Commit 1ac2e6ca authored by Robert Richter's avatar Robert Richter Committed by Ingo Molnar
Browse files

x86, perf: Make copy_from_user_nmi() a library function 



copy_from_user_nmi() is used in oprofile and perf. Moving it to other
library functions like copy_from_user(). As this is x86 code for 32
and 64 bits, create a new file usercopy.c for unified code.

Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110607172413.GJ20052@erda.amd.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 9985c20f

arch/x86/include/asm/uaccess.h

+3 −0
Original line number Diff line number Diff line
@@ -555,6 +555,9 @@ struct __large_struct { unsigned long buf[100]; }; 


#endif /* CONFIG_X86_WP_WORKS_OK */



extern unsigned long

copy_from_user_nmi(void *to, const void __user *from, unsigned long n);



/*

 * movsl can be slow when source and dest are not both 8-byte aligned

 */

arch/x86/kernel/cpu/perf_event.c

+0 −35
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ 
#include <linux/sched.h>

#include <linux/uaccess.h>

#include <linux/slab.h>

#include <linux/highmem.h>

#include <linux/cpu.h>

#include <linux/bitops.h>
@@ -67,40 +66,6 @@ enum extra_reg_type { 
	EXTRA_REG_MAX		/* number of entries needed */

};



/*

 * best effort, GUP based copy_from_user() that assumes IRQ or NMI context

 */

static unsigned long

copy_from_user_nmi(void *to, const void __user *from, unsigned long n)

{

	unsigned long offset, addr = (unsigned long)from;

	unsigned long size, len = 0;

	struct page *page;

	void *map;

	int ret;



	do {

		ret = __get_user_pages_fast(addr, 1, 0, &page);

		if (!ret)

			break;



		offset = addr & (PAGE_SIZE - 1);

		size = min(PAGE_SIZE - offset, n - len);



		map = kmap_atomic(page);

		memcpy(to, map+offset, size);

		kunmap_atomic(map);

		put_page(page);



		len  += size;

		to   += size;

		addr += size;



	} while (len < n);



	return len;

}



struct event_constraint {

	union {

		unsigned long	idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];

arch/x86/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o 


lib-y := delay.o

lib-y += thunk_$(BITS).o

lib-y += usercopy_$(BITS).o getuser.o putuser.o

lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o

lib-y += memcpy_$(BITS).o

lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o

arch/x86/lib/usercopy.c

0 → 100644
+43 −0
Original line number Diff line number Diff line 
/*

 * User address space access functions.

 *

 *  For licencing details see kernel-base/COPYING

 */



#include <linux/highmem.h>

#include <linux/module.h>



/*

 * best effort, GUP based copy_from_user() that is NMI-safe

 */

unsigned long

copy_from_user_nmi(void *to, const void __user *from, unsigned long n)

{

	unsigned long offset, addr = (unsigned long)from;

	unsigned long size, len = 0;

	struct page *page;

	void *map;

	int ret;



	do {

		ret = __get_user_pages_fast(addr, 1, 0, &page);

		if (!ret)

			break;



		offset = addr & (PAGE_SIZE - 1);

		size = min(PAGE_SIZE - offset, n - len);



		map = kmap_atomic(page);

		memcpy(to, map+offset, size);

		kunmap_atomic(map);

		put_page(page);



		len  += size;

		to   += size;

		addr += size;



	} while (len < n);



	return len;

}

EXPORT_SYMBOL_GPL(copy_from_user_nmi);

arch/x86/oprofile/backtrace.c

+1 −38
Original line number Diff line number Diff line
@@ -12,10 +12,9 @@ 
#include <linux/sched.h>

#include <linux/mm.h>

#include <linux/compat.h>

#include <linux/highmem.h>

#include <linux/uaccess.h>



#include <asm/ptrace.h>

#include <asm/uaccess.h>

#include <asm/stacktrace.h>



static int backtrace_stack(void *data, char *name)
@@ -38,42 +37,6 @@ static struct stacktrace_ops backtrace_ops = { 
	.walk_stack	= print_context_stack,

};



/* from arch/x86/kernel/cpu/perf_event.c: */



/*

 * best effort, GUP based copy_from_user() that assumes IRQ or NMI context

 */

static unsigned long

copy_from_user_nmi(void *to, const void __user *from, unsigned long n)

{

	unsigned long offset, addr = (unsigned long)from;

	unsigned long size, len = 0;

	struct page *page;

	void *map;

	int ret;



	do {

		ret = __get_user_pages_fast(addr, 1, 0, &page);

		if (!ret)

			break;



		offset = addr & (PAGE_SIZE - 1);

		size = min(PAGE_SIZE - offset, n - len);



		map = kmap_atomic(page);

		memcpy(to, map+offset, size);

		kunmap_atomic(map);

		put_page(page);



		len  += size;

		to   += size;

		addr += size;



	} while (len < n);



	return len;

}



#ifdef CONFIG_COMPAT

static struct stack_frame_ia32 *

dump_user_backtrace_32(struct stack_frame_ia32 *head)

CRA Git | Maintained and supported by SUSTech CRA and CCSE