Commit b9b8e5b7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull x86 boot updates from Thomas Gleixner:
 "Boot code updates for x86:

   - Allow to skip a given amount of huge pages for address layout
     randomization on the kernel command line to prevent regressions in
     the huge page allocation with small memory sizes

   - Various cleanups"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Use CC_SET()/CC_OUT() instead of open coding it
  x86/boot/KASLR: Make local variable mem_limit static
  x86/boot/KASLR: Skip specified number of 1GB huge pages when doing physical randomization (KASLR)
  x86/boot/KASLR: Add two new functions for 1GB huge pages handling
parents 66e22087 216a3720

arch/x86/boot/bitops.h

+2 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#define _LINUX_BITOPS_H		/* Inhibit inclusion of <linux/bitops.h> */



#include <linux/types.h>

#include <asm/asm.h>



static inline bool constant_test_bit(int nr, const void *addr)

{
@@ -28,7 +29,7 @@ static inline bool variable_test_bit(int nr, const void *addr) 
	bool v;

	const u32 *p = (const u32 *)addr;



	asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));

	asm("btl %2,%1" CC_SET(c) : CC_OUT(c) (v) : "m" (*p), "Ir" (nr));

	return v;

}

arch/x86/boot/compressed/kaslr.c

+92 −6
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ static bool memmap_too_large; 




/* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */

unsigned long long mem_limit = ULLONG_MAX;

static unsigned long long mem_limit = ULLONG_MAX;





enum mem_avoid_index {
@@ -215,7 +215,36 @@ static void mem_avoid_memmap(char *str) 
		memmap_too_large = true;

}



static int handle_mem_memmap(void)

/* Store the number of 1GB huge pages which users specified: */

static unsigned long max_gb_huge_pages;



static void parse_gb_huge_pages(char *param, char *val)

{

	static bool gbpage_sz;

	char *p;



	if (!strcmp(param, "hugepagesz")) {

		p = val;

		if (memparse(p, &p) != PUD_SIZE) {

			gbpage_sz = false;

			return;

		}



		if (gbpage_sz)

			warn("Repeatedly set hugeTLB page size of 1G!\n");

		gbpage_sz = true;

		return;

	}



	if (!strcmp(param, "hugepages") && gbpage_sz) {

		p = val;

		max_gb_huge_pages = simple_strtoull(p, &p, 0);

		return;

	}

}





static int handle_mem_options(void)

{

	char *args = (char *)get_cmd_line_ptr();

	size_t len = strlen((char *)args);
@@ -223,7 +252,8 @@ static int handle_mem_memmap(void) 
	char *param, *val;

	u64 mem_size;



	if (!strstr(args, "memmap=") && !strstr(args, "mem="))

	if (!strstr(args, "memmap=") && !strstr(args, "mem=") &&

		!strstr(args, "hugepages"))

		return 0;



	tmp_cmdline = malloc(len + 1);
@@ -248,6 +278,8 @@ static int handle_mem_memmap(void) 


		if (!strcmp(param, "memmap")) {

			mem_avoid_memmap(val);

		} else if (strstr(param, "hugepages")) {

			parse_gb_huge_pages(param, val);

		} else if (!strcmp(param, "mem")) {

			char *p = val;
@@ -387,7 +419,7 @@ 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 */

	handle_mem_memmap();

	handle_mem_options();



#ifdef CONFIG_X86_VERBOSE_BOOTUP

	/* Make sure video RAM can be used. */
@@ -466,6 +498,60 @@ static void store_slot_info(struct mem_vector *region, unsigned long image_size) 
	}

}



/*

 * Skip as many 1GB huge pages as possible in the passed region

 * according to the number which users specified:

 */

static void

process_gb_huge_pages(struct mem_vector *region, unsigned long image_size)

{

	unsigned long addr, size = 0;

	struct mem_vector tmp;

	int i = 0;



	if (!max_gb_huge_pages) {

		store_slot_info(region, image_size);

		return;

	}



	addr = ALIGN(region->start, PUD_SIZE);

	/* Did we raise the address above the passed in memory entry? */

	if (addr < region->start + region->size)

		size = region->size - (addr - region->start);



	/* Check how many 1GB huge pages can be filtered out: */

	while (size > PUD_SIZE && max_gb_huge_pages) {

		size -= PUD_SIZE;

		max_gb_huge_pages--;

		i++;

	}



	/* No good 1GB huge pages found: */

	if (!i) {

		store_slot_info(region, image_size);

		return;

	}



	/*

	 * Skip those 'i'*1GB good huge pages, and continue checking and

	 * processing the remaining head or tail part of the passed region

	 * if available.

	 */



	if (addr >= region->start + image_size) {

		tmp.start = region->start;

		tmp.size = addr - region->start;

		store_slot_info(&tmp, image_size);

	}



	size  = region->size - (addr - region->start) - i * PUD_SIZE;

	if (size >= image_size) {

		tmp.start = addr + i * PUD_SIZE;

		tmp.size = size;

		store_slot_info(&tmp, image_size);

	}

}



static unsigned long slots_fetch_random(void)

{

	unsigned long slot;
@@ -546,7 +632,7 @@ static void process_mem_region(struct mem_vector *entry, 


		/* If nothing overlaps, store the region and return. */

		if (!mem_avoid_overlap(&region, &overlap)) {

			store_slot_info(&region, image_size);

			process_gb_huge_pages(&region, image_size);

			return;

		}
@@ -556,7 +642,7 @@ static void process_mem_region(struct mem_vector *entry, 


			beginning.start = region.start;

			beginning.size = overlap.start - region.start;

			store_slot_info(&beginning, image_size);

			process_gb_huge_pages(&beginning, image_size);

		}



		/* Return if overlap extends to or past end of region. */

arch/x86/boot/string.c

+3 −2
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 */



#include <linux/types.h>

#include <asm/asm.h>

#include "ctype.h"

#include "string.h"
@@ -28,8 +29,8 @@ 
int memcmp(const void *s1, const void *s2, size_t len)

{

	bool diff;

	asm("repe; cmpsb; setnz %0"

	    : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));

	asm("repe; cmpsb" CC_SET(nz)

	    : CC_OUT(nz) (diff), "+D" (s1), "+S" (s2), "+c" (len));

	return diff;

}

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