| 1 | /* POSIX.1 `sigaction' call for Linux/i386. |
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| 2 | Copyright (C) 1991-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <signal.h> |
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| 20 | #include <ldsodefs.h> |
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| 21 | |
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| 22 | #define SA_RESTORER 0x04000000 |
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| 23 | |
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| 24 | extern void restore_rt (void) asm ("__restore_rt" ) attribute_hidden; |
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| 25 | extern void restore (void) asm ("__restore" ) attribute_hidden; |
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| 26 | |
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| 27 | #define SET_SA_RESTORER(kact, act) \ |
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| 28 | ({ \ |
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| 29 | if (GLRO(dl_sysinfo_dso) == NULL) \ |
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| 30 | { \ |
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| 31 | (kact)->sa_flags |= SA_RESTORER; \ |
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| 32 | (kact)->sa_restorer = (((act)->sa_flags & SA_SIGINFO) \ |
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| 33 | ? &restore_rt : &restore); \ |
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| 34 | } \ |
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| 35 | else \ |
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| 36 | (kact)->sa_restorer = NULL; \ |
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| 37 | }) |
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| 38 | |
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| 39 | #define RESET_SA_RESTORER(act, kact) \ |
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| 40 | (act)->sa_restorer = (kact)->sa_restorer |
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| 41 | |
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| 42 | #include <sysdeps/unix/sysv/linux/libc_sigaction.c> |
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| 43 | |
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| 44 | /* NOTE: Please think twice before making any changes to the bits of |
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| 45 | code below. GDB needs some intimate knowledge about it to |
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| 46 | recognize them as signal trampolines, and make backtraces through |
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| 47 | signal handlers work right. Important are both the names |
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| 48 | (__restore and __restore_rt) and the exact instruction sequence. |
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| 49 | If you ever feel the need to make any changes, please notify the |
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| 50 | appropriate GDB maintainer. */ |
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| 51 | |
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| 52 | #define RESTORE(name, syscall) RESTORE2 (name, syscall) |
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| 53 | #define RESTORE2(name, syscall) \ |
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| 54 | asm \ |
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| 55 | ( \ |
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| 56 | ".text\n" \ |
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| 57 | " .align 16\n" \ |
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| 58 | "__" #name ":\n" \ |
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| 59 | " movl $" #syscall ", %eax\n" \ |
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| 60 | " int $0x80" \ |
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| 61 | ); |
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| 62 | |
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| 63 | /* The return code for realtime-signals. */ |
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| 64 | RESTORE (restore_rt, __NR_rt_sigreturn) |
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| 65 | |
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| 66 | /* For the boring old signals. */ |
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| 67 | #undef RESTORE2 |
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| 68 | #define RESTORE2(name, syscall) \ |
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| 69 | asm \ |
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| 70 | ( \ |
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| 71 | ".text\n" \ |
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| 72 | " .align 8\n" \ |
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| 73 | "__" #name ":\n" \ |
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| 74 | " popl %eax\n" \ |
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| 75 | " movl $" #syscall ", %eax\n" \ |
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| 76 | " int $0x80" \ |
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| 77 | ); |
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| 78 | |
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| 79 | RESTORE (restore, __NR_sigreturn) |
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| 80 | |
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