407 lines
10 KiB
C
407 lines
10 KiB
C
/*
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* Standard user space access functions based on mvcp/mvcs and doing
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* interesting things in the secondary space mode.
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*
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* Copyright IBM Corp. 2006,2014
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Gerald Schaefer (gerald.schaefer@de.ibm.com)
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*/
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#include <linux/jump_label.h>
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#include <linux/uaccess.h>
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#include <linux/export.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <asm/mmu_context.h>
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#include <asm/facility.h>
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#ifndef CONFIG_64BIT
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#define AHI "ahi"
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#define ALR "alr"
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#define CLR "clr"
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#define LHI "lhi"
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#define SLR "slr"
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#else
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#define AHI "aghi"
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#define ALR "algr"
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#define CLR "clgr"
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#define LHI "lghi"
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#define SLR "slgr"
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#endif
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static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE;
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static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
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unsigned long size)
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{
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register unsigned long reg0 asm("0") = 0x81UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
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"9: jz 7f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 4f\n"
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"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
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"10:"SLR" %0,%4\n"
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" "ALR" %2,%4\n"
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"4:"LHI" %4,-1\n"
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" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
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" bras %3,6f\n" /* memset loop */
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" xc 0(1,%2),0(%2)\n"
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"5: xc 0(256,%2),0(%2)\n"
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" la %2,256(%2)\n"
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"6:"AHI" %4,-256\n"
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" jnm 5b\n"
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" ex %4,0(%3)\n"
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" j 8f\n"
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"7:"SLR" %0,%0\n"
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"8:\n"
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EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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load_kernel_asce();
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tmp1 = -256UL;
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asm volatile(
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" sacf 0\n"
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"0: mvcp 0(%0,%2),0(%1),%3\n"
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"10:jz 8f\n"
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"1:"ALR" %0,%3\n"
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" la %1,256(%1)\n"
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" la %2,256(%2)\n"
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"2: mvcp 0(%0,%2),0(%1),%3\n"
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"11:jnz 1b\n"
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" j 8f\n"
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"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
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" "LHI" %3,-4096\n"
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" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"4: mvcp 0(%4,%2),0(%1),%3\n"
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"12:"SLR" %0,%4\n"
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" "ALR" %2,%4\n"
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"5:"LHI" %4,-1\n"
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" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
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" bras %3,7f\n" /* memset loop */
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" xc 0(1,%2),0(%2)\n"
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"6: xc 0(256,%2),0(%2)\n"
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" la %2,256(%2)\n"
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"7:"AHI" %4,-256\n"
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" jnm 6b\n"
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" ex %4,0(%3)\n"
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" j 9f\n"
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"8:"SLR" %0,%0\n"
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"9: sacf 768\n"
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EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
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EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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if (static_key_false(&have_mvcos))
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return copy_from_user_mvcos(to, from, n);
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return copy_from_user_mvcp(to, from, n);
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}
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EXPORT_SYMBOL(__copy_from_user);
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static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
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unsigned long size)
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{
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register unsigned long reg0 asm("0") = 0x810000UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
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"6: jz 4f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
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"7:"SLR" %0,%4\n"
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" j 5f\n"
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"4:"SLR" %0,%0\n"
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"5:\n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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load_kernel_asce();
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tmp1 = -256UL;
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asm volatile(
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" sacf 0\n"
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"0: mvcs 0(%0,%1),0(%2),%3\n"
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"7: jz 5f\n"
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"1:"ALR" %0,%3\n"
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" la %1,256(%1)\n"
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" la %2,256(%2)\n"
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"2: mvcs 0(%0,%1),0(%2),%3\n"
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"8: jnz 1b\n"
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" j 5f\n"
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"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
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" "LHI" %3,-4096\n"
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" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 6f\n"
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"4: mvcs 0(%4,%1),0(%2),%3\n"
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"9:"SLR" %0,%4\n"
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" j 6f\n"
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"5:"SLR" %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
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EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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if (static_key_false(&have_mvcos))
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return copy_to_user_mvcos(to, from, n);
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return copy_to_user_mvcs(to, from, n);
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}
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EXPORT_SYMBOL(__copy_to_user);
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static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
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unsigned long size)
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{
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register unsigned long reg0 asm("0") = 0x810081UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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/* FIXME: copy with reduced length. */
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
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" jz 2f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2:"SLR" %0,%0\n"
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"3: \n"
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EX_TABLE(0b,3b)
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: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
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unsigned long size)
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{
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unsigned long tmp1;
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load_kernel_asce();
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asm volatile(
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" sacf 256\n"
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" "AHI" %0,-1\n"
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" jo 5f\n"
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" bras %3,3f\n"
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"0:"AHI" %0,257\n"
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"1: mvc 0(1,%1),0(%2)\n"
