projects / thirdparty / glibc.git / blame
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|---|---|---|
| b168057a | 1 | /* Copyright (C) 1996-2015 Free Software Foundation, Inc. |
| 3c7b2587 UD |
2 | This file is part of the GNU C Library. |
| 3 | Contributed by David Mosberger <davidm@azstarnet.com>, 1996. | |
| 6932e444 | 4 | |
| 3c7b2587 | 5 | The GNU C Library is free software; you can redistribute it and/or |
| 3214b89b AJ |
6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either | |
| 8 | version 2.1 of the License, or (at your option) any later version. | |
| 6932e444 | 9 | |
| 3c7b2587 UD |
10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 3214b89b | 13 | Lesser General Public License for more details. |
| 6932e444 | 14 | |
| 3214b89b | 15 | You should have received a copy of the GNU Lesser General Public |
| ab84e3ff PE |
16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ | |
| 6932e444 RM |
18 | |
| 19 | #include <sysdep.h> | |
| 20 | ||
| 21 | /* | |
| 22 | * This is for COMPATIBILITY with Linux/x86 only. Linux/Alpha system | |
| 5556231d | 23 | * calls return an error indication in a3. This allows arbitrary 64bit |
| 2e6c2875 AJ |
24 | * values to be returned in v0 (because negative values are not |
| 25 | * mistaken as error numbers). However, C allows only one value to | |
| 26 | * be returned, so the interface below folds the error indication passed in | |
| 6932e444 RM |
27 | * a3 back into v0: it sets v0 to -errno if an error occurs. Thus, |
| 28 | * no negative 64bit numbers can be returned. To avoid this problem, | |
| 29 | * use assembly stubs wherever possible/convenient. | |
| 30 | * | |
| 31 | * Usage: | |
| 32 | * | |
| f3ce45f3 | 33 | * long syscall(syscall_number, arg1, arg2, arg3, arg4, arg5, arg6) |
| 6932e444 RM |
34 | * |
| 35 | * syscall_number = the index of the system call we're invoking | |
| f3ce45f3 | 36 | * arg1-arg6 = up to 6 integer arguments to the system call |
| 6932e444 RM |
37 | * |
| 38 | * We need to do some arg shifting: the kernel expects the | |
| f3ce45f3 | 39 | * syscall number in v0 and the first six args in a0-a5. |
| 6932e444 RM |
40 | * |
| 41 | */ | |
| 42 | ||
| 43 | ||
| 24c177a0 | 44 | LEAF(__syscall, 0) |
| dd4b8913 UD |
45 | #ifdef PROF |
| 46 | ldgp gp, 0(pv) | |
| 3c7b2587 | 47 | .set noat |
| dd4b8913 UD |
48 | lda AT, _mcount |
| 49 | jsr AT, (AT), _mcount | |
| 3c7b2587 | 50 | .set at |
| dd4b8913 UD |
51 | .prologue 1 |
| 52 | #else | |
| 53 | .prologue 0 | |
| 54 | #endif | |
| 55 | ||
| 07f03a4d RM |
56 | mov a0, v0 /* Syscall number -> v0 */ |
| 57 | mov a1, a0 /* arg1-arg5 -> a0-a4 */ | |
| 58 | mov a2, a1 | |
| 59 | mov a3, a2 | |
| 60 | mov a4, a3 | |
| 61 | mov a5, a4 | |
| f3ce45f3 | 62 | ldq a5,0(sp) /* arg6 -> a5 */ |
| 07f03a4d RM |
63 | |
| 64 | call_pal PAL_callsys /* Invoke system call */ | |
| c18b7473 | 65 | bne a3, SYSCALL_ERROR_LABEL |
| 6932e444 RM |
66 | ret |
| 67 | ||
| c18b7473 | 68 | PSEUDO_END(__syscall) |
| 3c7b2587 | 69 | |
| 8796ce21 | 70 | weak_alias (__syscall, syscall) |