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kernel-49/arch/powerpc/lib/checksum_wrappers.c
Greg Kroah-Hartman e986e9737d Merge 4.9.245 into android-4.9-q
Changes in 4.9.245
	powerpc/64s: Define MASKABLE_RELON_EXCEPTION_PSERIES_OOL
	powerpc/64s: move some exception handlers out of line
	powerpc/64s: flush L1D on kernel entry
	powerpc: Add a framework for user access tracking
	powerpc: Implement user_access_begin and friends
	powerpc: Fix __clear_user() with KUAP enabled
	powerpc/uaccess: Evaluate macro arguments once, before user access is allowed
	powerpc/64s: flush L1D after user accesses
	i2c: imx: use clk notifier for rate changes
	i2c: imx: Fix external abort on interrupt in exit paths
	i2c: mux: pca954x: Add missing pca9546 definition to chip_desc
	powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
	Input: sunkbd - avoid use-after-free in teardown paths
	mac80211: always wind down STA state
	KVM: x86: clflushopt should be treated as a no-op by emulation
	ACPI: GED: fix -Wformat
	Linux 4.9.245

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I688b066e99eeb16270414e0c4cb4dc3bb244486c
2020-11-25 18:21:48 +03:00

107 lines
2.5 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2010
*
* Author: Anton Blanchard <anton@au.ibm.com>
*/
#include <linux/export.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/checksum.h>
#include <asm/uaccess.h>
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
unsigned int csum;
might_sleep();
allow_read_from_user(src, len);
*err_ptr = 0;
if (!len) {
csum = 0;
goto out;
}
if (unlikely((len < 0) || !access_ok(VERIFY_READ, src, len))) {
*err_ptr = -EFAULT;
csum = (__force unsigned int)sum;
goto out;
}
csum = csum_partial_copy_generic((void __force *)src, dst,
len, sum, err_ptr, NULL);
if (unlikely(*err_ptr)) {
int missing = __copy_from_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
} else {
*err_ptr = 0;
}
csum = csum_partial(dst, len, sum);
}
out:
prevent_read_from_user(src, len);
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_from_user);
__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
__wsum sum, int *err_ptr)
{
unsigned int csum;
might_sleep();
allow_write_to_user(dst, len);
*err_ptr = 0;
if (!len) {
csum = 0;
goto out;
}
if (unlikely((len < 0) || !access_ok(VERIFY_WRITE, dst, len))) {
*err_ptr = -EFAULT;
csum = -1; /* invalid checksum */
goto out;
}
csum = csum_partial_copy_generic(src, (void __force *)dst,
len, sum, NULL, err_ptr);
if (unlikely(*err_ptr)) {
csum = csum_partial(src, len, sum);
if (copy_to_user(dst, src, len)) {
*err_ptr = -EFAULT;
csum = -1; /* invalid checksum */
}
}
out:
prevent_write_to_user(dst, len);
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_to_user);