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" la %1,1(%1)\n"
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" la %2,1(%2)\n"
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" "AHI" %0,-1\n"
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" jnz 1b\n"
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" j 5f\n"
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"2: mvc 0(256,%1),0(%2)\n"
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" la %1,256(%1)\n"
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" la %2,256(%2)\n"
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"3:"AHI" %0,-256\n"
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" jnm 2b\n"
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"4: ex %0,1b-0b(%3)\n"
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"5: "SLR" %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
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: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
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: : "cc", "memory");
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return size;
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}
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unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
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{
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if (static_key_false(&have_mvcos))
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return copy_in_user_mvcos(to, from, n);
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return copy_in_user_mvc(to, from, n);
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}
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EXPORT_SYMBOL(__copy_in_user);
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static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
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{
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register unsigned long reg0 asm("0") = 0x810000UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
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" jz 4f\n"
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"1:"ALR" %0,%2\n"
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" "SLR" %1,%2\n"
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" j 0b\n"
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"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
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" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
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" "SLR" %3,%1\n"
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" "CLR" %0,%3\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
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" "SLR" %0,%3\n"
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" j 5f\n"
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"4:"SLR" %0,%0\n"
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"5:\n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b)
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: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
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: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
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return size;
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}
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static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
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{
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unsigned long tmp1, tmp2;
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load_kernel_asce();
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asm volatile(
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" sacf 256\n"
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" "AHI" %0,-1\n"
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" jo 5f\n"
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" bras %3,3f\n"
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" xc 0(1,%1),0(%1)\n"
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"0:"AHI" %0,257\n"
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" la %2,255(%1)\n" /* %2 = ptr + 255 */
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" srl %2,12\n"
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" sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
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" "SLR" %2,%1\n"
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" "CLR" %0,%2\n" /* clear crosses next page boundary? */
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" jnh 5f\n"
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" "AHI" %2,-1\n"
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"1: ex %2,0(%3)\n"
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" "AHI" %2,1\n"
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" "SLR" %0,%2\n"
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" j 5f\n"
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"2: xc 0(256,%1),0(%1)\n"
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" la %1,256(%1)\n"
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"3:"AHI" %0,-256\n"
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" jnm 2b\n"
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"4: ex %0,0(%3)\n"
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"5: "SLR" %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
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: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long __clear_user(void __user *to, unsigned long size)
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{
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if (static_key_false(&have_mvcos))
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return clear_user_mvcos(to, size);
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return clear_user_xc(to, size);
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}
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EXPORT_SYMBOL(__clear_user);
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static inline unsigned long strnlen_user_srst(const char __user *src,
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unsigned long size)
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{
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register unsigned long reg0 asm("0") = 0;
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unsigned long tmp1, tmp2;
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asm volatile(
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" la %2,0(%1)\n"
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" la %3,0(%0,%1)\n"
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" "SLR" %0,%0\n"
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" sacf 256\n"
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"0: srst %3,%2\n"
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" jo 0b\n"
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" la %0,1(%3)\n" /* strnlen_user results includes \0 */
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" "SLR" %0,%1\n"
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"1: sacf 768\n"
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EX_TABLE(0b,1b)
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: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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unsigned long __strnlen_user(const char __user *src, unsigned long size)
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{
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if (unlikely(!size))
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return 0;
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load_kernel_asce();
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return strnlen_user_srst(src, size);
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}
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EXPORT_SYMBOL(__strnlen_user);
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long __strncpy_from_user(char *dst, const char __user *src, long size)
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{
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size_t done, len, offset, len_str;
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if (unlikely(size <= 0))
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return 0;
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done = 0;
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do {
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offset = (size_t)src & ~PAGE_MASK;
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len = min(size - done, PAGE_SIZE - offset);
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if (copy_from_user(dst, src, len))
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return -EFAULT;
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len_str = strnlen(dst, len);
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done += len_str;
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src += len_str;
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dst += len_str;
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} while ((len_str == len) && (done < size));
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return done;
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}
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EXPORT_SYMBOL(__strncpy_from_user);
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/*
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* The "old" uaccess variant without mvcos can be enforced with the
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* uaccess_primary kernel parameter. This is mainly for debugging purposes.
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*/
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static int uaccess_primary __initdata;
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static int __init parse_uaccess_pt(char *__unused)
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{
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uaccess_primary = 1;
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return 0;
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}
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early_param("uaccess_primary", parse_uaccess_pt);
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static int __init uaccess_init(void)
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{
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if (IS_ENABLED(CONFIG_64BIT) && !uaccess_primary && test_facility(27))
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static_key_slow_inc(&have_mvcos);
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return 0;
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}
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early_initcall(uaccess_init);
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