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From:   Stephan Mueller <smueller@chronox.de>
To:     kbuild test robot <lkp@intel.com>
Cc:     kbuild-all@lists.01.org, Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-crypto@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        linux-api@vger.kernel.org,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        "Alexander E. Patrakov" <patrakov@gmail.com>,
        "Ahmed S. Darwish" <darwish.07@gmail.com>,
        "Theodore Y. Ts'o" <tytso@mit.edu>, Willy Tarreau <w@1wt.eu>,
        Matthew Garrett <mjg59@srcf.ucam.org>,
        Vito Caputo <vcaputo@pengaru.com>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>,
        William Jon McCann <mccann@jhu.edu>,
        zhangjs <zachary@baishancloud.com>,
        Andy Lutomirski <luto@kernel.org>,
        Florian Weimer <fweimer@redhat.com>,
        Lennart Poettering <mzxreary@0pointer.de>,
        Nicolai Stange <nstange@suse.de>,
        "Peter, Matthias" <matthias.peter@bsi.bund.de>,
        Marcelo Henrique Cerri <marcelo.cerri@canonical.com>,
        Roman Drahtmueller <draht@schaltsekun.de>,
        Neil Horman <nhorman@redhat.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Julia Lawall <julia.lawall@inria.fr>
Subject: Re: [PATCH v27 01/12] Linux Random Number Generator
Date:   Thu, 16 Jan 2020 07:41:48 +0100
Message-ID: <6012879.pHcDpAmSNa@tauon.chronox.de>
In-Reply-To: <202001161241.meGVaLli%lkp@intel.com>
References: <112781836.sNYxTrJJ31@positron.chronox.de> <202001161241.meGVaLli%lkp@intel.com>
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Am Donnerstag, 16. Januar 2020, 07:09:51 CET schrieb kbuild test robot:

Hi kbuild,

> Hi "Stephan,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on char-misc/char-misc-testing]
> [also build test WARNING on cryptodev/master crypto/master v5.5-rc6
> next-20200110] [if your patch is applied to the wrong git tree, please drop
> us a note to help improve the system. BTW, we also suggest to use '--base'
> option to specify the base tree in git format-patch, please see
> https://stackoverflow.com/a/37406982]

This patch requires the presence of patch 
75551dbf112c992bc6c99a972990b3f272247e23 from Ted Tso's kernel tree as 
documented in patch 0/12.

