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faf5f7ad | 1 | /* GNU/Linux on ARM target support. |
0fd88904 | 2 | |
28e7fd62 | 3 | Copyright (C) 1999-2013 Free Software Foundation, Inc. |
faf5f7ad SB |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
faf5f7ad SB |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
faf5f7ad SB |
19 | |
20 | #include "defs.h" | |
c20f6dea SB |
21 | #include "target.h" |
22 | #include "value.h" | |
faf5f7ad | 23 | #include "gdbtypes.h" |
134e61c4 | 24 | #include "floatformat.h" |
2a451106 KB |
25 | #include "gdbcore.h" |
26 | #include "frame.h" | |
4e052eda | 27 | #include "regcache.h" |
d16aafd8 | 28 | #include "doublest.h" |
7aa1783e | 29 | #include "solib-svr4.h" |
4be87837 | 30 | #include "osabi.h" |
cb587d83 | 31 | #include "regset.h" |
8e9d1a24 DJ |
32 | #include "trad-frame.h" |
33 | #include "tramp-frame.h" | |
daddc3c1 | 34 | #include "breakpoint.h" |
ef7e8358 | 35 | #include "auxv.h" |
9f948660 | 36 | #include "xml-syscall.h" |
faf5f7ad | 37 | |
34e8f22d | 38 | #include "arm-tdep.h" |
cb587d83 | 39 | #include "arm-linux-tdep.h" |
4aa995e1 | 40 | #include "linux-tdep.h" |
0670c0aa | 41 | #include "glibc-tdep.h" |
cca44b1b JB |
42 | #include "arch-utils.h" |
43 | #include "inferior.h" | |
44 | #include "gdbthread.h" | |
45 | #include "symfile.h" | |
a52e6aac | 46 | |
55aa24fb SDJ |
47 | #include "cli/cli-utils.h" |
48 | #include "stap-probe.h" | |
49 | #include "parser-defs.h" | |
50 | #include "user-regs.h" | |
51 | #include <ctype.h> | |
04a83fee | 52 | #include "elf/common.h" |
0e9f083f | 53 | #include <string.h> |
8e9d1a24 | 54 | |
cb587d83 DJ |
55 | extern int arm_apcs_32; |
56 | ||
fdf39c9a RE |
57 | /* Under ARM GNU/Linux the traditional way of performing a breakpoint |
58 | is to execute a particular software interrupt, rather than use a | |
59 | particular undefined instruction to provoke a trap. Upon exection | |
60 | of the software interrupt the kernel stops the inferior with a | |
498b1f87 | 61 | SIGTRAP, and wakes the debugger. */ |
66e810cd | 62 | |
948f8e3d | 63 | static const gdb_byte arm_linux_arm_le_breakpoint[] = { 0x01, 0x00, 0x9f, 0xef }; |
2ef47cd0 | 64 | |
948f8e3d | 65 | static const gdb_byte arm_linux_arm_be_breakpoint[] = { 0xef, 0x9f, 0x00, 0x01 }; |
66e810cd | 66 | |
c75a2cc8 DJ |
67 | /* However, the EABI syscall interface (new in Nov. 2005) does not look at |
68 | the operand of the swi if old-ABI compatibility is disabled. Therefore, | |
69 | use an undefined instruction instead. This is supported as of kernel | |
70 | version 2.5.70 (May 2003), so should be a safe assumption for EABI | |
71 | binaries. */ | |
72 | ||
948f8e3d | 73 | static const gdb_byte eabi_linux_arm_le_breakpoint[] = { 0xf0, 0x01, 0xf0, 0xe7 }; |
c75a2cc8 | 74 | |
948f8e3d | 75 | static const gdb_byte eabi_linux_arm_be_breakpoint[] = { 0xe7, 0xf0, 0x01, 0xf0 }; |
c75a2cc8 DJ |
76 | |
77 | /* All the kernels which support Thumb support using a specific undefined | |
78 | instruction for the Thumb breakpoint. */ | |
79 | ||
948f8e3d | 80 | static const gdb_byte arm_linux_thumb_be_breakpoint[] = {0xde, 0x01}; |
498b1f87 | 81 | |
948f8e3d | 82 | static const gdb_byte arm_linux_thumb_le_breakpoint[] = {0x01, 0xde}; |
498b1f87 | 83 | |
177321bd DJ |
84 | /* Because the 16-bit Thumb breakpoint is affected by Thumb-2 IT blocks, |
85 | we must use a length-appropriate breakpoint for 32-bit Thumb | |
86 | instructions. See also thumb_get_next_pc. */ | |
87 | ||
948f8e3d | 88 | static const gdb_byte arm_linux_thumb2_be_breakpoint[] = { 0xf7, 0xf0, 0xa0, 0x00 }; |
177321bd | 89 | |
948f8e3d | 90 | static const gdb_byte arm_linux_thumb2_le_breakpoint[] = { 0xf0, 0xf7, 0x00, 0xa0 }; |
177321bd | 91 | |
f8624c62 MGD |
92 | /* Description of the longjmp buffer. The buffer is treated as an array of |
93 | elements of size ARM_LINUX_JB_ELEMENT_SIZE. | |
94 | ||
95 | The location of saved registers in this buffer (in particular the PC | |
96 | to use after longjmp is called) varies depending on the ABI (in | |
97 | particular the FP model) and also (possibly) the C Library. | |
98 | ||
99 | For glibc, eglibc, and uclibc the following holds: If the FP model is | |
100 | SoftVFP or VFP (which implies EABI) then the PC is at offset 9 in the | |
101 | buffer. This is also true for the SoftFPA model. However, for the FPA | |
102 | model the PC is at offset 21 in the buffer. */ | |
7a5ea0d4 | 103 | #define ARM_LINUX_JB_ELEMENT_SIZE INT_REGISTER_SIZE |
f8624c62 MGD |
104 | #define ARM_LINUX_JB_PC_FPA 21 |
105 | #define ARM_LINUX_JB_PC_EABI 9 | |
faf5f7ad | 106 | |
f38e884d | 107 | /* |
fdf39c9a RE |
108 | Dynamic Linking on ARM GNU/Linux |
109 | -------------------------------- | |
f38e884d SB |
110 | |
111 | Note: PLT = procedure linkage table | |
112 | GOT = global offset table | |
113 | ||
114 | As much as possible, ELF dynamic linking defers the resolution of | |
0963b4bd | 115 | jump/call addresses until the last minute. The technique used is |
f38e884d SB |
116 | inspired by the i386 ELF design, and is based on the following |
117 | constraints. | |
118 | ||
119 | 1) The calling technique should not force a change in the assembly | |
120 | code produced for apps; it MAY cause changes in the way assembly | |
121 | code is produced for position independent code (i.e. shared | |
122 | libraries). | |
123 | ||
124 | 2) The technique must be such that all executable areas must not be | |
125 | modified; and any modified areas must not be executed. | |
126 | ||
127 | To do this, there are three steps involved in a typical jump: | |
128 | ||
129 | 1) in the code | |
130 | 2) through the PLT | |
131 | 3) using a pointer from the GOT | |
132 | ||
133 | When the executable or library is first loaded, each GOT entry is | |
134 | initialized to point to the code which implements dynamic name | |
135 | resolution and code finding. This is normally a function in the | |
fdf39c9a RE |
136 | program interpreter (on ARM GNU/Linux this is usually |
137 | ld-linux.so.2, but it does not have to be). On the first | |
138 | invocation, the function is located and the GOT entry is replaced | |
139 | with the real function address. Subsequent calls go through steps | |
140 | 1, 2 and 3 and end up calling the real code. | |
f38e884d SB |
141 | |
142 | 1) In the code: | |
143 | ||
144 | b function_call | |
145 | bl function_call | |
146 | ||
147 | This is typical ARM code using the 26 bit relative branch or branch | |
148 | and link instructions. The target of the instruction | |
149 | (function_call is usually the address of the function to be called. | |
150 | In position independent code, the target of the instruction is | |
151 | actually an entry in the PLT when calling functions in a shared | |
152 | library. Note that this call is identical to a normal function | |
153 | call, only the target differs. | |
