diff options
25 files changed, 188 insertions, 37 deletions
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index 7611b10..0b10ef2 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -48,4 +48,5 @@ generic-y += types.h generic-y += ucontext.h generic-y += user.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/avr32/include/asm/Kbuild b/arch/avr32/include/asm/Kbuild index f61f2dd..241b9b9 100644 --- a/arch/avr32/include/asm/Kbuild +++ b/arch/avr32/include/asm/Kbuild @@ -20,4 +20,5 @@ generic-y += sections.h generic-y += topology.h generic-y += trace_clock.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/blackfin/include/asm/Kbuild b/arch/blackfin/include/asm/Kbuild index 61cd1e7..91d49c0 100644 --- a/arch/blackfin/include/asm/Kbuild +++ b/arch/blackfin/include/asm/Kbuild @@ -46,4 +46,5 @@ generic-y += types.h generic-y += ucontext.h generic-y += unaligned.h generic-y += user.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild index f17c4dc..945544e 100644 --- a/arch/c6x/include/asm/Kbuild +++ b/arch/c6x/include/asm/Kbuild @@ -59,4 +59,5 @@ generic-y += types.h generic-y += ucontext.h generic-y += user.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild index b7f6819..1778805 100644 --- a/arch/cris/include/asm/Kbuild +++ b/arch/cris/include/asm/Kbuild @@ -43,4 +43,5 @@ generic-y += topology.h generic-y += trace_clock.h generic-y += types.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/frv/include/asm/Kbuild b/arch/frv/include/asm/Kbuild index 8e47b83..1fa084c 100644 --- a/arch/frv/include/asm/Kbuild +++ b/arch/frv/include/asm/Kbuild @@ -7,3 +7,4 @@ generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += trace_clock.h +generic-y += word-at-a-time.h diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index daee37b..db8ddab 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -58,4 +58,5 @@ generic-y += types.h generic-y += ucontext.h generic-y += unaligned.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild index 9de3ba1..502a91d 100644 --- a/arch/ia64/include/asm/Kbuild +++ b/arch/ia64/include/asm/Kbuild @@ -8,3 +8,4 @@ generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += trace_clock.h generic-y += vtime.h +generic-y += word-at-a-time.h diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild index e0eb704..fd104bd 100644 --- a/arch/m32r/include/asm/Kbuild +++ b/arch/m32r/include/asm/Kbuild @@ -9,3 +9,4 @@ generic-y += module.h generic-y += preempt.h generic-y += sections.h generic-y += trace_clock.h +generic-y += word-at-a-time.h diff --git a/arch/metag/include/asm/Kbuild b/arch/metag/include/asm/Kbuild index df31353..29acb89d 100644 --- a/arch/metag/include/asm/Kbuild +++ b/arch/metag/include/asm/Kbuild @@ -54,4 +54,5 @@ generic-y += ucontext.h generic-y += unaligned.h generic-y += user.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild index 2f222f3..b0ae88c 100644 --- a/arch/microblaze/include/asm/Kbuild +++ b/arch/microblaze/include/asm/Kbuild @@ -10,3 +10,4 @@ generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += syscalls.h generic-y += trace_clock.h +generic-y += word-at-a-time.h diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild index 40ec4ca..c7fe4d0 100644 --- a/arch/mips/include/asm/Kbuild +++ b/arch/mips/include/asm/Kbuild @@ -17,4 +17,5 @@ generic-y += segment.h generic-y += serial.h generic-y += trace_clock.h generic-y += user.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild index 6edb9ee..1c8dd0f 100644 --- a/arch/mn10300/include/asm/Kbuild +++ b/arch/mn10300/include/asm/Kbuild @@ -9,3 +9,4 @@ generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += sections.h generic-y += trace_clock.h +generic-y += word-at-a-time.h diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild index 914864e..d63330e 100644 --- a/arch/nios2/include/asm/Kbuild +++ b/arch/nios2/include/asm/Kbuild @@ -61,4 +61,5 @@ generic-y += types.h generic-y += unaligned.h generic-y += user.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index ab9f4e0..ac16629 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -7,3 +7,4 @@ generic-y += mcs_spinlock.h generic-y += preempt.h generic-y += rwsem.h generic-y += vtime.h +generic-y += word-at-a-time.h diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index 5ad26dd..9043d2e 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -6,3 +6,4 @@ generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += trace_clock.h +generic-y += word-at-a-time.h diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild index 92ffe39..a05218f 100644 --- a/arch/score/include/asm/Kbuild +++ b/arch/score/include/asm/Kbuild @@ -13,3 +13,4 @@ generic-y += sections.h generic-y += trace_clock.h generic-y += xor.h generic-y += serial.h +generic-y += word-at-a-time.h diff --git a/arch/tile/gxio/mpipe.c b/arch/tile/gxio/mpipe.c index ee186e1..f102048 100644 --- a/arch/tile/gxio/mpipe.c +++ b/arch/tile/gxio/mpipe.c @@ -19,6 +19,7 @@ #include <linux/errno.