c76c6c4ecb
Commit62b95a7b44("ARM: 9282/1: vfp: Manipulate task VFP state with softirqs disabled") replaced the en/disable preemption calls inside the VFP state handling code with en/disabling of soft IRQs, which is necessary to allow kernel use of the VFP/SIMD unit when handling a soft IRQ. Unfortunately, when lockdep is enabled (or other instrumentation that enables TRACE_IRQFLAGS), the disable path implemented in asm fails to perform the lockdep and RCU related bookkeeping, resulting in spurious warnings and other badness. Set let's rework the VFP entry code a little bit so we can make the local_bh_disable() call from C, with all the instrumentations that happen to have been configured. Calling local_bh_enable() can be done from asm, as it is a simple wrapper around __local_bh_enable_ip(), which is always a callable function. Link: https://lore.kernel.org/all/ZBBYCSZUJOWBg1s8@localhost.localdomain/ Fixes:62b95a7b44("ARM: 9282/1: vfp: Manipulate task VFP state with softirqs disabled") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
29 lines
700 B
ArmAsm
29 lines
700 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* linux/arch/arm/vfp/entry.S
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*
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* Copyright (C) 2004 ARM Limited.
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* Written by Deep Blue Solutions Limited.
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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <asm/thread_info.h>
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#include <asm/vfpmacros.h>
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#include <asm/assembler.h>
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#include <asm/asm-offsets.h>
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@ VFP entry point.
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@
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@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
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@ r2 = PC value to resume execution after successful emulation
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@ r9 = normal "successful" return address
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@ r10 = this threads thread_info structure
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@ lr = unrecognised instruction return address
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@ IRQs enabled.
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@
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ENTRY(do_vfp)
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mov r1, r10
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mov r3, r9
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b vfp_entry
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ENDPROC(do_vfp)
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