d6bb7a1ad3
gcc 4.2.1 for MN10300 is more agressive than the older gcc in reordering/moving other insns between an insn that sets flags and an insn that uses those flags. This leads to trouble with asm statements which are missing an explicit "cc" clobber. This patch adds the explicit "cc" clobber to asm statements which do indeed clobber the condition flags. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
167 lines
3.5 KiB
C
167 lines
3.5 KiB
C
/* MN10300 Userspace accessor functions
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*
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* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <asm/uaccess.h>
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unsigned long
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__generic_copy_to_user(void *to, const void *from, unsigned long n)
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{
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if (access_ok(VERIFY_WRITE, to, n))
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__copy_user(to, from, n);
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return n;
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}
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unsigned long
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__generic_copy_from_user(void *to, const void *from, unsigned long n)
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{
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if (access_ok(VERIFY_READ, from, n))
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__copy_user_zeroing(to, from, n);
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return n;
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}
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/*
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* Copy a null terminated string from userspace.
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*/
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#define __do_strncpy_from_user(dst, src, count, res) \
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do { \
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int w; \
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asm volatile( \
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" mov %1,%0\n" \
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" cmp 0,%1\n" \
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" beq 2f\n" \
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"0:\n" \
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" movbu (%5),%2\n" \
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"1:\n" \
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" movbu %2,(%6)\n" \
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" inc %5\n" \
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" inc %6\n" \
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" cmp 0,%2\n" \
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" beq 2f\n" \
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" add -1,%1\n" \
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" bne 0b\n" \
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"2:\n" \
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" sub %1,%0\n" \
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"3:\n" \
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" .section .fixup,\"ax\"\n" \
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"4:\n" \
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" mov %3,%0\n" \
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" jmp 3b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,4b\n" \
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" .long 1b,4b\n" \
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" .previous" \
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:"=&r"(res), "=r"(count), "=&r"(w) \
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:"i"(-EFAULT), "1"(count), "a"(src), "a"(dst) \
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: "memory", "cc"); \
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} while (0)
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long
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__strncpy_from_user(char *dst, const char *src, long count)
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{
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long res;
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__do_strncpy_from_user(dst, src, count, res);
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return res;
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}
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long
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strncpy_from_user(char *dst, const char *src, long count)
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{
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long res = -EFAULT;
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if (access_ok(VERIFY_READ, src, 1))
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__do_strncpy_from_user(dst, src, count, res);
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return res;
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}
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/*
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* Clear a userspace memory
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*/
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#define __do_clear_user(addr, size) \
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do { \
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int w; \
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asm volatile( \
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" cmp 0,%0\n" \
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" beq 1f\n" \
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" clr %1\n" \
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"0: movbu %1,(%3,%2)\n" \
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" inc %3\n" \
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" cmp %0,%3\n" \
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" bne 0b\n" \
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"1:\n" \
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" sub %3,%0\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3: jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n" \
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" .balign 4\n" \
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" .long 0b,3b\n" \
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".previous\n" \
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: "+r"(size), "=&r"(w) \
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: "a"(addr), "d"(0) \
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: "memory", "cc"); \
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} while (0)
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unsigned long
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__clear_user(void *to, unsigned long n)
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{
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__do_clear_user(to, n);
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return n;
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}
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unsigned long
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clear_user(void *to, unsigned long n)
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{
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if (access_ok(VERIFY_WRITE, to, n))
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__do_clear_user(to, n);
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return n;
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}
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/*
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* Return the size of a string (including the ending 0)
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*
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* Return 0 on exception, a value greater than N if too long
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*/
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long strnlen_user(const char *s, long n)
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{
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unsigned long res, w;
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if (!__addr_ok(s))
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return 0;
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if (n < 0 || n + (u_long) s > current_thread_info()->addr_limit.seg)
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n = current_thread_info()->addr_limit.seg - (u_long)s;
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asm volatile(
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"0: cmp %4,%0\n"
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" beq 2f\n"
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"1: movbu (%0,%3),%1\n"
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" inc %0\n"
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" cmp 0,%1\n"
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" beq 3f\n"
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" bra 0b\n"
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"2: clr %0\n"
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"3:\n"
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".section .fixup,\"ax\"\n"
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"4: jmp 2b\n"
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".previous\n"
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".section __ex_table,\"a\"\n"
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" .balign 4\n"
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" .long 1b,4b\n"
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".previous\n"
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:"=d"(res), "=&r"(w)
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:"0"(0), "a"(s), "r"(n)
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: "memory", "cc");
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return res;
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}
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