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/string.h> #include <gxio/iorpc_globals.h> #include <gxio/iorpc_mpipe.h> @@ -29,32 +30,6 @@ /* HACK: Avoid pointless "shadow" warnings. */ #define link link_shadow -/** - * strscpy - Copy a C-string into a sized buffer, but only if it fits - * @dest: Where to copy the string to - * @src: Where to copy the string from - * @size: size of destination buffer - * - * Use this routine to avoid copying too-long strings. - * The routine returns the total number of bytes copied - * (including the trailing NUL) or zero if the buffer wasn't - * big enough. To ensure that programmers pay attention - * to the return code, the destination has a single NUL - * written at the front (if size is non-zero) when the - * buffer is not big enough. - */ -static size_t strscpy(char *dest, const char *src, size_t size) -{ - size_t len = strnlen(src, size) + 1; - if (len > size) { - if (size) - dest[0] = '\0'; - return 0; - } - memcpy(dest, src, len); - return len; -} - int gxio_mpipe_init(gxio_mpipe_context_t *context, unsigned int mpipe_index) { char file[32]; @@ -540,7 +515,7 @@ int gxio_mpipe_link_instance(const char *link_name) if (!context) return GXIO_ERR_NO_DEVICE; - if (strscpy(name.name, link_name, sizeof(name.name)) == 0) + if (strscpy(name.name, link_name, sizeof(name.name)) < 0) return GXIO_ERR_NO_DEVICE; return gxio_mpipe_info_instance_aux(context, name); @@ -559,7 +534,7 @@ int gxio_mpipe_link_enumerate_mac(int idx, char *link_name, uint8_t *link_mac) rv = gxio_mpipe_info_enumerate_aux(context, idx, &name, &mac); if (rv >= 0) { - if (strscpy(link_name, name.name, sizeof(name.name)) == 0) + if (strscpy(link_name, name.name, sizeof(name.name)) < 0) return GXIO_ERR_INVAL_MEMORY_SIZE; memcpy(link_mac, mac.mac, sizeof(mac.mac)); } @@ -576,7 +551,7 @@ int gxio_mpipe_link_open(gxio_mpipe_link_t *link, _gxio_mpipe_link_name_t name; int rv; - if (strscpy(name.name, link_name, sizeof(name.name)) == 0) + if (strscpy(name.name, link_name, sizeof(name.name)) < 0) return GXIO_ERR_NO_DEVICE; rv = gxio_mpipe_link_open_aux(context, name, flags); diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild index ba35c41..0b6cacaa 100644 --- a/arch/tile/include/asm/Kbuild +++ b/arch/tile/include/asm/Kbuild @@ -40,4 +40,5 @@ generic-y += termbits.h generic-y += termios.h generic-y += trace_clock.h generic-y += types.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index 149ec55..904f3eb 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -25,4 +25,5 @@ generic-y += preempt.h generic-y += switch_to.h generic-y += topology.h generic-y += trace_clock.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild index 1fc7a28..256c45b 100644 --- a/arch/unicore32/include/asm/Kbuild +++ b/arch/unicore32/include/asm/Kbuild @@ -62,4 +62,5 @@ generic-y += ucontext.h generic-y += unaligned.h generic-y += user.h generic-y += vga.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index 63c223d..b56855a 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -28,4 +28,5 @@ generic-y += statfs.h generic-y += termios.h generic-y += topology.h generic-y += trace_clock.h +generic-y += word-at-a-time.h generic-y += xor.h diff --git a/include/asm-generic/word-at-a-time.h b/include/asm-generic/word-at-a-time.h index 94f9ea8..011dde0 100644 --- a/include/asm-generic/word-at-a-time.h +++ b/include/asm-generic/word-at-a-time.h @@ -1,15 +1,10 @@ #ifndef _ASM_WORD_AT_A_TIME_H #define _ASM_WORD_AT_A_TIME_H -/* - * This says "generic", but it's actually big-endian only. - * Little-endian can use more efficient versions of these - * interfaces, see for example - * arch/x86/include/asm/word-at-a-time.h - * for those. - */ - #include <linux/kernel.h> +#include <asm/byteorder.h> + +#ifdef __BIG_ENDIAN struct word_at_a_time { const unsigned long high_bits, low_bits; @@ -53,4 +48,73 @@ static inline bool has_zero(unsigned long val, unsigned long *data, const struct #define zero_bytemask(mask) (~1ul << __fls(mask)) #endif +#else + +/* + * The optimal byte mask counting is probably going to be something + * that is architecture-specific. If you have a reliably fast + * bit count instruction, that might be better than the multiply + * and shift, for example. + */ +struct word_at_a_time { + const unsigned long one_bits, high_bits; +}; + +#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } + +#ifdef CONFIG_64BIT + +/* + * Jan Achrenius on G+: microoptimized version of + * the simpler "(mask & ONEBYTES) * ONEBYTES >> 56" + * that works for