154 | ||
155 | 2) In the PLT: | |
156 | ||
0963b4bd MS |
157 | The PLT is a synthetic area, created by the linker. It exists in |
158 | both executables and libraries. It is an array of stubs, one per | |
159 | imported function call. It looks like this: | |
f38e884d SB |
160 | |
161 | PLT[0]: | |
162 | str lr, [sp, #-4]! @push the return address (lr) | |
163 | ldr lr, [pc, #16] @load from 6 words ahead | |
164 | add lr, pc, lr @form an address for GOT[0] | |
165 | ldr pc, [lr, #8]! @jump to the contents of that addr | |
166 | ||
167 | The return address (lr) is pushed on the stack and used for | |
168 | calculations. The load on the second line loads the lr with | |
169 | &GOT[3] - . - 20. The addition on the third leaves: | |
170 | ||
171 | lr = (&GOT[3] - . - 20) + (. + 8) | |
172 | lr = (&GOT[3] - 12) | |
173 | lr = &GOT[0] | |
174 | ||
175 | On the fourth line, the pc and lr are both updated, so that: | |
176 | ||
177 | pc = GOT[2] | |
178 | lr = &GOT[0] + 8 | |
179 | = &GOT[2] | |
180 | ||
0963b4bd | 181 | NOTE: PLT[0] borrows an offset .word from PLT[1]. This is a little |
f38e884d SB |
182 | "tight", but allows us to keep all the PLT entries the same size. |
183 | ||
184 | PLT[n+1]: | |
185 | ldr ip, [pc, #4] @load offset from gotoff | |
186 | add ip, pc, ip @add the offset to the pc | |
187 | ldr pc, [ip] @jump to that address | |
188 | gotoff: .word GOT[n+3] - . | |
189 | ||
190 | The load on the first line, gets an offset from the fourth word of | |
191 | the PLT entry. The add on the second line makes ip = &GOT[n+3], | |
192 | which contains either a pointer to PLT[0] (the fixup trampoline) or | |
193 | a pointer to the actual code. | |
194 | ||
195 | 3) In the GOT: | |
196 | ||
197 | The GOT contains helper pointers for both code (PLT) fixups and | |
0963b4bd | 198 | data fixups. The first 3 entries of the GOT are special. The next |
f38e884d | 199 | M entries (where M is the number of entries in the PLT) belong to |
0963b4bd MS |
200 | the PLT fixups. The next D (all remaining) entries belong to |
201 | various data fixups. The actual size of the GOT is 3 + M + D. | |
f38e884d | 202 | |
0963b4bd | 203 | The GOT is also a synthetic area, created by the linker. It exists |
f38e884d SB |
204 | in both executables and libraries. When the GOT is first |
205 | initialized , all the GOT entries relating to PLT fixups are | |
206 | pointing to code back at PLT[0]. | |
207 | ||
208 | The special entries in the GOT are: | |
209 | ||
210 | GOT[0] = linked list pointer used by the dynamic loader | |
211 | GOT[1] = pointer to the reloc table for this module | |
212 | GOT[2] = pointer to the fixup/resolver code | |
213 | ||
214 | The first invocation of function call comes through and uses the | |
215 | fixup/resolver code. On the entry to the fixup/resolver code: | |
216 | ||
217 | ip = &GOT[n+3] | |
218 | lr = &GOT[2] | |
219 | stack[0] = return address (lr) of the function call | |
220 | [r0, r1, r2, r3] are still the arguments to the function call | |
221 | ||
222 | This is enough information for the fixup/resolver code to work | |
223 | with. Before the fixup/resolver code returns, it actually calls | |
224 | the requested function and repairs &GOT[n+3]. */ | |
225 | ||
2a451106 KB |
226 | /* The constants below were determined by examining the following files |
227 | in the linux kernel sources: | |
228 | ||
229 | arch/arm/kernel/signal.c | |
230 | - see SWI_SYS_SIGRETURN and SWI_SYS_RT_SIGRETURN | |
231 | include/asm-arm/unistd.h | |
232 | - see __NR_sigreturn, __NR_rt_sigreturn, and __NR_SYSCALL_BASE */ | |
233 | ||
234 | #define ARM_LINUX_SIGRETURN_INSTR 0xef900077 | |
235 | #define ARM_LINUX_RT_SIGRETURN_INSTR 0xef9000ad | |
236 | ||
edfb1a26 DJ |
237 | /* For ARM EABI, the syscall number is not in the SWI instruction |
238 | (instead it is loaded into r7). We recognize the pattern that | |
239 | glibc uses... alternatively, we could arrange to do this by | |
240 | function name, but they are not always exported. */ | |
8e9d1a24 DJ |
241 | #define ARM_SET_R7_SIGRETURN 0xe3a07077 |
242 | #define ARM_SET_R7_RT_SIGRETURN 0xe3a070ad | |
243 | #define ARM_EABI_SYSCALL 0xef000000 | |
2a451106 | 244 | |
f1973203 MR |
245 | /* OABI syscall restart trampoline, used for EABI executables too |
246 | whenever OABI support has been enabled in the kernel. */ | |
247 | #define ARM_OABI_SYSCALL_RESTART_SYSCALL 0xef900000 | |
248 | #define ARM_LDR_PC_SP_12 0xe49df00c | |
478fd957 | 249 | #define ARM_LDR_PC_SP_4 0xe49df004 |
f1973203 | 250 | |
8e9d1a24 | 251 | static void |
a262aec2 | 252 | arm_linux_sigtramp_cache (struct frame_info *this_frame, |
8e9d1a24 DJ |
253 | struct trad_frame_cache *this_cache, |
254 | CORE_ADDR func, int regs_offset) | |
2a451106 | 255 | { |
a262aec2 | 256 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); |
8e9d1a24 DJ |
257 | CORE_ADDR base = sp + regs_offset; |
258 | int i; | |
2a451106 | 259 | |
8e9d1a24 DJ |
260 | for (i = 0; i < 16; i++) |
261 | trad_frame_set_reg_addr (this_cache, i, base + i * 4); | |
2a451106 | 262 | |
8e9d1a24 | 263 | trad_frame_set_reg_addr (this_cache, ARM_PS_REGNUM, base + 16 * 4); |
2a451106 | 264 | |
8e9d1a24 DJ |
265 | /* The VFP or iWMMXt registers may be saved on the stack, but there's |
266 | no reliable way to restore them (yet). */ | |
2a451106 | 267 | |
8e9d1a24 DJ |
268 | /* Save a frame ID. */ |
269 | trad_frame_set_id (this_cache, frame_id_build (sp, func)); | |
270 | } | |
2a451106 | 271 | |
edfb1a26 DJ |
272 | /* There are a couple of different possible stack layouts that |
273 | we need to support. | |
274 | ||
275 | Before version 2.6.18, the kernel used completely independent | |
276 | layouts for non-RT and RT signals. For non-RT signals the stack | |
277 | began directly with a struct sigcontext. For RT signals the stack | |
278 | began with two redundant pointers (to the siginfo and ucontext), | |
279 | and then the siginfo and ucontext. | |
280 | ||
281 | As of version 2.6.18, the non-RT signal frame layout starts with | |
282 | a ucontext and the RT signal frame starts with a siginfo and then | |
283 | a ucontext. Also, the ucontext now has a designated save area | |
284 | for coprocessor registers. | |
285 | ||
286 | For RT signals, it's easy to tell the difference: we look for | |
287 | pinfo, the pointer to the siginfo. If it has the expected | |
288 | value, we have an old layout. If it doesn't, we have the new | |
289 | layout. | |
290 | ||
291 | For non-RT signals, it's a bit harder. We need something in one | |
292 | layout or the other with a recognizable offset and value. We can't | |
293 | use the return trampoline, because ARM usually uses SA_RESTORER, | |
294 | in which case the stack return trampoline is not filled in. | |
295 | We can't use the saved stack pointer, because sigaltstack might | |
296 | be in use. So for now we guess the new layout... */ | |
