diff options
Diffstat (limited to 'arch/cris/arch-v32/lib/csumcpfruser.S')
-rw-r--r-- | arch/cris/arch-v32/lib/csumcpfruser.S | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/lib/csumcpfruser.S b/arch/cris/arch-v32/lib/csumcpfruser.S new file mode 100644 index 000000000000..600ec16b9f28 --- /dev/null +++ b/arch/cris/arch-v32/lib/csumcpfruser.S | |||
@@ -0,0 +1,69 @@ | |||
1 | /* | ||
2 | * Add-on to transform csum_partial_copy_nocheck in checksumcopy.S into | ||
3 | * csum_partial_copy_from_user by adding exception records. | ||
4 | * | ||
5 | * Copyright (C) 2001, 2003 Axis Communications AB. | ||
6 | * | ||
7 | * Author: Hans-Peter Nilsson. | ||
8 | */ | ||
9 | |||
10 | #include <asm/errno.h> | ||
11 | |||
12 | /* Same function body, but a different name. If we just added exception | ||
13 | records to _csum_partial_copy_nocheck and made it generic, we wouldn't | ||
14 | know a user fault from a kernel fault and we would have overhead in | ||
15 | each kernel caller for the error-pointer argument. | ||
16 | |||
17 | unsigned int csum_partial_copy_from_user | ||
18 | (const char *src, char *dst, int len, unsigned int sum, int *errptr); | ||
19 | |||
20 | Note that the errptr argument is only set if we encounter an error. | ||
21 | It is conveniently located on the stack, so the normal function body | ||
22 | does not have to handle it. */ | ||
23 | |||
24 | #define csum_partial_copy_nocheck csum_partial_copy_from_user | ||
25 | |||
26 | /* There are local labels numbered 1, 2 and 3 present to mark the | ||
27 | different from-user accesses. */ | ||
28 | #include "checksumcopy.S" | ||
29 | |||
30 | .section .fixup,"ax" | ||
31 | |||
32 | ;; Here from the movem loop; restore stack. | ||
33 | 4: | ||
34 | movem [$sp+],$r8 | ||
35 | ;; r12 is already decremented. Add back chunk_size-2. | ||
36 | addq 40-2,$r12 | ||
37 | |||
38 | ;; Here from the word loop; r12 is off by 2; add it back. | ||
39 | 5: | ||
40 | addq 2,$r12 | ||
41 | |||
42 | ;; Here from a failing single byte. | ||
43 | 6: | ||
44 | |||
45 | ;; Signal in *errptr that we had a failing access. | ||
46 | move.d [$sp],$acr | ||
47 | moveq -EFAULT,$r9 | ||
48 | subq 4,$sp | ||
49 | move.d $r9,[$acr] | ||
50 | |||
51 | ;; Clear the rest of the destination area using memset. Preserve the | ||
52 | ;; checksum for the readable bytes. | ||
53 | move.d $r13,[$sp] | ||
54 | subq 4,$sp | ||
55 | move.d $r11,$r10 | ||
56 | move $srp,[$sp] | ||
57 | jsr memset | ||
58 | clear.d $r11 | ||
59 | |||
60 | move [$sp+],$srp | ||
61 | ret | ||
62 | move.d [$sp+],$r10 | ||
63 | |||
64 | .previous | ||
65 | .section __ex_table,"a" | ||
66 | .dword 1b,4b | ||
67 | .dword 2b,5b | ||
68 | .dword 3b,6b | ||
69 | .previous | ||