c0959b4426
Replace the dummy C implementation of SpeculationBarrier() with implementations consisting of the recommended DSB SY + ISB sequence, as recommended by ARM in the whitepaper "Cache Speculation Side-channels" version 2.4, dated October 2018. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Liming Gao <liming.gao@intel.com> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
40 lines
1.0 KiB
ArmAsm
40 lines
1.0 KiB
ArmAsm
##------------------------------------------------------------------------------
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#
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# SpeculationBarrier() for AArch64
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#
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# Copyright (c) 2019, Linaro Ltd. All rights reserved.
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#
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# This program and the accompanying materials
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# are licensed and made available under the terms and conditions of the BSD License
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# which accompanies this distribution. The full text of the license may be found at
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# http://opensource.org/licenses/bsd-license.php.
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#
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# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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#
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##------------------------------------------------------------------------------
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.text
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.p2align 2
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GCC_ASM_EXPORT(SpeculationBarrier)
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#/**
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# Uses as a barrier to stop speculative execution.
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#
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# Ensures that no later instruction will execute speculatively, until all prior
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# instructions have completed.
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#
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#**/
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#VOID
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#EFIAPI
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#SpeculationBarrier (
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# VOID
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# );
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#
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ASM_PFX(SpeculationBarrier):
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dsb sy
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isb
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ret
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