diff options
Diffstat (limited to 'libc/arch-arm64/generic/bionic/memcpy.S')
| -rw-r--r-- | libc/arch-arm64/generic/bionic/memcpy.S | 227 |
1 files changed, 53 insertions, 174 deletions
diff --git a/libc/arch-arm64/generic/bionic/memcpy.S b/libc/arch-arm64/generic/bionic/memcpy.S index e1b1a72..85129fe 100644 --- a/libc/arch-arm64/generic/bionic/memcpy.S +++ b/libc/arch-arm64/generic/bionic/memcpy.S @@ -1,184 +1,63 @@ -/* Copyright (c) 2012, Linaro Limited - All rights reserved. - - Redistribution and use in source and binary forms, with or without - modification, are permitted provided that the following conditions are met: - * Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. - * Redistributions in binary form must reproduce the above copyright - notice, this list of conditions and the following disclaimer in the - documentation and/or other materials provided with the distribution. - * Neither the name of the Linaro nor the - names of its contributors may be used to endorse or promote products - derived from this software without specific prior written permission. - - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT - HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -*/ - -/* Assumptions: +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. * - * ARMv8-a, AArch64 - * Unaligned accesses + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. */ +// Prototype: void *memcpy (void *dst, const void *src, size_t count). + #include <private/bionic_asm.h> +#include <private/libc_events.h> -#define dstin x0 -#define src x1 -#define count x2 -#define tmp1 x3 -#define tmp1w w3 -#define tmp2 x4 -#define tmp2w w4 -#define tmp3 x5 -#define tmp3w w5 -#define dst x6 +ENTRY(__memcpy_chk) + cmp x2, x3 + b.hi __memcpy_chk_fail -#define A_l x7 -#define A_h x8 -#define B_l x9 -#define B_h x10 -#define C_l x11 -#define C_h x12 -#define D_l x13 -#define D_h x14 + // Fall through to memcpy... +END(__memcpy_chk) ENTRY(memcpy) - - mov dst, dstin - cmp count, #64 - b.ge .Lcpy_not_short - cmp count, #15 - b.le .Ltail15tiny - - /* Deal with small copies quickly by dropping straight into the - * exit block. */ -.Ltail63: - /* Copy up to 48 bytes of data. At this point we only need the - * bottom 6 bits of count to be accurate. */ - ands tmp1, count, #0x30 - b.eq .Ltail15 - add dst, dst, tmp1 - add src, src, tmp1 - cmp tmp1w, #0x20 - b.eq 1f - b.lt 2f - ldp A_l, A_h, [src, #-48] - stp A_l, A_h, [dst, #-48] -1: - ldp A_l, A_h, [src, #-32] - stp A_l, A_h, [dst, #-32] -2: - ldp A_l, A_h, [src, #-16] - stp A_l, A_h, [dst, #-16] - -.Ltail15: - ands count, count, #15 - beq 1f - add src, src, count - ldp A_l, A_h, [src, #-16] - add dst, dst, count - stp A_l, A_h, [dst, #-16] -1: - ret - -.Ltail15tiny: - /* Copy up to 15 bytes of data. Does not assume additional data - being copied. */ - tbz count, #3, 1f - ldr tmp1, [src], #8 - str tmp1, [dst], #8 -1: - tbz count, #2, 1f - ldr tmp1w, [src], #4 - str tmp1w, [dst], #4 -1: - tbz count, #1, 1f - ldrh tmp1w, [src], #2 - strh tmp1w, [dst], #2 -1: - tbz count, #0, 1f - ldrb tmp1w, [src] - strb tmp1w, [dst] -1: - ret - -.Lcpy_not_short: - /* We don't much care about the alignment of DST, but we want SRC - * to be 128-bit (16 byte) aligned so that we don't cross cache line - * boundaries on both loads and stores. */ - neg tmp2, src - ands tmp2, tmp2, #15 /* Bytes to reach alignment. */ - b.eq 2f - sub count, count, tmp2 - /* Copy more data than needed; it's faster than jumping - * around copying sub-Quadword quantities. We know that - * it can't overrun. */ - ldp A_l, A_h, [src] - add src, src, tmp2 - stp A_l, A_h, [dst] - add dst, dst, tmp2 - /* There may be less than 63 bytes to go now. */ - cmp count, #63 - b.le .Ltail63 -2: - subs count, count, #128 - b.ge .Lcpy_body_large - /* Less than 128 bytes to copy, so handle 64 here and then jump - * to the tail. */ - ldp A_l, A_h, [src] - ldp B_l, B_h, [src, #16] - ldp C_l, C_h, [src, #32] - ldp D_l, D_h, [src, #48] - stp A_l, A_h, [dst] - stp B_l, B_h, [dst, #16] - stp C_l, C_h, [dst, #32] - stp D_l, D_h, [dst, #48] - tst count, #0x3f - add src, src, #64 - add dst, dst, #64 - b.ne .Ltail63 - ret - - /* Critical loop. Start at a new cache line boundary. Assuming - * 64 bytes per line this ensures the entire loop is in one line. */ - .p2align 6 -.Lcpy_body_large: - /* There are at least 128 bytes to copy. */ - ldp A_l, A_h, [src, #0] - sub dst, dst, #16 /* Pre-bias. */ - ldp B_l, B_h, [src, #16] - ldp C_l, C_h, [src, #32] - ldp D_l, D_h, [src, #48]! /* src += 64 - Pre-bias. */ -1: - stp A_l, A_h, [dst, #16] - ldp A_l, A_h, [src, #16] - stp B_l, B_h, [dst, #32] - ldp B_l, B_h, [src, #32] - stp C_l, C_h, [dst, #48] - ldp C_l, C_h, [src, #48] - stp D_l, D_h, [dst, #64]! - ldp D_l, D_h, [src, #64]! - subs count, count, #64 - b.ge 1b - stp A_l, A_h, [dst, #16] - stp B_l, B_h, [dst, #32] - stp C_l, C_h, [dst, #48] - stp D_l, D_h, [dst, #64] - add src, src, #16 - add dst, dst, #64 + 16 - tst count, #0x3f - b.ne .Ltail63 - ret + #include "memcpy_base.S" END(memcpy) + +ENTRY_PRIVATE(__memcpy_chk_fail) + // Preserve for accurate backtrace. + stp x29, x30, [sp, -16]! + .cfi_def_cfa_offset 16 + .cfi_rel_offset x29, 0 + .cfi_rel_offset x30, 8 + + adrp x0, error_string + add x0, x0, :lo12:error_string + ldr x1, error_code + bl __fortify_chk_fail +error_code: + .word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW +END(__memcpy_chk_fail) + + .data + .align 2 +error_string: + .string "memcpy: prevented write past end of buffer" |