From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A7C7938642B for ; Mon, 16 Mar 2026 09:14:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773652469; cv=none; b=jBW9Wqw3m64YNwXxgR6Ge1tqyg3BhzKiLNmouZtyaAvL+YzmiSrN8m/9Upn/3UdEGFeZv4iGc0oSBK0I9t7wKWnHtMkYGTdhfbj+uC011SDVdmXrV3fUagFdzPVcU1HskW0T/guT6UIlSCPZHgaZAPWqtqvQ9eTjcxYYnxI/0TY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773652469; c=relaxed/simple; bh=suw4bfPaxCHP09DRw2uadC7n1J07483kf6hCmnJEn0g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mHs/kcKAQpKT6Ge3XxGXPFG1ZOM9NXYEBb5wVEdNNfRpnxqFV9gs4z2jvPpEgL2mqqUVfjiI6FMsL0rTeni4MoJbzHRI3CoWF5Pc9t+nUAaAn/82XWry8Un+rdLuQGfbYAPrfRrPYDci6vaX3kq+HdOX27DvrGYsBpEuzu4u/Pc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=P5AXSQNg; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=dZ21jLKk; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=JKfdmvDB; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=+mRN/9Oz; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="P5AXSQNg"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="dZ21jLKk"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="JKfdmvDB"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="+mRN/9Oz" Received: from imap1.dmz-prg2.suse.org (unknown [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-out1.suse.de (Postfix) with ESMTPS id AA75E4D202; Mon, 16 Mar 2026 09:14:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1773652465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=w5KCBPqD081N8TfZVfbYED0aaQMeoJhOd+mhW7Mw2l0=; b=P5AXSQNg9lsSTVMJwS4y1FXEPePcwtshbx5eeXbXUSUTWYlu+he1euLNPWKT0l3VYjzOuj lQLATieH9hVVR+xHB3t3csIzUpi2PAlb5WVaZYizxTa+3/a406aIvbpJ5yNOrBaLdnW1Sn wLaiUqX6rSJo9zvZZUCiqpDrNK+aAp4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1773652465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=w5KCBPqD081N8TfZVfbYED0aaQMeoJhOd+mhW7Mw2l0=; b=dZ21jLKkhqssqSKNpWx6mNeWTlPoQ7BP+/hspb4VE2T1D1BBEpKB3A48Vbu3BDtrm8hbwL NQImeGPHwRHyOzDg== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1773652464; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=w5KCBPqD081N8TfZVfbYED0aaQMeoJhOd+mhW7Mw2l0=; b=JKfdmvDBPvR/MbnSPv1VU4BwqRRg54u4dDWsCsdCvlRiO2HDi8WNeSoNApiAo866eA5FFn ertbm2/czsbpl3PlJXt05TCofLxjXwmKJ5aXKk5aKwMK0Gb4JVYzYg+bFl/X2y/Dv9Ef0U 33Ghme+QWqyz7kHYoqoumMUZXy1Zj80= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1773652464; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=w5KCBPqD081N8TfZVfbYED0aaQMeoJhOd+mhW7Mw2l0=; b=+mRN/9Oz6Capx8Nopfcw0d7ch9Xziifj7eRc1FMJ845DntiSE24se/7S9PClk7KBF2ZC1m LEZFzhI6HrVjPCCg== 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 6E38B4273B; Mon, 16 Mar 2026 09:14:24 +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 PxC5GfDJt2lADgAAD6G6ig (envelope-from ); Mon, 16 Mar 2026 09:14:24 +0000 Message-ID: <004c48cb-196a-4aac-bfc4-c440c9fd74d2@suse.de> Date: Mon, 16 Mar 2026 10:14:23 +0100 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 v3] drm/shmem-helper: Fix Map huge page mapping in fault handler To: Pedro Demarchi Gomes , Maarten Lankhorst , Maxime Ripard , David Airlie , Simona Vetter , Boris