x86/boot: Add kstrtoul() from lib/

Add kstrtoul() to ../boot/ to be used by facilities there too.

 [
   bp: Massage, make _kstrtoul() static. Prepend function names with
   "boot_". This is a temporary workaround for build errors like:

   ld: arch/x86/boot/compressed/acpi.o: in function `count_immovable_mem_regions':
   acpi.c:(.text+0x463): undefined reference to `_kstrtoul'
   make[2]: *** [arch/x86/boot/compressed/Makefile:117: arch/x86/boot/compressed/vmlinux] Error 1

   due to the namespace clash between x86/boot/ and kernel proper.
   Future reorg will get rid of the linux/linux/ namespace as much as
   possible so that x86/boot/ can be independent from kernel proper. ]

Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1587645588-7130-2-git-send-email-vamshi.k.sthambamkadi@gmail.com

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 8272a44..8a3fff9 100644 (file)
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -117,7 +117,6 @@ static unsigned int simple_guess_base(const char *cp)
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  */
-
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 {
        unsigned long long result = 0;
@@ -335,3 +334,45 @@ int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
                s++;
        return _kstrtoull(s, base, res);
 }
+
+static int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+       unsigned long long tmp;
+       int rv;
+
+       rv = kstrtoull(s, base, &tmp);
+       if (rv < 0)
+               return rv;
+       if (tmp != (unsigned long)tmp)
+               return -ERANGE;
+       *res = tmp;
+       return 0;
+}
+
+/**
+ * kstrtoul - convert a string to an unsigned 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 simple_strtoull.
+ */
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+       /*
+        * We want to shortcut function call, but
+        * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
+        */
+       if (sizeof(unsigned long) == sizeof(unsigned long long) &&
+           __alignof__(unsigned long) == __alignof__(unsigned long long))
+               return kstrtoull(s, base, (unsigned long long *)res);
+       else
+               return _kstrtoul(s, base, res);
+}

diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 38d8f2f..995f7b7 100644 (file)
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -30,4 +30,5 @@ 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);
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res);
 #endif /* BOOT_STRING_H */