kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 kernel/arch/arm/lib/csumpartialcopyuser.S
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@@ -1,14 +1,10 @@
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+/* SPDX-License-Identifier: GPL-2.0-only */
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 /*
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  *  linux/arch/arm/lib/csumpartialcopyuser.S
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  *
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  *  Copyright (C) 1995-1998 Russell King
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  *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2 as
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- * published by the Free Software Foundation.
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- *
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  * 27/03/03 Ian Molton Clean up CONFIG_CPU
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- *
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  */
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 #include <linux/linkage.h>
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 #include <asm/assembler.h>
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@@ -66,9 +62,9 @@
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 /*
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  * unsigned int
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- * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
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- *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
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- *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
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+ * csum_partial_copy_from_user(const char *src, char *dst, int len)
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+ *  r0 = src, r1 = dst, r2 = len
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+ *  Returns : r0 = checksum or 0
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  */
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 #define FN_ENTRY	ENTRY(csum_partial_copy_from_user)
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@@ -77,25 +73,11 @@
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 #include "csumpartialcopygeneric.S"
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 /*
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- * FIXME: minor buglet here
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- * We don't return the checksum for the data present in the buffer.  To do
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- * so properly, we would have to add in whatever registers were loaded before
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- * the fault, which, with the current asm above is not predictable.
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+ * We report fault by returning 0 csum - impossible in normal case, since
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+ * we start with 0xffffffff for initial sum.
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  */
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 		.pushsection .text.fixup,"ax"
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 		.align	4
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-9001:		mov	r4, #-EFAULT
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-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
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-		ldr	r5, [sp, #9*4]		@ *err_ptr
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-#else
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-		ldr	r5, [sp, #8*4]		@ *err_ptr
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-#endif
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-		str	r4, [r5]
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-		ldmia	sp, {r1, r2}		@ retrieve dst, len
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-		add	r2, r2, r1
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-		mov	r0, #0			@ zero the buffer
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-9002:		teq	r2, r1
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-		strneb	r0, [r1], #1
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-		bne	9002b
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+9001:		mov	r0, #0
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 		load_regs
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 		.popsection