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 | ||
