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 picard.linux.it (picard.linux.it [213.254.12.146]) (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 9D15AEE20A8 for ; Fri, 6 Feb 2026 14:48:19 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 498B83CDE8D for ; Fri, 6 Feb 2026 15:48:18 +0100 (CET) Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id AC79E3CD17F for ; Fri, 6 Feb 2026 15:47:57 +0100 (CET) Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id 22606601D47 for ; Fri, 6 Feb 2026 15:47:56 +0100 (CET) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id B352F5BCC2; Fri, 6 Feb 2026 14:47:56 +0000 (UTC) Authentication-Results: smtp-out2.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 68BAA3EA63; Fri, 6 Feb 2026 14:47:56 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 7vPXFRz/hWnTBgAAD6G6ig (envelope-from ); Fri, 06 Feb 2026 14:47:56 +0000 Date: Fri, 6 Feb 2026 15:47:54 +0100 From: Petr Vorel To: Ricardo Branco Message-ID: <20260206144754.GA404539@pevik> References: <20260205205609.147851-1-rbranco@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20260205205609.147851-1-rbranco@suse.de> X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Rspamd-Queue-Id: B352F5BCC2 X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Virus-Scanned: clamav-milter 1.0.9 at in-2.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] userfaultfd: Add test using UFFDIO_POISON X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Petr Vorel Cc: ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hi Ricardo, ... > +static void sigbus_handler(int sig) > +{ > + if (sig == SIGBUS) { > + sigbus_seen = 1; > + siglongjmp(jmpbuf, 1); > + } > +} > + > +static void set_pages(void) > +{ > + page_size = sysconf(_SC_PAGE_SIZE); > + page = SAFE_MMAP(NULL, page_size, PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); > +} > + > +static void reset_pages(void) > +{ > + SAFE_MUNMAP(page, page_size); > +} > + > +static void *handle_thread(void) > +{ > + static struct uffd_msg msg; > + struct uffdio_poison uffdio_poison = {}; > + struct pollfd pollfd; > + int nready; > + > + SAFE_PTHREAD_BARRIER_WAIT(&barrier); > + > + pollfd.fd = uffd; > + pollfd.events = POLLIN; > + nready = poll(&pollfd, 1, -1); > + if (nready == -1) > + tst_brk(TBROK | TERRNO, "Error on poll"); > + > + SAFE_READ(1, uffd, &msg, sizeof(msg)); > + > + if (msg.event != UFFD_EVENT_PAGEFAULT) > + tst_brk(TFAIL, "Received unexpected UFFD_EVENT %d", msg.event); > + > + poison_fault_seen = 1; > + > + /* Poison the page that triggered the fault */ > + uffdio_poison.range.start = msg.arg.pagefault.address & ~(page_size - 1); > + uffdio_poison.range.len = page_size; > + > + SAFE_IOCTL(uffd, UFFDIO_POISON, &uffdio_poison); CI shows old toolchains fail due: error: 'UFFDIO_POISON' undeclared We need a fallback definition in include/lapi/userfaultfd.h. > + > + close(uffd); > + return NULL; > +} > + > +static void run(void) > +{ > + pthread_t thr; > + struct uffdio_api uffdio_api = {}; > + struct uffdio_register uffdio_register; > + struct sigaction sa = {}; > + volatile char dummy; > + > + sa.sa_handler = sigbus_handler; > + sigemptyset(&sa.sa_mask); > + SAFE_SIGACTION(SIGBUS, &sa, NULL); > + > + set_pages(); > + > + uffd = SAFE_USERFAULTFD(O_CLOEXEC | O_NONBLOCK, false); > + > + uffdio_api.api = UFFD_API; > + uffdio_api.features = UFFD_FEATURE_POISON; > + > + SAFE_IOCTL(uffd, UFFDIO_API, &uffdio_api); > + > + uffdio_register.range.start = (unsigned long) page; > + uffdio_register.range.len = page_size; > + uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; > + > + SAFE_IOCTL(uffd, UFFDIO_REGISTER, &uffdio_register); > + > + SAFE_PTHREAD_BARRIER_INIT(&barrier, NULL, 2); > + SAFE_PTHREAD_CREATE(&thr, NULL, (void *) handle_thread, NULL); > + > + SAFE_PTHREAD_BARRIER_WAIT(&barrier); > + > + /* Try to read from the page: should trigger fault, get poisoned, then SIGBUS */ > + if (sigsetjmp(jmpbuf, 1) == 0) { > + dummy = page[0]; > + (void)dummy; > + } > + > + SAFE_PTHREAD_JOIN(thr, NULL); > + SAFE_PTHREAD_BARRIER_DESTROY(&barrier); > + reset_pages(); If any of the SAFE_* functions fail, reset_pages() is not called. We should call it also in cleanup(), guard it with variable not to be munmapped twice. The rest LGTM. Kind regards, Petr > + > + if (poison_fault_seen && sigbus_seen) { > + tst_res(TPASS, "POISON successfully triggered SIGBUS"); > + } else if (poison_fault_seen && !sigbus_seen) { > + tst_res(TFAIL, "POISON fault seen but no SIGBUS received"); > + } else if (!poison_fault_seen && sigbus_seen) { > + tst_res(TFAIL, "SIGBUS received but no poison fault seen"); > + } else { > + tst_res(TFAIL, "No poison fault or SIGBUS observed"); > + } > +} > + > +static struct tst_test test = { > + .test_all = run, > + .min_kver = "6.6", > +}; -- Mailing list info: https://lists.linux.it/listinfo/ltp