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-rw-r--r--arch/s390/lib/uaccess.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
new file mode 100644
index 000000000..d44214072
--- /dev/null
+++ b/arch/s390/lib/uaccess.c
@@ -0,0 +1,180 @@
+// 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/uaccess.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <asm/asm-extable.h>
+
+#ifdef CONFIG_DEBUG_ENTRY
+void debug_user_asce(int exit)
+{
+ unsigned long cr1, cr7;
+
+ __ctl_store(cr1, 1, 1);
+ __ctl_store(cr7, 7, 7);
+ if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
+ return;
+ panic("incorrect ASCE on kernel %s\n"
+ "cr1: %016lx cr7: %016lx\n"
+ "kernel: %016llx user: %016llx\n",
+ exit ? "exit" : "entry", cr1, cr7,
+ S390_lowcore.kernel_asce, S390_lowcore.user_asce);
+
+}
+#endif /*CONFIG_DEBUG_ENTRY */
+
+static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
+ unsigned long size, unsigned long key)
+{
+ unsigned long tmp1, tmp2;
+ union oac spec = {
+ .oac2.key = key,
+ .oac2.as = PSW_BITS_AS_SECONDARY,
+ .oac2.k = 1,
+ .oac2.a = 1,
+ };
+
+ tmp1 = -4096UL;
+ asm volatile(
+ " lr 0,%[spec]\n"
+ "0: mvcos 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: mvcos 0(%2),0(%1),%4\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" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+ : [spec] "d" (spec.val)
+ : "cc", "memory", "0");
+ return size;
+}
+
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ return raw_copy_from_user_key(to, from, n, 0);
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+unsigned long _copy_from_user_key(void *to, const void __user *from,
+ unsigned long n, unsigned long key)
+{
+ unsigned long res = n;
+
+ might_fault();
+ if (!should_fail_usercopy()) {
+ instrument_copy_from_user_before(to, from, n);
+ res = raw_copy_from_user_key(to, from, n, key);
+ instrument_copy_from_user_after(to, from, n, res);
+ }
+ if (unlikely(res))
+ memset(to + (n - res), 0, res);
+ return res;
+}
+EXPORT_SYMBOL(_copy_from_user_key);
+
+static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
+ unsigned long size, unsigned long key)
+{
+ unsigned long tmp1, tmp2;
+ union oac spec = {
+ .oac1.key = key,
+ .oac1.as = PSW_BITS_AS_SECONDARY,
+ .oac1.k = 1,
+ .oac1.a = 1,
+ };
+
+ tmp1 = -4096UL;
+ asm volatile(
+ " lr 0,%[spec]\n"
+ "0: mvcos 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: mvcos 0(%1),0(%2),%4\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" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+ : [spec] "d" (spec.val)
+ : "cc", "memory", "0");
+ return size;
+}
+
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ return raw_copy_to_user_key(to, from, n, 0);
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+unsigned long _copy_to_user_key(void __user *to, const void *from,
+ unsigned long n, unsigned long key)
+{
+ might_fault();
+ if (should_fail_usercopy())
+ return n;
+ instrument_copy_to_user(to, from, n);
+ return raw_copy_to_user_key(to, from, n, key);
+}
+EXPORT_SYMBOL(_copy_to_user_key);
+
+unsigned long __clear_user(void __user *to, unsigned long size)
+{
+ unsigned long tmp1, tmp2;
+ union oac spec = {
+ .oac1.as = PSW_BITS_AS_SECONDARY,
+ .oac1.a = 1,
+ };
+
+ tmp1 = -4096UL;
+ asm volatile(
+ " lr 0,%[spec]\n"
+ "0: mvcos 0(%1),0(%4),%0\n"
+ "6: 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: mvcos 0(%1),0(%4),%3\n"
+ "7: slgr %0,%3\n"
+ " j 5f\n"
+ "4: slgr %0,%0\n"
+ "5:\n"
+ EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b)
+ : "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
+ : "a" (empty_zero_page), [spec] "d" (spec.val)
+ : "cc", "memory", "0");
+ return size;
+}
+EXPORT_SYMBOL(__clear_user);