1 /* DWARF2 EH unwinding support for PowerPC and PowerPC64 Linux.
2 Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published
8 by the Free Software Foundation; either version 2, or (at your
9 option) any later version.
11 In addition to the permissions in the GNU General Public License,
12 the Free Software Foundation gives you unlimited permission to link
13 the compiled version of this file with other programs, and to
14 distribute those programs without any restriction coming from the
15 use of this file. (The General Public License restrictions do
16 apply in other respects; for example, they cover modification of
17 the file, and distribution when not linked into another program.)
19 GCC is distributed in the hope that it will be useful, but WITHOUT
20 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
21 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
22 License for more details.
24 You should have received a copy of the GNU General Public License
25 along with GCC; see the file COPYING. If not, write to the
26 Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
27 MA 02110-1301, USA. */
29 /* This file defines our own versions of various kernel and user
30 structs, so that system headers are not needed, which otherwise
31 can make bootstrapping a new toolchain difficult. Do not use
32 these structs elsewhere; Many fields are missing, particularly
33 from the end of the structures. */
37 __attribute__ ((vector_size (16))) int vr[32];
52 unsigned long gpr[32];
55 unsigned long orig_gpr3;
65 unsigned long pad1[4];
74 struct gcc_vregs vregs;
80 unsigned long pad[28];
82 unsigned long pad[12];
84 struct gcc_regs *regs;
85 struct gcc_regs rsave;
90 enum { SIGNAL_FRAMESIZE = 128 };
92 /* If PC is at a sigreturn trampoline, return a pointer to the
93 regs. Otherwise return NULL. */
95 static struct gcc_regs *
96 get_regs (struct _Unwind_Context *context)
98 const unsigned char *pc = context->ra;
100 /* addi r1, r1, 128; li r0, 0x0077; sc (sigreturn) */
101 /* addi r1, r1, 128; li r0, 0x00AC; sc (rt_sigreturn) */
102 if (*(unsigned int *) (pc + 0) != 0x38210000 + SIGNAL_FRAMESIZE
103 || *(unsigned int *) (pc + 8) != 0x44000002)
105 if (*(unsigned int *) (pc + 4) == 0x38000077)
108 char gap[SIGNAL_FRAMESIZE];
109 unsigned long pad[7];
110 struct gcc_regs *regs;
111 } *frame = (struct sigframe *) context->cfa;
114 else if (*(unsigned int *) (pc + 4) == 0x380000AC)
116 /* This works for 2.4 kernels, but not for 2.6 kernels with vdso
117 because pc isn't pointing into the stack. Can be removed when
118 no one is running 2.4.19 or 2.4.20, the first two ppc64
120 struct rt_sigframe_24 {
123 struct gcc_ucontext *puc;
124 } *frame24 = (struct rt_sigframe_24 *) pc;
126 /* Test for magic value in *puc of vdso. */
127 if ((long) frame24->puc != -21 * 8)
128 return frame24->puc->regs;
131 /* This works for 2.4.21 and later kernels. */
133 char gap[SIGNAL_FRAMESIZE];
134 struct gcc_ucontext uc;
135 unsigned long pad[2];
138 struct gcc_ucontext *puc;
139 } *frame = (struct rt_sigframe *) context->cfa;
140 return frame->uc.regs;
146 #else /* !__powerpc64__ */
148 enum { SIGNAL_FRAMESIZE = 64 };
150 static struct gcc_regs *
151 get_regs (struct _Unwind_Context *context)
153 const unsigned char *pc = context->ra;
155 /* li r0, 0x7777; sc (sigreturn old) */
156 /* li r0, 0x0077; sc (sigreturn new) */
157 /* li r0, 0x6666; sc (rt_sigreturn old) */
158 /* li r0, 0x00AC; sc (rt_sigreturn new) */
159 if (*(unsigned int *) (pc + 4) != 0x44000002)
161 if (*(unsigned int *) (pc + 0) == 0x38007777
162 || *(unsigned int *) (pc + 0) == 0x38000077)
165 char gap[SIGNAL_FRAMESIZE];
166 unsigned long pad[7];
167 struct gcc_regs *regs;
168 } *frame = (struct sigframe *) context->cfa;
171 else if (*(unsigned int *) (pc + 0) == 0x38006666
172 || *(unsigned int *) (pc + 0) == 0x380000AC)
175 char gap[SIGNAL_FRAMESIZE + 16];
177 struct gcc_ucontext uc;
178 } *frame = (struct rt_sigframe *) context->cfa;
179 return frame->uc.regs;
185 /* Find an entry in the process auxiliary vector. The canonical way to
186 test for VMX is to look at AT_HWCAP. */
189 ppc_linux_aux_vector (long which)
191 /* __libc_stack_end holds the original stack passed to a process. */
