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:
 "The main changes in this cycle were KASLR improvements for rare
  environments with special boot options, by Baoquan He. Also misc
  smaller changes/cleanups"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/debug: Extend the lower bound of crash kernel low reservations
  x86/boot: Remove unused copy_*_gs() functions
  x86/KASLR: Use the right memcpy() implementation
  Documentation/kernel-parameters.txt: Update 'memmap=' boot option description
  x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' boot options
  x86/KASLR: Parse all 'memmap=' boot option entries

Documentation/admin-guide/kernel-parameters.txt

@@ -2136,6 +2136,12 @@
 	memmap=nn[KMG]@ss[KMG]
 			[KNL] Force usage of a specific region of memory.
 			Region of memory to be used is from ss to ss+nn.
+			If @ss[KMG] is omitted, it is equivalent to mem=nn[KMG],
+			which limits max address to nn[KMG].
+			Multiple different regions can be specified,
+			comma delimited.
+			Example:
+				memmap=100M@2G,100M#3G,1G!1024G
 
 	memmap=nn[KMG]#ss[KMG]
 			[KNL,ACPI] Mark specific memory as ACPI data.
@@ -2148,6 +2154,9 @@
 			         memmap=64K$0x18690000
 			         or
 			         memmap=0x10000$0x18690000
+			Some bootloaders may need an escape character before '$',
+			like Grub2, otherwise '$' and the following number
+			will be eaten.
 
 	memmap=nn[KMG]!ss[KMG]
 			[KNL,X86] Mark specific memory as protected.

arch/x86/boot/compressed/cmdline.c

@@ -13,7 +13,7 @@ static inline char rdfs8(addr_t addr)
 	return *((char *)(fs + addr));
 }
 #include "../cmdline.c"
-static unsigned long get_cmd_line_ptr(void)
+unsigned long get_cmd_line_ptr(void)
 {
 	unsigned long cmd_line_ptr = boot_params->hdr.cmd_line_ptr;
 

arch/x86/boot/compressed/kaslr.c

@@ -9,16 +9,42 @@
  * contain the entire properly aligned running kernel image.
  *
  */
+
+/*
+ * isspace() in linux/ctype.h is expected by next_args() to filter
+ * out "space/lf/tab". While boot/ctype.h conflicts with linux/ctype.h,
+ * since isdigit() is implemented in both of them. Hence disable it
+ * here.
+ */
+#define BOOT_CTYPE_H
+
+/*
+ * _ctype[] in lib/ctype.c is needed by isspace() of linux/ctype.h.
+ * While both lib/ctype.c and lib/cmdline.c will bring EXPORT_SYMBOL
+ * which is meaningless and will cause compiling error in some cases.
+ * So do not include linux/export.h and define EXPORT_SYMBOL(sym)
+ * as empty.
+ */
+#define _LINUX_EXPORT_H
+#define EXPORT_SYMBOL(sym)
+
 #include "misc.h"
 #include "error.h"
-#include "../boot.h"
+#include "../string.h"
 
 #include <generated/compile.h>
 #include <linux/module.h>
 #include <linux/uts.h>
 #include <linux/utsname.h>
+#include <linux/ctype.h>
 #include <generated/utsrelease.h>
 
+/* Macros used by the included decompressor code below. */
+#define STATIC
+#include <linux/decompress/mm.h>
+
+extern unsigned long get_cmd_line_ptr(void);
+
 /* Simplified build-specific string for starting entropy. */
 static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
 		LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
@@ -62,6 +88,11 @@ struct mem_vector {
 
 static bool memmap_too_large;
 
+
+/* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */
+unsigned long long mem_limit = ULLONG_MAX;
+
+
 enum mem_avoid_index {
 	MEM_AVOID_ZO_RANGE = 0,
 	MEM_AVOID_INITRD,
@@ -85,49 +116,14 @@ static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two)
 	return true;
 }
 
