From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 775313CF69C; Tue, 28 Jul 2026 19:06:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785265612; cv=none; b=PPlZbTnDUw3e5jB/PEpQyPsfce/6YbNwKeZXPB6A2P9dH8GiET2W/rLBElHA2O9MdLFB2+vdYnj4CEptt+heTJKCLVvgleF5mfmppSbMpFRMzFJma0/Llb4IZaPch+Ou8rK2wQb0vZ7ZVkw/wsSwVUc+vLAj1ahWgd7bbCJnsLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785265612; c=relaxed/simple; bh=45ibzyQMSRFT7vWQKf7iyKPohQO+ImhHpc5MCyl0atk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=n3pQ8bFewFLeDlfkalejyPQuYKBM+cDT9sODvKIBtoQF3yZEMXPo3icQClXud7vBj7ODbra+WkxnYBgyypMFO6L2z0Hj7g16gt1P3BNFM+PjvNeS4JeuU5UrMoDuuzA6LmuHu7WEvJYnNjdryVKDM6ayA5Gz0JEmcwI3y+Bn+hA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Jx3hyKmp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Jx3hyKmp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CE0C1F000E9; Tue, 28 Jul 2026 19:06:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785265608; bh=kS5Ahv5hQkigaERDueET9kXWoep0bjurNYYMquRhpgk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Jx3hyKmpQyVSEPuGQT9uPq1Lhrnp5I1P7jdiGbpZ2JXtgPmWmdk7NZbALHV7ckZv4 j/8c/aRCOL7zhaPU6PfmpYlv3Qzj0xlJNHnSWwCq7CzNOuQILedY3apjyT7kW0UHIF y0RGgeN1NpGcd3TUD36gKEuOo2Y7LOAONG3V1nXpnckDyon+j0tceMFi8jctAYXHia +vGqoE/pMeIPX2FP5VLUwoUfxAN0u2Mwv3OqaHpI50eZkm4pPL+fjU2XPeBEv4ZDvd VJ72GNPROgSCvNmXhVda6VBbBII48KMFsYL77IImvwjr6f7Krknr28Qiodelc77/wM Z/kZrU1iLCCBA== Message-ID: <744290ab-b5b3-40b4-bb70-006231fcb328@kernel.org> Date: Tue, 28 Jul 2026 21:06:42 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: unpoison pages in memory-failure teardown To: Muhammad Usama Anjum Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Miaohe Lin , Naoya Horiguchi , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan References: <20260727095415.385026-1-usama.anjum@arm.com> <9a289152-70c1-4e13-a0d5-f77bdee72d8a@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <9a289152-70c1-4e13-a0d5-f77bdee72d8a@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/28/26 16:22, Muhammad Usama Anjum wrote: > On 27/07/2026 1:31 pm, David Hildenbrand (Arm) wrote: >> On 7/27/26 11:54, Muhammad Usama Anjum wrote: >>> The memory-failure tests call cleanup() only after all result checks. >>> A failed ASSERT_* invokes fixture teardown and aborts the test, so it >>> skips cleanup() and leaves the injected page hardware-poisoned. >>> >>> Invoke cleanup() from FIXTURE_TEARDOWN() instead. Guard it with >>> self->triggered so tests that exit before injection do not try to >>> unpoison a page when no injection was attempted. This runs the existing >>> HWPoison and HardwareCorrupted checks on both normal and assertion-failure >>> paths. >>> >>> Fixes: ff4ef2fbd101 ("selftests/mm: add memory failure anonymous page test") >>> Signed-off-by: Muhammad Usama Anjum >>> --- >>> tools/testing/selftests/mm/memory-failure.c | 26 +++++++++------------ >>> 1 file changed, 11 insertions(+), 15 deletions(-) >>> >>> diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c >>> index 5d00aab31f9b5..eaa8b9bd401a1 100644 >>> --- a/tools/testing/selftests/mm/memory-failure.c >>> +++ b/tools/testing/selftests/mm/memory-failure.c >>> @@ -122,13 +122,6 @@ static void teardown_sighandler(void) >>> sigaction(SIGBUS, &sa, NULL); >>> } >>> >>> -FIXTURE_TEARDOWN(memory_failure) >>> -{ >>> - close(self->kpageflags_fd); >>> - close(self->pagemap_fd); >>> - teardown_sighandler(); >>> -} >>> - >>> static void prepare(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self, >>> void *vaddr) >>> { >>> @@ -200,8 +193,7 @@ static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure >>> ASSERT_EQ(pfn_flags & KPF_HWPOISON, KPF_HWPOISON); >>> } >>> >>> -static void cleanup(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self, >>> - void *vaddr) >>> +static void cleanup(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure) * self) >>> { >>> unsigned long size; >>> uint64_t pfn_flags; >>> @@ -217,6 +209,16 @@ static void cleanup(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failu >>> ASSERT_EQ(size, self->corrupted_size); >>> } >>> >>> +FIXTURE_TEARDOWN(memory_failure) >>> +{ >>> + if (self->triggered) >>> + cleanup(_metadata, self); >> >> If the variant->inject(self, addr) fails, self->triggered would already have >> been set. >> >> Wouldn't it be cleaner to have a new self->poisoned that we set only after >> ->inject succeeded? > Setting self->poisoned after variant->inject() returns would not cover the > MADV_HARD signal path. > > The call path of madvise(MADV_HWPOISON) is: > > madvise() -> madvise_do_behavior() -> madvise_inject_error(MF_ACTION_REQUIRED) -> > memory_failure() -> hwpoison_user_mappings() -> kill_procs(BUS_MCEERR_AR) -> > kill_proc() -> force_sig_mceerr() > > SIGBUS is therefore queued while the madvise system call is executing and > delivered on return to userspace, before execution can continue after > variant->inject(). > > The test's sigbus_action() then calls siglongjmp(), so an assignment placed > after variant->inject() would be bypassed. The flag would remain false and > the test would attempt the injection again after returning to sigsetjmp(). > > Also, memory_failure() sets PG_hwpoison before several recovery paths that > can return an error, so a failed injection return does not prove that the > page was not poisoned. > > Maybe renaming triggered to injection_attempted is more precise here. Yes, that would make it clearer. + adding a comment that we want to cleanup even when injection was attempted, but failed. Thanks! -- Cheers, David