1 /* DWARF2 EH unwinding support for PA HP-UX.
2    Copyright (C) 2005-2022 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC 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
14 GNU General Public License for more details.
15 
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19 
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 <http://www.gnu.org/licenses/>.  */
24 
25 /* Do code reading to identify a signal frame, and set the frame
26    state data appropriately.  See unwind-dw2.c for the structs.  */
27 
28 /* Don't use this if inhibit_libc is set.
29    The build for this target will fail trying to include missing headers. */
30 #ifndef inhibit_libc
31 #include <signal.h>
32 #include <sys/ucontext.h>
33 #include <unistd.h>
34 
35 /* FIXME: We currently ignore the high halves of general, space and
36    control registers on PA 2.0 machines for applications using the
37    32-bit runtime.  We don't restore space registers or the floating
38    point status registers.  */
39 
40 #define MD_FALLBACK_FRAME_STATE_FOR pa_fallback_frame_state
41 
42 /* HP-UX 10.X doesn't define GetSSReg.  */
43 #ifndef GetSSReg
44 #define GetSSReg(ssp, ss_reg) \
45   ((UseWideRegs (ssp))							\
46    ? (ssp)->ss_wide.ss_32.ss_reg ## _lo					\
47    : (ssp)->ss_narrow.ss_reg)
48 #endif
49 
50 #if TARGET_64BIT
51 #define GetSSRegAddr(ssp, ss_reg) ((long) &((ssp)->ss_wide.ss_64.ss_reg))
52 #else
53 #define GetSSRegAddr(ssp, ss_reg) \
54   ((UseWideRegs (ssp))							\
55    ? (long) &((ssp)->ss_wide.ss_32.ss_reg ## _lo)			\
56    : (long) &((ssp)->ss_narrow.ss_reg))
57 #endif
58 
59 #define UPDATE_FS_FOR_SAR(FS, N) \
60   (FS)->regs.reg[N].how = REG_SAVED_OFFSET;				\
61   (FS)->regs.reg[N].loc.offset = GetSSRegAddr (mc, ss_cr11) - new_cfa
62 
63 #define UPDATE_FS_FOR_GR(FS, GRN, N) \
64   (FS)->regs.reg[N].how = REG_SAVED_OFFSET;				\
65   (FS)->regs.reg[N].loc.offset = GetSSRegAddr (mc, ss_gr##GRN) - new_cfa
66 
67 #define UPDATE_FS_FOR_FR(FS, FRN, N) \
68   (FS)->regs.reg[N].how = REG_SAVED_OFFSET;				\
69   (FS)->regs.reg[N].loc.offset = (long) &(mc->ss_fr##FRN) - new_cfa;
70 
71 #define UPDATE_FS_FOR_PC(FS, N) \
72   (FS)->regs.reg[N].how = REG_SAVED_OFFSET;				\
73   (FS)->regs.reg[N].loc.offset = GetSSRegAddr (mc, ss_pcoq_head) - new_cfa
74 
75 /* Extract bit field from word using HP's numbering (MSB = 0).  */
76 #define GET_FIELD(X, FROM, TO) \
77   ((X) >> (31 - (TO)) & ((1 << ((TO) - (FROM) + 1)) - 1))
78 
79 static inline int
sign_extend(int x,int len)80 sign_extend (int x, int len)
81 {
82   int signbit = (1 << (len - 1));
83   int mask = (signbit << 1) - 1;
84   return ((x & mask) ^ signbit) - signbit;
85 }
86 
