linux/drivers/char/random.c, branch v5.5

random: don't forget compat_ioctl on urandom

2019-12-17T18:19:24Z

Recently, there's been some compat ioctl cleanup, in which large hardcoded lists were replaced with compat_ptr_ioctl. One of these changes involved removing the random.c hardcoded list entries and adding a compat ioctl function pointer to the random.c fops. In the process, urandom was forgotten about, so this commit fixes that oversight. Fixes: 507e4e2b430b ("compat_ioctl: remove /dev/random commands") Cc: Arnd Bergmann Signed-off-by: Jason A. Donenfeld Link: https://lore.kernel.org/r/20191217172455.186395-1-Jason@zx2c4.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2019-12-01T21:46:15Z

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2019-11-17T02:14:32Z

Pull crypto fix from Herbert Xu: "This reverts a number of changes to the khwrng thread which feeds the kernel random number pool from hwrng drivers. They were trying to fix issues with suspend-and-resume but ended up causing regressions" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: Revert "hwrng: core - Freeze khwrng thread during suspend"

Revert "hwrng: core - Freeze khwrng thread during suspend"

2019-11-17T00:48:17Z

This reverts commit 03a3bb7ae631 ("hwrng: core - Freeze khwrng thread during suspend"), ff296293b353 ("random: Support freezable kthreads in add_hwgenerator_randomness()") and 59b569480dc8 ("random: Use wait_event_freezable() in add_hwgenerator_randomness()"). These patches introduced regressions and we need more time to get them ready for mainline. Signed-off-by: Herbert Xu

compat_ioctl: remove /dev/random commands

2019-10-23T15:23:45Z

These are all handled by the random driver, so instead of listing each ioctl, we can use the generic compat_ptr_ioctl() helper. Acked-by: Greg Kroah-Hartman Signed-off-by: Arnd Bergmann

char/random: Add a newline at the end of the file

2019-10-02T20:49:43Z

On Tue, Oct 01, 2019 at 10:14:40AM -0700, Linus Torvalds wrote: > The previous state of the file didn't have that 0xa at the end, so you get that > > > -EXPORT_SYMBOL_GPL(add_bootloader_randomness); > \ No newline at end of file > +EXPORT_SYMBOL_GPL(add_bootloader_randomness); > > which is "the '-' line doesn't have a newline, the '+' line does" marker. Aaha, that makes total sense, thanks for explaining. Oh well, let's fix it then so that people don't scratch heads like me. Signed-off-by: Linus Torvalds

Merge branch 'entropy'

2019-09-30T02:25:39Z

Merge active entropy generation updates. This is admittedly partly "for discussion". We need to have a way forward for the boot time deadlocks where user space ends up waiting for more entropy, but no entropy is forthcoming because the system is entirely idle just waiting for something to happen. While this was triggered by what is arguably a user space bug with GDM/gnome-session asking for secure randomness during early boot, when they didn't even need any such truly secure thing, the issue ends up being that our "getrandom()" interface is prone to that kind of confusion, because people don't think very hard about whether they want to block for sufficient amounts of entropy. The approach here-in is to decide to not just passively wait for entropy to happen, but to start actively collecting it if it is missing. This is not necessarily always possible, but if the architecture has a CPU cycle counter, there is a fair amount of noise in the exact timings of reasonably complex loads. We may end up tweaking the load and the entropy estimates, but this should be at least a reasonable starting point. As part of this, we also revert the revert of the ext4 IO pattern improvement that ended up triggering the reported lack of external entropy. * getrandom() active entropy waiting: Revert "Revert "ext4: make __ext4_get_inode_loc plug"" random: try to actively add entropy rather than passively wait for it

