1142b71d85
Commit 8b592783 added a Thumb-2 variant of usracc which, when it is
called with \rept=2, calls usraccoff once with an offset of 0 and
secondly with a hard-coded offset of 4 in order to avoid incrementing
the pointer again. If \inc != 4 then we will store the data to the wrong
offset from \ptr. Luckily, the only caller that passes \rept=2 to this
function is __clear_user so we haven't been actively corrupting user data.
This patch fixes usracc to pass \inc instead of #4 to usraccoff
when it is called a second time.
Cc: <stable@kernel.org>
Reported-by: Tony Thompson <tony.thompson@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
276 lines
5.8 KiB
C
276 lines
5.8 KiB
C
/*
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* arch/arm/include/asm/assembler.h
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*
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* Copyright (C) 1996-2000 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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* This file contains arm architecture specific defines
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* for the different processors.
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*
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* Do not include any C declarations in this file - it is included by
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* assembler source.
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*/
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#ifndef __ASSEMBLY__
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#error "Only include this from assembly code"
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#endif
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#include <asm/ptrace.h>
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/*
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* Endian independent macros for shifting bytes within registers.
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*/
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#ifndef __ARMEB__
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#define pull lsr
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#define push lsl
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#define get_byte_0 lsl #0
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#define get_byte_1 lsr #8
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#define get_byte_2 lsr #16
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#define get_byte_3 lsr #24
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#define put_byte_0 lsl #0
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#define put_byte_1 lsl #8
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#define put_byte_2 lsl #16
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#define put_byte_3 lsl #24
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#else
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#define pull lsl
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#define push lsr
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#define get_byte_0 lsr #24
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#define get_byte_1 lsr #16
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#define get_byte_2 lsr #8
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#define get_byte_3 lsl #0
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#define put_byte_0 lsl #24
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#define put_byte_1 lsl #16
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#define put_byte_2 lsl #8
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#define put_byte_3 lsl #0
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#endif
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/*
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* Data preload for architectures that support it
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*/
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#if __LINUX_ARM_ARCH__ >= 5
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#define PLD(code...) code
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#else
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#define PLD(code...)
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#endif
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/*
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* This can be used to enable code to cacheline align the destination
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* pointer when bulk writing to memory. Experiments on StrongARM and
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* XScale didn't show this a worthwhile thing to do when the cache is not
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* set to write-allocate (this would need further testing on XScale when WA
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* is used).
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*
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* On Feroceon there is much to gain however, regardless of cache mode.
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*/
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#ifdef CONFIG_CPU_FEROCEON
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#define CALGN(code...) code
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#else
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#define CALGN(code...)
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#endif
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/*
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* Enable and disable interrupts
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*/
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#if __LINUX_ARM_ARCH__ >= 6
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.macro disable_irq_notrace
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cpsid i
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.endm
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.macro enable_irq_notrace
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cpsie i
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.endm
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#else
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.macro disable_irq_notrace
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msr cpsr_c, #PSR_I_BIT | SVC_MODE
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.endm
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.macro enable_irq_notrace
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msr cpsr_c, #SVC_MODE
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.endm
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#endif
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.macro asm_trace_hardirqs_off
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#if defined(CONFIG_TRACE_IRQFLAGS)
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stmdb sp!, {r0-r3, ip, lr}
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bl trace_hardirqs_off
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ldmia sp!, {r0-r3, ip, lr}
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#endif
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.endm
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.macro asm_trace_hardirqs_on_cond, cond
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#if defined(CONFIG_TRACE_IRQFLAGS)
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/*
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* actually the registers should be pushed and pop'd conditionally, but
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* after bl the flags are certainly clobbered
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*/
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stmdb sp!, {r0-r3, ip, lr}
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bl\cond trace_hardirqs_on
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ldmia sp!, {r0-r3, ip, lr}
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#endif
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.endm
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.macro asm_trace_hardirqs_on
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asm_trace_hardirqs_on_cond al
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.endm
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.macro disable_irq
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disable_irq_notrace
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asm_trace_hardirqs_off
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.endm
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.macro enable_irq
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asm_trace_hardirqs_on
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enable_irq_notrace
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.endm
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/*
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* Save the current IRQ state and disable IRQs. Note that this macro
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* assumes FIQs are enabled, and that the processor is in SVC mode.
