diff options
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/crypto/arch_random.c | 111 | ||||
| -rw-r--r-- | arch/s390/hypfs/hypfs_diag.c | 2 | ||||
| -rw-r--r-- | arch/s390/hypfs/inode.c | 2 | ||||
| -rw-r--r-- | arch/s390/include/asm/archrandom.h | 28 | ||||
| -rw-r--r-- | arch/s390/kernel/process.c | 22 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 5 | ||||
| -rw-r--r-- | arch/s390/mm/fault.c | 4 |
7 files changed, 44 insertions, 130 deletions
diff --git a/arch/s390/crypto/arch_random.c b/arch/s390/crypto/arch_random.c index 4cbb4b6d85a8..1f2d40993c4d 100644 --- a/arch/s390/crypto/arch_random.c +++ b/arch/s390/crypto/arch_random.c @@ -2,126 +2,17 @@ /* * s390 arch random implementation. * - * Copyright IBM Corp. 2017, 2018 + * Copyright IBM Corp. 2017, 2020 * 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); 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) -{ - /* max hunk is ARCH_RNG_BUF_SIZE */ - if (nbytes > ARCH_RNG_BUF_SIZE) - return false; - - /* 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) -{ - /* 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_initcall(s390_arch_random_init); diff --git a/arch/s390/hypfs/hypfs_diag.c b/arch/s390/hypfs/hypfs_diag.c index 3452e18bb1ca..38105ba35c81 100644 --- a/arch/s390/hypfs/hypfs_diag.c +++ b/arch/s390/hypfs/hypfs_diag.c @@ -437,7 +437,7 @@ __init int hypfs_diag_init(void) int rc; if (diag204_probe()) { - pr_err("The hardware system does not support hypfs\n"); + pr_info("The hardware system does not support hypfs\n"); return -ENODATA; } if (diag204_info_type == DIAG204_INFO_EXT) { diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c index e4d17d9ea93d..4af5c0dd9fbe 100644 --- a/arch/s390/hypfs/inode.c +++ b/arch/s390/hypfs/inode.c @@ -494,9 +494,9 @@ fail_hypfs_vm_exit: hypfs_vm_exit(); fail_hypfs_diag_exit: hypfs_diag_exit(); + pr_err("Initialization of hypfs failed with rc=%i\n", rc); fail_dbfs_exit: hypfs_dbfs_exit(); - pr_err("Initialization of hypfs failed with rc=%i\n", rc); return rc; } device_initcall(hypfs_init) diff --git a/arch/s390/include/asm/archrandom.h b/arch/s390/include/asm/archrandom.h index 9a6835137a16..4120c428dc37 100644 --- a/arch/s390/include/asm/archrandom.h +++ b/arch/s390/include/asm/archrandom.h @@ -2,7 +2,7 @@ /* * Kernel interface for the s390 arch_random_* functions * - * Copyright IBM Corp. 2017 + * Copyright IBM Corp. 2017, 2022 * * Author: Harald Freudenberger <freude@de.ibm.com> * @@ -14,35 +14,41 @@ #ifdef CONFIG_ARCH_RANDOM #include <linux/static_key.h> +#include <linux/preempt.h> #include <linux/atomic.h> +#include <asm/cpacf.h> DECLARE_STATIC_KEY_FALSE(s390_arch_random_available); extern atomic64_t s390_arch_random_counter; -bool s390_arch_random_generate(u8 *buf, unsigned int nbytes); - -static inline bool arch_get_random_long(unsigned long *v) +static inline bool __must_check arch_get_random_long(unsigned long *v) { return false; } -static inline bool arch_get_random_int(unsigned int *v) +static inline bool __must_check arch_get_random_int(unsigned int *v) { return false; } -static inline bool arch_get_random_seed_long(unsigned long *v) +static inline bool __must_check arch_get_random_seed_long(unsigned long *v) { - if (static_branch_likely(&s390_arch_random_available)) { - return s390_arch_random_generate((u8 *)v, sizeof(*v)); + if (static_branch_likely(&s390_arch_random_available) && + in_task()) { + cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v)); + atomic64_add(sizeof(*v), &s390_arch_random_counter); + return true; } return false; } -static inline bool arch_get_random_seed_int(unsigned int *v) +static inline bool __must_check arch_get_random_seed_int(unsigned int *v) { - if (static_branch_likely(&s390_arch_random_available)) { - return s390_arch_random_generate((u8 *)v, sizeof(*v)); + if (static_branch_likely(&s390_arch_random_available) && + in_task()) { + cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v)); + atomic64_add(sizeof(*v), &s390_arch_random_counter); + return true; } return false; } diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 99ef537e548a..5772ef90dd26 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -75,6 +75,18 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) memcpy(dst, src, arch_task_struct_size); dst->thread.fpu.regs = dst->thread.fpu.fprs; + + /* + * Don't transfer over the runtime instrumentation or the guarded + * storage control block pointers. These fields are cleared here instead + * of in copy_thread() to avoid premature freeing of associated memory + * on fork() failure. Wait to clear the RI flag because ->stack still + * refers to the source thread. + */ + dst->thread.ri_cb = NULL; + dst->thread.gs_cb = NULL; + dst->thread.gs_bc_cb = NULL; + return 0; } @@ -131,13 +143,11 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, frame->childregs.flags = 0; if (new_stackp) frame->childregs.gprs[15] = new_stackp; - - /* Don't copy runtime instrumentation info */ - p->thread.ri_cb = NULL; + /* + * Clear the runtime instrumentation flag after the above childregs + * copy. The CB pointer was already cleared in arch_dup_task_struct(). + */ frame->childregs.psw.mask &= ~PSW_MASK_RI; - /* Don't copy guarded storage control block */ - p->thread.gs_cb = NULL; - p->thread.gs_bc_cb = NULL; /* Set a new TLS ? */ if (clone_flags & CLONE_SETTLS) { diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 098794fc5dc8..bfd6c01a68f0 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -851,6 +851,11 @@ static void __init setup_randomness(void) if (stsi(vmms, 3, 2, 2) == 0 && vmms->count) add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count); memblock_free((unsigned long) vmms, PAGE_SIZE); + +#ifdef CONFIG_ARCH_RANDOM + if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG)) + static_branch_enable(&s390_arch_random_available); +#endif } /* diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index a6e3c7022245..d64b180caeda 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -455,7 +455,9 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (user_mode(regs)) flags |= FAULT_FLAG_USER; - if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) + if ((trans_exc_code & store_indication) == 0x400) + access = VM_WRITE; + if (access == VM_WRITE) flags |= FAULT_FLAG_WRITE; down_read(&mm->mmap_sem); |