297 | ||
298 | /* There are three words (trap_no, error_code, oldmask) in | |
299 | struct sigcontext before r0. */ | |
300 | #define ARM_SIGCONTEXT_R0 0xc | |
301 | ||
302 | /* There are five words (uc_flags, uc_link, and three for uc_stack) | |
303 | in the ucontext_t before the sigcontext. */ | |
304 | #define ARM_UCONTEXT_SIGCONTEXT 0x14 | |
305 | ||
306 | /* There are three elements in an rt_sigframe before the ucontext: | |
307 | pinfo, puc, and info. The first two are pointers and the third | |
308 | is a struct siginfo, with size 128 bytes. We could follow puc | |
309 | to the ucontext, but it's simpler to skip the whole thing. */ | |
310 | #define ARM_OLD_RT_SIGFRAME_SIGINFO 0x8 | |
311 | #define ARM_OLD_RT_SIGFRAME_UCONTEXT 0x88 | |
312 | ||
313 | #define ARM_NEW_RT_SIGFRAME_UCONTEXT 0x80 | |
314 | ||
315 | #define ARM_NEW_SIGFRAME_MAGIC 0x5ac3c35a | |
316 | ||
8e9d1a24 DJ |
317 | static void |
318 | arm_linux_sigreturn_init (const struct tramp_frame *self, | |
a262aec2 | 319 | struct frame_info *this_frame, |
8e9d1a24 DJ |
320 | struct trad_frame_cache *this_cache, |
321 | CORE_ADDR func) | |
2a451106 | 322 | { |
e17a4113 UW |
323 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
324 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
a262aec2 | 325 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); |
e17a4113 | 326 | ULONGEST uc_flags = read_memory_unsigned_integer (sp, 4, byte_order); |
edfb1a26 DJ |
327 | |
328 | if (uc_flags == ARM_NEW_SIGFRAME_MAGIC) | |
a262aec2 | 329 | arm_linux_sigtramp_cache (this_frame, this_cache, func, |
edfb1a26 DJ |
330 | ARM_UCONTEXT_SIGCONTEXT |
331 | + ARM_SIGCONTEXT_R0); | |
332 | else | |
a262aec2 | 333 | arm_linux_sigtramp_cache (this_frame, this_cache, func, |
edfb1a26 | 334 | ARM_SIGCONTEXT_R0); |
8e9d1a24 | 335 | } |
2a451106 | 336 | |
8e9d1a24 DJ |
337 | static void |
338 | arm_linux_rt_sigreturn_init (const struct tramp_frame *self, | |
a262aec2 | 339 | struct frame_info *this_frame, |
8e9d1a24 DJ |
340 | struct trad_frame_cache *this_cache, |
341 | CORE_ADDR func) | |
342 | { | |
e17a4113 UW |
343 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
344 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
a262aec2 | 345 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); |
e17a4113 | 346 | ULONGEST pinfo = read_memory_unsigned_integer (sp, 4, byte_order); |
edfb1a26 DJ |
347 | |
348 | if (pinfo == sp + ARM_OLD_RT_SIGFRAME_SIGINFO) | |
a262aec2 | 349 | arm_linux_sigtramp_cache (this_frame, this_cache, func, |
edfb1a26 DJ |
350 | ARM_OLD_RT_SIGFRAME_UCONTEXT |
351 | + ARM_UCONTEXT_SIGCONTEXT | |
352 | + ARM_SIGCONTEXT_R0); | |
353 | else | |
a262aec2 | 354 | arm_linux_sigtramp_cache (this_frame, this_cache, func, |
edfb1a26 DJ |
355 | ARM_NEW_RT_SIGFRAME_UCONTEXT |
356 | + ARM_UCONTEXT_SIGCONTEXT | |
357 | + ARM_SIGCONTEXT_R0); | |
2a451106 KB |
358 | } |
359 | ||
f1973203 MR |
360 | static void |
361 | arm_linux_restart_syscall_init (const struct tramp_frame *self, | |
362 | struct frame_info *this_frame, | |
363 | struct trad_frame_cache *this_cache, | |
364 | CORE_ADDR func) | |
365 | { | |
478fd957 | 366 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
f1973203 | 367 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); |
478fd957 UW |
368 | CORE_ADDR pc = get_frame_memory_unsigned (this_frame, sp, 4); |
369 | CORE_ADDR cpsr = get_frame_register_unsigned (this_frame, ARM_PS_REGNUM); | |
370 | ULONGEST t_bit = arm_psr_thumb_bit (gdbarch); | |
371 | int sp_offset; | |
372 | ||
373 | /* There are two variants of this trampoline; with older kernels, the | |
374 | stub is placed on the stack, while newer kernels use the stub from | |
375 | the vector page. They are identical except that the older version | |
376 | increments SP by 12 (to skip stored PC and the stub itself), while | |
377 | the newer version increments SP only by 4 (just the stored PC). */ | |
378 | if (self->insn[1].bytes == ARM_LDR_PC_SP_4) | |
379 | sp_offset = 4; | |
380 | else | |
381 | sp_offset = 12; | |
382 | ||
383 | /* Update Thumb bit in CPSR. */ | |
384 | if (pc & 1) | |
385 | cpsr |= t_bit; | |
386 | else | |
387 | cpsr &= ~t_bit; | |
f1973203 | 388 | |
478fd957 UW |
389 | /* Remove Thumb bit from PC. */ |
390 | pc = gdbarch_addr_bits_remove (gdbarch, pc); | |
391 | ||
392 | /* Save previous register values. */ | |
393 | trad_frame_set_reg_value (this_cache, ARM_SP_REGNUM, sp + sp_offset); | |
394 | trad_frame_set_reg_value (this_cache, ARM_PC_REGNUM, pc); | |
395 | trad_frame_set_reg_value (this_cache, ARM_PS_REGNUM, cpsr); | |
f1973203 MR |
396 | |
397 | /* Save a frame ID. */ | |
398 | trad_frame_set_id (this_cache, frame_id_build (sp, func)); | |
399 | } | |
400 | ||
8e9d1a24 DJ |
401 | static struct tramp_frame arm_linux_sigreturn_tramp_frame = { |
402 | SIGTRAMP_FRAME, | |
403 | 4, | |
404 | { | |
405 | { ARM_LINUX_SIGRETURN_INSTR, -1 }, | |
406 | { TRAMP_SENTINEL_INSN } | |
407 | }, | |
408 | arm_linux_sigreturn_init | |
409 | }; | |
410 | ||
411 | static struct tramp_frame arm_linux_rt_sigreturn_tramp_frame = { | |
412 | SIGTRAMP_FRAME, | |
413 | 4, | |
414 | { | |
415 | { ARM_LINUX_RT_SIGRETURN_INSTR, -1 }, | |
416 | { TRAMP_SENTINEL_INSN } | |
417 | }, | |
418 | arm_linux_rt_sigreturn_init | |
419 | }; | |
420 | ||
421 | static struct tramp_frame arm_eabi_linux_sigreturn_tramp_frame = { | |
422 | SIGTRAMP_FRAME, | |
423 | 4, | |
424 | { | |
425 | { ARM_SET_R7_SIGRETURN, -1 }, | |
426 | { ARM_EABI_SYSCALL, -1 }, | |
427 | { TRAMP_SENTINEL_INSN } | |
428 | }, | |
429 | arm_linux_sigreturn_init | |
430 | }; | |
431 | ||
432 | static struct tramp_frame arm_eabi_linux_rt_sigreturn_tramp_frame = { | |
433 | SIGTRAMP_FRAME, | |
434 | 4, | |
435 | { | |
436 | { ARM_SET_R7_RT_SIGRETURN, -1 }, | |
437 | { ARM_EABI_SYSCALL, -1 }, | |
438 | { TRAMP_SENTINEL_INSN } | |
439 | }, | |
440 | arm_linux_rt_sigreturn_init | |
441 | }; | |
442 | ||
f1973203 MR |
443 | static struct tramp_frame arm_linux_restart_syscall_tramp_frame = { |
444 | NORMAL_FRAME, | |
445 | 4, | |
446 | { | |
447 | { ARM_OABI_SYSCALL_RESTART_SYSCALL, -1 }, | |
448 | { ARM_LDR_PC_SP_12, -1 }, | |
449 | { TRAMP_SENTINEL_INSN } | |
450 | }, | |
451 | arm_linux_restart_syscall_init | |
452 | }; | |
453 | ||
478fd957 UW |
454 | static struct tramp_frame arm_kernel_linux_restart_syscall_tramp_frame = { |
455 | NORMAL_FRAME, | |
456 | 4, | |
457 | { | |
458 | { ARM_OABI_SYSCALL_RESTART_SYSCALL, -1 }, | |
459 | { ARM_LDR_PC_SP_4, -1 }, | |
460 | { TRAMP_SENTINEL_INSN } | |
461 | }, | |
462 | arm_linux_restart_syscall_init | |
463 | }; | |
464 | ||
cb587d83 DJ |
465 | /* Core file and register set support. */ |
466 | ||
467 | #define ARM_LINUX_SIZEOF_GREGSET (18 * INT_REGISTER_SIZE) | |
468 | ||
469 | void | |
470 | arm_linux_supply_gregset (const struct regset *regset, | |
