67 lines
1.8 KiB
ArmAsm
67 lines
1.8 KiB
ArmAsm
// Copyright 2020 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Restartable sequences critical sections.
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// Loops continuously until aborted.
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//
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// void rseq_loop(struct rseq* r, struct rseq_cs* cs)
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.text
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.globl rseq_loop
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.type rseq_loop, @function
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rseq_loop:
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b begin
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// Abort block before the critical section.
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// Abort signature.
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.byte 0x90, 0x90, 0x90, 0x90
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.globl rseq_loop_early_abort
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rseq_loop_early_abort:
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ret
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begin:
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// r->rseq_cs = cs
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str x1, [x0, #8]
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// N.B. rseq_cs will be cleared by any preempt, even outside the critical
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// section. Thus it must be set in or immediately before the critical section
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// to ensure it is not cleared before the section begins.
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.globl rseq_loop_start
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rseq_loop_start:
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b rseq_loop_start
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// "Pre-commit": extra instructions inside the critical section. These are
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// used as the abort point in TestAbortPreCommit, which is not valid.
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.globl rseq_loop_pre_commit
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rseq_loop_pre_commit:
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// Extra abort signature + nop for TestAbortPostCommit.
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.byte 0x90, 0x90, 0x90, 0x90
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nop
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// "Post-commit": never reached in this case.
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.globl rseq_loop_post_commit
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rseq_loop_post_commit:
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// Abort signature.
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.byte 0x90, 0x90, 0x90, 0x90
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.globl rseq_loop_abort
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rseq_loop_abort:
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ret
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.size rseq_loop,.-rseq_loop
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.section .note.GNU-stack,"",@progbits
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