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a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1716968723; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=v6FAbaz9f1j/G5lLHBL8K04Ed2sbYL7jFU9Ly0m88VY=; b=vhYz3JsaR/FB9g4OsE74iv1r8AOGlE5G/PnLfuBYkHpEM8Su30LIhMkyb7JoEyeqMByGcs uZ9ZXSqr47nUn3jTxz2If6xwnMA72TyDDtTHB65HiEMaDPES9HlsjvcqwFzFYSP/H0FPOD 6RfZeZ+mffFOclBBw7R43p2Mg0rXXwF6muOYsJDdivvSePrEKFHFTnYMXLg56RpBWUVOw8 IIxKccCQvwFSt/YoQLt/q20zcXLNrjpHGmxHJIw0ZfBt5+pjuCEQZ+/W+rGOun9q1LNfrI RdWHo9vvLqrTfr86jin5r/V4maM1OdvU5Hj74hHOHRpM5SSEwFS2DIKxLYIYJA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1716968723; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=v6FAbaz9f1j/G5lLHBL8K04Ed2sbYL7jFU9Ly0m88VY=; b=mrfnR8kQlISi1x6fh4gKv2+CgjE7t8wsGPsovZ31Xa1OWO4Ex+B27zAaN8AzdUsSqGiIX4 b1Rc1HNnB0jICjDw== To: Tony W Wang-oc , Dave Hansen , mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, keescook@chromium.org, tony.luck@intel.com, gpiccoli@igalia.com, mat.jonczyk@o2.pl, rdunlap@infradead.org, alexandre.belloni@bootlin.com, mario.limonciello@amd.com, yaolu@kylinos.cn, bhelgaas@google.com, justinstitt@google.com, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Cc: CobeChen@zhaoxin.com, TimGuo@zhaoxin.com, LeoLiu-oc@zhaoxin.com, Linus Torvalds Subject: Re: [PATCH] x86/hpet: Read HPET directly if panic in progress In-Reply-To: <199ba55d-8eb8-47df-9f42-55a865b51ab7@zhaoxin.com> References: <20240528063836.5248-1-TonyWWang-oc@zhaoxin.com> <50fc1bd3-909e-41c4-a991-9d81e32ef92c@intel.com> <87wmnda8mc.ffs@tglx> <2553dd17-f763-4894-89b7-5f76c03d3a37@zhaoxin.com> <199ba55d-8eb8-47df-9f42-55a865b51ab7@zhaoxin.com> Date: Wed, 29 May 2024 09:45:22 +0200 Message-ID: <87fru19i3x.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Wed, May 29 2024 at 14:44, Tony W Wang-oc wrote: > Actually, this scenario is what this patch is trying to solve. > > We encountered hpet_lock deadlock from the call path of the MCE handler, > and this hpet_lock deadlock scenario may happen when others exceptions' > handler like #PF/#GP... to call the panic. So read_hpet should avoid > deadlock if panic in progress. That's not what your changelog says.