87 /* Extract a 17-bit signed constant from branch instructions.  */
88 static inline int
extract_17(unsigned word)89 extract_17 (unsigned word)
90 {
91   return sign_extend (GET_FIELD (word, 19, 28)
92 		      | GET_FIELD (word, 29, 29) << 10
93 		      | GET_FIELD (word, 11, 15) << 11
94 		      | (word & 0x1) << 16, 17);
95 }
96 
97 /* Extract a 22-bit signed constant from branch instructions.  */
98 static inline int
extract_22(unsigned word)99 extract_22 (unsigned word)
100 {
101   return sign_extend (GET_FIELD (word, 19, 28)
102 		      | GET_FIELD (word, 29, 29) << 10
103 		      | GET_FIELD (word, 11, 15) << 11
104 		      | GET_FIELD (word, 6, 10) << 16
105 		      | (word & 0x1) << 21, 22);
106 }
107 
108 static _Unwind_Reason_Code
pa_fallback_frame_state(struct _Unwind_Context * context,_Unwind_FrameState * fs)109 pa_fallback_frame_state (struct _Unwind_Context *context,
110 			 _Unwind_FrameState *fs)
111 {
112   static long cpu;
113   unsigned int *pc = (unsigned int *) context->ra;
114 
115   if (pc == 0)
116     return _URC_END_OF_STACK;
117 
118   /* Check for relocation of the return value.  */
119   if (!TARGET_64BIT
120       && *(pc + 0) == 0x2fd01224		/* fstd,ma fr4,8(sp) */
121       && *(pc + 1) == 0x0fd9109d		/* ldw -4(sp),ret1 */
122       && *(pc + 2) == 0x0fd130bc)		/* ldw,mb -8(sp),ret0 */
123     pc += 3;
124   else if (!TARGET_64BIT
125 	   && *(pc + 0) == 0x27d01224		/* fstw,ma fr4,8(sp) */
126 	   && *(pc + 1) == 0x0fd130bc)		/* ldw,mb -8(sp),ret0 */
127     pc += 2;
128   else if (!TARGET_64BIT
129 	   && *(pc + 0) == 0x0fdc12b0		/* stw,ma ret0,8(sp) */
130 	   && *(pc + 1) == 0x0fdd1299		/* stw ret1,-4(sp) */
131 	   && *(pc + 2) == 0x2fd13024)		/* fldd,mb -8(sp),fr4 */
132     pc += 3;
133   else if (!TARGET_64BIT
134 	   && *(pc + 0) == 0x0fdc12b0		/* stw,ma ret0,8(sp) */
135 	   && *(pc + 1) == 0x27d13024)		/* fldw,mb -8(sp),fr4 */
136     pc += 2;
137 
138   /* Check if the return address points to an export stub (PA 1.1 or 2.0).  */
139   if ((!TARGET_64BIT
140        && *(pc + 0) == 0x4bc23fd1		/* ldw -18(sp),rp */
141        && *(pc + 1) == 0x004010a1		/* ldsid (rp),r1 */
142        && *(pc + 2) == 0x00011820		/* mtsp r1,sr0 */
143        && *(pc + 3) == 0xe0400002)		/* be,n 0(sr0,rp) */
144       ||
145       (!TARGET_64BIT
146        && *(pc + 0) == 0x4bc23fd1		/* ldw -18(sp),rp */
147        && *(pc + 1) == 0xe840d002))		/* bve,n (rp) */
148     {
149       fs->regs.cfa_how    = CFA_REG_OFFSET;
150       fs->regs.cfa_reg    = 30;
151       fs->regs.cfa_offset = 0;
152 
153       fs->retaddr_column = 0;
154       fs->regs.reg[0].how = REG_SAVED_OFFSET;
155       fs->regs.reg[0].loc.offset = -24;
156 
