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kernel
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linux
ARM: entry: avoid clobbering R9 in IRQ handler
Avoid using R9 in the IRQ handler code, as the entry code uses it for
tsk, and expects it to remain untouched between the IRQ entry and exit
code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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arch/arm/kernel/entry-armv.S
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arch/arm/kernel/entry-armv.S
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#ifdef CONFIG_UNWINDER_ARM
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mov fpreg, sp @ Preserve original SP
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#else
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-
mov r8, fp @ Preserve original FP
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mov r9, sp @ Preserve original SP
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mov r7, fp @ Preserve original FP
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mov r8, sp @ Preserve original SP
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#endif
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ldr_this_cpu sp, irq_stack_ptr, r2, r3
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-
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.if \from_user == 0
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UNWIND( .setfp fpreg, sp )
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@
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#ifdef CONFIG_UNWINDER_ARM
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mov sp, fpreg @ Restore original SP
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#else
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mov fp, r8 @ Restore original FP
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mov sp, r9 @ Restore original SP
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mov fp, r7 @ Restore original FP
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mov sp, r8 @ Restore original SP
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#endif // CONFIG_UNWINDER_ARM
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#endif // CONFIG_IRQSTACKS
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.endm