471 | struct regcache *regcache, | |
472 | int regnum, const void *gregs_buf, size_t len) | |
473 | { | |
e17a4113 UW |
474 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
475 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
cb587d83 DJ |
476 | const gdb_byte *gregs = gregs_buf; |
477 | int regno; | |
478 | CORE_ADDR reg_pc; | |
479 | gdb_byte pc_buf[INT_REGISTER_SIZE]; | |
480 | ||
481 | for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++) | |
482 | if (regnum == -1 || regnum == regno) | |
483 | regcache_raw_supply (regcache, regno, | |
484 | gregs + INT_REGISTER_SIZE * regno); | |
485 | ||
486 | if (regnum == ARM_PS_REGNUM || regnum == -1) | |
487 | { | |
488 | if (arm_apcs_32) | |
489 | regcache_raw_supply (regcache, ARM_PS_REGNUM, | |
17c12639 | 490 | gregs + INT_REGISTER_SIZE * ARM_CPSR_GREGNUM); |
cb587d83 DJ |
491 | else |
492 | regcache_raw_supply (regcache, ARM_PS_REGNUM, | |
493 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
494 | } | |
495 | ||
496 | if (regnum == ARM_PC_REGNUM || regnum == -1) | |
497 | { | |
498 | reg_pc = extract_unsigned_integer (gregs | |
499 | + INT_REGISTER_SIZE * ARM_PC_REGNUM, | |
e17a4113 UW |
500 | INT_REGISTER_SIZE, byte_order); |
501 | reg_pc = gdbarch_addr_bits_remove (gdbarch, reg_pc); | |
502 | store_unsigned_integer (pc_buf, INT_REGISTER_SIZE, byte_order, reg_pc); | |
cb587d83 DJ |
503 | regcache_raw_supply (regcache, ARM_PC_REGNUM, pc_buf); |
504 | } | |
505 | } | |
506 | ||
507 | void | |
508 | arm_linux_collect_gregset (const struct regset *regset, | |
509 | const struct regcache *regcache, | |
510 | int regnum, void *gregs_buf, size_t len) | |
511 | { | |
512 | gdb_byte *gregs = gregs_buf; | |
513 | int regno; | |
514 | ||
515 | for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++) | |
516 | if (regnum == -1 || regnum == regno) | |
517 | regcache_raw_collect (regcache, regno, | |
518 | gregs + INT_REGISTER_SIZE * regno); | |
519 | ||
520 | if (regnum == ARM_PS_REGNUM || regnum == -1) | |
521 | { | |
522 | if (arm_apcs_32) | |
523 | regcache_raw_collect (regcache, ARM_PS_REGNUM, | |
17c12639 | 524 | gregs + INT_REGISTER_SIZE * ARM_CPSR_GREGNUM); |
cb587d83 DJ |
525 | else |
526 | regcache_raw_collect (regcache, ARM_PS_REGNUM, | |
527 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
528 | } | |
529 | ||
530 | if (regnum == ARM_PC_REGNUM || regnum == -1) | |
531 | regcache_raw_collect (regcache, ARM_PC_REGNUM, | |
532 | gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM); | |
533 | } | |
534 | ||
535 | /* Support for register format used by the NWFPE FPA emulator. */ | |
536 | ||
537 | #define typeNone 0x00 | |
538 | #define typeSingle 0x01 | |
539 | #define typeDouble 0x02 | |
540 | #define typeExtended 0x03 | |
541 | ||
542 | void | |
543 | supply_nwfpe_register (struct regcache *regcache, int regno, | |
544 | const gdb_byte *regs) | |
545 | { | |
546 | const gdb_byte *reg_data; | |
547 | gdb_byte reg_tag; | |
548 | gdb_byte buf[FP_REGISTER_SIZE]; | |
549 | ||
550 | reg_data = regs + (regno - ARM_F0_REGNUM) * FP_REGISTER_SIZE; | |
551 | reg_tag = regs[(regno - ARM_F0_REGNUM) + NWFPE_TAGS_OFFSET]; | |
552 | memset (buf, 0, FP_REGISTER_SIZE); | |
553 | ||
554 | switch (reg_tag) | |
555 | { | |
556 | case typeSingle: | |
557 | memcpy (buf, reg_data, 4); | |
558 | break; | |
559 | case typeDouble: | |
560 | memcpy (buf, reg_data + 4, 4); | |
561 | memcpy (buf + 4, reg_data, 4); | |
562 | break; | |
563 | case typeExtended: | |
564 | /* We want sign and exponent, then least significant bits, | |
565 | then most significant. NWFPE does sign, most, least. */ | |
566 | memcpy (buf, reg_data, 4); | |
567 | memcpy (buf + 4, reg_data + 8, 4); | |
568 | memcpy (buf + 8, reg_data + 4, 4); | |
569 | break; | |
570 | default: | |
571 | break; | |
572 | } | |
573 | ||
574 | regcache_raw_supply (regcache, regno, buf); | |
575 | } | |
576 | ||
577 | void | |
578 | collect_nwfpe_register (const struct regcache *regcache, int regno, | |
579 | gdb_byte *regs) | |
580 | { | |
581 | gdb_byte *reg_data; | |
582 | gdb_byte reg_tag; | |
583 | gdb_byte buf[FP_REGISTER_SIZE]; | |
584 | ||
585 | regcache_raw_collect (regcache, regno, buf); | |
586 | ||
587 | /* NOTE drow/2006-06-07: This code uses the tag already in the | |
588 | register buffer. I've preserved that when moving the code | |
589 | from the native file to the target file. But this doesn't | |
590 | always make sense. */ | |
591 | ||
592 | reg_data = regs + (regno - ARM_F0_REGNUM) * FP_REGISTER_SIZE; | |
593 | reg_tag = regs[(regno - ARM_F0_REGNUM) + NWFPE_TAGS_OFFSET]; | |
594 | ||
595 | switch (reg_tag) | |
596 | { | |
597 | case typeSingle: | |
598 | memcpy (reg_data, buf, 4); | |
599 | break; | |
600 | case typeDouble: | |
601 | memcpy (reg_data, buf + 4, 4); | |
602 | memcpy (reg_data + 4, buf, 4); | |
603 | break; | |
604 | case typeExtended: | |
605 | memcpy (reg_data, buf, 4); | |
606 | memcpy (reg_data + 4, buf + 8, 4); | |
607 | memcpy (reg_data + 8, buf + 4, 4); | |
608 | break; | |
609 | default: | |
610 | break; | |
611 | } | |
612 | } | |
613 | ||
614 | void | |
615 | arm_linux_supply_nwfpe (const struct regset *regset, | |
616 | struct regcache *regcache, | |
617 | int regnum, const void *regs_buf, size_t len) | |
618 | { | |
619 | const gdb_byte *regs = regs_buf; | |
620 | int regno; | |
621 | ||
622 | if (regnum == ARM_FPS_REGNUM || regnum == -1) | |
623 | regcache_raw_supply (regcache, ARM_FPS_REGNUM, | |
624 | regs + NWFPE_FPSR_OFFSET); | |
625 | ||
626 | for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) | |
627 | if (regnum == -1 || regnum == regno) | |
628 | supply_nwfpe_register (regcache, regno, regs); | |
629 | } | |
630 | ||
631 | void | |
632 | arm_linux_collect_nwfpe (const struct regset *regset, | |
633 | const struct regcache *regcache, | |
634 | int regnum, void *regs_buf, size_t len) | |
635 | { | |
636 | gdb_byte *regs = regs_buf; | |
637 | int regno; | |
638 | ||
639 | for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) | |
640 | if (regnum == -1 || regnum == regno) | |
641 | collect_nwfpe_register (regcache, regno, regs); | |
642 | ||
643 | if (regnum == ARM_FPS_REGNUM || regnum == -1) | |
644 | regcache_raw_collect (regcache, ARM_FPS_REGNUM, | |
645 | regs + INT_REGISTER_SIZE * ARM_FPS_REGNUM); | |
646 | } | |
647 | ||
ef7e8358 UW |
648 | /* Support VFP register format. */ |
649 | ||
650 | #define ARM_LINUX_SIZEOF_VFP (32 * 8 + 4) | |
651 | ||
652 | static void | |
653 | arm_linux_supply_vfp (const struct regset *regset, | |
654 | struct regcache *regcache, | |
655 | int regnum, const void *regs_buf, size_t len) | |
656 | { | |
657 | const gdb_byte *regs = regs_buf; | |
658 | int regno; | |
659 | ||
660 | if (regnum == ARM_FPSCR_REGNUM || regnum == -1) | |
661 | regcache_raw_supply (regcache, ARM_FPSCR_REGNUM, regs + 32 * 8); | |
662 | ||
