[PATCH v9 2/8] x86/boot: Copy kstrtoull() to compressed period

Chao Fan
2018-10-17T10:20:06Z

Copy kstrtoull() to 'compressed' directory so that
we can use it to change the address in cmdline from
string to unsigned long long.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/misc.c | 88 +++++++++++++++++++++++++++++++++
arch/x86/boot/compressed/misc.h | 4 ++
2 files changed, 92 insertions(+)

diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 8dd1d5ccae58..5b9b24949337 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -426,3 +426,91 @@ void fortify_panic(const char *name)
{
error("detected buffer overflow");
}
+
+#define KSTRTOX_OVERFLOW (1U << 31)
+
+static inline char _tolower(const char c)
+{
+ return c | 0x20;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 008fdc47a29c..40378408d980 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -63,6 +63,10 @@ static inline void debug_puthex(const char *s)

#endif

+#if (defined CONFIG_RANDOMIZE_BASE) && (defined CONFIG_RANDOMIZE_BASE)
+int kstrtoull(const char *s, unsigned int base, unsigned long long *res);
+#endif
+
#if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
/* cmdline.c */
int cmdline_find_option(const char *option, char *buffer, int bufsize);
--
2.17.2