From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6ECDFC2A09B for ; Fri, 7 Aug 2026 16:29:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To :Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zhBDyENIGSwZtQI1mO040SeQxcBm4D5J8P9tXaVMOZ8=; b=sY9BPRbndQ8g8C05Q+ROd5zHeN umLUcbTjuDZSdOFl2RNN8fMIMe5gN4d2RLRoKm/iYhXqXgKPlwP6WlhaPgU26xeojd4yvMl5tIfe8 JGsF9pQrtHK2iT76l03b2oJs7gzB1vuyztPjnIGrTXoZyQJDE0ugGnilBhiHZ68juksylj2dNT83/ ERB/M0oW1yFRDtABA60N+fQ+e05CUEk+qMSLdCVjS+wxv+zxyQoxO3zkINbC81nni34IuSna4+6sQ VwiXKpinlhlfGyoj7Vd0o/ix+y8OPHcJU9oSA9Jr6UBPV87XFY5fZhgXteNyOm3Jvjf1NiJ1eQaPl bUk3GG1g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsNS1-00000008QNk-3NEq; Fri, 07 Aug 2026 16:29:41 +0000 Received: from stravinsky.debian.org ([2001:41b8:202:deb::311:108]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsNRz-00000008QNQ-1UFI for linux-arm-kernel@lists.infradead.org; Fri, 07 Aug 2026 16:29:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=zhBDyENIGSwZtQI1mO040SeQxcBm4D5J8P9tXaVMOZ8=; b=v8k0yg/S9xgrZnqDl1XJV9HBGK Z7aGiqoART4XAKAqdjg1PC9v+rTvg+Yr2n3k3NPl/7WbiiHrTJvgRobQdJX2m7WKgJRzlYQ/cg4XO oAX673RWxfA+LdthIaZ1HRNYHhSQAfsBa2M+AhVsjD3rk/fK1PWmJIU9dkkux/CmH21OdOjSqivGt aIT03iIwFH9iZt1Pq+cF1OL6zBzNYGUxPCWMA3RIDK+1I0kPXog3yqfgnALIUwZdu48k6wdcnmL6t WhGSlH/65DJ3QyZVOwf0bAv90OjbFoveKx9ZCMN6BTDbOmYT7eEY5gDKOOV6N824FtTeJnc7YFVpP PLXsBIcg==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wsNRd-000YhX-27; Fri, 07 Aug 2026 16:29:17 +0000 Date: Fri, 7 Aug 2026 09:29:12 -0700 From: Breno Leitao To: Mark Rutland Subject: Re: [PATCH RFC] arm64: entry: PSTATE_I_SET is leaking on pseudo NMI mode Message-ID: References: <20260807-arm64_fix-v1-1-d069ccf9d71b@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Debian-User: leitao X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260807_092939_397100_021F7966 X-CRM114-Status: UNSURE ( 7.94 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Murzin , rmikey@meta.com, "Peter Zijlstra \(Intel\)" , Catalin Marinas , Jinjie Ruan , kernel-team@meta.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Will Deacon , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Aug 07, 2026 at 07:58:21AM -0700, Breno Leitao wrote: > Meanwhile, I will try to ftrace the writes to PMR and regs->pmr to get > a better grasp of the states machine we are in (probably on Monday). It seems LLM found a very easy to reproduce this: bash-5.1# dmesg bash-5.1# cd /sys/kernel/tracing echo 'r:pmr vfs_read bad=+0($retval):u64' >> kprobe_events echo 1 > events/kprobes/pmr/enable bash-5.1# dmesg [ 54.997498] ------------[ cut here ]------------ [ 54.997506] WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xc0/0xc8, CPU#1: bash/185 [ 54.997530] Modules linked in: [ 54.997535] CPU: 1 UID: 0 PID: 185 Comm: bash Not tainted 7.2.0-rc6-next-20260806upstream #15 PREEMPT(full) [ 54.997538] Hardware name: linux,dummy-virt (DT) [ 54.997540] pstate: 234003c5 (nzCv DAIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) [ 54.997542] pc : arm64_exit_to_kernel_mode+0xc0/0xc8 [ 54.997544] lr : el1_abort+0x5c/0x80 [ 54.997547] sp : ffff800088ba35f0 [ 54.997548] pmr: 000000f0 [ 54.997550] x29: ffff800088ba35f0 x28: ffff0000c3cd0000 x27: 0000000000000000 [ 54.997554] x26: ffff0000c3f277d0 x25: 0000000000000030 x24: 0000000000000001 [ 54.997557] x23: 00000000834003c5 x22: 0000000000000000 x21: 0000000000000001 [ 54.997566] x20: ffff800088ba3650 x19: 0000000000000000 x18: 0000000000000000 [ 54.997569] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000001 [ 54.997572] x14: 0000000040000000 x13: ffff800086b171f8 x12: fff080007fe00000 [ 54.997576] x11: 0000000000000001 x10: aaaaaaaaaaaaaaab x9 : 000000000000001f [ 54.997579] x8 : 00000000000000d0 x7 : 0000000000000000 x6 : ffff0000c0adf02c [ 54.997582] x5 : ffff0000c0adf034 x4 : ffff800081408b08 x3 : 000000000000000c [ 54.997585] x2 : 00000000000002fe x1 : 0000000000000000 x0 : ffff800088ba3650 [ 54.997589] Call trace: [ 54.997590] arm64_exit_to_kernel_mode+0xc0/0xc8 (P) [ 54.997593] el1_abort+0x5c/0x80 [ 54.997595] el1h_64_sync_handler+0x50/0x100 [ 54.997597] el1h_64_sync+0x80/0x88 [ 54.997601] __arch_copy_from_user+0x220/0x240 (P) [ 54.997604] process_fetch_insn+0x450/0x8b0 [ 54.997608] kretprobe_trace_func+0x1b0/0x298 [ 54.997611] kretprobe_dispatcher+0x5c/0x88 [ 54.997613] __kretprobe_trampoline_handler+0xc4/0x168 [ 54.997617] kretprobe_brk_handler+0x40/0x68 [ 54.997620] call_el1_break_hook+0x74/0xa0 [ 54.997623] do_el1_brk64+0x30/0x60 [ 54.997624] el1_brk64+0x2c/0x48 [ 54.997626] el1h_64_sync_handler+0x80/0x100 [ 54.997628] el1h_64_sync+0x80/0x88 [ 54.997630] ksys_read+0x80/0x100 (P) [ 54.997634] __arm64_sys_read+0x28/0x40 [ 54.997636] invoke_syscall+0x54/0xf0 [ 54.997640] do_el0_svc+0x7c/0xb8 [ 54.997642] el0_svc+0x60/0x188 [ 54.997644] el0t_64_sync_handler+0x84/0x130 [ 54.997645] el0t_64_sync+0x1ac/0x1b0 [ 54.997647] ---[ end trace 0000000000000000 ]---