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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/arm/lib/strncpy_from_user.S | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/arm/lib/strncpy_from_user.S')
-rw-r--r-- | arch/arm/lib/strncpy_from_user.S | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm/lib/strncpy_from_user.S b/arch/arm/lib/strncpy_from_user.S new file mode 100644 index 00000000..f202d7bd --- /dev/null +++ b/arch/arm/lib/strncpy_from_user.S @@ -0,0 +1,43 @@ +/* + * linux/arch/arm/lib/strncpy_from_user.S + * + * Copyright (C) 1995-2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/errno.h> + + .text + .align 5 + +/* + * Copy a string from user space to kernel space. + * r0 = dst, r1 = src, r2 = byte length + * returns the number of characters copied (strlen of copied string), + * -EFAULT on exception, or "len" if we fill the whole buffer + */ +ENTRY(__strncpy_from_user) + mov ip, r1 +1: subs r2, r2, #1 + ldrusr r3, r1, 1, pl + bmi 2f + strb r3, [r0], #1 + teq r3, #0 + bne 1b + sub r1, r1, #1 @ take NUL character out of count +2: sub r0, r1, ip + mov pc, lr +ENDPROC(__strncpy_from_user) + + .pushsection .fixup,"ax" + .align 0 +9001: mov r3, #0 + strb r3, [r0, #0] @ null terminate + mov r0, #-EFAULT + mov pc, lr + .popsection + |