Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot updates from Ingo Molnar:
 "Most of the changes center around the difficult problem of KASLR
  pinning down hot-removable memory regions. At the very early stage
  KASRL is making irreversible kernel address layout decisions we don't
  have full knowledge about the memory maps yet.

  So the changes from Chao Fan add this (parsing the RSDP table early),
  together with fixes from Borislav Petkov"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed/64: Do not read legacy ROM on EFI system
  x86/boot: Correct RSDP parsing with 32-bit EFI
  x86/kexec: Fill in acpi_rsdp_addr from the first kernel
  x86/boot: Fix randconfig build error due to MEMORY_HOTREMOVE
  x86/boot: Fix cmdline_find_option() prototype visibility
  x86/boot/KASLR: Limit KASLR to extract the kernel in immovable memory only
  x86/boot: Parse SRAT table and count immovable memory regions
  x86/boot: Early parse RSDP and save it in boot_params
  x86/boot: Search for RSDP in memory
  x86/boot: Search for RSDP in the EFI tables
  x86/boot: Add "acpi_rsdp=" early parsing
  x86/boot: Copy kstrtoull() to boot/string.c
  x86/boot: Build the command line parsing code unconditionally

1 files changed, 141 insertions, 0 deletions

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index c4428a176973..315a67b8896b 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -13,10 +13,14 @@
  */
 
 #include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
 #include <asm/asm.h>
 #include "ctype.h"
 #include "string.h"
 
+#define KSTRTOX_OVERFLOW       (1U << 31)
+
 /*
  * Undef these macros so that the functions that we provide
  * here will have the correct names regardless of how string.h
@@ -187,3 +191,140 @@ 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;
+}
+
+static 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.
+ */
+static 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);
+}