Messages in this thread | | | Date | Wed, 12 Dec 2018 16:10:32 +0800 | From | Chao Fan <> | Subject | Re: [PATCH v13 1/6] x86/boot: Introduce kstrtoull() to boot directory instead of simple_strtoull() |
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On Wed, Dec 12, 2018 at 03:46:15PM +0800, Baoquan He wrote: >On 12/12/18 at 11:10am, Chao Fan wrote: >> Introduce kstrtoull() from lib/kstrtox.c to boot directory so that code > >It's not introducing kstrtoull(), just copying kstrtoull() from >lib/kstrtox.c to boot.
Oops, maybe I misunderstand 'introduce'.
Thanks, Chao Fan
> >> in boot/ can use kstrtoull() and the old simple_strtoull() can be >> replaced. >> >> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> >> --- >> arch/x86/boot/string.c | 137 +++++++++++++++++++++++++++++++++++++++++ >> arch/x86/boot/string.h | 2 + >> 2 files changed, 139 insertions(+) >> >> diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c >> index c4428a176973..e02405f20f98 100644 >> --- a/arch/x86/boot/string.c >> +++ b/arch/x86/boot/string.c >> @@ -12,7 +12,10 @@ >> * Very basic string functions >> */ >> >> +#define _LINUX_CTYPE_H >> #include <linux/types.h> >> +#include <linux/kernel.h> >> +#include <linux/errno.h> >> #include <asm/asm.h> >> #include "ctype.h" >> #include "string.h" >> @@ -187,3 +190,137 @@ char *strchr(const char *s, int c) >> return NULL; >> return (char *)s; >> } >> + >> +static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) >> +{ >> + union { >> + u64 v64; >> + u32 v32[2]; >> + } d = { dividend }; >> + u32 upper; >> + >> + upper = d.v32[1]; >> + d.v32[1] = 0; >> + if (upper >= divisor) { >> + d.v32[1] = upper / divisor; >> + upper %= divisor; >> + } >> + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : >> + "rm" (divisor), "0" (d.v32[0]), "1" (upper)); >> + return d.v64; >> +} >> + >> +static inline u64 div_u64(u64 dividend, u32 divisor) >> +{ >> + u32 remainder; >> + return div_u64_rem(dividend, divisor, &remainder); >> +} >> + >> +static inline char _tolower(const char c) >> +{ >> + return c | 0x20; >> +} >> + >> +const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) >> +{ >> + if (*base == 0) { >> + if (s[0] == '0') { >> + if (_tolower(s[1]) == 'x' && isxdigit(s[2])) >> + *base = 16; >> + else >> + *base = 8; >> + } else >> + *base = 10; >> + } >> + if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') >> + s += 2; >> + return s; >> +} >> + >> +/* >> + * Convert non-negative integer string representation in explicitly given radix >> + * to an integer. >> + * Return number of characters consumed maybe or-ed with overflow bit. >> + * If overflow occurs, result integer (incorrect) is still returned. >> + * >> + * Don't you dare use this function. >> + */ >> +unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) >> +{ >> + unsigned long long res; >> + unsigned int rv; >> + >> + res = 0; >> + rv = 0; >> + while (1) { >> + unsigned int c = *s; >> + unsigned int lc = c | 0x20; /* don't tolower() this line */ >> + unsigned int val; >> + >> + if ('0' <= c && c <= '9') >> + val = c - '0'; >> + else if ('a' <= lc && lc <= 'f') >> + val = lc - 'a' + 10; >> + else >> + break; >> + >> + if (val >= base) >> + break; >> + /* >> + * Check for overflow only if we are within range of >> + * it in the max base we support (16) >> + */ >> + if (unlikely(res & (~0ull << 60))) { >> + if (res > div_u64(ULLONG_MAX - val, base)) >> + rv |= KSTRTOX_OVERFLOW; >> + } >> + res = res * base + val; >> + rv++; >> + s++; >> + } >> + *p = res; >> + return rv; >> +} >> + >> +static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) >> +{ >> + unsigned long long _res; >> + unsigned int rv; >> + >> + s = _parse_integer_fixup_radix(s, &base); >> + rv = _parse_integer(s, base, &_res); >> + if (rv & KSTRTOX_OVERFLOW) >> + return -ERANGE; >> + if (rv == 0) >> + return -EINVAL; >> + s += rv; >> + if (*s == '\n') >> + s++; >> + if (*s) >> + return -EINVAL; >> + *res = _res; >> + return 0; >> +} >> + >> +/** >> + * kstrtoull - convert a string to an unsigned long long >> + * @s: The start of the string. The string must be null-terminated, and may also >> + * include a single newline before its terminating null. The first character >> + * may also be a plus sign, but not a minus sign. >> + * @base: The number base to use. The maximum supported base is 16. If base is >> + * given as 0, then the base of the string is automatically detected with the >> + * conventional semantics - If it begins with 0x the number will be parsed as a >> + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be >> + * parsed as an octal number. Otherwise it will be parsed as a decimal. >> + * @res: Where to write the result of the conversion on success. >> + * >> + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. >> + * Used as a replacement for the obsolete simple_strtoull. Return code must >> + * be checked. >> + */ >> +int kstrtoull(const char *s, unsigned int base, unsigned long long *res) >> +{ >> + if (s[0] == '+') >> + s++; >> + return _kstrtoull(s, base, res); >> +} >> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h >> index 3d78e27077f4..171007c99acc 100644 >> --- a/arch/x86/boot/string.h >> +++ b/arch/x86/boot/string.h >> @@ -29,4 +29,6 @@ extern unsigned int atou(const char *s); >> extern unsigned long long simple_strtoull(const char *cp, char **endp, >> unsigned int base); >> >> +int kstrtoull(const char *s, unsigned int base, unsigned long long *res); >> +#define KSTRTOX_OVERFLOW (1U << 31) >> #endif /* BOOT_STRING_H */ >> -- >> 2.19.2 >> >> >> > >
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