Brezillon Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20260316002649.211819-1-pedrodemargomes@gmail.com> Content-Language: en-US From: Thomas Zimmermann Autocrypt: addr=tzimmermann@suse.de; keydata= xsBNBFs50uABCADEHPidWt974CaxBVbrIBwqcq/WURinJ3+2WlIrKWspiP83vfZKaXhFYsdg XH47fDVbPPj+d6tQrw5lPQCyqjwrCPYnq3WlIBnGPJ4/jreTL6V+qfKRDlGLWFjZcsrPJGE0 BeB5BbqP5erN1qylK9i3gPoQjXGhpBpQYwRrEyQyjuvk+Ev0K1Jc5tVDeJAuau3TGNgah4Yc hdHm3bkPjz9EErV85RwvImQ1dptvx6s7xzwXTgGAsaYZsL8WCwDaTuqFa1d1jjlaxg6+tZsB 9GluwvIhSezPgnEmimZDkGnZRRSFiGP8yjqTjjWuf0bSj5rUnTGiyLyRZRNGcXmu6hjlABEB AAHNJ1Rob21hcyBaaW1tZXJtYW5uIDx0emltbWVybWFubkBzdXNlLmRlPsLAjgQTAQgAOAIb AwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftODH AAoJEGgNwR1TC3ojx1wH/0hKGWugiqDgLNXLRD/4TfHBEKmxIrmfu9Z5t7vwUKfwhFL6hqvo lXPJJKQpQ2z8+X2vZm/slsLn7J1yjrOsoJhKABDi+3QWWSGkaGwRJAdPVVyJMfJRNNNIKwVb U6B1BkX2XDKDGffF4TxlOpSQzdtNI/9gleOoUA8+jy8knnDYzjBNOZqLG2FuTdicBXblz0Mf vg41gd9kCwYXDnD91rJU8tzylXv03E75NCaTxTM+FBXPmsAVYQ4GYhhgFt8S2UWMoaaABLDe 7l5FdnLdDEcbmd8uLU2CaG4W2cLrUaI4jz2XbkcPQkqTQ3EB67hYkjiEE6Zy3ggOitiQGcqp j//OwE0EWznS4AEIAMYmP4M/V+T5RY5at/g7rUdNsLhWv1APYrh9RQefODYHrNRHUE9eosYb T6XMryR9hT8XlGOYRwKWwiQBoWSDiTMo/Xi29jUnn4BXfI2px2DTXwc22LKtLAgTRjP+qbU6 3Y0xnQN29UGDbYgyyK51DW3H0If2a3JNsheAAK+Xc9baj0LGIc8T9uiEWHBnCH+RdhgATnWW GKdDegUR5BkDfDg5O/FISymJBHx2Dyoklv5g4BzkgqTqwmaYzsl8UxZKvbaxq0zbehDda8lv hFXodNFMAgTLJlLuDYOGLK2AwbrS3Sp0AEbkpdJBb44qVlGm5bApZouHeJ/+n+7r12+lqdsA EQEAAcLAdgQYAQgAIAIbDBYhBHIX+6yM6c9jRKFo5WgNwR1TC3ojBQJftOH6AAoJEGgNwR1T C3ojVSkIALpAPkIJPQoURPb1VWjh34l0HlglmYHvZszJWTXYwavHR8+k6Baa6H7ufXNQtThR yIxJrQLW6rV5lm7TjhffEhxVCn37+cg0zZ3j7zIsSS0rx/aMwi6VhFJA5hfn3T0TtrijKP4A SAQO9xD1Zk9/61JWk8OysuIh7MXkl0fxbRKWE93XeQBhIJHQfnc+YBLprdnxR446Sh8Wn/2D Ya8cavuWf2zrB6cZurs048xe0UbSW5AOSo4V9M0jzYI4nZqTmPxYyXbm30Kvmz0rYVRaitYJ 4kyYYMhuULvrJDMjZRvaNe52tkKAvMevcGdt38H4KSVXAylqyQOW5zvPc4/sq9c= In-Reply-To: <20260316002649.211819-1-pedrodemargomes@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Score: -4.30 X-Spam-Level: X-Spamd-Result: default: False [-4.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; FREEMAIL_TO(0.00)[gmail.com,linux.intel.com,kernel.org,ffwll.ch,collabora.com]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[8]; FUZZY_RATELIMITED(0.00)[rspamd.com]; MID_RHS_MATCH_FROM(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_TLS_ALL(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:mid,imap1.dmz-prg2.suse.org:helo,suse.com:url] X-Spam-Flag: NO Hi Am 16.03.26 um 01:26 schrieb Pedro Demarchi Gomes: > When running ./tools/testing/selftests/mm/split_huge_page_test multiple > times with /sys/kernel/mm/transparent_hugepage/shmem_enabled and > /sys/kernel/mm/transparent_hugepage/enabled set as always the following BUG > occurs: > > [ 232.728858] ------------[ cut here ]------------ > [ 232.729458] kernel BUG at mm/memory.c:2276! > [ 232.729726] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI > [ 232.730217] CPU: 19 UID: 60578 PID: 1497 Comm: llvmpipe-9 Not tainted 7.0.0-rc1mm-new+ #19 PREEMPT(lazy) > [ 232.730855] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/10/2025 > [ 