mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-27 13:05:03 +08:00
56e62a7370
This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.
There are a few special things on s390:
- PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't
know about our PIF flags in exit_to_user_mode_loop().
- The old code had several ways to restart syscalls:
a) PIF_SYSCALL_RESTART, which was only set during execve to force a
restart after upgrading a process (usually qemu-kvm) to pgste page
table extensions.
b) PIF_SYSCALL, which is set by do_signal() to indicate that the
current syscall should be restarted. This is changed so that
do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use
PIF_SYSCALL doesn't work with the generic code, and changing it
to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART
more unique.
- On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by
executing a svc instruction on the process stack which causes a fault.
While handling that fault the fault code sets PIF_SYSCALL to hand over
processing to the syscall code on exit to usermode.
The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets
a return value for a syscall. The s390x ptrace ABI uses r2 both for the
syscall number and return value, so ptrace cannot set the syscall number +
return value at the same time. The flag makes handling that a bit easier.
do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET
is set.
CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY.
CR1/7/13 will be checked both on kernel entry and exit to contain the
correct asces.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
388 lines
9.8 KiB
C
388 lines
9.8 KiB
C
// 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>
|
|
|
|
#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 */
|
|
|
|
#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
|
|
|
|
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"
|
|
"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;
|
|
|
|
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");
|
|
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") = 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: 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;
|
|
|
|
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");
|
|
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") = 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: 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)
|
|
{
|
|
unsigned long tmp1;
|
|
|
|
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");
|
|
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") = 0x810000UL;
|
|
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)
|
|
{
|
|
unsigned long tmp1, tmp2;
|
|
|
|
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");
|
|
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)
|
|
{
|
|
if (unlikely(!size))
|
|
return 0;
|
|
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 & (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);
|