663 | for (regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++) | |
664 | if (regnum == -1 || regnum == regno) | |
665 | regcache_raw_supply (regcache, regno, | |
666 | regs + (regno - ARM_D0_REGNUM) * 8); | |
667 | } | |
668 | ||
669 | static void | |
670 | arm_linux_collect_vfp (const struct regset *regset, | |
671 | const struct regcache *regcache, | |
672 | int regnum, void *regs_buf, size_t len) | |
673 | { | |
674 | gdb_byte *regs = regs_buf; | |
675 | int regno; | |
676 | ||
677 | if (regnum == ARM_FPSCR_REGNUM || regnum == -1) | |
678 | regcache_raw_collect (regcache, ARM_FPSCR_REGNUM, regs + 32 * 8); | |
679 | ||
680 | for (regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++) | |
681 | if (regnum == -1 || regnum == regno) | |
682 | regcache_raw_collect (regcache, regno, | |
683 | regs + (regno - ARM_D0_REGNUM) * 8); | |
684 | } | |
685 | ||
cb587d83 DJ |
686 | /* Return the appropriate register set for the core section identified |
687 | by SECT_NAME and SECT_SIZE. */ | |
688 | ||
689 | static const struct regset * | |
690 | arm_linux_regset_from_core_section (struct gdbarch *gdbarch, | |
691 | const char *sect_name, size_t sect_size) | |
692 | { | |
693 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
694 | ||
695 | if (strcmp (sect_name, ".reg") == 0 | |
696 | && sect_size == ARM_LINUX_SIZEOF_GREGSET) | |
697 | { | |
698 | if (tdep->gregset == NULL) | |
699 | tdep->gregset = regset_alloc (gdbarch, arm_linux_supply_gregset, | |
700 | arm_linux_collect_gregset); | |
701 | return tdep->gregset; | |
702 | } | |
703 | ||
704 | if (strcmp (sect_name, ".reg2") == 0 | |
705 | && sect_size == ARM_LINUX_SIZEOF_NWFPE) | |
706 | { | |
707 | if (tdep->fpregset == NULL) | |
708 | tdep->fpregset = regset_alloc (gdbarch, arm_linux_supply_nwfpe, | |
709 | arm_linux_collect_nwfpe); | |
710 | return tdep->fpregset; | |
711 | } | |
712 | ||
ef7e8358 UW |
713 | if (strcmp (sect_name, ".reg-arm-vfp") == 0 |
714 | && sect_size == ARM_LINUX_SIZEOF_VFP) | |
715 | { | |
716 | if (tdep->vfpregset == NULL) | |
717 | tdep->vfpregset = regset_alloc (gdbarch, arm_linux_supply_vfp, | |
718 | arm_linux_collect_vfp); | |
719 | return tdep->vfpregset; | |
720 | } | |
721 | ||
722 | return NULL; | |
723 | } | |
724 | ||
725 | /* Core file register set sections. */ | |
726 | ||
727 | static struct core_regset_section arm_linux_fpa_regset_sections[] = | |
728 | { | |
729 | { ".reg", ARM_LINUX_SIZEOF_GREGSET, "general-purpose" }, | |
730 | { ".reg2", ARM_LINUX_SIZEOF_NWFPE, "FPA floating-point" }, | |
731 | { NULL, 0} | |
732 | }; | |
733 | ||
734 | static struct core_regset_section arm_linux_vfp_regset_sections[] = | |
735 | { | |
736 | { ".reg", ARM_LINUX_SIZEOF_GREGSET, "general-purpose" }, | |
737 | { ".reg-arm-vfp", ARM_LINUX_SIZEOF_VFP, "VFP floating-point" }, | |
738 | { NULL, 0} | |
739 | }; | |
740 | ||
741 | /* Determine target description from core file. */ | |
742 | ||
743 | static const struct target_desc * | |
744 | arm_linux_core_read_description (struct gdbarch *gdbarch, | |
745 | struct target_ops *target, | |
746 | bfd *abfd) | |
747 | { | |
748 | CORE_ADDR arm_hwcap = 0; | |
749 | ||
750 | if (target_auxv_search (target, AT_HWCAP, &arm_hwcap) != 1) | |
751 | return NULL; | |
752 | ||
753 | if (arm_hwcap & HWCAP_VFP) | |
754 | { | |
755 | /* NEON implies VFPv3-D32 or no-VFP unit. Say that we only support | |
756 | Neon with VFPv3-D32. */ | |
757 | if (arm_hwcap & HWCAP_NEON) | |
758 | return tdesc_arm_with_neon; | |
759 | else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3) | |
760 | return tdesc_arm_with_vfpv3; | |
761 | else | |
762 | return tdesc_arm_with_vfpv2; | |
763 | } | |
764 | ||
cb587d83 DJ |
765 | return NULL; |
766 | } | |
767 | ||
ef7e8358 | 768 | |
25b41d01 | 769 | /* Copy the value of next pc of sigreturn and rt_sigrturn into PC, |
18819fa6 UW |
770 | return 1. In addition, set IS_THUMB depending on whether we |
771 | will return to ARM or Thumb code. Return 0 if it is not a | |
772 | rt_sigreturn/sigreturn syscall. */ | |
25b41d01 YQ |
773 | static int |
774 | arm_linux_sigreturn_return_addr (struct frame_info *frame, | |
775 | unsigned long svc_number, | |
18819fa6 | 776 | CORE_ADDR *pc, int *is_thumb) |
25b41d01 YQ |
777 | { |
778 | /* Is this a sigreturn or rt_sigreturn syscall? */ | |
779 | if (svc_number == 119 || svc_number == 173) | |
780 | { | |
781 | if (get_frame_type (frame) == SIGTRAMP_FRAME) | |
782 | { | |
18819fa6 UW |
783 | ULONGEST t_bit = arm_psr_thumb_bit (frame_unwind_arch (frame)); |
784 | CORE_ADDR cpsr | |
785 | = frame_unwind_register_unsigned (frame, ARM_PS_REGNUM); | |
786 | ||
787 | *is_thumb = (cpsr & t_bit) != 0; | |
25b41d01 YQ |
788 | *pc = frame_unwind_caller_pc (frame); |
789 | return 1; | |
790 | } | |
791 | } | |
792 | return 0; | |
793 | } | |
794 | ||
9f948660 SDJ |
795 | /* At a ptrace syscall-stop, return the syscall number. This either |
796 | comes from the SWI instruction (OABI) or from r7 (EABI). | |
797 | ||
798 | When the function fails, it should return -1. */ | |
799 | ||
800 | static LONGEST | |
801 | arm_linux_get_syscall_number (struct gdbarch *gdbarch, | |
802 | ptid_t ptid) | |
803 | { | |
804 | struct regcache *regs = get_thread_regcache (ptid); | |
805 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
806 | ||
807 | ULONGEST pc; | |
808 | ULONGEST cpsr; | |
809 | ULONGEST t_bit = arm_psr_thumb_bit (gdbarch); | |
810 | int is_thumb; | |
811 | ULONGEST svc_number = -1; | |
812 | ||
813 | regcache_cooked_read_unsigned (regs, ARM_PC_REGNUM, &pc); | |
814 | regcache_cooked_read_unsigned (regs, ARM_PS_REGNUM, &cpsr); | |
815 | is_thumb = (cpsr & t_bit) != 0; | |
816 | ||
817 | if (is_thumb) | |
818 | { | |
819 | regcache_cooked_read_unsigned (regs, 7, &svc_number); | |
820 | } | |
821 | else | |
822 | { | |
823 | enum bfd_endian byte_order_for_code = | |
824 | gdbarch_byte_order_for_code (gdbarch); | |
825 | ||
826 | /* PC gets incremented before the syscall-stop, so read the | |
827 | previous instruction. */ | |
828 | unsigned long this_instr = | |
829 | read_memory_unsigned_integer (pc - 4, 4, byte_order_for_code); | |
830 | ||
831 | unsigned long svc_operand = (0x00ffffff & this_instr); | |
832 | ||
833 | if (svc_operand) | |
834 | { | |
835 | /* OABI */ | |
836 | svc_number = svc_operand - 0x900000; | |
837 | } | |
838 | else | |
839 | { | |
840 | /* EABI */ | |
841 | regcache_cooked_read_unsigned (regs, 7, &svc_number); | |
842 | } | |
843 | } | |
844 | ||
845 | return svc_number; | |
846 | } | |
847 | ||
25b41d01 YQ |
848 | /* When FRAME is at a syscall instruction, return the PC of the next |
849 | instruction to be executed. */ | |
850 | ||
851 | static CORE_ADDR | |
852 | arm_linux_syscall_next_pc (struct frame_info *frame) | |
853 | { | |
854 | CORE_ADDR pc = get_frame_pc (frame); | |
855 | CORE_ADDR return_addr = 0; | |
856 | int is_thumb = arm_frame_is_thumb (frame); | |
