From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=82.195.75.108 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793123046; b=1/ekN3UrFzB5s3k+vbQ7KUS6AddrUX3FgRYbUXLatZSTLblp/TP1XZIdwW2SOo4uupj9 mFUPij6f/D5bbTXMTzeFSOs8HgYGNOJdiCwlRfpJjN4HfFhXV2EeOQw/H1NT131PdSbLh j01c0T5p8ZfVEM1J5bN+kAMPQwPnD3doRRsOK0Emf+WpVAWYdOp/ZmFoO24JIhaMrC1qI HbCDt4TAHEFOikZ4GgsfmqIu2pBGY8QybVJoBL5vW8MS5vrPHKEYX+mYa+7uEjjKmKmto eq4oF4V58lTlC9BccOYbcRDefd3/UdSUVFvkpXh1oq8NCgvGnuB1QUeWHIYCmF4kUJA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793123046; h=DMARC-Filter:DKIM-Signature:Received:Date:From:To:Cc:Subject: Message-ID:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To:X-Debian-User; bh=H3ftQVE2wpbEBVJ+VF6gtFWZg3t1dZyf8PCd3991cFQ=; b=JYcxeGPwx3hMlOyDslhvr8+PELAzh3Ni0lIc9syXhMEc2S66tw5tb43YoS6/rWjQpdAk lbJUyQQrCdFeJ0aj2/IUM3DepAt3ixUwf41rdlAit2kWHXPWEFvuEjVXt9dbamUgUAZjG oNYJwfcjlxe6Vw0TP9Bzz5QKnBXgC6poEtCqb64tS9I2VfGkqZCfOeFVb1RL9rZ3BA9TO yeS6V9X46D640s/GEck1qlLglx9ubKliqHf9OCqEff/pHkrSTMil+PBvOR3AIQgcwjhgf HlU8pXqOYemQrWRsRLVAGR4+XqnuTaRpplpMvLiINAVGCjnTpI6uSvnPV6vN9rCw/lQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass header.d=debian.org header.i=@debian.org header.a=rsa-sha256 header.s=smtpauto.stravinsky header.b="WTisWFK/"; arc=none smtp.remote-ip=82.195.75.108 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E526D606A31D for ; Tue, 27 Oct 2026 17:44:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E526D606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=debian.org header.i=@debian.org header.a=rsa-sha256 header.s=smtpauto.stravinsky header.b=WTisWFK/ 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=H3ftQVE2wpbEBVJ+VF6gtFWZg3t1dZyf8PCd3991cFQ=; b=WTisWFK/3oAI1YP0Kukj3qvckU X8myHQGiZo+Icm2ALRrAH9WKVI4kSc1rZJQiGRVyBCnVgF4xZwbu8ppfhXIoj49Nj929q9J2uwUu8 4ghdyX2lXwZ1I+UBOWoJgJ9PuDGQmh0IfqrI7mU+KaUnSggXY5AKA3sTtmZy4D79QT4qdrBhIoZqm rGaeRnzmJYUx1miPVFhGNJb+4hufekcLRyWbhhQaTL1qsfvGUOYGR2RNPbpryMEf/vxny3uPVw5P5 hfvhmZYN+TGOQt2aiz6WPZDLGnOpK/6VYN2kLahwh1i32ZhtiCWLTr8L3lDqbq3w4LjBs+BaL+DBK mh8g8XWg==; 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 1xLlDK-001d8b-1f; Tue, 27 Oct 2026 17:43:58 +0000 Date: Tue, 27 Oct 2026 10:43:54 -0700 From: Breno Leitao To: Petr Mladek Cc: John Ogness , Ryan Roberts , Andrew Morton , Steven Rostedt , Sergey Senozhatsky , Rio , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v1] panic: Flush unsafe consoles before panic reboot Message-ID: References: <20260915100140.3631650-1-ryan.roberts@arm.com> <87bj8kkfwk.fsf@jogness.linutronix.de> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Debian-User: leitao On Tue, Oct 27, 2026 at 09:12:09AM -0700, Breno Leitao wrote: > So netconsole, or any CON_NBCON_ATOMIC_UNSAFE console, prints nothing > on kdump hosts. For flushing unsafe on nbcon on hosts with kdump environment, this seems to do the work, but, maybe this is too unsafe !? diff --git a/kernel/crash_core.c b/kernel/crash_core.c index d0bd2d0cf8990b..9f1a89e301ff01 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -140,6 +140,8 @@ void __noclone __crash_kexec(struct pt_regs *regs) crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); + /* Flush consoles with an unsafe write_atomic(), e.g. netconsole. */ + nbcon_atomic_flush_unsafe(); machine_crash_shutdown(&fixed_regs); crash_cma_clear_pending_dma(); machine_kexec(kexec_crash_image);