From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D72DF15442C; Mon, 24 Feb 2025 14:48:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740408539; cv=none; b=VZL75q1yerkGbnF2rjVhDFekEBMGBk7s3BKSNdt1BCzSj+6qk3LgujdHhFANJKZY0it5aBQo8trxUpFmNPWhQOKYmee4VT3PEmkCtFzIanHB2jgH2QbkCaisWhh+/QwHjvw6B4az3U5xRw2hNmgmME57Wanzy7NTotsUxhgKkxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740408539; c=relaxed/simple; bh=/9uEFDGvSmE2REwoYTHI2X2vBWr7fd8yoBqqykK3u8c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E95OwtlZgp+0Mq3k/9Wn3wldGqFeDOkMKzl4sCRuNfoXFiPfbOybxbdmbsLq5Qmj4Bxn6i7V3xXfcAJYKMOEtU9wLOxssmJkMf3mkRGIT3mVcO0xtoqlWSnh03/GXumAkOv78RtyLmBdj93DxeGBAsZjQEFDtoNVJy/XCJKApXE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0l6AzFdN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0l6AzFdN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47191C4CED6; Mon, 24 Feb 2025 14:48:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1740408539; bh=/9uEFDGvSmE2REwoYTHI2X2vBWr7fd8yoBqqykK3u8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0l6AzFdNMK9t+TovwjJ4St2O1D7Z/8Iezwfd1408oMK3oLvxN4ZcJ16WDYe38j+wX GP72ORJsjMR+JSnNj2nuEk9rS5wi9cHx5ttl/Yd/u5Mb6jAaO2dUuFM65xtv+DzUV+ hJuFYn5da/sQP/0bI7Gl/uRdHoTypeVsz2nHG3Ng= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Colm Harrington , Alexei Starovoitov , Alan Maguire , Sasha Levin Subject: [PATCH 6.12 086/154] bpf: Fix softlockup in arena_map_free on 64k page kernel Date: Mon, 24 Feb 2025 15:34:45 +0100 Message-ID: <20250224142610.441876868@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224142607.058226288@linuxfoundation.org> References: <20250224142607.058226288@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Maguire [ Upstream commit 517e8a7835e8cfb398a0aeb0133de50e31cae32b ] On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y, arena_htab tests cause a segmentation fault and soft lockup. The same failure is not observed with 4k pages on aarch64. It turns out arena_map_free() is calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned the code ends up calling apply_to_pte_range() with that unaligned address causing soft lockup. Fix it by round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value. Fixes: 317460317a02 ("bpf: Introduce bpf_arena.") Reported-by: Colm Harrington Suggested-by: Alexei Starovoitov Signed-off-by: Alan Maguire Link: https://lore.kernel.org/r/20250205170059.427458-1-alan.maguire@oracle.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/arena.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index 93e48c7cad4ef..8c775a1401d3e 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -37,7 +37,7 @@ */ /* number of bytes addressable by LDX/STX insn with 16-bit 'off' field */ -#define GUARD_SZ (1ull << sizeof_field(struct bpf_insn, off) * 8) +#define GUARD_SZ round_up(1ull << sizeof_field(struct bpf_insn, off) * 8, PAGE_SIZE << 1) #define KERN_VM_SZ (SZ_4G + GUARD_SZ) struct bpf_arena { -- 2.39.5