857 | ULONGEST svc_number = 0; | |
25b41d01 YQ |
858 | |
859 | if (is_thumb) | |
860 | { | |
861 | svc_number = get_frame_register_unsigned (frame, 7); | |
18819fa6 | 862 | return_addr = pc + 2; |
25b41d01 YQ |
863 | } |
864 | else | |
865 | { | |
866 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
867 | enum bfd_endian byte_order_for_code = | |
868 | gdbarch_byte_order_for_code (gdbarch); | |
869 | unsigned long this_instr = | |
870 | read_memory_unsigned_integer (pc, 4, byte_order_for_code); | |
871 | ||
872 | unsigned long svc_operand = (0x00ffffff & this_instr); | |
873 | if (svc_operand) /* OABI. */ | |
874 | { | |
875 | svc_number = svc_operand - 0x900000; | |
876 | } | |
877 | else /* EABI. */ | |
878 | { | |
879 | svc_number = get_frame_register_unsigned (frame, 7); | |
880 | } | |
18819fa6 UW |
881 | |
882 | return_addr = pc + 4; | |
25b41d01 YQ |
883 | } |
884 | ||
18819fa6 | 885 | arm_linux_sigreturn_return_addr (frame, svc_number, &return_addr, &is_thumb); |
25b41d01 | 886 | |
18819fa6 | 887 | /* Addresses for calling Thumb functions have the bit 0 set. */ |
25b41d01 | 888 | if (is_thumb) |
18819fa6 | 889 | return_addr |= 1; |
25b41d01 YQ |
890 | |
891 | return return_addr; | |
892 | } | |
893 | ||
894 | ||
daddc3c1 DJ |
895 | /* Insert a single step breakpoint at the next executed instruction. */ |
896 | ||
63807e1d | 897 | static int |
daddc3c1 DJ |
898 | arm_linux_software_single_step (struct frame_info *frame) |
899 | { | |
a6d9a66e | 900 | struct gdbarch *gdbarch = get_frame_arch (frame); |
6c95b8df | 901 | struct address_space *aspace = get_frame_address_space (frame); |
35f73cfc UW |
902 | CORE_ADDR next_pc; |
903 | ||
904 | if (arm_deal_with_atomic_sequence (frame)) | |
905 | return 1; | |
906 | ||
907 | next_pc = arm_get_next_pc (frame, get_frame_pc (frame)); | |
daddc3c1 DJ |
908 | |
909 | /* The Linux kernel offers some user-mode helpers in a high page. We can | |
910 | not read this page (as of 2.6.23), and even if we could then we couldn't | |
911 | set breakpoints in it, and even if we could then the atomic operations | |
912 | would fail when interrupted. They are all called as functions and return | |
913 | to the address in LR, so step to there instead. */ | |
914 | if (next_pc > 0xffff0000) | |
915 | next_pc = get_frame_register_unsigned (frame, ARM_LR_REGNUM); | |
916 | ||
18819fa6 | 917 | arm_insert_single_step_breakpoint (gdbarch, aspace, next_pc); |
daddc3c1 DJ |
918 | |
919 | return 1; | |
920 | } | |
921 | ||
cca44b1b JB |
922 | /* Support for displaced stepping of Linux SVC instructions. */ |
923 | ||
924 | static void | |
6e39997a | 925 | arm_linux_cleanup_svc (struct gdbarch *gdbarch, |
cca44b1b JB |
926 | struct regcache *regs, |
927 | struct displaced_step_closure *dsc) | |
928 | { | |
929 | CORE_ADDR from = dsc->insn_addr; | |
930 | ULONGEST apparent_pc; | |
931 | int within_scratch; | |
932 | ||
933 | regcache_cooked_read_unsigned (regs, ARM_PC_REGNUM, &apparent_pc); | |
934 | ||
935 | within_scratch = (apparent_pc >= dsc->scratch_base | |
936 | && apparent_pc < (dsc->scratch_base | |
937 | + DISPLACED_MODIFIED_INSNS * 4 + 4)); | |
938 | ||
939 | if (debug_displaced) | |
940 | { | |
941 | fprintf_unfiltered (gdb_stdlog, "displaced: PC is apparently %.8lx after " | |
942 | "SVC step ", (unsigned long) apparent_pc); | |
943 | if (within_scratch) | |
944 | fprintf_unfiltered (gdb_stdlog, "(within scratch space)\n"); | |
945 | else | |
946 | fprintf_unfiltered (gdb_stdlog, "(outside scratch space)\n"); | |
947 | } | |
948 | ||
949 | if (within_scratch) | |
950 | displaced_write_reg (regs, dsc, ARM_PC_REGNUM, from + 4, BRANCH_WRITE_PC); | |
951 | } | |
952 | ||
953 | static int | |
bd18283a YQ |
954 | arm_linux_copy_svc (struct gdbarch *gdbarch, struct regcache *regs, |
955 | struct displaced_step_closure *dsc) | |
cca44b1b | 956 | { |
25b41d01 YQ |
957 | CORE_ADDR return_to = 0; |
958 | ||
cca44b1b | 959 | struct frame_info *frame; |
36073a92 | 960 | unsigned int svc_number = displaced_read_reg (regs, dsc, 7); |
25b41d01 | 961 | int is_sigreturn = 0; |
18819fa6 | 962 | int is_thumb; |
cca44b1b | 963 | |
cca44b1b JB |
964 | frame = get_current_frame (); |
965 | ||
25b41d01 | 966 | is_sigreturn = arm_linux_sigreturn_return_addr(frame, svc_number, |
18819fa6 | 967 | &return_to, &is_thumb); |
25b41d01 | 968 | if (is_sigreturn) |
cca44b1b | 969 | { |
cca44b1b JB |
970 | struct symtab_and_line sal; |
971 | ||
972 | if (debug_displaced) | |
973 | fprintf_unfiltered (gdb_stdlog, "displaced: found " | |
0963b4bd | 974 | "sigreturn/rt_sigreturn SVC call. PC in frame = %lx\n", |
cca44b1b JB |
975 | (unsigned long) get_frame_pc (frame)); |
976 | ||
cca44b1b | 977 | if (debug_displaced) |
0963b4bd | 978 | fprintf_unfiltered (gdb_stdlog, "displaced: unwind pc = %lx. " |
cca44b1b JB |
979 | "Setting momentary breakpoint.\n", (unsigned long) return_to); |
980 | ||
8358c15c JK |
981 | gdb_assert (inferior_thread ()->control.step_resume_breakpoint |
982 | == NULL); | |
cca44b1b JB |
983 | |
984 | sal = find_pc_line (return_to, 0); | |
985 | sal.pc = return_to; | |
986 | sal.section = find_pc_overlay (return_to); | |
987 | sal.explicit_pc = 1; | |
988 | ||
989 | frame = get_prev_frame (frame); | |
990 | ||
991 | if (frame) | |
992 | { | |
8358c15c | 993 | inferior_thread ()->control.step_resume_breakpoint |
cca44b1b JB |
994 | = set_momentary_breakpoint (gdbarch, sal, get_frame_id (frame), |
995 | bp_step_resume); | |
996 | ||
c70a6932 JK |
997 | /* set_momentary_breakpoint invalidates FRAME. */ |
998 | frame = NULL; | |
999 | ||
cca44b1b JB |
1000 | /* We need to make sure we actually insert the momentary |
1001 | breakpoint set above. */ | |
1002 | insert_breakpoints (); | |
1003 | } | |
1004 | else if (debug_displaced) | |
1005 | fprintf_unfiltered (gdb_stderr, "displaced: couldn't find previous " | |
1006 | "frame to set momentary breakpoint for " | |
1007 | "sigreturn/rt_sigreturn\n"); | |
1008 | } | |
1009 | else if (debug_displaced) | |
1010 | fprintf_unfiltered (gdb_stdlog, "displaced: sigreturn/rt_sigreturn " | |
1011 | "SVC call not in signal trampoline frame\n"); | |
25b41d01 | 1012 | |
cca44b1b JB |
1013 | |
1014 | /* Preparation: If we detect sigreturn, set momentary breakpoint at resume | |
1015 | location, else nothing. | |
1016 | Insn: unmodified svc. | |
1017 | Cleanup: if pc lands in scratch space, pc <- insn_addr + 4 | |
1018 | else leave pc alone. */ | |
1019 | ||
cca44b1b JB |
1020 | |
1021 | dsc->cleanup = &arm_linux_cleanup_svc; | |
1022 | /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next | |
1023 | instruction. */ | |
1024 | dsc->wrote_to_pc = 1; | |
1025 | ||
1026 | return 0; | |
1027 | } | |
1028 | ||
1029 | ||
1030 | /* The following two functions implement single-stepping over calls to Linux | |