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*/
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.macro save_and_disable_irqs, oldcpsr
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mrs \oldcpsr, cpsr
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disable_irq
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.endm
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/*
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* Restore interrupt state previously stored in a register. We don't
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* guarantee that this will preserve the flags.
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*/
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.macro restore_irqs_notrace, oldcpsr
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msr cpsr_c, \oldcpsr
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.endm
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.macro restore_irqs, oldcpsr
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tst \oldcpsr, #PSR_I_BIT
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asm_trace_hardirqs_on_cond eq
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restore_irqs_notrace \oldcpsr
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.endm
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#define USER(x...) \
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9999: x; \
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.pushsection __ex_table,"a"; \
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.align 3; \
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.long 9999b,9001f; \
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.popsection
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#ifdef CONFIG_SMP
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#define ALT_SMP(instr...) \
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9998: instr
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#define ALT_UP(instr...) \
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.pushsection ".alt.smp.init", "a" ;\
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.long 9998b ;\
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instr ;\
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.popsection
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#define ALT_UP_B(label) \
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.equ up_b_offset, label - 9998b ;\
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.pushsection ".alt.smp.init", "a" ;\
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.long 9998b ;\
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b . + up_b_offset ;\
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.popsection
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#else
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#define ALT_SMP(instr...)
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#define ALT_UP(instr...) instr
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#define ALT_UP_B(label) b label
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#endif
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/*
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* SMP data memory barrier
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*/
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.macro smp_dmb
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#ifdef CONFIG_SMP
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#if __LINUX_ARM_ARCH__ >= 7
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ALT_SMP(dmb)
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#elif __LINUX_ARM_ARCH__ == 6
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ALT_SMP(mcr p15, 0, r0, c7, c10, 5) @ dmb
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#else
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#error Incompatible SMP platform
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#endif
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ALT_UP(nop)
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#endif
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.endm
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#ifdef CONFIG_THUMB2_KERNEL
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.macro setmode, mode, reg
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mov \reg, #\mode
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msr cpsr_c, \reg
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.endm
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#else
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.macro setmode, mode, reg
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msr cpsr_c, #\mode
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.endm
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#endif
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/*
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* STRT/LDRT access macros with ARM and Thumb-2 variants
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*/
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#ifdef CONFIG_THUMB2_KERNEL
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.macro usraccoff, instr, reg, ptr, inc, off, cond, abort
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9999:
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.if \inc == 1
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\instr\cond\()bt \reg, [\ptr, #\off]
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.elseif \inc == 4
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\instr\cond\()t \reg, [\ptr, #\off]
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.else
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.error "Unsupported inc macro argument"
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.endif
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.pushsection __ex_table,"a"
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.align 3
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.long 9999b, \abort
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.popsection
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.endm
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.macro usracc, instr, reg, ptr, inc, cond, rept, abort
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@ explicit IT instruction needed because of the label
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@ introduced by the USER macro
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.ifnc \cond,al
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.if \rept == 1
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itt \cond
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.elseif \rept == 2
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ittt \cond
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.else
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.error "Unsupported rept macro argument"
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.endif
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.endif
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@ Slightly optimised to avoid incrementing the pointer twice
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usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort
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.if \rept == 2
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usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort
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.endif
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add\cond \ptr, #\rept * \inc
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.endm
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#else /* !CONFIG_THUMB2_KERNEL */
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.macro usracc, instr, reg, ptr, inc, cond, rept, abort
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.rept \rept
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9999:
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.if \inc == 1
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\instr\cond\()bt \reg, [\ptr], #\inc
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.elseif \inc == 4
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\instr\cond\()t \reg, [\ptr], #\inc
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.else
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.error "Unsupported inc macro argument"
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.endif
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.pushsection __ex_table,"a"
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.align 3
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.long 9999b, \abort
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.popsection
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.endr
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.endm
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#endif /* CONFIG_THUMB2_KERNEL */
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.macro strusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
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usracc str, \reg, \ptr, \inc, \cond, \rept, \abort
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.endm
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.macro ldrusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
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usracc ldr, \reg, \ptr, \inc, \cond, \rept, \abort
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.endm
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