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-rw-r--r--arch/arm/lib/getuser.S167
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/lib/getuser.S
+ *
+ * Copyright (C) 2001 Russell King
+ *
+ * Idea from x86 version, (C) Copyright 1998 Linus Torvalds
+ *
+ * These functions have a non-standard call interface to make them more
+ * efficient, especially as they return an error value in addition to
+ * the "real" return value.
+ *
+ * __get_user_X
+ *
+ * Inputs: r0 contains the address
+ * r1 contains the address limit, which must be preserved
+ * Outputs: r0 is the error code
+ * r2, r3 contains the zero-extended value
+ * lr corrupted
+ *
+ * No other registers must be altered. (see <asm/uaccess.h>
+ * for specific ASM register usage).
+ *
+ * Note that ADDR_LIMIT is either 0 or 0xc0000000.
+ * Note also that it is intended that __get_user_bad is not global.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+#include <asm/domain.h>
+
+ENTRY(__get_user_1)
+ check_uaccess r0, 1, r1, r2, __get_user_bad
+1: TUSER(ldrb) r2, [r0]
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_1)
+_ASM_NOKPROBE(__get_user_1)
+
+ENTRY(__get_user_2)
+ check_uaccess r0, 2, r1, r2, __get_user_bad
+#if __LINUX_ARM_ARCH__ >= 6
+
+2: TUSER(ldrh) r2, [r0]
+
+#else
+
+#ifdef CONFIG_CPU_USE_DOMAINS
+rb .req ip
+2: ldrbt r2, [r0], #1
+3: ldrbt rb, [r0], #0
+#else
+rb .req r0
+2: ldrb r2, [r0]
+3: ldrb rb, [r0, #1]
+#endif
+#ifndef __ARMEB__
+ orr r2, r2, rb, lsl #8
+#else
+ orr r2, rb, r2, lsl #8
+#endif
+
+#endif /* __LINUX_ARM_ARCH__ >= 6 */
+
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_2)
+_ASM_NOKPROBE(__get_user_2)
+
+ENTRY(__get_user_4)
+ check_uaccess r0, 4, r1, r2, __get_user_bad
+4: TUSER(ldr) r2, [r0]
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_4)
+_ASM_NOKPROBE(__get_user_4)
+
+ENTRY(__get_user_8)
+ check_uaccess r0, 8, r1, r2, __get_user_bad8
+#ifdef CONFIG_THUMB2_KERNEL
+5: TUSER(ldr) r2, [r0]
+6: TUSER(ldr) r3, [r0, #4]
+#else
+5: TUSER(ldr) r2, [r0], #4
+6: TUSER(ldr) r3, [r0]
+#endif
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_8)
+_ASM_NOKPROBE(__get_user_8)
+
+#ifdef __ARMEB__
+ENTRY(__get_user_32t_8)
+ check_uaccess r0, 8, r1, r2, __get_user_bad
+#ifdef CONFIG_CPU_USE_DOMAINS
+ add r0, r0, #4
+7: ldrt r2, [r0]
+#else
+7: ldr r2, [r0, #4]
+#endif
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_32t_8)
+_ASM_NOKPROBE(__get_user_32t_8)
+
+ENTRY(__get_user_64t_1)
+ check_uaccess r0, 1, r1, r2, __get_user_bad8
+8: TUSER(ldrb) r3, [r0]
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_64t_1)
+_ASM_NOKPROBE(__get_user_64t_1)
+
+ENTRY(__get_user_64t_2)
+ check_uaccess r0, 2, r1, r2, __get_user_bad8
+#ifdef CONFIG_CPU_USE_DOMAINS
+rb .req ip
+9: ldrbt r3, [r0], #1
+10: ldrbt rb, [r0], #0
+#else
+rb .req r0
+9: ldrb r3, [r0]
+10: ldrb rb, [r0, #1]
+#endif
+ orr r3, rb, r3, lsl #8
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_64t_2)
+_ASM_NOKPROBE(__get_user_64t_2)
+
+ENTRY(__get_user_64t_4)
+ check_uaccess r0, 4, r1, r2, __get_user_bad8
+11: TUSER(ldr) r3, [r0]
+ mov r0, #0
+ ret lr
+ENDPROC(__get_user_64t_4)
+_ASM_NOKPROBE(__get_user_64t_4)
+#endif
+
+__get_user_bad8:
+ mov r3, #0
+__get_user_bad:
+ mov r2, #0
+ mov r0, #-EFAULT
+ ret lr
+ENDPROC(__get_user_bad)
+ENDPROC(__get_user_bad8)
+_ASM_NOKPROBE(__get_user_bad)
+_ASM_NOKPROBE(__get_user_bad8)
+
+.pushsection __ex_table, "a"
+ .long 1b, __get_user_bad
+ .long 2b, __get_user_bad
+#if __LINUX_ARM_ARCH__ < 6
+ .long 3b, __get_user_bad
+#endif
+ .long 4b, __get_user_bad
+ .long 5b, __get_user_bad8
+ .long 6b, __get_user_bad8
+#ifdef __ARMEB__
+ .long 7b, __get_user_bad
+ .long 8b, __get_user_bad8
+ .long 9b, __get_user_bad8
+ .long 10b, __get_user_bad8
+ .long 11b, __get_user_bad8
+#endif
+.popsection