1031 | kernel helper routines, which perform e.g. atomic operations on architecture | |
1032 | variants which don't support them natively. | |
1033 | ||
1034 | When this function is called, the PC will be pointing at the kernel helper | |
1035 | (at an address inaccessible to GDB), and r14 will point to the return | |
1036 | address. Displaced stepping always executes code in the copy area: | |
1037 | so, make the copy-area instruction branch back to the kernel helper (the | |
1038 | "from" address), and make r14 point to the breakpoint in the copy area. In | |
1039 | that way, we regain control once the kernel helper returns, and can clean | |
1040 | up appropriately (as if we had just returned from the kernel helper as it | |
1041 | would have been called from the non-displaced location). */ | |
1042 | ||
1043 | static void | |
6e39997a | 1044 | cleanup_kernel_helper_return (struct gdbarch *gdbarch, |
cca44b1b JB |
1045 | struct regcache *regs, |
1046 | struct displaced_step_closure *dsc) | |
1047 | { | |
1048 | displaced_write_reg (regs, dsc, ARM_LR_REGNUM, dsc->tmp[0], CANNOT_WRITE_PC); | |
1049 | displaced_write_reg (regs, dsc, ARM_PC_REGNUM, dsc->tmp[0], BRANCH_WRITE_PC); | |
1050 | } | |
1051 | ||
1052 | static void | |
1053 | arm_catch_kernel_helper_return (struct gdbarch *gdbarch, CORE_ADDR from, | |
1054 | CORE_ADDR to, struct regcache *regs, | |
1055 | struct displaced_step_closure *dsc) | |
1056 | { | |
1057 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1058 | ||
1059 | dsc->numinsns = 1; | |
1060 | dsc->insn_addr = from; | |
1061 | dsc->cleanup = &cleanup_kernel_helper_return; | |
1062 | /* Say we wrote to the PC, else cleanup will set PC to the next | |
1063 | instruction in the helper, which isn't helpful. */ | |
1064 | dsc->wrote_to_pc = 1; | |
1065 | ||
1066 | /* Preparation: tmp[0] <- r14 | |
1067 | r14 <- <scratch space>+4 | |
1068 | *(<scratch space>+8) <- from | |
1069 | Insn: ldr pc, [r14, #4] | |
1070 | Cleanup: r14 <- tmp[0], pc <- tmp[0]. */ | |
1071 | ||
36073a92 | 1072 | dsc->tmp[0] = displaced_read_reg (regs, dsc, ARM_LR_REGNUM); |
cca44b1b JB |
1073 | displaced_write_reg (regs, dsc, ARM_LR_REGNUM, (ULONGEST) to + 4, |
1074 | CANNOT_WRITE_PC); | |
1075 | write_memory_unsigned_integer (to + 8, 4, byte_order, from); | |
1076 | ||
1077 | dsc->modinsn[0] = 0xe59ef004; /* ldr pc, [lr, #4]. */ | |
1078 | } | |
1079 | ||
1080 | /* Linux-specific displaced step instruction copying function. Detects when | |
1081 | the program has stepped into a Linux kernel helper routine (which must be | |
1082 | handled as a special case), falling back to arm_displaced_step_copy_insn() | |
1083 | if it hasn't. */ | |
1084 | ||
1085 | static struct displaced_step_closure * | |
1086 | arm_linux_displaced_step_copy_insn (struct gdbarch *gdbarch, | |
1087 | CORE_ADDR from, CORE_ADDR to, | |
1088 | struct regcache *regs) | |
1089 | { | |
1090 | struct displaced_step_closure *dsc | |
1091 | = xmalloc (sizeof (struct displaced_step_closure)); | |
1092 | ||
1093 | /* Detect when we enter an (inaccessible by GDB) Linux kernel helper, and | |
1094 | stop at the return location. */ | |
1095 | if (from > 0xffff0000) | |
1096 | { | |
1097 | if (debug_displaced) | |
1098 | fprintf_unfiltered (gdb_stdlog, "displaced: detected kernel helper " | |
1099 | "at %.8lx\n", (unsigned long) from); | |
1100 | ||
1101 | arm_catch_kernel_helper_return (gdbarch, from, to, regs, dsc); | |
1102 | } | |
1103 | else | |
1104 | { | |
cca44b1b JB |
1105 | /* Override the default handling of SVC instructions. */ |
1106 | dsc->u.svc.copy_svc_os = arm_linux_copy_svc; | |
1107 | ||
b434a28f | 1108 | arm_process_displaced_insn (gdbarch, from, to, regs, dsc); |
cca44b1b JB |
1109 | } |
1110 | ||
1111 | arm_displaced_init_closure (gdbarch, from, to, dsc); | |
1112 | ||
1113 | return dsc; | |
1114 | } | |
1115 | ||
55aa24fb SDJ |
1116 | static int |
1117 | arm_stap_is_single_operand (struct gdbarch *gdbarch, const char *s) | |
1118 | { | |
1119 | return (*s == '#' /* Literal number. */ | |
1120 | || *s == '[' /* Register indirection or | |
1121 | displacement. */ | |
1122 | || isalpha (*s)); /* Register value. */ | |
1123 | } | |
1124 | ||
1125 | /* This routine is used to parse a special token in ARM's assembly. | |
1126 | ||
1127 | The special tokens parsed by it are: | |
1128 | ||
1129 | - Register displacement (e.g, [fp, #-8]) | |
1130 | ||
1131 | It returns one if the special token has been parsed successfully, | |
1132 | or zero if the current token is not considered special. */ | |
1133 | ||
1134 | static int | |
1135 | arm_stap_parse_special_token (struct gdbarch *gdbarch, | |
1136 | struct stap_parse_info *p) | |
1137 | { | |
1138 | if (*p->arg == '[') | |
1139 | { | |
1140 | /* Temporary holder for lookahead. */ | |
1141 | const char *tmp = p->arg; | |
a0bcdaa7 | 1142 | char *endp; |
55aa24fb SDJ |
1143 | /* Used to save the register name. */ |
1144 | const char *start; | |
1145 | char *regname; | |
1146 | int len, offset; | |
1147 | int got_minus = 0; | |
1148 | long displacement; | |
1149 | struct stoken str; | |
1150 | ||
1151 | ++tmp; | |
1152 | start = tmp; | |
1153 | ||
1154 | /* Register name. */ | |
1155 | while (isalnum (*tmp)) | |
1156 | ++tmp; | |
1157 | ||
1158 | if (*tmp != ',') | |
1159 | return 0; | |
1160 | ||
1161 | len = tmp - start; | |
1162 | regname = alloca (len + 2); | |
1163 | ||
1164 | offset = 0; | |
1165 | if (isdigit (*start)) | |
1166 | { | |
1167 | /* If we are dealing with a register whose name begins with a | |
1168 | digit, it means we should prefix the name with the letter | |
1169 | `r', because GDB expects this name pattern. Otherwise (e.g., | |
1170 | we are dealing with the register `fp'), we don't need to | |
1171 | add such a prefix. */ | |
1172 | regname[0] = 'r'; | |
1173 | offset = 1; | |
1174 | } | |
1175 | ||
1176 | strncpy (regname + offset, start, len); | |
1177 | len += offset; | |
1178 | regname[len] = '\0'; | |
1179 | ||
1180 | if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1) | |
1181 | error (_("Invalid register name `%s' on expression `%s'."), | |
1182 | regname, p->saved_arg); | |
1183 | ||
1184 | ++tmp; | |
1185 | tmp = skip_spaces_const (tmp); | |
1186 | if (*tmp++ != '#') | |
1187 | return 0; | |
1188 | ||
1189 | if (*tmp == '-') | |
1190 | { | |
1191 | ++tmp; | |
1192 | got_minus = 1; | |
1193 | } | |
1194 | ||
a0bcdaa7 PA |
1195 | displacement = strtol (tmp, &endp, 10); |
1196 | tmp = endp; | |
55aa24fb SDJ |
1197 | |
1198 | /* Skipping last `]'. */ | |
1199 | if (*tmp++ != ']') | |
1200 | return 0; | |
1201 | ||
1202 | /* The displacement. */ | |
1203 | write_exp_elt_opcode (OP_LONG); | |
1204 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); | |
1205 | write_exp_elt_longcst (displacement); | |
1206 | write_exp_elt_opcode (OP_LONG); | |
1207 | if (got_minus) | |
1208 | write_exp_elt_opcode (UNOP_NEG); | |
