block: Fix overrun in lcm() and move it to lib (2cda2728) · Commits · 戴 / test

block/blk-settings.c

+1 −10

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		#include <linux/blkdev.h>
		#include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
		#include <linux/gcd.h>
		#include <linux/lcm.h>
		#include <linux/jiffies.h>

		#include "blk.h"
		@@ -461,16 +462,6 @@ void blk_queue_stack_limits(struct request_queue t, struct request_queue b)
		}
		EXPORT_SYMBOL(blk_queue_stack_limits);

		static unsigned int lcm(unsigned int a, unsigned int b)
		{
		if (a && b)
		return (a * b) / gcd(a, b);
		else if (b)
		return b;

		return a;
		}

		/**
		* blk_stack_limits - adjust queue_limits for stacked devices
		* @t: the stacking driver limits (top device)

0 → 100644

+8 −0

Original line number	Diff line number	Diff line
		#ifndef _LCM_H
		#define _LCM_H

		#include <linux/compiler.h>

		unsigned long lcm(unsigned long a, unsigned long b) __attribute_const__;

		#endif /* _LCM_H */

+1 −1

Original line number	Diff line number	Diff line
		@@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o

		obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
		bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
		string_helpers.o gcd.o list_sort.o
		string_helpers.o gcd.o lcm.o list_sort.o

		ifeq ($(CONFIG_DEBUG_KOBJECT),y)
		CFLAGS_kobject.o += -DDEBUG

0 → 100644

+15 −0

Original line number	Diff line number	Diff line
		#include <linux/kernel.h>
		#include <linux/gcd.h>
		#include <linux/module.h>

		/* Lowest common multiple */
		unsigned long lcm(unsigned long a, unsigned long b)
		{
		if (a && b)
		return (a * b) / gcd(a, b);
		else if (b)
		return b;

		return a;
		}
		EXPORT_SYMBOL_GPL(lcm);