Messages in this thread | | | Date | Thu, 10 Jan 2019 09:15:59 +0800 | From | Chao Fan <> | Subject | Re: [PATCH v15 1/6] x86/boot: Copy kstrtoull() to boot/string.c instead of using simple_strtoull() |
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On Wed, Jan 09, 2019 at 01:48:53PM +0100, Borislav Petkov wrote: >On Mon, Jan 07, 2019 at 11:22:38AM +0800, Chao Fan wrote: >> Copy kstrtoull() and necessary functions from lib/kstrtox.c to >> boot/string.c so that code in boot/ can use kstrtoull() and the old >> simple_strtoull() can be replaced. >> >> In boot/string.c, using div_u64() from math64.h directly will cause the >> dividend handled as 64-bit value and bring ld error. The solution is to >> separate the dividend to upper and lower in boot/string.o. So copy the >> useful div_u64() and div_u64_rem() to boot/string.c also. To avoid >> redefinition in i386, rename them as __div_u64() and __div_u64_rem(). >> >> 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(+) > >... > >> +static inline char _tolower(const char c) >> +{ >> + return c | 0x20; >> +} >> + >> +const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) > >static
Will add it.
> >> +{ >> + 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) > >static
Will add it.
Thanks, Chao Fan
> >> +{ >> + 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; >> +} > > >-- >Regards/Gruss, > Boris. > >Good mailing practices for 400: avoid top-posting and trim the reply. > >
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