1209 | ||
1210 | /* The register name. */ | |
1211 | write_exp_elt_opcode (OP_REGISTER); | |
1212 | str.ptr = regname; | |
1213 | str.length = len; | |
1214 | write_exp_string (str); | |
1215 | write_exp_elt_opcode (OP_REGISTER); | |
1216 | ||
1217 | write_exp_elt_opcode (BINOP_ADD); | |
1218 | ||
1219 | /* Casting to the expected type. */ | |
1220 | write_exp_elt_opcode (UNOP_CAST); | |
1221 | write_exp_elt_type (lookup_pointer_type (p->arg_type)); | |
1222 | write_exp_elt_opcode (UNOP_CAST); | |
1223 | ||
1224 | write_exp_elt_opcode (UNOP_IND); | |
1225 | ||
1226 | p->arg = tmp; | |
1227 | } | |
1228 | else | |
1229 | return 0; | |
1230 | ||
1231 | return 1; | |
1232 | } | |
1233 | ||
97e03143 RE |
1234 | static void |
1235 | arm_linux_init_abi (struct gdbarch_info info, | |
1236 | struct gdbarch *gdbarch) | |
1237 | { | |
1238 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
1239 | ||
a5ee0f0c PA |
1240 | linux_init_abi (info, gdbarch); |
1241 | ||
97e03143 | 1242 | tdep->lowest_pc = 0x8000; |
2ef47cd0 | 1243 | if (info.byte_order == BFD_ENDIAN_BIG) |
498b1f87 | 1244 | { |
c75a2cc8 DJ |
1245 | if (tdep->arm_abi == ARM_ABI_AAPCS) |
1246 | tdep->arm_breakpoint = eabi_linux_arm_be_breakpoint; | |
1247 | else | |
1248 | tdep->arm_breakpoint = arm_linux_arm_be_breakpoint; | |
498b1f87 | 1249 | tdep->thumb_breakpoint = arm_linux_thumb_be_breakpoint; |
177321bd | 1250 | tdep->thumb2_breakpoint = arm_linux_thumb2_be_breakpoint; |
498b1f87 | 1251 | } |
2ef47cd0 | 1252 | else |
498b1f87 | 1253 | { |
c75a2cc8 DJ |
1254 | if (tdep->arm_abi == ARM_ABI_AAPCS) |
1255 | tdep->arm_breakpoint = eabi_linux_arm_le_breakpoint; | |
1256 | else | |
1257 | tdep->arm_breakpoint = arm_linux_arm_le_breakpoint; | |
498b1f87 | 1258 | tdep->thumb_breakpoint = arm_linux_thumb_le_breakpoint; |
177321bd | 1259 | tdep->thumb2_breakpoint = arm_linux_thumb2_le_breakpoint; |
498b1f87 | 1260 | } |
66e810cd | 1261 | tdep->arm_breakpoint_size = sizeof (arm_linux_arm_le_breakpoint); |
498b1f87 | 1262 | tdep->thumb_breakpoint_size = sizeof (arm_linux_thumb_le_breakpoint); |
177321bd | 1263 | tdep->thumb2_breakpoint_size = sizeof (arm_linux_thumb2_le_breakpoint); |
9df628e0 | 1264 | |
28e97307 DJ |
1265 | if (tdep->fp_model == ARM_FLOAT_AUTO) |
1266 | tdep->fp_model = ARM_FLOAT_FPA; | |
fd50bc42 | 1267 | |
f8624c62 MGD |
1268 | switch (tdep->fp_model) |
1269 | { | |
1270 | case ARM_FLOAT_FPA: | |
1271 | tdep->jb_pc = ARM_LINUX_JB_PC_FPA; | |
1272 | break; | |
1273 | case ARM_FLOAT_SOFT_FPA: | |
1274 | case ARM_FLOAT_SOFT_VFP: | |
1275 | case ARM_FLOAT_VFP: | |
1276 | tdep->jb_pc = ARM_LINUX_JB_PC_EABI; | |
1277 | break; | |
1278 | default: | |
1279 | internal_error | |
1280 | (__FILE__, __LINE__, | |
1281 | _("arm_linux_init_abi: Floating point model not supported")); | |
1282 | break; | |
1283 | } | |
a6cdd8c5 | 1284 | tdep->jb_elt_size = ARM_LINUX_JB_ELEMENT_SIZE; |
19d3fc80 | 1285 | |
7aa1783e | 1286 | set_solib_svr4_fetch_link_map_offsets |
76a9d10f | 1287 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
7aa1783e | 1288 | |
190dce09 | 1289 | /* Single stepping. */ |
daddc3c1 | 1290 | set_gdbarch_software_single_step (gdbarch, arm_linux_software_single_step); |
190dce09 | 1291 | |
0e18d038 | 1292 | /* Shared library handling. */ |
0e18d038 | 1293 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
bb41a796 | 1294 | set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); |
b2756930 KB |
1295 | |
1296 | /* Enable TLS support. */ | |
1297 | set_gdbarch_fetch_tls_load_module_address (gdbarch, | |
1298 | svr4_fetch_objfile_link_map); | |
8e9d1a24 DJ |
1299 | |
1300 | tramp_frame_prepend_unwinder (gdbarch, | |
1301 | &arm_linux_sigreturn_tramp_frame); | |
1302 | tramp_frame_prepend_unwinder (gdbarch, | |
1303 | &arm_linux_rt_sigreturn_tramp_frame); | |
1304 | tramp_frame_prepend_unwinder (gdbarch, | |
1305 | &arm_eabi_linux_sigreturn_tramp_frame); | |
1306 | tramp_frame_prepend_unwinder (gdbarch, | |
1307 | &arm_eabi_linux_rt_sigreturn_tramp_frame); | |
f1973203 MR |
1308 | tramp_frame_prepend_unwinder (gdbarch, |
1309 | &arm_linux_restart_syscall_tramp_frame); | |
478fd957 UW |
1310 | tramp_frame_prepend_unwinder (gdbarch, |
1311 | &arm_kernel_linux_restart_syscall_tramp_frame); | |
cb587d83 DJ |
1312 | |
1313 | /* Core file support. */ | |
1314 | set_gdbarch_regset_from_core_section (gdbarch, | |
1315 | arm_linux_regset_from_core_section); | |
ef7e8358 UW |
1316 | set_gdbarch_core_read_description (gdbarch, arm_linux_core_read_description); |
1317 | ||
1318 | if (tdep->have_vfp_registers) | |
1319 | set_gdbarch_core_regset_sections (gdbarch, arm_linux_vfp_regset_sections); | |
1320 | else if (tdep->have_fpa_registers) | |
1321 | set_gdbarch_core_regset_sections (gdbarch, arm_linux_fpa_regset_sections); | |
4aa995e1 PA |
1322 | |
1323 | set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type); | |
cca44b1b JB |
1324 | |
1325 | /* Displaced stepping. */ | |
1326 | set_gdbarch_displaced_step_copy_insn (gdbarch, | |
1327 | arm_linux_displaced_step_copy_insn); | |
1328 | set_gdbarch_displaced_step_fixup (gdbarch, arm_displaced_step_fixup); | |
1329 | set_gdbarch_displaced_step_free_closure (gdbarch, | |
1330 | simple_displaced_step_free_closure); | |
1331 | set_gdbarch_displaced_step_location (gdbarch, displaced_step_at_entry_point); | |
25b41d01 | 1332 | |
72508ac0 PO |
1333 | /* Reversible debugging, process record. */ |
1334 | set_gdbarch_process_record (gdbarch, arm_process_record); | |
25b41d01 | 1335 | |
55aa24fb SDJ |
1336 | /* SystemTap functions. */ |
1337 | set_gdbarch_stap_integer_prefix (gdbarch, "#"); | |
1338 | set_gdbarch_stap_register_prefix (gdbarch, "r"); | |
1339 | set_gdbarch_stap_register_indirection_prefix (gdbarch, "["); | |
1340 | set_gdbarch_stap_register_indirection_suffix (gdbarch, "]"); | |
1341 | set_gdbarch_stap_gdb_register_prefix (gdbarch, "r"); | |
1342 | set_gdbarch_stap_is_single_operand (gdbarch, arm_stap_is_single_operand); | |
1343 | set_gdbarch_stap_parse_special_token (gdbarch, | |
1344 | arm_stap_parse_special_token); | |
1345 | ||
25b41d01 | 1346 | tdep->syscall_next_pc = arm_linux_syscall_next_pc; |
72508ac0 | 1347 | |
9f948660 SDJ |
1348 | /* `catch syscall' */ |
1349 | set_xml_syscall_file_name ("syscalls/arm-linux.xml"); | |
1350 | set_gdbarch_get_syscall_number (gdbarch, arm_linux_get_syscall_number); | |
1351 | ||
72508ac0 PO |
1352 | /* Syscall record. */ |
1353 | tdep->arm_swi_record = NULL; | |
97e03143 RE |
1354 | } |
1355 | ||
63807e1d PA |
1356 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
1357 | extern initialize_file_ftype _initialize_arm_linux_tdep; | |
1358 | ||
faf5f7ad SB |
1359 | void |
1360 | _initialize_arm_linux_tdep (void) | |
1361 | { | |
05816f70 MK |
1362 | gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_LINUX, |
1363 | arm_linux_init_abi); | |
faf5f7ad | 1364 | } |