157       /* Update context to describe the stub frame.  */
158       uw_update_context (context, fs);
159 
160       /* Set up fs to describe the FDE for the caller of this stub.  */
161       return uw_frame_state_for (context, fs);
162     }
163   /* Check if the return address points to a relocation stub.  */
164   else if (!TARGET_64BIT
165 	   && *(pc + 0) == 0x0fd11082		/* ldw -8(sp),rp */
166 	   && (*(pc + 1) == 0xe840c002		/* bv,n r0(rp) */
167 	       || *(pc + 1) == 0xe840d002))	/* bve,n (rp) */
168     {
169       fs->regs.cfa_how    = CFA_REG_OFFSET;
170       fs->regs.cfa_reg    = 30;
171       fs->regs.cfa_offset = 0;
172 
173       fs->retaddr_column = 0;
174       fs->regs.reg[0].how = REG_SAVED_OFFSET;
175       fs->regs.reg[0].loc.offset = -8;
176 
177       /* Update context to describe the stub frame.  */
178       uw_update_context (context, fs);
179 
180       /* Set up fs to describe the FDE for the caller of this stub.  */
181       return uw_frame_state_for (context, fs);
182     }
183 
184   /* Check if the return address is an export stub as signal handlers
185      may return via an export stub.  */
186   if (!TARGET_64BIT
187       && (*pc & 0xffe0e002) == 0xe8400000	/* bl x,r2 */
188       && *(pc + 1) == 0x08000240		/* nop */
189       && *(pc + 2) == 0x4bc23fd1		/* ldw -18(sp),rp */
190       && *(pc + 3) == 0x004010a1		/* ldsid (rp),r1 */
191       && *(pc + 4) == 0x00011820		/* mtsp r1,sr0 */
192       && *(pc + 5) == 0xe0400002)		/* be,n 0(sr0,rp) */
193     /* Extract target address from PA 1.x 17-bit branch.  */
194     pc += extract_17 (*pc) + 2;
195   else if (!TARGET_64BIT
196 	   && (*pc & 0xfc00e002) == 0xe800a000	/* b,l x,r2 */
197 	   && *(pc + 1) == 0x08000240		/* nop */
198 	   && *(pc + 2) == 0x4bc23fd1		/* ldw -18(sp),rp */
199 	   && *(pc + 3) == 0xe840d002)		/* bve,n (rp) */
200     /* Extract target address from PA 2.0 22-bit branch.  */
201     pc += extract_22 (*pc) + 2;
202 
203   /* Now check if the return address is one of the signal handler
204      returns, _sigreturn or _sigsetreturn.  */
205   if ((TARGET_64BIT
206        && *(pc + 0)  == 0x53db3f51		/* ldd -58(sp),dp */
207        && *(pc + 8)  == 0x34160116		/* ldi 8b,r22 */
208        && *(pc + 9)  == 0x08360ac1		/* shladd,l r22,3,r1,r1 */
209        && *(pc + 10) == 0x0c2010c1		/* ldd 0(r1),r1 */
210        && *(pc + 11) == 0xe4202000)		/* be,l 0(sr4,r1) */
211       ||
212       (TARGET_64BIT
213        && *(pc + 0)  == 0x36dc0000		/* ldo 0(r22),ret0 */
214        && *(pc + 6)  == 0x341601c0		/* ldi e0,r22 */
215        && *(pc + 7)  == 0x08360ac1		/* shladd,l r22,3,r1,r1 */
216        && *(pc + 8)  == 0x0c2010c1		/* ldd 0(r1),r1 */
