projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| a678c13b | 1 | /* Save current context and install the given one. |
| 2b778ceb | 2 | Copyright (C) 2001-2021 Free Software Foundation, Inc. |
| a678c13b TS |
3 | This file is part of the GNU C Library. |
| 4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2001. | |
| 5 | ||
| 6 | The GNU C Library is free software; you can redistribute it and/or | |
| 7 | modify it under the terms of the GNU Lesser General Public | |
| 8 | License as published by the Free Software Foundation; either | |
| 9 | version 2.1 of the License, or (at your option) any later version. | |
| 10 | ||
| 11 | The GNU C Library is distributed in the hope that it will be useful, | |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 | Lesser General Public License for more details. | |
| 15 | ||
| 16 | You should have received a copy of the GNU Lesser General Public | |
| 17 | License along with the GNU C Library; if not, see | |
| 18 | <https://www.gnu.org/licenses/>. */ | |
| 19 | ||
| 20 | #include <sysdep.h> | |
| 21 | ||
| 22 | #include "ucontext_i.h" | |
| 23 | ||
| 24 | ||
| 25 | ENTRY(__swapcontext) | |
| 26 | /* Load address of the context data structure we save in. */ | |
| 27 | movl 4(%esp), %eax | |
| 28 | ||
| 29 | /* Return value of swapcontext. EAX is the only register whose | |
| 30 | value is not preserved. */ | |
| 31 | movl $0, oEAX(%eax) | |
| 32 | ||
| 33 | /* Save the 32-bit register values and the return address. */ | |
| 34 | movl %ecx, oECX(%eax) | |
| 35 | movl %edx, oEDX(%eax) | |
| 36 | movl %edi, oEDI(%eax) | |
| 37 | movl %esi, oESI(%eax) | |
| 38 | movl %ebp, oEBP(%eax) | |
| 39 | movl (%esp), %ecx | |
| 40 | movl %ecx, oEIP(%eax) | |
| 41 | leal 4(%esp), %ecx | |
| 42 | movl %ecx, oESP(%eax) | |
| 43 | movl %ebx, oEBX(%eax) | |
| 44 | ||
| 45 | /* Save the FS segment register. */ | |
| 46 | xorl %edx, %edx | |
| 47 | movw %fs, %dx | |
| 48 | movl %edx, oFS(%eax) | |
| 49 | ||
| 50 | leal oFPREGS(%eax), %ecx | |
| 51 | /* Save the floating-point context. */ | |
| 52 | fnstenv (%ecx) | |
| 53 | ||
| 54 | /* Load address of the context data structure we have to load. */ | |
| 55 | movl 8(%esp), %ecx | |
| 56 | ||
| 57 | /* Save the current signal mask and install the new one. */ | |
| 58 | subl $12, %esp | |
| 59 | cfi_adjust_cfa_offset (12) | |
| 60 | leal oSIGMASK(%eax), %eax | |
| 61 | movl %eax, 8(%esp) | |
| 62 | leal oSIGMASK(%ecx), %eax | |
| 63 | movl %eax, 4(%esp) | |
| 64 | movl $SIG_SETMASK, (%esp) | |
| 65 | call HIDDEN_JUMPTARGET (__sigprocmask) | |
| 66 | addl $12, %esp | |
| 67 | cfi_adjust_cfa_offset (-12) | |
| 68 | testl %eax, %eax | |
| 69 | jne L(pseudo_end) | |
| 70 | ||
| 71 | /* EAX was modified, reload it. */ | |
| 72 | movl 8(%esp), %eax | |
| 73 | ||
| 74 | /* Restore the floating-point context. Not the registers, only the | |
| 75 | rest. */ | |
| 76 | leal oFPREGS(%eax), %ecx | |
| 77 | fldenv (%ecx) | |
| 78 | ||
| 79 | /* Restore the FS segment register. We don't touch the GS register | |
| 80 | since it is used for threads. */ | |
| 81 | movl oFS(%eax), %edx | |
| 82 | movw %dx, %fs | |
| 83 | ||
| 84 | /* Fetch the address to return to. */ | |
| 85 | movl oEIP(%eax), %ecx | |
| 86 | ||
| 87 | /* Load the new stack pointer. */ | |
| 88 | movl oESP(%eax), %esp | |
| 89 | ||
| 90 | /* Push the return address on the new stack so we can return there. */ | |
| 91 | pushl %ecx | |
| 92 | ||
| 93 | /* Load the values of all the 32-bit registers (except ESP). | |
| 94 | Since we are loading from EAX, it must be last. */ | |
| 95 | movl oEDI(%eax), %edi | |
| 96 | movl oESI(%eax), %esi | |
| 97 | movl oEBP(%eax), %ebp | |
| 98 | movl oEBX(%eax), %ebx | |
| 99 | movl oEDX(%eax), %edx | |
| 100 | movl oECX(%eax), %ecx | |
| 101 | movl oEAX(%eax), %eax | |
| 102 | ||
| 103 | /* The following 'ret' will pop the address of the code and jump | |
| 104 | to it. */ | |
| 105 | ||
| 106 | L(pseudo_end): | |
| 107 | ret | |
| 108 | PSEUDO_END(__swapcontext) | |
| 109 | ||
| 110 | weak_alias (__swapcontext, swapcontext) |