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Diffstat (limited to 'arch/s390/lib/uaccess.c')
-rw-r--r--arch/s390/lib/uaccess.c406
1 files changed, 406 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
new file mode 100644
index 00000000000..53dd5d7a0c9
--- /dev/null
+++ b/arch/s390/lib/uaccess.c
@@ -0,0 +1,406 @@
+/*
+ * 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_64BIT
+#define AHI "ahi"
+#define ALR "alr"
+#define CLR "clr"
+#define LHI "lhi"
+#define SLR "slr"
+#else
+#define AHI "aghi"
+#define ALR "algr"
+#define CLR "clgr"
+#define LHI "lghi"
+#define SLR "slgr"
+#endif
+
+static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE;
+
+static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
+ unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x81UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+ "9: jz 7f\n"
+ "1:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 4f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+ "10:"SLR" %0,%4\n"
+ " "ALR" %2,%4\n"
+ "4:"LHI" %4,-1\n"
+ " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
+ " bras %3,6f\n" /* memset loop */
+ " xc 0(1,%2),0(%2)\n"
+ "5: xc 0(256,%2),0(%2)\n"
+ " la %2,256(%2)\n"
+ "6:"AHI" %4,-256\n"
+ " jnm 5b\n"
+ " ex %4,0(%3)\n"
+ " j 8f\n"
+ "7:"SLR" %0,%0\n"
+ "8:\n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
+ : "+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;
+
+ load_kernel_asce();
+ tmp1 = -256UL;
+ asm volatile(
+ " sacf 0\n"
+ "0: mvcp 0(%0,%2),0(%1),%3\n"
+ "10:jz 8f\n"
+ "1:"ALR" %0,%3\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "2: mvcp 0(%0,%2),0(%1),%3\n"
+ "11:jnz 1b\n"
+ " j 8f\n"
+ "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "4: mvcp 0(%4,%2),0(%1),%3\n"
+ "12:"SLR" %0,%4\n"
+ " "ALR" %2,%4\n"
+ "5:"LHI" %4,-1\n"
+ " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
+ " bras %3,7f\n" /* memset loop */
+ " xc 0(1,%2),0(%2)\n"
+ "6: xc 0(256,%2),0(%2)\n"
+ " la %2,256(%2)\n"
+ "7:"AHI" %4,-256\n"
+ " jnm 6b\n"
+ " ex %4,0(%3)\n"
+ " j 9f\n"
+ "8:"SLR" %0,%0\n"
+ "9: sacf 768\n"
+ EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
+ EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_from_user_mvcos(to, from, n);
+ return copy_from_user_mvcp(to, from, n);
+}
+EXPORT_SYMBOL(__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") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+ "6: jz 4f\n"
+ "1:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+ "7:"SLR" %0,%4\n"
+ " j 5f\n"
+ "4:"SLR" %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;
+
+ load_kernel_asce();
+ tmp1 = -256UL;
+ asm volatile(
+ " sacf 0\n"
+ "0: mvcs 0(%0,%1),0(%2),%3\n"
+ "7: jz 5f\n"
+ "1:"ALR" %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 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 6f\n"
+ "4: mvcs 0(%4,%1),0(%2),%3\n"
+ "9:"SLR" %0,%4\n"
+ " j 6f\n"
+ "5:"SLR" %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");
+ return size;
+}
+
+unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_to_user_mvcos(to, from, n);
+ return copy_to_user_mvcs(to, from, n);
+}
+EXPORT_SYMBOL(__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") = 0x810081UL;
+ 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:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2:"SLR" %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)
+{
+ unsigned long tmp1;
+
+ load_kernel_asce();
+ asm volatile(
+ " sacf 256\n"
+ " "AHI" %0,-1\n"
+ " jo 5f\n"
+ " bras %3,3f\n"
+ "0:"AHI" %0,257\n"
+ "1: mvc 0(1,%1),0(%2)\n"
+ " la %1,1(%1)\n"
+ " la %2,1(%2)\n"
+ " "AHI" %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:"AHI" %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,1b-0b(%3)\n"
+ "5: "SLR" %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");
+ return size;
+}
+
+unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+ if (static_key_false(&have_mvcos))
+ return copy_in_user_mvcos(to, from, n);
+ return copy_in_user_mvc(to, from, n);
+}
+EXPORT_SYMBOL(__copy_in_user);
+
+static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
+{
+ register unsigned long reg0 asm("0") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+ " jz 4f\n"
+ "1:"ALR" %0,%2\n"
+ " "SLR" %1,%2\n"
+ " j 0b\n"
+ "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
+ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
+ " "SLR" %3,%1\n"
+ " "CLR" %0,%3\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+ " "SLR" %0,%3\n"
+ " j 5f\n"
+ "4:"SLR" %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)
+{
+ unsigned long tmp1, tmp2;
+
+ load_kernel_asce();
+ asm volatile(
+ " sacf 256\n"
+ " "AHI" %0,-1\n"
+ " jo 5f\n"
+ " bras %3,3f\n"
+ " xc 0(1,%1),0(%1)\n"
+ "0:"AHI" %0,257\n"
+ " la %2,255(%1)\n" /* %2 = ptr + 255 */
+ " srl %2,12\n"
+ " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
+ " "SLR" %2,%1\n"
+ " "CLR" %0,%2\n" /* clear crosses next page boundary? */
+ " jnh 5f\n"
+ " "AHI" %2,-1\n"
+ "1: ex %2,0(%3)\n"
+ " "AHI" %2,1\n"
+ " "SLR" %0,%2\n"
+ " j 5f\n"
+ "2: xc 0(256,%1),0(%1)\n"
+ " la %1,256(%1)\n"
+ "3:"AHI" %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,0(%3)\n"
+ "5: "SLR" %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");
+ return size;
+}
+
+unsigned long __clear_user(void __user *to, unsigned long size)
+{
+ if (static_key_false(&have_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"
+ " "SLR" %0,%0\n"
+ " sacf 256\n"
+ "0: srst %3,%2\n"
+ " jo 0b\n"
+ " la %0,1(%3)\n" /* strnlen_user results includes \0 */
+ " "SLR" %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)
+{
+ if (unlikely(!size))
+ return 0;
+ load_kernel_asce();
+ return strnlen_user_srst(src, size);
+}
+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 & ~PAGE_MASK;
+ len = min(size - done, PAGE_SIZE - 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);
+
+/*
+ * The "old" uaccess variant without mvcos can be enforced with the
+ * uaccess_primary kernel parameter. This is mainly for debugging purposes.
+ */
+static int uaccess_primary __initdata;
+
+static int __init parse_uaccess_pt(char *__unused)
+{
+ uaccess_primary = 1;
+ return 0;
+}
+early_param("uaccess_primary", parse_uaccess_pt);
+
+static int __init uaccess_init(void)
+{
+ if (IS_ENABLED(CONFIG_64BIT) && !uaccess_primary && test_facility(27))
+ static_key_slow_inc(&have_mvcos);
+ return 0;
+}
+early_initcall(uaccess_init);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 11:14:55 +0000