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Commit 5037be16 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 

Pull s390 updates from Martin Schwidefsky:

 - A rework for the s390 arch random code, the TRNG instruction is
   rather slow and should not be used on the interrupt path

 - A fix for a memory leak in the zcrypt driver

 - Changes to the early boot code to add a compile time check for code
   that may not use the .bss section, with the goal to avoid initrd
   corruptions

 - Add an interface to get the physical network ID (pnetid), this is
   useful to group network devices that are attached to the same network

 - Some cleanup for the linker script

 - Some code improvement for the dasd driver

 - Two fixes for the perf sampling support

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: Fix CCA and EP11 CPRB processing failure memory leak.
  s390/archrandom: Rework arch random implementation.
  s390/net: add pnetid support
  s390/dasd: simplify locking in dasd_times_out
  s390/cio: add test for ccwgroup device
  s390/cio: add helper to query utility strings per given ccw device
  s390: remove no-op macro VMLINUX_SYMBOL()
  s390: remove closung punctuation from spectre messages
  s390: introduce compile time check for empty .bss section
  s390/early: move functions which may not access bss section to extra file
  s390/early: get rid of #ifdef CONFIG_BLK_DEV_INITRD
  s390/early: get rid of memmove_early
  s390/cpum_sf: Add data entry sizes to sampling trailer entry
  perf: fix invalid bit in diagnostic entry
parents eab733af 89a0c0ec

arch/s390/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -838,6 +838,10 @@ config CCW 


source "drivers/Kconfig"



config HAVE_PNETID

	tristate

	default (SMC || CCWGROUP)



source "fs/Kconfig"



source "arch/s390/Kconfig.debug"

arch/s390/crypto/arch_random.c

+99 −4
Original line number Diff line number Diff line
@@ -2,14 +2,37 @@ 
/*

 * s390 arch random implementation.

 *

 * Copyright IBM Corp. 2017

 * Author(s): Harald Freudenberger <freude@de.ibm.com>

 * Copyright IBM Corp. 2017, 2018

 * Author(s): Harald Freudenberger

 *

 * The s390_arch_random_generate() function may be called from random.c

 * in interrupt context. So this implementation does the best to be very

 * fast. There is a buffer of random data which is asynchronously checked

 * and filled by a workqueue thread.

 * If there are enough bytes in the buffer the s390_arch_random_generate()

 * just delivers these bytes. Otherwise false is returned until the

 * worker thread refills the buffer.

 * The worker fills the rng buffer by pulling fresh entropy from the

 * high quality (but slow) true hardware random generator. This entropy

 * is then spread over the buffer with an pseudo random generator PRNG.

 * As the arch_get_random_seed_long() fetches 8 bytes and the calling

 * function add_interrupt_randomness() counts this as 1 bit entropy the

 * distribution needs to make sure there is in fact 1 bit entropy contained

 * in 8 bytes of the buffer. The current values pull 32 byte entropy

 * and scatter this into a 2048 byte buffer. So 8 byte in the buffer

 * will contain 1 bit of entropy.

 * The worker thread is rescheduled based on the charge level of the

 * buffer but at least with 500 ms delay to avoid too much CPU consumption.

 * So the max. amount of rng data delivered via arch_get_random_seed is

 * limited to 4k bytes per second.

 */



#include <linux/kernel.h>

#include <linux/atomic.h>

#include <linux/random.h>

#include <linux/slab.h>

#include <linux/static_key.h>

#include <linux/workqueue.h>

#include <asm/cpacf.h>



DEFINE_STATIC_KEY_FALSE(s390_arch_random_available);
@@ -17,11 +40,83 @@ DEFINE_STATIC_KEY_FALSE(s390_arch_random_available); 
atomic64_t s390_arch_random_counter = ATOMIC64_INIT(0);

EXPORT_SYMBOL(s390_arch_random_counter);



#define ARCH_REFILL_TICKS (HZ/2)

#define ARCH_PRNG_SEED_SIZE 32

#define ARCH_RNG_BUF_SIZE 2048



static DEFINE_SPINLOCK(arch_rng_lock);

static u8 *arch_rng_buf;

static unsigned int arch_rng_buf_idx;



static void arch_rng_refill_buffer(struct work_struct *);

static DECLARE_DELAYED_WORK(arch_rng_work, arch_rng_refill_buffer);



bool s390_arch_random_generate(u8 *buf, unsigned int nbytes)

{

	/* lock rng buffer */

	if (!spin_trylock(&arch_rng_lock))

		return false;



	/* try to resolve the requested amount of bytes from the buffer */

	arch_rng_buf_idx -= nbytes;

	if (arch_rng_buf_idx < ARCH_RNG_BUF_SIZE) {

		memcpy(buf, arch_rng_buf + arch_rng_buf_idx, nbytes);

		atomic64_add(nbytes, &s390_arch_random_counter);

		spin_unlock(&arch_rng_lock);

		return true;

	}



	/* not enough bytes in rng buffer, refill is done asynchronously */

	spin_unlock(&arch_rng_lock);



	return false;

