diff options
Diffstat (limited to 'pkg/sentry/platform/safecopy/memclr_arm64.s')
| -rw-r--r-- | pkg/sentry/platform/safecopy/memclr_arm64.s | 74 |
1 files changed, 0 insertions, 74 deletions
diff --git a/pkg/sentry/platform/safecopy/memclr_arm64.s b/pkg/sentry/platform/safecopy/memclr_arm64.s deleted file mode 100644 index 7361b9067..000000000 --- a/pkg/sentry/platform/safecopy/memclr_arm64.s +++ /dev/null @@ -1,74 +0,0 @@ -// Copyright 2014 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -#include "textflag.h" - -// handleMemclrFault returns (the value stored in R0, the value stored in R1). -// Control is transferred to it when memclr below receives SIGSEGV or SIGBUS, -// with the faulting address stored in R0 and the signal number stored in R1. -// -// It must have the same frame configuration as memclr so that it can undo any -// potential call frame set up by the assembler. -TEXT handleMemclrFault(SB), NOSPLIT, $0-28 - MOVD R0, addr+16(FP) - MOVW R1, sig+24(FP) - RET - -// See the corresponding doc in safecopy_unsafe.go -// -// The code is derived from runtime.memclrNoHeapPointers. -// -// func memclr(ptr unsafe.Pointer, n uintptr) (fault unsafe.Pointer, sig int32) -TEXT ·memclr(SB), NOSPLIT, $0-28 - // Store 0 as the returned signal number. If we run to completion, - // this is the value the caller will see; if a signal is received, - // handleMemclrFault will store a different value in this address. - MOVW $0, sig+24(FP) - MOVD ptr+0(FP), R0 - MOVD n+8(FP), R1 - - // If size is less than 16 bytes, use tail_zero to zero what remains - CMP $16, R1 - BLT tail_zero - // Get buffer offset into 16 byte aligned address for better performance - ANDS $15, R0, ZR - BNE unaligned_to_16 -aligned_to_16: - LSR $4, R1, R2 -zero_by_16: - STP.P (ZR, ZR), 16(R0) // Store pair with post index. - SUBS $1, R2, R2 - BNE zero_by_16 - ANDS $15, R1, R1 - BEQ end - - // Zero buffer with size=R1 < 16 -tail_zero: - TBZ $3, R1, tail_zero_4 - MOVD.P ZR, 8(R0) -tail_zero_4: - TBZ $2, R1, tail_zero_2 - MOVW.P ZR, 4(R0) -tail_zero_2: - TBZ $1, R1, tail_zero_1 - MOVH.P ZR, 2(R0) -tail_zero_1: - TBZ $0, R1, end - MOVB ZR, (R0) -end: - RET - -unaligned_to_16: - MOVD R0, R2 -head_loop: - MOVBU.P ZR, 1(R0) - ANDS $15, R0, ZR - BNE head_loop - // Adjust length for what remains - SUB R2, R0, R3 - SUB R3, R1 - // If size is less than 16 bytes, use tail_zero to zero what remains - CMP $16, R1 - BLT tail_zero - B aligned_to_16 |