Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 448 insertions, 0 deletions

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
new file mode 100644
index 000000000..0267405ab
--- /dev/null
+++ b/arch/s390/lib/uaccess.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Standard user space access functions based on mvcp/mvcs and doing
+ *  interesting things in the secondary space mode.
+ *
+ *    Copyright IBM Corp. 2006,2014
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <asm/mmu_context.h>
+#include <asm/facility.h>
+
+#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
+static DEFINE_STATIC_KEY_FALSE(have_mvcos);
+
+static int __init uaccess_init(void)
+{
+	if (test_facility(27))
+		static_branch_enable(&have_mvcos);
+	return 0;
+}
+early_initcall(uaccess_init);
+
+static inline int copy_with_mvcos(void)
+{
+	if (static_branch_likely(&have_mvcos))
+		return 1;
+	return 0;
+}
+#else
+static inline int copy_with_mvcos(void)
+{
+	return 1;
+}
+#endif
+
+void set_fs(mm_segment_t fs)
+{
+	current->thread.mm_segment = fs;
+	if (fs == USER_DS) {
+		__ctl_load(S390_lowcore.user_asce, 1, 1);
+		clear_cpu_flag(CIF_ASCE_PRIMARY);
+	} else {
+		__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+		set_cpu_flag(CIF_ASCE_PRIMARY);
+	}
+	if (fs & 1) {
+		if (fs == USER_DS_SACF)
+			__ctl_load(S390_lowcore.user_asce, 7, 7);
+		else
+			__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+		set_cpu_flag(CIF_ASCE_SECONDARY);
+	}
+}
+EXPORT_SYMBOL(set_fs);
+
+mm_segment_t enable_sacf_uaccess(void)
+{
+	mm_segment_t old_fs;
+	unsigned long asce, cr;
+	unsigned long flags;
+
+	old_fs = current->thread.mm_segment;
+	if (old_fs & 1)
+		return old_fs;
+	/* protect against a concurrent page table upgrade */
+	local_irq_save(flags);
+	current->thread.mm_segment |= 1;
+	asce = S390_lowcore.kernel_asce;
+	if (likely(old_fs == USER_DS)) {
+		__ctl_store(cr, 1, 1);
+		if (cr != S390_lowcore.kernel_asce) {
+			__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+			set_cpu_flag(CIF_ASCE_PRIMARY);
+		}
+		asce = S390_lowcore.user_asce;
+	}
+	__ctl_store(cr, 7, 7);
+	if (cr != asce) {
+		__ctl_load(asce, 7, 7);
+		set_cpu_flag(CIF_ASCE_SECONDARY);
+	}
+	local_irq_restore(flags);
+	return old_fs;
+}
+EXPORT_SYMBOL(enable_sacf_uaccess);
+
+void disable_sacf_uaccess(mm_segment_t old_fs)
+{
+	current->thread.mm_segment = old_fs;
+	if (old_fs == USER_DS && test_facility(27)) {
+		__ctl_load(S390_lowcore.user_asce, 1, 1);
+		clear_cpu_flag(CIF_ASCE_PRIMARY);
+	}
+}
+EXPORT_SYMBOL(disable_sacf_uaccess);
+
+static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
+						 unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x01UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+		"6: jz    4f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j     0b\n"
+		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   5f\n"
+		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+		"7: slgr  %0,%4\n"
+		"   j     5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
+						unsigned long size)
+{
+	unsigned long tmp1, tmp2;
+	mm_segment_t old_fs;
+
+	old_fs = enable_sacf_uaccess();
+	tmp1 = -256UL;
+	asm volatile(
+		"   sacf  0\n"
+		"0: mvcp  0(%0,%2),0(%1),%3\n"
+		"7: jz    5f\n"
+		"1: algr  %0,%3\n"
+		"   la    %1,256(%1)\n"
+		"   la    %2,256(%2)\n"
+		"2: mvcp  0(%0,%2),0(%1),%3\n"
+		"8: jnz   1b\n"
+		"   j     5f\n"
+		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
+		"   lghi  %3,-4096\n"
+		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   6f\n"
+		"4: mvcp  0(%4,%2),0(%1),%3\n"
+		"9: slgr  %0,%4\n"
+		"   j     6f\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_from_user_mvcos(to, from, n);
+	return copy_from_user_mvcp(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
+					       unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010000UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+		"6: jz    4f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j     0b\n"
+		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   5f\n"
+		"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+		"7: slgr  %0,%4\n"
+		"   j     5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
+					      unsigned long size)
+{
+	unsigned long tmp1, tmp2;
+	mm_segment_t old_fs;
+
+	old_fs = enable_sacf_uaccess();
+	tmp1 = -256UL;
+	asm volatile(
+		"   sacf  0\n"
+		"0: mvcs  0(%0,%1),0(%2),%3\n"
+		"7: jz    5f\n"
+		"1: algr  %0,%3\n"
+		"   la    %1,256(%1)\n"
+		"   la    %2,256(%2)\n"
+		"2: mvcs  0(%0,%1),0(%2),%3\n"
