From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3210330566A; Wed, 30 Sep 2026 18:59:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790794772; cv=none; b=cZU3Iw9/OetPISTvEpdV/AMCz4j8nj3u1sOOqh1ejB7YDf4vTgt2PtNbpWCW/hgNrJjVIAw9oK6VYXlu1ZW38fFGGd//3HGeSmxGbc97WVB/HSE99H8nMju1tCZL1MQsd6ae10euyQei6J59DKo0PW1enIwaVjGq+BF/drCuPkU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790794772; c=relaxed/simple; bh=EAGAGdMKjQ7ymTRndlOdB8e2GAv/wKJI4ZgwMWGOIK4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=douxuskxfVNPwBVeYWRe6n4WnnNCODuCFeS/f7dM+ZPtp+Xt3ifXv9j+ZXW6gXS0/kEAXT60xU+tB9dDyVKLuxlAiyXIO0M60XrlPeikHZ00hTKVCCt0iRWAbw9t+4x6E4a7yrQZT8R7FiZhq9xz2/W+vTO120ll1OUDqO5+7bU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QmGvTPfG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="QmGvTPfG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DF631F000FF; Wed, 30 Sep 2026 18:59:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790794770; bh=RcSr2NNLB/zRAI3H708Q44NMedkWRJN/x3yNb4GANYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QmGvTPfG87RhXrU67T4/o27S3E9bHuFHkqMJwAyDFYkn3dk3bh5u76emYq4MskqUp vfnChDqEqwiGIZ/dBPLTEVLxNWr5opvwtbwcGtYxFeCkVVoAMppE2voDhT4UuZ1NBa jm9BgK8GIqE0AVUZBnPh3konYJz7ZwWiwsoQ8c+k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Perry Yuan , Yifan Zhang , =?UTF-8?q?Christian=20K=C3=B6nig?= , Alex Deucher , Sasha Levin Subject: [PATCH 6.6 0283/1193] drm/amdgpu: flush pending RCU callbacks on module unload Date: Wed, 30 Sep 2026 17:16:07 +0200 Message-ID: <20260930152440.452167616@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Perry Yuan [ Upstream commit 67a654b41cfa73c3b83402c4a01b2689cad5b9bc ] Call rcu_barrier() in module exit to wait for outstanding call_rcu() callbacks before freeing module text, preventing late callback execution in freed memory. BUG: unable to handle page fault for address: ffffffffc1d59c40 PGD 6a12067 P4D 6a12067 PUD 6a14067 PMD 13698b067 PTE 0 Oops: 0010 [#1] SMP NOPTI RIP: 0010:0xffffffffc1d59c40 Code: Unable to access opcode bytes at RIP 0xffffffffc1d59c16. RSP: 0018:ffffc900198c0f28 EFLAGS: 00010286 RAX: ffffffffc1d59c40 RBX: ffff897c7d6b61c0 RCX: ffff88826aff4590 RDX: ffff8884d8b35490 RSI: ffffc900198c0f30 RDI: ffff88812af67290 RBP: 000000000000000a (DONE segment entries) R08: 0000000000000000 R09: 0000000000000100 R10: 0000000000000000 R11: ffffffff82a06100 R12: ffff88811a4e3700 R13: 0000000000000000 R14: ffff897c7d6b6270 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff897c7d680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc1d59c16 CR3: 00000104a980a001 CR4: 0000000002770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? rcu_do_batch+0x163/0x450 ? rcu_core+0x177/0x1c0 ? __do_softirq+0xc1/0x280 ? asm_call_irq_on_stack+0xf/0x20 ? do_softirq_own_stack+0x37/0x50 ? irq_exit_rcu+0xc4/0x100 ? sysvec_apic_timer_interrupt+0x36/0x80 ? asm_sysvec_apic_timer_interrupt+0x12/0x20 ? cpuidle_enter_state+0xd4/0x360 ? cpuidle_enter+0x29/0x40 ? cpuidle_idle_call+0x108/0x1a0 ? do_idle+0x77/0xf0 ? cpu_startup_entry+0x19/0x20 ? secondary_startup_64_no_verify+0xbf/0xcb Signed-off-by: Perry Yuan Reviewed-by: Yifan Zhang Reviewed-by: Christian König Signed-off-by: Alex Deucher (cherry picked from commit feaa5039f6c12acc9aa934c2d45dcd251a12c69f) Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 90fe4833240f4..bb137063bae11 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -2938,6 +2938,14 @@ static void __exit amdgpu_exit(void) amdgpu_fence_slab_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); + + /* + * Flush outstanding call_rcu() callbacks before the + * module text is freed. Otherwise a grace period elapsing after + * unload invokes a callback in already-freed module memory and + * faults in rcu_do_batch(). + */ + rcu_barrier(); } module_init(amdgpu_init); -- 2.53.0