-/**
- *	_memparse - Parse a string with mem suffixes into a number
- *	@ptr: Where parse begins
- *	@retptr: (output) Optional pointer to next char after parse completes
- *
- *	Parses a string into a number.  The number stored at @ptr is
- *	potentially suffixed with K, M, G, T, P, E.
- */
-static unsigned long long _memparse(const char *ptr, char **retptr)
+char *skip_spaces(const char *str)
 {
-	char *endptr;	/* Local pointer to end of parsed string */
-
-	unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
-
-	switch (*endptr) {
-	case 'E':
-	case 'e':
-		ret <<= 10;
-	case 'P':
-	case 'p':
-		ret <<= 10;
-	case 'T':
-	case 't':
-		ret <<= 10;
-	case 'G':
-	case 'g':
-		ret <<= 10;
-	case 'M':
-	case 'm':
-		ret <<= 10;
-	case 'K':
-	case 'k':
-		ret <<= 10;
-		endptr++;
-	default:
-		break;
-	}
-
-	if (retptr)
-		*retptr = endptr;
-
-	return ret;
+	while (isspace(*str))
+		++str;
+	return (char *)str;
 }
+#include "../../../../lib/ctype.c"
+#include "../../../../lib/cmdline.c"
 
 static int
 parse_memmap(char *p, unsigned long long *start, unsigned long long *size)
@@ -142,40 +138,41 @@ parse_memmap(char *p, unsigned long long *start, unsigned long long *size)
 		return -EINVAL;
 
 	oldp = p;
-	*size = _memparse(p, &p);
+	*size = memparse(p, &p);
 	if (p == oldp)
 		return -EINVAL;
 
 	switch (*p) {
-	case '@':
-		/* Skip this region, usable */
-		*start = 0;
-		*size = 0;
-		return 0;
 	case '#':
 	case '$':
 	case '!':
-		*start = _memparse(p + 1, &p);
+		*start = memparse(p + 1, &p);
+		return 0;
+	case '@':
+		/* memmap=nn@ss specifies usable region, should be skipped */
+		*size = 0;
+		/* Fall through */
+	default:
+		/*
+		 * If w/o offset, only size specified, memmap=nn[KMG] has the
+		 * same behaviour as mem=nn[KMG]. It limits the max address
+		 * system can use. Region above the limit should be avoided.
+		 */
+		*start = 0;
 		return 0;
 	}
 
 	return -EINVAL;
 }
 
-static void mem_avoid_memmap(void)
+static void mem_avoid_memmap(char *str)
 {
-	char arg[128];
+	static int i;
 	int rc;
-	int i;
-	char *str;
 
-	/* See if we have any memmap areas */
-	rc = cmdline_find_option("memmap", arg, sizeof(arg));
-	if (rc <= 0)
+	if (i >= MAX_MEMMAP_REGIONS)
 		return;
 
-	i = 0;
-	str = arg;
 	while (str && (i < MAX_MEMMAP_REGIONS)) {
 		int rc;
 		unsigned long long start, size;
@@ -188,9 +185,14 @@ static void mem_avoid_memmap(void)
 		if (rc < 0)
 			break;
 		str = k;
-		/* A usable region that should not be skipped */
-		if (size == 0)
+
+		if (start == 0) {
+			/* Store the specified memory limit if size > 0 */
+			if (size > 0)
+				mem_limit = size;
+
 			continue;
+		}
 
 		mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].start = start;
 		mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].size = size;
@@ -202,6 +204,57 @@ static void mem_avoid_memmap(void)
 		memmap_too_large = true;
 }
 