I am not sure how to document it for the kbuild system.
> 
> url:   
> https://github.com/0day-ci/linux/commits/Stephan-M-ller/dev-random-a-new-ap
> proach-with-full-SP800-90B/20200110-084934 base:  
> https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> 68faa679b8be1a74e6663c21c3a9d25d32f1c079 reproduce:
>         # apt-get install sparse
>         # sparse version: v0.6.1-130-g1a803e7a-dirty
>         make ARCH=x86_64 allmodconfig
>         make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> 
> >> drivers/char/lrng/lrng_interfaces.c:455:16: sparse: sparse: incorrect
> >> type in return expression (different base types)
> >> drivers/char/lrng/lrng_interfaces.c:455:16: sparse:    expected unsigned
> >> int drivers/char/lrng/lrng_interfaces.c:455:16: sparse:    got
> >> restricted __poll_t [assigned] [usertype] mask
> >> drivers/char/lrng/lrng_interfaces.c:586:18: sparse: sparse: incorrect
> >> type in initializer (different base types)
> >> drivers/char/lrng/lrng_interfaces.c:586:18: sparse:    expected
> >> restricted __poll_t ( *poll )( ... )
> >> drivers/char/lrng/lrng_interfaces.c:586:18: sparse:    got unsigned int
> >> ( * )( ... )
>    drivers/char/lrng/lrng_interfaces.c:605:49: sparse: sparse: undefined
> identifier 'GRND_INSECURE' drivers/char/lrng/lrng_interfaces.c:613:15:
> sparse: sparse: undefined identifier 'GRND_INSECURE'
> drivers/char/lrng/lrng_interfaces.c:613:47: sparse: sparse: undefined
> identifier 'GRND_INSECURE' drivers/char/lrng/lrng_interfaces.c:619:21:
> sparse: sparse: undefined identifier 'GRND_INSECURE' --
>    drivers/char/lrng/lrng_drng.c:378:6: sparse: sparse: symbol 'lrng_reset'
> was not declared. Should it be static?
> >> drivers/char/lrng/lrng_internal.h:235:39: sparse: sparse: context
> >> imbalance in 'lrng_drng_inject' - unexpected unlock
> >> drivers/char/lrng/lrng_internal.h:235:39: sparse: sparse: context
> >> imbalance in 'lrng_drng_seed' - unexpected unlock
> >> drivers/char/lrng/lrng_internal.h:235:39: sparse: sparse: context
> >> imbalance in 'lrng_drng_get' - unexpected unlock
> >> drivers/char/lrng/lrng_internal.h:235:39: sparse: sparse: context
> >> imbalance in 'lrng_drngs_init_cc20' - unexpected unlock
> >> drivers/char/lrng/lrng_internal.h:235:39: sparse: sparse: context
> >> imbalance in '_lrng_reset' - unexpected unlock
> vim +455 drivers/char/lrng/lrng_interfaces.c
> 
>    442
>    443	static unsigned int lrng_random_poll(struct file *file, poll_table
> *wait) 444	{
>    445		__poll_t mask;
>    446
>    447		poll_wait(file, &lrng_init_wait, wait);
>    448		poll_wait(file, &lrng_write_wait, wait);
>    449		mask = 0;
>    450		if (lrng_state_operational())
>    451			mask |= EPOLLIN | EPOLLRDNORM;
>    452		if (lrng_need_entropy() ||
>    453		    lrng_state_exseed_allow(lrng_noise_source_user))
>    454			mask |= EPOLLOUT | EPOLLWRNORM;
> 
>  > 455		return mask;
> 
>    456	}
>    457
>    458	static ssize_t lrng_drng_write_common(const char __user *buffer,
> size_t count, 459					      u32 
entropy_bits)
>    460	{
>    461		ssize_t ret = 0;
>    462		u8 buf[64] __aligned(LRNG_KCAPI_ALIGN);
>    463		const char __user *p = buffer;
>    464		u32 orig_entropy_bits = entropy_bits;
>    465
>    466		if (!lrng_get_available())
>    467			return -EAGAIN;
>    468
>    469		count = min_t(size_t, count, INT_MAX);
>    470		while (count > 0) {
>    471			size_t bytes = min_t(size_t, count, sizeof(buf));
>    472			u32 ent = min_t(u32, bytes<<3, entropy_bits);
>    473
>    474			if (copy_from_user(&buf, p, bytes))
>    475				return -EFAULT;
>    476			/* Inject data into entropy pool */
>    477			lrng_pool_lfsr(buf, bytes);
>    478			lrng_pool_add_entropy(ent);
>    479
>    480			count -= bytes;
>    481			p += bytes;
>    482			ret += bytes;
>    483			entropy_bits -= ent;
>    484
>    485			cond_resched();
>    486		}
>    487
>    488		/* Force reseed of DRNG during next data request. */
