Merging upstream version 4.19.260.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 59 insertions, 132 deletions

diff --git a/arch/s390/crypto/arch_random.c b/arch/s390/crypto/arch_random.c
index 4cbb4b6d8..1f2d40993 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 3452e18bb..38105ba35 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 e4d17d9ea..4af5c0dd9 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 9a6835137..4120c428d 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/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 2d1afa58a..23e575194 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -30,9 +30,11 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 static inline int prepare_hugepage_range(struct file *file,
 			unsigned long addr, unsigned long len)
 {
-	if (len & ~HPAGE_MASK)
+	struct hstate *h = hstate_file(file);
+
+	if (len & ~huge_page_mask(h))
 		return -EINVAL;
-	if (addr & ~HPAGE_MASK)
+	if (addr & ~huge_page_mask(h))
 		return -EINVAL;
 	return 0;
 }
diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h
index 825dd0f7f..ba9b0e764 100644
--- a/arch/s390/include/asm/kexec.h
+++ b/arch/s390/include/asm/kexec.h
@@ -9,6 +9,8 @@
 #ifndef _S390_KEXEC_H
 #define _S390_KEXEC_H
 
+#include <linux/module.h>
+
 #include <asm/processor.h>
 #include <asm/page.h>
 /*
@@ -69,4 +71,12 @@ int *kexec_file_update_kernel(struct kimage *iamge,
 extern const struct kexec_file_ops s390_kexec_image_ops;
 extern const struct kexec_file_ops s390_kexec_elf_ops;
 
+#ifdef CONFIG_KEXEC_FILE
+struct purgatory_info;
+int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+				     Elf_Shdr *section,
+				     const Elf_Shdr *relsec,
+				     const Elf_Shdr *symtab);
+#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add
+#endif
 #endif /*_S390_KEXEC_H */
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 99ef537e5..5772ef90d 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 098794fc5..bfd6c01a6 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/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 18ede6e80..160a05c6c 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -121,6 +121,7 @@ SECTIONS
 	/*
 	 * Table with the patch locations to undo expolines
 	*/
+	. = ALIGN(4);
 	.nospec_call_table : {
 		__nospec_call_start = . ;
 		*(.s390_indirect*)
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index a6e3c7022..d64b180ca 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);