+		"8: jnz   1b\n"
+		"   j     5f\n"
+		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
+		"   lghi  %3,-4096\n"
+		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   6f\n"
+		"4: mvcs  0(%4,%1),0(%2),%3\n"
+		"9: slgr  %0,%4\n"
+		"   j     6f\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_to_user_mvcos(to, from, n);
+	return copy_to_user_mvcs(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
+					       unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010001UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	/* FIXME: copy with reduced length. */
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+		"   jz	  2f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j	  0b\n"
+		"2:slgr  %0,%0\n"
+		"3: \n"
+		EX_TABLE(0b,3b)
+		: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
+					     unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long tmp1;
+
+	old_fs = enable_sacf_uaccess();
+	asm volatile(
+		"   sacf  256\n"
+		"   aghi  %0,-1\n"
+		"   jo	  5f\n"
+		"   bras  %3,3f\n"
+		"0: aghi  %0,257\n"
+		"1: mvc	  0(1,%1),0(%2)\n"
+		"   la	  %1,1(%1)\n"
+		"   la	  %2,1(%2)\n"
+		"   aghi  %0,-1\n"
+		"   jnz	  1b\n"
+		"   j	  5f\n"
+		"2: mvc	  0(256,%1),0(%2)\n"
+		"   la	  %1,256(%1)\n"
+		"   la	  %2,256(%2)\n"
+		"3: aghi  %0,-256\n"
+		"   jnm	  2b\n"
+		"4: ex	  %0,1b-0b(%3)\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+		: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_in_user_mvcos(to, from, n);
+	return copy_in_user_mvc(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_in_user);
+
+static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010000UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+		"   jz	  4f\n"
+		"1: algr  %0,%2\n"
+		"   slgr  %1,%2\n"
+		"   j	  0b\n"
+		"2: la	  %3,4095(%1)\n"/* %4 = to + 4095 */
+		"   nr	  %3,%2\n"	/* %4 = (to + 4095) & -4096 */
+		"   slgr  %3,%1\n"
+		"   clgr  %0,%3\n"	/* copy crosses next page boundary? */
+		"   jnh	  5f\n"
+		"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+		"   slgr  %0,%3\n"
+		"   j	  5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+		: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long tmp1, tmp2;
+
+	old_fs = enable_sacf_uaccess();
+	asm volatile(
+		"   sacf  256\n"
+		"   aghi  %0,-1\n"
+		"   jo    5f\n"
+		"   bras  %3,3f\n"
+		"   xc    0(1,%1),0(%1)\n"
+		"0: aghi  %0,257\n"
+		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
+		"   srl   %2,12\n"
+		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
+		"   slgr  %2,%1\n"
+		"   clgr  %0,%2\n"	/* clear crosses next page boundary? */
+		"   jnh   5f\n"
+		"   aghi  %2,-1\n"
+		"1: ex    %2,0(%3)\n"
+		"   aghi  %2,1\n"
+		"   slgr  %0,%2\n"
+		"   j     5f\n"
+		"2: xc    0(256,%1),0(%1)\n"
+		"   la    %1,256(%1)\n"
+		"3: aghi  %0,-256\n"
+		"   jnm   2b\n"
+		"4: ex    %0,0(%3)\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+		: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long __clear_user(void __user *to, unsigned long size)
+{
+	if (copy_with_mvcos())
+			return clear_user_mvcos(to, size);
+	return clear_user_xc(to, size);
+}
+EXPORT_SYMBOL(__clear_user);
+
+static inline unsigned long strnlen_user_srst(const char __user *src,
+					      unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0;
+	unsigned long tmp1, tmp2;
+
+	asm volatile(
+		"   la    %2,0(%1)\n"
+		"   la    %3,0(%0,%1)\n"
+		"   slgr  %0,%0\n"
+		"   sacf  256\n"
+		"0: srst  %3,%2\n"
+		"   jo    0b\n"
+		"   la    %0,1(%3)\n"	/* strnlen_user results includes \0 */
+		"   slgr  %0,%1\n"
+		"1: sacf  768\n"
+		EX_TABLE(0b,1b)
+		: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+unsigned long __strnlen_user(const char __user *src, unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long len;
+
+	if (unlikely(!size))
+		return 0;
+	old_fs = enable_sacf_uaccess();
+	len = strnlen_user_srst(src, size);
+	disable_sacf_uaccess(old_fs);
+	return len;
+}
+EXPORT_SYMBOL(__strnlen_user);
+
+long __strncpy_from_user(char *dst, const char __user *src, long size)
+{
+	size_t done, len, offset, len_str;
+
+	if (unlikely(size <= 0))
+		return 0;
+	done = 0;
+	do {
+		offset = (size_t)src & (L1_CACHE_BYTES - 1);
+		len = min(size - done, L1_CACHE_BYTES - offset);
+		if (copy_from_user(dst, src, len))
+			return -EFAULT;
+		len_str = strnlen(dst, len);
+		done += len_str;
+		src += len_str;
+		dst += len_str;
+	} while ((len_str == len) && (done < size));
+	return done;
+}
+EXPORT_SYMBOL(__strncpy_from_user);