>    489		if (!orig_entropy_bits)
>    490			lrng_drng_force_reseed();
>    491
>    492		return ret;
>    493	}
>    494
>    495	static ssize_t lrng_drng_read(struct file *file, char __user *buf,
>    496				      size_t nbytes, loff_t *ppos)
>    497	{
>    498		if (!lrng_state_min_seeded())
>    499			pr_notice_ratelimited("%s - use of insufficiently 
seeded DRNG "
>    500					      "(%zu bytes read)\n", current-
>comm,
>    501					      nbytes);
>    502		else if (!lrng_state_operational())
>    503			pr_debug_ratelimited("%s - use of not fully seeded 
DRNG (%zu "
>    504					     "bytes read)\n", current->comm, 
nbytes);
>    505
>    506		return lrng_read_common(buf, nbytes);
>    507	}
>    508
>    509	static ssize_t lrng_drng_write(struct file *file, const char __user
> *buffer, 510				       size_t count, loff_t *ppos)
>    511	{
>    512		return lrng_drng_write_common(buffer, count, 0);
>    513	}
>    514
>    515	static long lrng_ioctl(struct file *f, unsigned int cmd, unsigned
> long arg) 516	{
>    517		int size, ent_count_bits;
>    518		int __user *p = (int __user *)arg;
>    519
>    520		switch (cmd) {
>    521		case RNDGETENTCNT:
>    522			ent_count_bits = lrng_avail_entropy();
>    523			if (put_user(ent_count_bits, p))
>    524				return -EFAULT;
>    525			return 0;
>    526		case RNDADDTOENTCNT:
>    527			if (!capable(CAP_SYS_ADMIN))
>    528				return -EPERM;
>    529			if (get_user(ent_count_bits, p))
>    530				return -EFAULT;
>    531			ent_count_bits = (int)lrng_avail_entropy() + 
ent_count_bits;
>    532			if (ent_count_bits < 0)
>    533				ent_count_bits = 0;
>    534			if (ent_count_bits > LRNG_POOL_SIZE_BITS)
>    535				ent_count_bits = LRNG_POOL_SIZE_BITS;
>    536			lrng_pool_set_entropy(ent_count_bits);
>    537			return 0;
>    538		case RNDADDENTROPY:
>    539			if (!capable(CAP_SYS_ADMIN))
>    540				return -EPERM;
>    541			if (get_user(ent_count_bits, p++))
>    542				return -EFAULT;
>    543			if (ent_count_bits < 0)
>    544				return -EINVAL;
>    545			if (get_user(size, p++))
>    546				return -EFAULT;
>    547			if (size < 0)
>    548				return -EINVAL;
>    549			lrng_state_exseed_set(lrng_noise_source_user, false);
>    550			/* there cannot be more entropy than data */
>    551			ent_count_bits = min(ent_count_bits, size<<3);
>    552			return lrng_drng_write_common((const char __user *)p, 
size,
>    553						      ent_count_bits);
>    554		case RNDZAPENTCNT:
>    555		case RNDCLEARPOOL:
>    556			/* Clear the entropy pool counter. */
>    557			if (!capable(CAP_SYS_ADMIN))
>    558				return -EPERM;
>    559			lrng_pool_set_entropy(0);
>    560			return 0;
>    561		case RNDRESEEDCRNG:
>    562			/*
>    563			 * We leave the capability check here since it is 
present
>    564			 * in the upstream's RNG implementation. Yet, user 
space
>    565			 * can trigger a reseed as easy as writing into /dev/
random
>    566			 * or /dev/urandom where no privilege is needed.
>    567			 */
>    568			if (!capable(CAP_SYS_ADMIN))
>    569				return -EPERM;
>    570			/* Force a reseed of all DRNGs */
>    571			lrng_drng_force_reseed();
>    572			return 0;
>    573		default:
>    574			return -EINVAL;
>    575		}
>    576	}
>    577
>    578	static int lrng_fasync(int fd, struct file *filp, int on)
>    579	{
>    580		return fasync_helper(fd, filp, on, &fasync);
>    581	}
>    582
>    583	const struct file_operations random_fops = {
>    584		.read  = lrng_drng_read_block,
>    585		.write = lrng_drng_write,
> 
>  > 586		.poll  = lrng_random_poll,
> 
>    587		.unlocked_ioctl = lrng_ioctl,
>    588		.compat_ioctl = compat_ptr_ioctl,
>    589		.fasync = lrng_fasync,
>    590		.llseek = noop_llseek,
>    591	};
>    592
> 
> ---
> 0-DAY kernel test infrastructure                 Open Source Technology
> Center https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel
> Corporation


Ciao
Stephan