192 extern long *__libc_stack_end;
202 /* The Linux kernel puts argc first on the stack. */
203 argc = __libc_stack_end[0];
204 /* Followed by argv, NULL terminated. */
205 argv = (char **) __libc_stack_end + 1;
206 /* Followed by environment string pointers, NULL terminated. */
207 envp = argv + argc + 1;
210 /* Followed by the aux vector, zero terminated. */
211 for (auxp = (struct auxv *) envp; auxp->a_type != 0; ++auxp)
212 if (auxp->a_type == which)
217 /* Do code reading to identify a signal frame, and set the frame
218 state data appropriately. See unwind-dw2.c for the structs. */
220 #define MD_FALLBACK_FRAME_STATE_FOR ppc_fallback_frame_state
222 static _Unwind_Reason_Code
223 ppc_fallback_frame_state (struct _Unwind_Context *context,
224 _Unwind_FrameState *fs)
226 static long hwcap = 0;
227 struct gcc_regs *regs = get_regs (context);
232 return _URC_END_OF_STACK;
234 new_cfa = regs->gpr[STACK_POINTER_REGNUM];
235 fs->cfa_how = CFA_REG_OFFSET;
236 fs->cfa_reg = STACK_POINTER_REGNUM;
237 fs->cfa_offset = new_cfa - (long) context->cfa;
239 for (i = 0; i < 32; i++)
240 if (i != STACK_POINTER_REGNUM)
242 fs->regs.reg[i].how = REG_SAVED_OFFSET;
243 fs->regs.reg[i].loc.offset = (long) ®s->gpr[i] - new_cfa;
246 fs->regs.reg[CR2_REGNO].how = REG_SAVED_OFFSET;
247 fs->regs.reg[CR2_REGNO].loc.offset = (long) ®s->ccr - new_cfa;
249 fs->regs.reg[LINK_REGISTER_REGNUM].how = REG_SAVED_OFFSET;
250 fs->regs.reg[LINK_REGISTER_REGNUM].loc.offset = (long) ®s->link - new_cfa;
252 fs->regs.reg[ARG_POINTER_REGNUM].how = REG_SAVED_OFFSET;
253 fs->regs.reg[ARG_POINTER_REGNUM].loc.offset = (long) ®s->nip - new_cfa;
254 fs->retaddr_column = ARG_POINTER_REGNUM;
255 fs->signal_frame = 1;
259 hwcap = ppc_linux_aux_vector (16);
260 /* These will already be set if we found AT_HWCAP. A nonzero
261 value stops us looking again if for some reason we couldn't
270 /* If we have a FPU... */
271 if (hwcap & 0x08000000)
272 for (i = 0; i < 32; i++)
274 fs->regs.reg[i + 32].how = REG_SAVED_OFFSET;
275 fs->regs.reg[i + 32].loc.offset = (long) ®s->fpr[i] - new_cfa;
278 /* If we have a VMX unit... */
279 if (hwcap & 0x10000000)
281 struct gcc_vregs *vregs;
285 vregs = ®s->vregs;
287 if (regs->msr & (1 << 25))
289 for (i = 0; i < 32; i++)
291 fs->regs.reg[i + FIRST_ALTIVEC_REGNO].how = REG_SAVED_OFFSET;
292 fs->regs.reg[i + FIRST_ALTIVEC_REGNO].loc.offset
293 = (long) &vregs[i] - new_cfa;
296 fs->regs.reg[VSCR_REGNO].how = REG_SAVED_OFFSET;
297 fs->regs.reg[VSCR_REGNO].loc.offset = (long) &vregs->vscr - new_cfa;
300 fs->regs.reg[VRSAVE_REGNO].how = REG_SAVED_OFFSET;
301 fs->regs.reg[VRSAVE_REGNO].loc.offset = (long) &vregs->vsave - new_cfa;
304 return _URC_NO_REASON;
307 #define MD_FROB_UPDATE_CONTEXT frob_update_context
310 frob_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs ATTRIBUTE_UNUSED)
312 const unsigned int *pc = (const unsigned int *) context->ra;
314 /* Fix up for 2.6.12 - 2.6.16 Linux kernels that have vDSO, but don't
315 have S flag in it. */
317 /* addi r1, r1, 128; li r0, 0x0077; sc (sigreturn) */
318 /* addi r1, r1, 128; li r0, 0x00AC; sc (rt_sigreturn) */
319 if (pc[0] == 0x38210000 + SIGNAL_FRAMESIZE
320 && (pc[1] == 0x38000077 || pc[1] == 0x380000AC)
321 && pc[2] == 0x44000002)
322 _Unwind_SetSignalFrame (context, 1);
324 /* li r0, 0x7777; sc (sigreturn old) */
325 /* li r0, 0x0077; sc (sigreturn new) */
326 /* li r0, 0x6666; sc (rt_sigreturn old) */
327 /* li r0, 0x00AC; sc (rt_sigreturn new) */
328 if ((pc[0] == 0x38007777 || pc[0] == 0x38000077
329 || pc[0] == 0x38006666 || pc[0] == 0x380000AC)
330 && pc[1] == 0x44000002)
331 _Unwind_SetSignalFrame (context, 1);
335 if (fs->regs.reg[2].how == REG_UNSAVED)
337 /* If the current unwind info (FS) does not contain explicit info
338 saving R2, then we have to do a minor amount of code reading to
339 figure out if it was saved. The big problem here is that the
340 code that does the save/restore is generated by the linker, so
341 we have no good way to determine at compile time what to do. */
343 = (unsigned int *) _Unwind_GetGR (context, LINK_REGISTER_REGNUM);
344 if (*insn == 0xE8410028)
345 _Unwind_SetGRPtr (context, 2, context->cfa + 40);