217        && *(pc + 9)  == 0xe4202000)		/* be,l 0(sr4,r1) */
218       ||
219       (!TARGET_64BIT
220        && *(pc + 0)  == 0x379a0000		/* ldo 0(ret0),r26 */
221        && *(pc + 1)  == 0x6bd33fc9		/* stw r19,-1c(sp) */
222        && *(pc + 2)  == 0x20200801		/* ldil L%-40000000,r1 */
223        && *(pc + 3)  == 0xe420e008		/* be,l 4(sr7,r1) */
224        && *(pc + 4)  == 0x34160116)		/* ldi 8b,r22 */
225       ||
226       (!TARGET_64BIT
227        && *(pc + 0)  == 0x6bd33fc9		/* stw r19,-1c(sp) */
228        && *(pc + 1)  == 0x20200801		/* ldil L%-40000000,r1 */
229        && *(pc + 2)  == 0xe420e008		/* be,l 4(sr7,r1) */
230        && *(pc + 3)  == 0x341601c0))		/* ldi e0,r22 */
231     {
232       /* The previous stack pointer is saved at (long *)SP - 1.  The
233 	 ucontext structure is offset from the start of the previous
234 	 frame by the siglocal_misc structure.  */
235       struct siglocalx *sl = (struct siglocalx *)
236 	(*((long *) context->cfa - 1));
237       mcontext_t *mc = &(sl->sl_uc.uc_mcontext);
238 
239       long new_cfa = GetSSReg (mc, ss_sp);
240 
241       fs->regs.cfa_how = CFA_REG_OFFSET;
242       fs->regs.cfa_reg = 30;
243       fs->regs.cfa_offset = new_cfa - (long) context->cfa;
244 
245       UPDATE_FS_FOR_GR (fs, 1, 1);
246       UPDATE_FS_FOR_GR (fs, 2, 2);
247       UPDATE_FS_FOR_GR (fs, 3, 3);
248       UPDATE_FS_FOR_GR (fs, 4, 4);
249       UPDATE_FS_FOR_GR (fs, 5, 5);
250       UPDATE_FS_FOR_GR (fs, 6, 6);
251       UPDATE_FS_FOR_GR (fs, 7, 7);
252       UPDATE_FS_FOR_GR (fs, 8, 8);
253       UPDATE_FS_FOR_GR (fs, 9, 9);
254       UPDATE_FS_FOR_GR (fs, 10, 10);
255       UPDATE_FS_FOR_GR (fs, 11, 11);
256       UPDATE_FS_FOR_GR (fs, 12, 12);
257       UPDATE_FS_FOR_GR (fs, 13, 13);
258       UPDATE_FS_FOR_GR (fs, 14, 14);
259       UPDATE_FS_FOR_GR (fs, 15, 15);
260       UPDATE_FS_FOR_GR (fs, 16, 16);
261       UPDATE_FS_FOR_GR (fs, 17, 17);
262       UPDATE_FS_FOR_GR (fs, 18, 18);
263       UPDATE_FS_FOR_GR (fs, 19, 19);
264       UPDATE_FS_FOR_GR (fs, 20, 20);
265       UPDATE_FS_FOR_GR (fs, 21, 21);
266       UPDATE_FS_FOR_GR (fs, 22, 22);
267       UPDATE_FS_FOR_GR (fs, 23, 23);
268       UPDATE_FS_FOR_GR (fs, 24, 24);
269       UPDATE_FS_FOR_GR (fs, 25, 25);
270       UPDATE_FS_FOR_GR (fs, 26, 26);
271       UPDATE_FS_FOR_GR (fs, 27, 27);
272       UPDATE_FS_FOR_GR (fs, 28, 28);
273       UPDATE_FS_FOR_GR (fs, 29, 29);
274       UPDATE_FS_FOR_GR (fs, 30, 30);
275       UPDATE_FS_FOR_GR (fs, 31, 31);
276 
277       if (TARGET_64BIT)
278 	{
279 	  UPDATE_FS_FOR_FR (fs, 4, 32);
280 	  UPDATE_FS_FOR_FR (fs, 5, 33);
281 	  UPDATE_FS_FOR_FR (fs, 6, 34);
282 	  UPDATE_FS_FOR_FR (fs, 7, 35);
