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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/arch-v10/lib/csumcpfruser.S | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/cris/arch-v10/lib/csumcpfruser.S')
-rw-r--r-- | arch/cris/arch-v10/lib/csumcpfruser.S | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/lib/csumcpfruser.S b/arch/cris/arch-v10/lib/csumcpfruser.S new file mode 100644 index 000000000000..5f41ccd62754 --- /dev/null +++ b/arch/cris/arch-v10/lib/csumcpfruser.S @@ -0,0 +1,64 @@ +/* + * Add-on to transform csum_partial_copy_nocheck in checksumcopy.S into + * csum_partial_copy_from_user by adding exception records. + * + * Copyright (C) 2001 Axis Communications AB. + * + * Author: Hans-Peter Nilsson. + */ + +#include <asm/errno.h> + +/* Same function body, but a different name. If we just added exception + records to _csum_partial_copy_nocheck and made it generic, we wouldn't + know a user fault from a kernel fault and we would have overhead in + each kernel caller for the error-pointer argument. + + unsigned int csum_partial_copy_from_user + (const char *src, char *dst, int len, unsigned int sum, int *errptr); + + Note that the errptr argument is only set if we encounter an error. + It is conveniently located on the stack, so the normal function body + does not have to handle it. */ + +#define csum_partial_copy_nocheck csum_partial_copy_from_user + +/* There are local labels numbered 1, 2 and 3 present to mark the + different from-user accesses. */ +#include "checksumcopy.S" + + .section .fixup,"ax" + +;; Here from the movem loop; restore stack. +4: + movem [$sp+],$r8 +;; r12 is already decremented. Add back chunk_size-2. + addq 40-2,$r12 + +;; Here from the word loop; r12 is off by 2; add it back. +5: + addq 2,$r12 + +;; Here from a failing single byte. +6: + +;; Signal in *errptr that we had a failing access. + moveq -EFAULT,$r9 + move.d $r9,[[$sp]] + +;; Clear the rest of the destination area using memset. Preserve the +;; checksum for the readable bytes. + push $srp + push $r13 + move.d $r11,$r10 + clear.d $r11 + jsr memset + pop $r10 + jump [$sp+] + + .previous + .section __ex_table,"a" + .dword 1b,4b + .dword 2b,5b + .dword 3b,6b + .previous |