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 770AB433AD; Thu, 17 Sep 2026 17:06:27 +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=1789664788; cv=none; b=HydHGAtgzERKmBmkMApNvATEFrY5R/z1ySEQxtO0xwUERGQUQBbxN7IXFBk+bxNxBbk/Z2mtCdDF+tjjrqHXZcMFGhU3yInm48NN5TQRH7OHBa2J48hMVBBNkdRXP+QpL9tWJuEbIdss2kXumrK9gNZbQtyWTdLoS3EWvg33dBM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789664788; c=relaxed/simple; bh=nQQyF+W1P6guDd5P0P52YBKOsvFFykBA/bYp7pKXXtE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=EdnddDDRtoN4teawW0Mf7A4QZ6kGH0iCBOLGEWsmXixBaZzDNpepBavngz9wysYkRCNr6ArzbVWHRbplZM2RAQWgNh4cSAVwdtCQd2C5XhLg6RSqzJsICVdVGINNb4Rt2WvhCj9az83XXrEUcpt8TpWt/fZ5Lb0nPgMLdi3y5so= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o8bDMB8q; 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="o8bDMB8q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD7671F00893; Thu, 17 Sep 2026 17:06:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789664787; bh=VsE7irDojpDHkeyOCv+FvjAF2u9kcH2PtWmbc7czOs8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=o8bDMB8q6FfzksjY/+EPHExhrhNmOuIMgl69EMWkMLhzhOG2vL1R9V8EjoVA48alC EOWOkpVLItYUJqGTFdHQrg5DgdafTV/Kz4j8pn9a6cj0RQFtjqpbO7/yeYJNmbpMFy Znq3Gp73aBfgwvDlPPOZ2k/N9GfeUUJYCgbawrLk= 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 6.18 0489/1250] drm/amdgpu: flush pending RCU callbacks on module unload Date: Thu, 17 Sep 2026 16:04:44 +0100 Message-ID: <20260917151605.222148159@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@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 6.18-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 9b17a47304615..fb753613e00d7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -3218,6 +3218,14 @@ static void __exit amdgpu_exit(void) amdgpu_userq_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