projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae | 1 | /********************************************************************** |
| f91f0fd5 | 2 | Copyright(c) 2011-2018 Intel Corporation All rights reserved. |
| 7c673cae FG |
3 | |
| 4 | Redistribution and use in source and binary forms, with or without | |
| 5 | modification, are permitted provided that the following conditions | |
| 6 | are met: | |
| 7 | * Redistributions of source code must retain the above copyright | |
| 8 | notice, this list of conditions and the following disclaimer. | |
| 9 | * Redistributions in binary form must reproduce the above copyright | |
| 10 | notice, this list of conditions and the following disclaimer in | |
| 11 | the documentation and/or other materials provided with the | |
| 12 | distribution. | |
| 13 | * Neither the name of Intel Corporation nor the names of its | |
| 14 | contributors may be used to endorse or promote products derived | |
| 15 | from this software without specific prior written permission. | |
| 16 | ||
| 17 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 18 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 19 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| 20 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
| 21 | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 22 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 23 | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 24 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 25 | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 26 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 27 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 28 | **********************************************************************/ | |
| 29 | ||
| f91f0fd5 TL |
30 | #include <stdint.h> |
| 31 | #include <stddef.h> | |
| 32 | #include "unaligned.h" | |
| 7c673cae | 33 | |
| f91f0fd5 | 34 | int mem_zero_detect_base(void *buf, size_t n) |
| 7c673cae | 35 | { |
| f91f0fd5 TL |
36 | uint8_t *c = buf; |
| 37 | uintmax_t a = 0; | |
| 38 | ||
| 39 | // Check buffer in native machine width comparisons | |
| 40 | while (n >= sizeof(uintmax_t)) { | |
| 41 | n -= sizeof(uintmax_t); | |
| 42 | if (load_umax(c) != 0) | |
| 43 | return -1; | |
| 44 | c += sizeof(uintmax_t); | |
| 7c673cae FG |
45 | } |
| 46 | ||
| f91f0fd5 TL |
47 | // Check remaining bytes |
| 48 | switch (n) { | |
| 49 | case 7: | |
| 50 | a |= *c++; // fall through to case 6,5,4 | |
| 51 | case 6: | |
| 52 | a |= *c++; // fall through to case 5,4 | |
| 53 | case 5: | |
| 54 | a |= *c++; // fall through to case 4 | |
| 55 | case 4: | |
| 56 | a |= load_u32(c); | |
| 57 | break; | |
| 58 | case 3: | |
| 59 | a |= *c++; // fall through to case 2 | |
| 60 | case 2: | |
| 61 | a |= load_u16(c); | |
| 62 | break; | |
| 63 | case 1: | |
| 64 | a |= *c; | |
| 65 | break; | |
| 7c673cae | 66 | } |
| f91f0fd5 TL |
67 | |
| 68 | return (a == 0) ? 0 : -1; | |
| 7c673cae | 69 | } |