the bytemasks without having to + * mask them first. + */ +static inline long count_masked_bytes(unsigned long mask) +{ + return mask*0x0001020304050608ul >> 56; +} + +#else /* 32-bit case */ + +/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */ +static inline long count_masked_bytes(long mask) +{ + /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */ + long a = (0x0ff0001+mask) >> 23; + /* Fix the 1 for 00 case */ + return a & mask; +} + +#endif + +/* Return nonzero if it has a zero */ +static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c) +{ + unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits; + *bits = mask; + return mask; +} + +static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c) +{ + return bits; +} + +static inline unsigned long create_zero_mask(unsigned long bits) +{ + bits = (bits - 1) & ~bits; + return bits >> 7; +} + +/* The mask we created is directly usable as a bytemask */ +#define zero_bytemask(mask) (mask) + +static inline unsigned long find_zero(unsigned long mask) +{ + return count_masked_bytes(mask); +} + +#endif /* __BIG_ENDIAN */ + #endif /* _ASM_WORD_AT_A_TIME_H */ diff --git a/include/linux/string.h b/include/linux/string.h index a8d90db..9ef7795 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -25,6 +25,9 @@ extern char * strncpy(char *,const char *, __kernel_size_t); #ifndef __HAVE_ARCH_STRLCPY size_t strlcpy(char *, const char *, size_t); #endif +#ifndef __HAVE_ARCH_STRSCPY +ssize_t __must_check strscpy(char *, const char *, size_t); +#endif #ifndef __HAVE_ARCH_STRCAT extern char * strcat(char *, const char *); #endif diff --git a/lib/string.c b/lib/string.c index 13d1e84..8dbb7b1 100644 --- a/lib/string.c +++ b/lib/string.c @@ -27,6 +27,10 @@ #include <linux/bug.h> #include <linux/errno.h> +#include <asm/byteorder.h> +#include <asm/word-at-a-time.h> +#include <asm/page.h> + #ifndef __HAVE_ARCH_STRNCASECMP /** * strncasecmp - Case insensitive, length-limited string comparison @@ -146,6 +150,90 @@ size_t strlcpy(char *dest, const char *src, size_t size) EXPORT_SYMBOL(strlcpy); #endif +#ifndef __HAVE_ARCH_STRSCPY +/** + * strscpy - Copy a C-string into a sized buffer + * @dest: Where to copy the string to + * @src: Where to copy the string from + * @count: Size of destination buffer + * + * Copy the string, or as much of it as fits, into the dest buffer. + * The routine returns the number of characters copied (not including + * the trailing NUL) or -E2BIG if the destination buffer wasn't big enough. + * The behavior is undefined if the string buffers overlap. + * The destination buffer is always NUL terminated, unless it's zero-sized. + * + * Preferred to strlcpy() since the API doesn't require reading memory + * from the src string beyond the specified "count" bytes, and since + * the return value is easier to error-check than strlcpy()'s. + * In addition, the implementation is robust to the string changing out + * from underneath it, unlike the current strlcpy() implementation. + * + * Preferred to strncpy() since it always returns a valid string, and + * doesn't unnecessarily force the tail of the destination buffer to be + * zeroed. If the zeroing is desired, it's likely cleaner to use strscpy() + * with an overflow test, then just memset() the tail of the dest buffer. + */ +ssize_t strscpy(char *dest, const char *src, size_t count) +{ + const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; + size_t max = count; + long res = 0; + + if (count == 0) + return -E2BIG; + +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + /* + * If src is unaligned, don't cross a page boundary, + * since we don't know if the next page is mapped. + */ + if ((long)src & (sizeof(long) - 1)) { + size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1)); + if (limit < max) + max = limit; + } +#else + /* If src or dest is unaligned, don't do word-at-a-time. */ + if (((long) dest | (long) src) & (sizeof(long) - 1)) + max = 0; +#endif + + while (max >= sizeof(unsigned long)) { + unsigned long c, data; + + c = *(unsigned long *)(src+res); + *(unsigned long *)(dest+res) = c; + if (has_zero(c, &data, &constants)) { + data = prep_zero_mask(c, data, &constants); + data = create_zero_mask(data); + return res + find_zero(data); + } + res += sizeof(unsigned long); + count -= sizeof(unsigned long); + max -= sizeof(unsigned long); + } + + while (count) { + char c; + + c = src[res]; + dest[res] = c; + if (!c) + return res; + res++; + count--; + } + + /* Hit buffer length without finding a NUL; force NUL-termination. */ + if (res) + dest[res-1] = '\0'; + + return -E2BIG; +} +EXPORT_SYMBOL(strscpy); +#endif + #ifndef __HAVE_ARCH_STRCAT /** * strcat - Append one %NUL-terminated string to another |
