From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/arm/lib/csumpartialcopyuser.S | 32 +++++++-------------------------
1 files changed, 7 insertions(+), 25 deletions(-)
diff --git a/kernel/arch/arm/lib/csumpartialcopyuser.S b/kernel/arch/arm/lib/csumpartialcopyuser.S
index b83fdc0..6928781 100644
--- a/kernel/arch/arm/lib/csumpartialcopyuser.S
+++ b/kernel/arch/arm/lib/csumpartialcopyuser.S
@@ -1,14 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/lib/csumpartialcopyuser.S
*
* Copyright (C) 1995-1998 Russell King
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
* 27/03/03 Ian Molton Clean up CONFIG_CPU
- *
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
@@ -66,9 +62,9 @@
/*
* unsigned int
- * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
- * r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
- * Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
+ * csum_partial_copy_from_user(const char *src, char *dst, int len)
+ * r0 = src, r1 = dst, r2 = len
+ * Returns : r0 = checksum or 0
*/
#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
@@ -77,25 +73,11 @@
#include "csumpartialcopygeneric.S"
/*
- * FIXME: minor buglet here
- * We don't return the checksum for the data present in the buffer. To do
- * so properly, we would have to add in whatever registers were loaded before
- * the fault, which, with the current asm above is not predictable.
+ * We report fault by returning 0 csum - impossible in normal case, since
+ * we start with 0xffffffff for initial sum.
*/
.pushsection .text.fixup,"ax"
.align 4
-9001: mov r4, #-EFAULT
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- ldr r5, [sp, #9*4] @ *err_ptr
-#else
- ldr r5, [sp, #8*4] @ *err_ptr
-#endif
- str r4, [r5]
- ldmia sp, {r1, r2} @ retrieve dst, len
- add r2, r2, r1
- mov r0, #0 @ zero the buffer
-9002: teq r2, r1
- strneb r0, [r1], #1
- bne 9002b
+9001: mov r0, #0
load_regs
.popsection
--
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