1 /* Set up a context to call a function.
2 Copyright (C) 2002-2013 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
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.
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
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
20 #include <shlib-compat.h>
23 #include <asm/ptrace.h>
24 #include "ucontext_i.h"
27 /* Set up the first 7 args to the function in its registers */
28 lwz r11,_UC_REGS_PTR(r3)
29 stw r6,_UC_GREGS+(PT_R3*4)(r11)
30 stw r7,_UC_GREGS+(PT_R4*4)(r11)
31 stw r8,_UC_GREGS+(PT_R5*4)(r11)
32 stw r9,_UC_GREGS+(PT_R6*4)(r11)
33 stw r10,_UC_GREGS+(PT_R7*4)(r11)
36 stw r8,_UC_GREGS+(PT_R8*4)(r11)
37 stw r9,_UC_GREGS+(PT_R9*4)(r11)
39 /* Set the NIP to the start of the function */
40 stw r4,_UC_GREGS+(PT_NIP*4)(r11)
42 /* Set the function's r31 to ucp->uc_link for the exitcode below. */
44 stw r7,_UC_GREGS+(PT_R31*4)(r11)
46 /* Set the function's LR to point to the exitcode below. */
52 addi r6,r6,L(exitcode)-1b
57 addi r6,r6,L(exitcode)@l
59 stw r6,_UC_GREGS+(PT_LNK*4)(r11)
62 * Set up the stack frame for the function.
63 * If we have more than 5 args to the function (8 args to makecontext),
64 * there will be some arguments on the stack which have to end up
65 * in registers. If there are more than 8 args to the function,
66 * we have to copy (argc - 8) args from our stack to the functions'
67 * stack (and allow space for them in the frame).
69 lwz r4,_UC_STACK_SP(r3)
70 lwz r8,_UC_STACK_SIZE(r3)
72 rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
73 addi r7,r4,-16 /* stack frame for fn's caller */
75 blt 2f /* less than 8 args is easy */
77 stw r10,_UC_GREGS+(PT_R10*4)(r11)
78 beq 2f /* if exactly 8 args */
83 mtctr r5 /* copy the 9th and following args */
89 2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
96 * If the function returns, it comes here. We put ucp->uc_link in
97 * r31, which is a callee-saved register. We have to continue with
98 * the context that r31 points to, or exit if it is 0.
103 bl __setcontext@local
104 4: bl HIDDEN_JUMPTARGET(exit)
109 versioned_symbol (libc, __makecontext, makecontext, GLIBC_2_3_4)
111 #if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
114 ENTRY(__novec_makecontext)
115 /* Set up the first 7 args to the function in its registers */
116 addi r11,r3,_UC_REG_SPACE
117 stw r11,_UC_REGS_PTR(r3)
118 stw r6,_UC_GREGS+(PT_R3*4)(r11)
119 stw r7,_UC_GREGS+(PT_R4*4)(r11)
120 stw r8,_UC_GREGS+(PT_R5*4)(r11)
121 stw r9,_UC_GREGS+(PT_R6*4)(r11)
122 stw r10,_UC_GREGS+(PT_R7*4)(r11)
125 stw r8,_UC_GREGS+(PT_R8*4)(r11)
126 stw r9,_UC_GREGS+(PT_R9*4)(r11)
128 /* Set the NIP to the start of the function */
129 stw r4,_UC_GREGS+(PT_NIP*4)(r11)
131 /* Set the function's r31 to ucp->uc_link for the exitcode below. */
133 stw r7,_UC_GREGS+(PT_R31*4)(r11)
135 /* Set the function's LR to point to the exitcode below. */
141 addi r6,r6,L(novec_exitcode)-1b
145 lis r6,L(novec_exitcode)@ha
146 addi r6,r6,L(novec_exitcode)@l
148 stw r6,_UC_GREGS+(PT_LNK*4)(r11)
151 * Set up the stack frame for the function.
152 * If we have more than 5 args to the function (8 args to makecontext),
153 * there will be some arguments on the stack which have to end up
154 * in registers. If there are more than 8 args to the function,
155 * we have to copy (argc - 8) args from our stack to the functions'
156 * stack (and allow space for them in the frame).
158 lwz r4,_UC_STACK_SP(r3)
159 lwz r8,_UC_STACK_SIZE(r3)
161 rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
162 addi r7,r4,-16 /* stack frame for fn's caller */
164 blt 2f /* less than 8 args is easy */
166 stw r10,_UC_GREGS+(PT_R10*4)(r11)
167 beq 2f /* if exactly 8 args */
172 mtctr r5 /* copy the 9th and following args */
178 2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
185 * If the function returns, it comes here. We put ucp->uc_link in
186 * r31, which is a callee-saved register. We have to continue with
187 * the context that r31 points to, or exit if it is 0.
192 bl __novec_setcontext@local
193 4: bl HIDDEN_JUMPTARGET(exit)
196 END(__novec_makecontext)
199 compat_symbol (libc, __novec_makecontext, makecontext, GLIBC_2_3_3)
202 #if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3_3)
205 #include <bits/errno.h>
208 ENTRY (__makecontext_stub)
210 b __syscall_error@local
211 END (__makecontext_stub)
214 compat_symbol (libc, __makecontext_stub, makecontext, GLIBC_2_1)