283 	  UPDATE_FS_FOR_FR (fs, 8, 36);
284 	  UPDATE_FS_FOR_FR (fs, 9, 37);
285 	  UPDATE_FS_FOR_FR (fs, 10, 38);
286 	  UPDATE_FS_FOR_FR (fs, 11, 39);
287 	  UPDATE_FS_FOR_FR (fs, 12, 40);
288 	  UPDATE_FS_FOR_FR (fs, 13, 41);
289 	  UPDATE_FS_FOR_FR (fs, 14, 42);
290 	  UPDATE_FS_FOR_FR (fs, 15, 43);
291 	  UPDATE_FS_FOR_FR (fs, 16, 44);
292 	  UPDATE_FS_FOR_FR (fs, 17, 45);
293 	  UPDATE_FS_FOR_FR (fs, 18, 46);
294 	  UPDATE_FS_FOR_FR (fs, 19, 47);
295 	  UPDATE_FS_FOR_FR (fs, 20, 48);
296 	  UPDATE_FS_FOR_FR (fs, 21, 49);
297 	  UPDATE_FS_FOR_FR (fs, 22, 50);
298 	  UPDATE_FS_FOR_FR (fs, 23, 51);
299 	  UPDATE_FS_FOR_FR (fs, 24, 52);
300 	  UPDATE_FS_FOR_FR (fs, 25, 53);
301 	  UPDATE_FS_FOR_FR (fs, 26, 54);
302 	  UPDATE_FS_FOR_FR (fs, 27, 55);
303 	  UPDATE_FS_FOR_FR (fs, 28, 56);
304 	  UPDATE_FS_FOR_FR (fs, 29, 57);
305 	  UPDATE_FS_FOR_FR (fs, 30, 58);
306 	  UPDATE_FS_FOR_FR (fs, 31, 59);
307 
308 	  UPDATE_FS_FOR_SAR (fs, 60);
309 	}
310       else
311 	{
312 	  UPDATE_FS_FOR_FR (fs, 4, 32);
313 	  UPDATE_FS_FOR_FR (fs, 5, 34);
314 	  UPDATE_FS_FOR_FR (fs, 6, 36);
315 	  UPDATE_FS_FOR_FR (fs, 7, 38);
316 	  UPDATE_FS_FOR_FR (fs, 8, 40);
317 	  UPDATE_FS_FOR_FR (fs, 9, 44);
318 	  UPDATE_FS_FOR_FR (fs, 10, 44);
319 	  UPDATE_FS_FOR_FR (fs, 11, 46);
320 	  UPDATE_FS_FOR_FR (fs, 12, 48);
321 	  UPDATE_FS_FOR_FR (fs, 13, 50);
322 	  UPDATE_FS_FOR_FR (fs, 14, 52);
323 	  UPDATE_FS_FOR_FR (fs, 15, 54);
324 
325 	  if (!cpu)
326 	    cpu = sysconf (_SC_CPU_VERSION);
327 
328 	  /* PA-RISC 1.0 only has 16 floating point registers.  */
329 	  if (cpu != CPU_PA_RISC1_0)
330 	    {
331 	      UPDATE_FS_FOR_FR (fs, 16, 56);
332 	      UPDATE_FS_FOR_FR (fs, 17, 58);
333 	      UPDATE_FS_FOR_FR (fs, 18, 60);
334 	      UPDATE_FS_FOR_FR (fs, 19, 62);
335 	      UPDATE_FS_FOR_FR (fs, 20, 64);
336 	      UPDATE_FS_FOR_FR (fs, 21, 66);
337 	      UPDATE_FS_FOR_FR (fs, 22, 68);
338 	      UPDATE_FS_FOR_FR (fs, 23, 70);
339 	      UPDATE_FS_FOR_FR (fs, 24, 72);
340 	      UPDATE_FS_FOR_FR (fs, 25, 74);
341 	      UPDATE_FS_FOR_FR (fs, 26, 76);
342 	      UPDATE_FS_FOR_FR (fs, 27, 78);
343 	      UPDATE_FS_FOR_FR (fs, 28, 80);
344 	      UPDATE_FS_FOR_FR (fs, 29, 82);
345 	      UPDATE_FS_FOR_FR (fs, 30, 84);
346 	      UPDATE_FS_FOR_FR (fs, 31, 86);
347 	    }
348 
349 	  UPDATE_FS_FOR_SAR (fs, 88);
350 	}
351 
352       fs->retaddr_column = __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__;
353       UPDATE_FS_FOR_PC (fs, __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__);
354       fs->signal_frame = 1;
355 
356       return _URC_NO_REASON;
357     }
358 
359   return _URC_END_OF_STACK;
360 }
361 #endif /* inhibit_libc */
362