From nobody Thu Oct 2 11:52:36 2025 Received: from chinatelecom.cn (smtpnm6-10.21cn.com [182.42.147.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6BF9C25FA34 for ; Wed, 17 Sep 2025 03:38:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=182.42.147.92 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758080287; cv=none; b=vBo+HJIFHi/hrLA0Wg30ui0psMAaqEEk+gkRy4D/UuRA/oEouTqjeVpsGc4DeWNfVwnaKGFW2Xsbw680WD0vy1uzbFhP6VSL/7mVQTVrciLCLh/IgMv6ZwlV2c9KDyqcCyAbvkoQMiu6ve4bbKtHVw7MVnmB8WO1CJF3gu84JkY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758080287; c=relaxed/simple; bh=08VUFcXpF6AYclk8y6n1SHrN774oN8kabGwclYrzuCI=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Ac69WKIykLEsf9JSpMbWg8qq3f/PMEMjM1rdhlAHHDDzODfpXIR+B/jurDbBpeZni7PNsFWzB2OXIwxdTOgO8KOKFFGgJjPFj0RADugg8bMeWtvLH7mTjrIVfmN87zGqTg6f3wMEyi7oF3tae/sxBS/thzkMQmuZFLxCEs0k6u8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chinatelecom.cn; spf=pass smtp.mailfrom=chinatelecom.cn; arc=none smtp.client-ip=182.42.147.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chinatelecom.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chinatelecom.cn HMM_SOURCE_IP: 192.168.139.44:0.1676807570 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-36.111.64.84 (unknown [192.168.139.44]) by chinatelecom.cn (HERMES) with SMTP id 46200B023C14; Wed, 17 Sep 2025 11:29:15 +0800 (CST) X-189-SAVE-TO-SEND: +liuq131@chinatelecom.cn Received: from ([36.111.64.84]) by gateway-ssl-dep-79cdd9d55b-z742x with ESMTP id 5da354203705446287f19055e82e39d7 for tglx@linutronix.de; Wed, 17 Sep 2025 11:29:28 CST X-Transaction-ID: 5da354203705446287f19055e82e39d7 X-Real-From: liuq131@chinatelecom.cn X-Receive-IP: 36.111.64.84 X-MEDUSA-Status: 0 Sender: liuq131@chinatelecom.cn From: Qiang Liu To: tglx@linutronix.de Cc: bp@alien8.de, peterz@infradead.org, jpoimboe@kernel.org, pawan.kumar.gupta@linux.intel.com, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, Qiang Liu Subject: [PATCH] x86/bugs: Rate-limit the SPECTRE_V2 messages Date: Wed, 17 Sep 2025 11:28:57 +0800 Message-Id: <20250917032857.22441-1-liuq131@chinatelecom.cn> X-Mailer: git-send-email 2.27.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" During stress-ng testing, excessive SPECTRE_V2 messages overwhelmed the low-speed serial device, causing system soft lockup. This issue can be resolved by implementing rate-limiting for the relevant log outputs. The log as below: [121017.083236] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.098606] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.102398] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.102421] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.102532] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.102550] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.102569] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.133670] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.148497] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.163674] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.185720] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.287675] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.300205] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.335075] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.346428] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.428517] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.450328] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.592131] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121017.592865] Spectre V2 : WARNING: Unprivileged eBPF is enabled with eIB= RS on, data leaks possible via Spectre v2 BHB attacks! [121037.642577] watchdog: BUG: soft lockup - CPU#68 stuck for 23s! [stress-= ng-procf:2483051] [121037.642578] Modules linked in: ... [121037.642697] CPU: 68 PID: 2483051 Comm: stress-ng-procf Kdump: loaded Ta= inted: ... [121037.642698] Hardware name: XFUSION 2288H V6/BC13MBSBC, BIOS 1.29 11/25/= 2022 [121037.642706] RIP: 0010:console_unlock+0x283/0x350 [121037.642709] Code: 00 e8 01 15 00 00 55 9d 45 84 f6 0f 84 46 ff ff ff e8= 71 f8 ff ff 85 c0 0f 85 e8 fd ff ff e9 34 ff ff ff e8 df 14 00 00 55 9d <8= b> 44 24 04 85 c0 0f 84 f8 fd ff ff e8 9c 84 99 00 e9 ee fd ff ff [121037.642710] RSP: 0018:ff607726b60abc00 EFLAGS: 00000246 [121037.642711] RAX: 0000000000000000 RBX: ffffffffaef699cc RCX: 0000000000= 000008 [121037.642712] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffae= f6c228 [121037.642713] RBP: 0000000000000246 R08: ffffffffadabd540 R09: 0000000000= aaaaaa [121037.642713] R10: 0000000000000001 R11: ff2cf962c6a5b550 R12: ff2cf962c2= 700000 [121037.642714] R13: 0000000000000000 R14: ffffffffaef6c228 R15: 0000000000= 00008c [121037.642715] FS: 00007f2021c07640(0000) GS:ff2cf9e0be700000(0000) knlGS= :0000000000000000 [121037.642715] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [121037.642716] CR2: 0000000000e3b7a0 CR3: 0000003f41266005 CR4: 0000000000= 771ee0 [121037.642716] PKRU: 55555554 [121037.642717] Call Trace: [121037.642722] vprintk_emit+0x118/0x120 [121037.642727] printk+0x58/0x73 [121037.642731] bpf_unpriv_handler+0xbf/0x180 [121037.642733] ? proc_taint+0x1d0/0x1d0 [121037.642738] proc_sys_call_handler+0x13e/0x250 [121037.642742] new_sync_read+0x10d/0x1b0 [121037.642745] vfs_read+0x14e/0x1b0 [121037.642747] ksys_read+0x5f/0xe0 [121037.642750] do_syscall_64+0x3d/0x80 [121037.642753] entry_SYSCALL_64_after_hwframe+0x61/0xc6 Fixes: 0de05d056afd ("x86/speculation: Warn about eIBRS + LFENCE + Unprivil= eged eBPF + SMT") Fixes: 44a3918c8245 ("x86/speculation: Include unprivileged eBPF status in = Spectre v2 mitigation reporting") Signed-off-by: Qiang Liu --- arch/x86/kernel/cpu/bugs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 36dcfc5105be..22fb2113cbe6 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1809,11 +1809,11 @@ void unpriv_ebpf_notify(int new_state) =20 switch (spectre_v2_enabled) { case SPECTRE_V2_EIBRS: - pr_err(SPECTRE_V2_EIBRS_EBPF_MSG); + pr_err_ratelimited(SPECTRE_V2_EIBRS_EBPF_MSG); break; case SPECTRE_V2_EIBRS_LFENCE: if (sched_smt_active()) - pr_err(SPECTRE_V2_EIBRS_LFENCE_EBPF_SMT_MSG); + pr_err_ratelimited(SPECTRE_V2_EIBRS_LFENCE_EBPF_SMT_MSG); break; default: break; --=20 2.46.0