linux_dsm_epyc7002/arch/sparc/kernel/una_asm_32.S
Daniel Hellstrom 2492218c63 sparc32: unaligned memory access (MNA) trap handler bug
Since commit f0e98c387e ("[SPARC]: Fix
link errors with gcc-4.3") the MNA trap handler does not emulate
stores to unaligned addresses correctly. MNA operation from both
kernel and user space are affected.

A typical effect of this bug is nr_frags in skbs are overwritten
during buffer copying/checksum-calculation, or maximally 6 bytes
of data in the network buffer will be overwitten with garbage.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-01 12:39:59 -08:00

154 lines
2.9 KiB
ArmAsm

/* una_asm.S: Kernel unaligned trap assembler helpers.
*
* Copyright (C) 1996,2005,2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/errno.h>
.text
retl_efault:
retl
mov -EFAULT, %o0
/* int __do_int_store(unsigned long *dst_addr, int size,
* unsigned long *src_val)
*
* %o0 = dest_addr
* %o1 = size
* %o2 = src_val
*
* Return '0' on success, -EFAULT on failure.
*/
.globl __do_int_store
__do_int_store:
ld [%o2], %g1
cmp %o1, 2
be 2f
cmp %o1, 4
be 1f
srl %g1, 24, %g2
srl %g1, 16, %g7
4: stb %g2, [%o0]
srl %g1, 8, %g2
5: stb %g7, [%o0 + 1]
ld [%o2 + 4], %g7
6: stb %g2, [%o0 + 2]
srl %g7, 24, %g2
7: stb %g1, [%o0 + 3]
srl %g7, 16, %g1
8: stb %g2, [%o0 + 4]
srl %g7, 8, %g2
9: stb %g1, [%o0 + 5]
10: stb %g2, [%o0 + 6]
b 0f
11: stb %g7, [%o0 + 7]
1: srl %g1, 16, %g7
12: stb %g2, [%o0]
srl %g1, 8, %g2
13: stb %g7, [%o0 + 1]
14: stb %g2, [%o0 + 2]
b 0f
15: stb %g1, [%o0 + 3]
2: srl %g1, 8, %g2
16: stb %g2, [%o0]
17: stb %g1, [%o0 + 1]
0: retl
mov 0, %o0
.section __ex_table,#alloc
.word 4b, retl_efault
.word 5b, retl_efault
.word 6b, retl_efault
.word 7b, retl_efault
.word 8b, retl_efault
.word 9b, retl_efault
.word 10b, retl_efault
.word 11b, retl_efault
.word 12b, retl_efault
.word 13b, retl_efault
.word 14b, retl_efault
.word 15b, retl_efault
.word 16b, retl_efault
.word 17b, retl_efault
.previous
/* int do_int_load(unsigned long *dest_reg, int size,
* unsigned long *saddr, int is_signed)
*
* %o0 = dest_reg
* %o1 = size
* %o2 = saddr
* %o3 = is_signed
*
* Return '0' on success, -EFAULT on failure.
*/
.globl do_int_load
do_int_load:
cmp %o1, 8
be 9f
cmp %o1, 4
be 6f
4: ldub [%o2], %g1
5: ldub [%o2 + 1], %g2
sll %g1, 8, %g1
tst %o3
be 3f
or %g1, %g2, %g1
sll %g1, 16, %g1
sra %g1, 16, %g1
3: b 0f
st %g1, [%o0]
6: ldub [%o2 + 1], %g2
sll %g1, 24, %g1
7: ldub [%o2 + 2], %g7
sll %g2, 16, %g2
8: ldub [%o2 + 3], %g3
sll %g7, 8, %g7
or %g3, %g2, %g3
or %g7, %g3, %g7
or %g1, %g7, %g1
b 0f
st %g1, [%o0]
9: ldub [%o2], %g1
10: ldub [%o2 + 1], %g2
sll %g1, 24, %g1
11: ldub [%o2 + 2], %g7
sll %g2, 16, %g2
12: ldub [%o2 + 3], %g3
sll %g7, 8, %g7
or %g1, %g2, %g1
or %g7, %g3, %g7
or %g1, %g7, %g7
13: ldub [%o2 + 4], %g1
st %g7, [%o0]
14: ldub [%o2 + 5], %g2
sll %g1, 24, %g1
15: ldub [%o2 + 6], %g7
sll %g2, 16, %g2
16: ldub [%o2 + 7], %g3
sll %g7, 8, %g7
or %g1, %g2, %g1
or %g7, %g3, %g7
or %g1, %g7, %g7
st %g7, [%o0 + 4]
0: retl
mov 0, %o0
.section __ex_table,#alloc
.word 4b, retl_efault
.word 5b, retl_efault
.word 6b, retl_efault
.word 7b, retl_efault
.word 8b, retl_efault
.word 9b, retl_efault
.word 10b, retl_efault
.word 11b, retl_efault
.word 12b, retl_efault
.word 13b, retl_efault
.word 14b, retl_efault
.word 15b, retl_efault
.word 16b, retl_efault
.previous