}

EXPORT_SYMBOL(s390_arch_random_generate);



static void arch_rng_refill_buffer(struct work_struct *unused)

{

	unsigned int delay = ARCH_REFILL_TICKS;



	spin_lock(&arch_rng_lock);

	if (arch_rng_buf_idx > ARCH_RNG_BUF_SIZE) {

		/* buffer is exhausted and needs refill */

		u8 seed[ARCH_PRNG_SEED_SIZE];

		u8 prng_wa[240];

		/* fetch ARCH_PRNG_SEED_SIZE bytes of entropy */

		cpacf_trng(NULL, 0, seed, sizeof(seed));

		/* blow this entropy up to ARCH_RNG_BUF_SIZE with PRNG */

		memset(prng_wa, 0, sizeof(prng_wa));

		cpacf_prno(CPACF_PRNO_SHA512_DRNG_SEED,

			   &prng_wa, NULL, 0, seed, sizeof(seed));

		cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN,

			   &prng_wa, arch_rng_buf, ARCH_RNG_BUF_SIZE, NULL, 0);

		arch_rng_buf_idx = ARCH_RNG_BUF_SIZE;

	}

	delay += (ARCH_REFILL_TICKS * arch_rng_buf_idx) / ARCH_RNG_BUF_SIZE;

	spin_unlock(&arch_rng_lock);



	/* kick next check */

	queue_delayed_work(system_long_wq, &arch_rng_work, delay);

}



static int __init s390_arch_random_init(void)

{

	/* check if subfunction CPACF_PRNO_TRNG is available */

	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))

	/* all the needed PRNO subfunctions available ? */

	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG) &&

	    cpacf_query_func(CPACF_PRNO, CPACF_PRNO_SHA512_DRNG_GEN)) {



		/* alloc arch random working buffer */

		arch_rng_buf = kmalloc(ARCH_RNG_BUF_SIZE, GFP_KERNEL);

		if (!arch_rng_buf)

			return -ENOMEM;



		/* kick worker queue job to fill the random buffer */

		queue_delayed_work(system_long_wq,

				   &arch_rng_work, ARCH_REFILL_TICKS);



		/* enable arch random to the outside world */

		static_branch_enable(&s390_arch_random_available);

	}



	return 0;

}

arch/s390/include/asm/archrandom.h

+3 −10
Original line number Diff line number Diff line
@@ -15,16 +15,11 @@ 


#include <linux/static_key.h>

#include <linux/atomic.h>

#include <asm/cpacf.h>



DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);

extern atomic64_t s390_arch_random_counter;



static void s390_arch_random_generate(u8 *buf, unsigned int nbytes)

{

	cpacf_trng(NULL, 0, buf, nbytes);

	atomic64_add(nbytes, &s390_arch_random_counter);

}

bool s390_arch_random_generate(u8 *buf, unsigned int nbytes);



static inline bool arch_has_random(void)

{
@@ -51,8 +46,7 @@ static inline bool arch_get_random_int(unsigned int *v) 
static inline bool arch_get_random_seed_long(unsigned long *v)

{

	if (static_branch_likely(&s390_arch_random_available)) {

		s390_arch_random_generate((u8 *)v, sizeof(*v));

		return true;

		return s390_arch_random_generate((u8 *)v, sizeof(*v));

	}

	return false;

}
@@ -60,8 +54,7 @@ static inline bool arch_get_random_seed_long(unsigned long *v) 
static inline bool arch_get_random_seed_int(unsigned int *v)

{

	if (static_branch_likely(&s390_arch_random_available)) {

		s390_arch_random_generate((u8 *)v, sizeof(*v));

		return true;

		return s390_arch_random_generate((u8 *)v, sizeof(*v));

	}

	return false;

}

arch/s390/include/asm/ccwdev.h

+1 −0
Original line number Diff line number Diff line
@@ -231,4 +231,5 @@ int ccw_device_siosl(struct ccw_device *); 
extern void ccw_device_get_schid(struct ccw_device *, struct subchannel_id *);



struct channel_path_desc_fmt0 *ccw_device_get_chp_desc(struct ccw_device *, int);

u8 *ccw_device_get_util_str(struct ccw_device *cdev, int chp_idx);

#endif /* _S390_CCWDEV_H_ */

arch/s390/include/asm/ccwgroup.h

+10 −0
Original line number Diff line number Diff line
@@ -73,4 +73,14 @@ extern void ccwgroup_remove_ccwdev(struct ccw_device *cdev); 


#define to_ccwgroupdev(x) container_of((x), struct ccwgroup_device, dev)

#define to_ccwgroupdrv(x) container_of((x), struct ccwgroup_driver, driver)



#if IS_ENABLED(CONFIG_CCWGROUP)

bool dev_is_ccwgroup(struct device *dev);

#else /* CONFIG_CCWGROUP */

static inline bool dev_is_ccwgroup(struct device *dev)

{

	return false;

}

#endif /* CONFIG_CCWGROUP */



#endif