+static int handle_mem_memmap(void)
+{
+	char *args = (char *)get_cmd_line_ptr();
+	size_t len = strlen((char *)args);
+	char *tmp_cmdline;
+	char *param, *val;
+	u64 mem_size;
+
+	if (!strstr(args, "memmap=") && !strstr(args, "mem="))
+		return 0;
+
+	tmp_cmdline = malloc(len + 1);
+	if (!tmp_cmdline )
+		error("Failed to allocate space for tmp_cmdline");
+
+	memcpy(tmp_cmdline, args, len);
+	tmp_cmdline[len] = 0;
+	args = tmp_cmdline;
+
+	/* Chew leading spaces */
+	args = skip_spaces(args);
+
+	while (*args) {
+		args = next_arg(args, &param, &val);
+		/* Stop at -- */
+		if (!val && strcmp(param, "--") == 0) {
+			warn("Only '--' specified in cmdline");
+			free(tmp_cmdline);
+			return -1;
+		}
+
+		if (!strcmp(param, "memmap")) {
+			mem_avoid_memmap(val);
+		} else if (!strcmp(param, "mem")) {
+			char *p = val;
+
+			if (!strcmp(p, "nopentium"))
+				continue;
+			mem_size = memparse(p, &p);
+			if (mem_size == 0) {
+				free(tmp_cmdline);
+				return -EINVAL;
+			}
+			mem_limit = mem_size;
+		}
+	}
+
+	free(tmp_cmdline);
+	return 0;
+}
+
 /*
  * In theory, KASLR can put the kernel anywhere in the range of [16M, 64T).
  * The mem_avoid array is used to store the ranges that need to be avoided
@@ -323,7 +376,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 	/* We don't need to set a mapping for setup_data. */
 
 	/* Mark the memmap regions we need to avoid */
-	mem_avoid_memmap();
+	handle_mem_memmap();
 
 #ifdef CONFIG_X86_VERBOSE_BOOTUP
 	/* Make sure video RAM can be used. */
@@ -432,7 +485,8 @@ static void process_e820_entry(struct boot_e820_entry *entry,
 {
 	struct mem_vector region, overlap;
 	struct slot_area slot_area;
-	unsigned long start_orig;
+	unsigned long start_orig, end;
+	struct boot_e820_entry cur_entry;
 
 	/* Skip non-RAM entries. */
 	if (entry->type != E820_TYPE_RAM)
@@ -446,8 +500,15 @@ static void process_e820_entry(struct boot_e820_entry *entry,
 	if (entry->addr + entry->size < minimum)
 		return;
 
-	region.start = entry->addr;
-	region.size = entry->size;
+	/* Ignore entries above memory limit */
+	end = min(entry->size + entry->addr, mem_limit);
+	if (entry->addr >= end)
+		return;
+	cur_entry.addr = entry->addr;
+	cur_entry.size = end - entry->addr;
+
+	region.start = cur_entry.addr;
+	region.size = cur_entry.size;
 
 	/* Give up if slot area array is full. */
 	while (slot_area_index < MAX_SLOT_AREA) {
@@ -461,7 +522,7 @@ static void process_e820_entry(struct boot_e820_entry *entry,
 		region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN);
 
 		/* Did we raise the address above this e820 region? */
-		if (region.start > entry->addr + entry->size)
+		if (region.start > cur_entry.addr + cur_entry.size)
 			return;
 
 		/* Reduce size by any delta from the original address. */

arch/x86/boot/copy.S

@@ -65,23 +65,3 @@ GLOBAL(copy_to_fs)
 	popw	%es
 	retl
 ENDPROC(copy_to_fs)
-
-#if 0 /* Not currently used, but can be enabled as needed */
-GLOBAL(copy_from_gs)
-	pushw	%ds
-	pushw	%gs
-	popw	%ds
-	calll	memcpy
-	popw	%ds
-	retl
-ENDPROC(copy_from_gs)
-
-GLOBAL(copy_to_gs)
-	pushw	%es
-	pushw	%gs
-	popw	%es
-	calll	memcpy
-	popw	%es
-	retl
-ENDPROC(copy_to_gs)
-#endif

arch/x86/boot/string.c

@@ -122,6 +122,14 @@ unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int bas
 	return result;
 }
 
+long simple_strtol(const char *cp, char **endp, unsigned int base)
+{
+	if (*cp == '-')
+		return -simple_strtoull(cp + 1, endp, base);
+
+	return simple_strtoull(cp, endp, base);
+}
+
 /**
  * strlen - Find the length of a string
  * @s: The string to be sized

arch/x86/kernel/setup.c

@@ -503,7 +503,7 @@ static int __init reserve_crashkernel_low(void)
 			return 0;
 	}
 
-	low_base = memblock_find_in_range(low_size, 1ULL << 32, low_size, CRASH_ALIGN);
+	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
 	if (!low_base) {
 		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
 		       (unsigned long)(low_size >> 20));