random: try to actively add entropy rather than passively wait for it

2019-09-30T00:38:52Z

For 5.3 we had to revert a nice ext4 IO pattern improvement, because it caused a bootup regression due to lack of entropy at bootup together with arguably broken user space that was asking for secure random numbers when it really didn't need to. See commit 72dbcf721566 (Revert "ext4: make __ext4_get_inode_loc plug"). This aims to solve the issue by actively generating entropy noise using the CPU cycle counter when waiting for the random number generator to initialize. This only works when you have a high-frequency time stamp counter available, but that's the case on all modern x86 CPU's, and on most other modern CPU's too. What we do is to generate jitter entropy from the CPU cycle counter under a somewhat complex load: calling the scheduler while also guaranteeing a certain amount of timing noise by also triggering a timer. I'm sure we can tweak this, and that people will want to look at other alternatives, but there's been a number of papers written on jitter entropy, and this should really be fairly conservative by crediting one bit of entropy for every timer-induced jump in the cycle counter. Not because the timer itself would be all that unpredictable, but because the interaction between the timer and the loop is going to be. Even if (and perhaps particularly if) the timer actually happens on another CPU, the cacheline interaction between the loop that reads the cycle counter and the timer itself firing is going to add perturbations to the cycle counter values that get mixed into the entropy pool. As Thomas pointed out, with a modern out-of-order CPU, even quite simple loops show a fair amount of hard-to-predict timing variability even in the absense of external interrupts. But this tries to take that further by actually having a fairly complex interaction. This is not going to solve the entropy issue for architectures that have no CPU cycle counter, but it's not clear how (and if) that is solvable, and the hardware in question is largely starting to be irrelevant. And by doing this we can at least avoid some of the even more contentious approaches (like making the entropy waiting time out in order to avoid the possibly unbounded waiting). Cc: Ahmed Darwish Cc: Thomas Gleixner Cc: Theodore Ts'o Cc: Nicholas Mc Guire Cc: Andy Lutomirski Cc: Kees Cook Cc: Willy Tarreau Cc: Alexander E. Patrakov Cc: Lennart Poettering Signed-off-by: Linus Torvalds

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2019-09-18T19:11:14Z

Pull crypto updates from Herbert Xu: "API: - Add the ability to abort a skcipher walk. Algorithms: - Fix XTS to actually do the stealing. - Add library helpers for AES and DES for single-block users. - Add library helpers for SHA256. - Add new DES key verification helper. - Add surrounding bits for ESSIV generator. - Add accelerations for aegis128. - Add test vectors for lzo-rle. Drivers: - Add i.MX8MQ support to caam. - Add gcm/ccm/cfb/ofb aes support in inside-secure. - Add ofb/cfb aes support in media-tek. - Add HiSilicon ZIP accelerator support. Others: - Fix potential race condition in padata. - Use unbound workqueues in padata" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (311 commits) crypto: caam - Cast to long first before pointer conversion crypto: ccree - enable CTS support in AES-XTS crypto: inside-secure - Probe transform record cache RAM sizes crypto: inside-secure - Base RD fetchcount on actual RD FIFO size crypto: inside-secure - Base CD fetchcount on actual CD FIFO size crypto: inside-secure - Enable extended algorithms on newer HW crypto: inside-secure: Corrected configuration of EIP96_TOKEN_CTRL crypto: inside-secure - Add EIP97/EIP197 and endianness detection padata: remove cpu_index from the parallel_queue padata: unbind parallel jobs from specific CPUs padata: use separate workqueues for parallel and serial work padata, pcrypt: take CPU hotplug lock internally in padata_alloc_possible crypto: pcrypt - remove padata cpumask notifier padata: make padata_do_parallel find alternate callback CPU workqueue: require CPU hotplug read exclusion for apply_workqueue_attrs workqueue: unconfine alloc/apply/free_workqueue_attrs() padata: allocate workqueue internally arm64: dts: imx8mq: Add CAAM node random: Use wait_event_freezable() in add_hwgenerator_randomness() crypto: ux500 - Fix COMPILE_TEST warnings ...

random: Use wait_event_freezable() in add_hwgenerator_randomness()

2019-09-09T13:48:41Z

Sebastian reports that after commit ff296293b353 ("random: Support freezable kthreads in add_hwgenerator_randomness()") we can call might_sleep() when the task state is TASK_INTERRUPTIBLE (state=1). This leads to the following warning. do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000349d1489>] prepare_to_wait_event+0x5a/0x180 WARNING: CPU: 0 PID: 828 at kernel/sched/core.c:6741 __might_sleep+0x6f/0x80 Modules linked in: CPU: 0 PID: 828 Comm: hwrng Not tainted 5.3.0-rc7-next-20190903+ #46 RIP: 0010:__might_sleep+0x6f/0x80 Call Trace: kthread_freezable_should_stop+0x1b/0x60 add_hwgenerator_randomness+0xdd/0x130 hwrng_fillfn+0xbf/0x120 kthread+0x10c/0x140 ret_from_fork+0x27/0x50 We shouldn't call kthread_freezable_should_stop() from deep within the wait_event code because the task state is still set as TASK_INTERRUPTIBLE instead of TASK_RUNNING and kthread_freezable_should_stop() will try to call into the freezer with the task in the wrong state. Use wait_event_freezable() instead so that it calls schedule() in the right place and tries to enter the freezer when the task state is TASK_RUNNING instead. Reported-by: Sebastian Andrzej Siewior Tested-by: Sebastian Andrzej Siewior Cc: Keerthy Fixes: ff296293b353 ("random: Support freezable kthreads in add_hwgenerator_randomness()") Signed-off-by: Stephen Boyd Signed-off-by: Herbert Xu