232.731360] RIP: 0010:walk_to_pmd+0x29e/0x3c0 > [ 232.731569] Code: d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 89 ea 48 89 de 4c 89 f7 e8 ae 85 ff ff 85 c0 0f 84 1f fe ff ff 31 db eb d0 <0f> 0b 48 89 ea 48 89 de 4c 89 f7 e8 92 8b ff ff 85 c0 75 e8 48 b8 > [ 232.732614] RSP: 0000:ffff8881aa6ff9a8 EFLAGS: 00010282 > [ 232.732991] RAX: 8000000142e002e7 RBX: ffff8881433cae10 RCX: dffffc0000000000 > [ 232.733362] RDX: 0000000000000000 RSI: 00007fb47840b000 RDI: 8000000142e002e7 > [ 232.733801] RBP: 00007fb47840b000 R08: 0000000000000000 R09: 1ffff110354dff46 > [ 232.734168] R10: fffffbfff0cb921d R11: 00000000910da5ce R12: 1ffffffff0c1fcdd > [ 232.734459] R13: 1ffffffff0c23f36 R14: ffff888171628040 R15: 0000000000000000 > [ 232.734861] FS: 00007fb4907f86c0(0000) GS:ffff888791f2c000(0000) knlGS:0000000000000000 > [ 232.735265] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 232.735548] CR2: 00007fb47840be00 CR3: 000000015e6dc000 CR4: 00000000000006f0 > [ 232.736031] Call Trace: > [ 232.736273] > [ 232.736500] get_locked_pte+0x1f/0xa0 > [ 232.736878] insert_pfn+0x9f/0x350 > [ 232.737190] ? __pfx_pat_pagerange_is_ram+0x10/0x10 > [ 232.737614] ? __pfx_insert_pfn+0x10/0x10 > [ 232.737990] ? __pfx_css_rstat_updated+0x10/0x10 > [ 232.738281] ? __pfx_pfn_modify_allowed+0x10/0x10 > [ 232.738552] ? lookup_memtype+0x62/0x180 > [ 232.738761] vmf_insert_pfn_prot+0x14b/0x340 > [ 232.739012] ? __pfx_vmf_insert_pfn_prot+0x10/0x10 > [ 232.739247] ? __pfx___might_resched+0x10/0x10 > [ 232.739475] drm_gem_shmem_fault.cold+0x18/0x39 > [ 232.739677] ? rcu_read_unlock+0x20/0x70 > [ 232.739882] __do_fault+0x251/0x7b0 > [ 232.740028] do_fault+0x6e1/0xc00 > [ 232.740167] ? __lock_acquire+0x590/0xc40 > [ 232.740335] handle_pte_fault+0x439/0x760 > [ 232.740498] ? mtree_range_walk+0x252/0xae0 > [ 232.740669] ? __pfx_handle_pte_fault+0x10/0x10 > [ 232.740899] __handle_mm_fault+0xa02/0xf30 > [ 232.741066] ? __pfx___handle_mm_fault+0x10/0x10 > [ 232.741255] ? find_vma+0xa1/0x120 > [ 232.741403] handle_mm_fault+0x2bf/0x8f0 > [ 232.741564] do_user_addr_fault+0x2d3/0xed0 > [ 232.741736] ? trace_page_fault_user+0x1bf/0x240 > [ 232.741969] exc_page_fault+0x87/0x120 > [ 232.742124] asm_exc_page_fault+0x26/0x30 > [ 232.742288] RIP: 0033:0x7fb4d73ed546 > [ 232.742441] Code: 66 41 0f 6f fb 66 44 0f 6d dc 66 44 0f 6f c6 66 41 0f 6d f1 66 0f 6c fc 66 45 0f 6c c1 66 44 0f 6f c9 66 0f 6d ca 66 0f db f0 <66> 0f df 04 08 66 44 0f 6c ca 66 45 0f db c2 66 44 0f df 10 66 44 > [ 232.743193] RSP: 002b:00007fb4907f68a0 EFLAGS: 00010206 > [ 232.743565] RAX: 00007fb47840aa00 RBX: 00007fb4d73ec070 RCX: 0000000000001400 > [ 232.743871] RDX: 0000000000002800 RSI: 0000000000003c00 RDI: 0000000000000001 > [ 232.744150] RBP: 0000000000000004 R08: 0000000000001400 R09: 00007fb4d73ec060 > [ 232.744433] R10: 000055f0261a4288 R11: 00007fb4c013da40 R12: 0000000000000008 > [ 232.744712] R13: 0000000000000000 R14: 4332322132212110 R15: 0000000000000004 > [ 232.746616] > [ 232.746711] Modules linked in: nft_nat nft_masq veth bridge stp llc snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore overlay