lock);