Merge tag 's390-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:
 "Just a couple of small improvements, bug fixes and cleanups:

   - Add Eric Farman as maintainer for s390 virtio drivers.

   - Improve machine check handling, and avoid incorrectly injecting a
     machine check into a kvm guest.

   - Add cond_resched() call to gmap page table walker in order to avoid
     possible huge latencies. Also use non-quiesing sske instruction to
     speed up storage key handling.

   - Add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP so s390 behaves
     similar like common code.

   - Get sie control block address from correct stack slot in perf event
     code. This fixes potential random memory accesses.

   - Change uaccess code so that the exception handler sets the result
     of get_user() and __get_kernel_nofault() to zero in case of a
     fault. Until now this was done via input parameters for inline
     assemblies. Doing it via fault handling is what most or even all
     other architectures are doing.

   - Couple of other small cleanups and fixes"

* tag 's390-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/stack: add union to reflect kvm stack slot usages
  s390/stack: merge empty stack frame slots
  s390/uaccess: whitespace cleanup
  s390/uaccess: use __noreturn instead of __attribute__((noreturn))
  s390/uaccess: use exception handler to zero result on get_user() failure
  s390/uaccess: use symbolic names for inline assembler operands
  s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flag
  s390/mm: use non-quiescing sske for KVM switch to keyed guest
  s390/gmap: voluntarily schedule during key setting
  MAINTAINERS: Update s390 virtio-ccw
  s390/kexec: add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP
  s390/Kconfig.debug: fix indentation
  s390/Kconfig: fix indentation
  s390/perf: obtain sie_block from the right address
  s390: generate register offsets into pt_regs automatically
  s390: simplify early program check handler
  s390/crypto: fix scatterwalk_unmap() callers in AES-GCM

3 files changed, 50 insertions, 5 deletions

diff --git a/arch/s390/mm/extable.c b/arch/s390/mm/extable.c
index 8ac8ad2474a0..1e4d2187541a 100644
--- a/arch/s390/mm/extable.c
+++ b/arch/s390/mm/extable.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 
+#include <linux/bitfield.h>
 #include <linux/extable.h>
+#include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/panic.h>
 #include <asm/asm-extable.h>
@@ -24,9 +26,34 @@ static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_r
 	return true;
 }
 
-static bool ex_handler_uaccess(const struct exception_table_entry *ex, struct pt_regs *regs)
+static bool ex_handler_ua_store(const struct exception_table_entry *ex, struct pt_regs *regs)
 {
-	regs->gprs[ex->data] = -EFAULT;
+	unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+
+	regs->gprs[reg_err] = -EFAULT;
+	regs->psw.addr = extable_fixup(ex);
+	return true;
+}
+
+static bool ex_handler_ua_load_mem(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+	unsigned int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
+	unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+	size_t len = FIELD_GET(EX_DATA_LEN, ex->data);
+
+	regs->gprs[reg_err] = -EFAULT;
+	memset((void *)regs->gprs[reg_addr], 0, len);
+	regs->psw.addr = extable_fixup(ex);
+	return true;
+}
+
+static bool ex_handler_ua_load_reg(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+	unsigned int reg_zero = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
+	unsigned int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+
+	regs->gprs[reg_err] = -EFAULT;
+	regs->gprs[reg_zero] = 0;
 	regs->psw.addr = extable_fixup(ex);
 	return true;
 }
@@ -43,8 +70,12 @@ bool fixup_exception(struct pt_regs *regs)
 		return ex_handler_fixup(ex, regs);
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
-	case EX_TYPE_UACCESS:
-		return ex_handler_uaccess(ex, regs);
+	case EX_TYPE_UA_STORE:
+		return ex_handler_ua_store(ex, regs);
+	case EX_TYPE_UA_LOAD_MEM:
+		return ex_handler_ua_load_mem(ex, regs);
+	case EX_TYPE_UA_LOAD_REG:
+		return ex_handler_ua_load_reg(ex, regs);
 	}
 	panic("invalid exception table entry");
 }
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 1ac73917a8d3..b8ae4a4aa2ba 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2608,6 +2608,18 @@ static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
 	return 0;
 }
 
+/*
+ * Give a chance to schedule after setting a key to 256 pages.
+ * We only hold the mm lock, which is a rwsem and the kvm srcu.
+ * Both can sleep.
+ */
+static int __s390_enable_skey_pmd(pmd_t *pmd, unsigned long addr,
+				  unsigned long next, struct mm_walk *walk)
+{
+	cond_resched();
+	return 0;
+}
+
 static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
 				      unsigned long hmask, unsigned long next,
 				      struct mm_walk *walk)
@@ -2630,12 +2642,14 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
 	end = start + HPAGE_SIZE - 1;
 	__storage_key_init_range(start, end);
 	set_bit(PG_arch_1, &page->flags);
+	cond_resched();
 	return 0;
 }
 
 static const struct mm_walk_ops enable_skey_walk_ops = {
 	.hugetlb_entry		= __s390_enable_skey_hugetlb,
 	.pte_entry		= __s390_enable_skey_pte,
+	.pmd_entry		= __s390_enable_skey_pmd,
 };
 
 int s390_enable_skey(void)
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 697df02362af..4909dcd762e8 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -748,7 +748,7 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 	pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
 	ptev = pte_val(*ptep);
 	if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
-		page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
+		page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0);
 	pgste_set_unlock(ptep, pgste);
 	preempt_enable();
 }