rfkill nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables qrtr ppdev 9pnet_virtio 9pnet parport_pc i2c_piix4 netfs pcspkr parport i2c_smbus joydev sunrpc vfat fat loop dm_multipath nfnetlink vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport zram lz4hc_compress vmw_vmci lz4_compress vsock e1000 bochs serio_raw ata_generic pata_acpi scsi_dh_rdac scsi_dh_emc scsi_dh_alua i2c_dev fuse qemu_fw_cfg > [ 232.749308] ---[ end trace 0000000000000000 ]--- > [ 232.749507] RIP: 0010:walk_to_pmd+0x29e/0x3c0 > [ 232.749692] Code: d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 89 ea 48 89 de 4c 89 f7 e8 ae 85 ff ff 85 c0 0f 84 1f fe ff ff 31 db eb d0 <0f> 0b 48 89 ea 48 89 de 4c 89 f7 e8 92 8b ff ff 85 c0 75 e8 48 b8 > [ 232.750428] RSP: 0000:ffff8881aa6ff9a8 EFLAGS: 00010282 > [ 232.750645] RAX: 8000000142e002e7 RBX: ffff8881433cae10 RCX: dffffc0000000000 > [ 232.750954] RDX: 0000000000000000 RSI: 00007fb47840b000 RDI: 8000000142e002e7 > [ 232.751232] RBP: 00007fb47840b000 R08: 0000000000000000 R09: 1ffff110354dff46 > [ 232.751514] R10: fffffbfff0cb921d R11: 00000000910da5ce R12: 1ffffffff0c1fcdd > [ 232.751837] R13: 1ffffffff0c23f36 R14: ffff888171628040 R15: 0000000000000000 > [ 232.752124] FS: 00007fb4907f86c0(0000) GS:ffff888791f2c000(0000) knlGS:0000000000000000 > [ 232.752441] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 232.752674] CR2: 00007fb47840be00 CR3: 000000015e6dc000 CR4: 00000000000006f0 > [ 232.752983] Kernel panic - not syncing: Fatal exception > [ 232.753510] Kernel Offset: disabled > [ 232.754643] ---[ end Kernel panic - not syncing: Fatal exception ]--- > > This happens when two concurrent page faults occur within the same PMD range. > One fault installs a PMD mapping through vmf_insert_pfn_pmd(), while the other > attempts to install a PTE mapping via vmf_insert_pfn(). The bug is > triggered because a pmd_trans_huge is not expected when walking the page > table inside vmf_insert_pfn. > > Avoid this race by adding a huge_fault callback to drm_gem_shmem_vm_ops so that > PMD-sized mappings are handled through the appropriate huge page fault path. > > Fixes: 211b9a39f261 ("drm/shmem-helper: Map huge pages in fault handler") > Signed-off-by: Pedro Demarchi Gomes > --- > > Changes in v3: > - Pass a try_pmd boolean parameter to drm_gem_shmem_any_fault > - Compile drm_gem_shmem_huge_fault only if CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > is defined to avoid a build warning > > Changes in v2: https://lore.kernel.org/dri-devel/20260313141719.3949700-1-pedrodemargomes@gmail.com/ > - Keep the #ifdef unindented > - Create drm_gem_shmem_any_fault to handle faults of any order and use > drm_gem_shmem_[huge_]fault() as wrappers > > v1: https://lore.kernel.org/all/20260312155027.1682606-1-pedrodemargomes@gmail.com/ > > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 63 ++++++++++++++------------ > 1 file changed, 35 insertions(+), 28 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index 7b5a49935ae4..9428c3ab7283 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -550,36 +550,18 @@ int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); > > -static bool drm_gem_shmem_try_map_pmd(struct vm_fault *vmf, unsigned long addr, > - struct page *page) > -{ > -#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > - unsigned long pfn = page_to_pfn(page); > - unsigned long paddr = pfn << PAGE_SHIFT; > - bool aligned = (addr & ~PMD_MASK) == (paddr & ~PMD_MASK); > - > - if (aligned && > - pmd_none(*vmf->pmd) && > - folio_test_pmd_mappable(page_folio(page))) { > - pfn &= PMD_MASK >> PAGE_SHIFT; > - if (vmf_insert_pfn_pmd(vmf, pfn, false) == VM_FAULT_NOPAGE) > - return true; > - } > -#endif > - > - return false; > -} > - > -static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > +static vm_fault_t drm_gem_shmem_any_fault(struct vm_fault *vmf, bool try_pmd) Please write two functions. One for huge pages and one for regular page faults. Best regards Thomas > { > struct vm_area_struct *vma = vmf->vma; > struct drm_gem_object *obj = vma->vm_private_data; > struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > loff_t num_pages = obj->size >> PAGE_SHIFT; > - vm_fault_t ret; > + vm_fault_t ret = VM_FAULT_FALLBACK; > struct page **pages = shmem->pages; > pgoff_t page_offset; > unsigned long pfn; > + unsigned long paddr; > + bool aligned; > > /* Offset to faulty address in the VMA. */ > page_offset = vmf->pgoff - vma->vm_pgoff; > @@ -593,13 +575,19 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > goto out; > } > > - if (drm_gem_shmem_try_map_pmd(vmf, vmf->address, pages[page_offset])) { > - ret = VM_FAULT_NOPAGE; > - goto out; > - } > - > pfn = page_to_pfn(pages[page_offset]); > - ret = vmf_insert_pfn(vma, vmf->address, pfn); > + if (try_pmd) { > + paddr = pfn << PAGE_SHIFT; > + aligned = (vmf->address & ~PMD_MASK) == (paddr & ~PMD_MASK); > + > + if (aligned && > + folio_test_pmd_mappable(page_folio(pages[page_offset]))) { > + pfn &= PMD_MASK >> PAGE_SHIFT; > + ret = vmf_insert_pfn_pmd(vmf, pfn, false); > + } > + } else { > + ret = vmf_insert_pfn(vma, vmf->address, pfn); > + } > > out: > dma_resv_unlock(shmem->base.resv); > @@ -607,6 +595,22 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > return ret; > } > > +#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > +static vm_fault_t drm_gem_shmem_huge_fault(struct vm_fault *vmf, > + unsigned int order) > +{ > + if (order != PMD_ORDER) > + return VM_FAULT_FALLBACK; > + > + return drm_gem_shmem_any_fault(vmf, true); > +} > +#endif > + > +static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > +{ > + return drm_gem_shmem_any_fault(vmf, false); > +} > + > static void drm_gem_shmem_vm_open(struct vm_area_struct *vma) > { > struct drm_gem_object *obj = vma->vm_private_data; > @@ -643,6 +647,9 @@ static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) > > const struct vm_operations_struct drm_gem_shmem_vm_ops = { > .fault = drm_gem_shmem_fault, > +#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > + .huge_fault = drm_gem_shmem_huge_fault, > +#endif > .open = drm_gem_shmem_vm_open, > .close = drm_gem_shmem_vm_close, > }; > -- > 2.47.3 > -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)