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aarch64-fbsd-nat.c
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1/* Native-dependent code for FreeBSD/aarch64.
2
3 Copyright (C) 2017-2023 Free Software Foundation, Inc.
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
9 the Free Software Foundation; either version 3 of the License, or
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
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20#include "defs.h"
21#include "arch-utils.h"
22#include "inferior.h"
23#include "regcache.h"
24#include "target.h"
26
27#include "elf/common.h"
28
29#include <sys/param.h>
30#include <sys/ptrace.h>
31#include <machine/armreg.h>
32#include <machine/reg.h>
33
34#include "fbsd-nat.h"
35#include "aarch64-tdep.h"
36#include "aarch64-fbsd-tdep.h"
37#include "aarch64-nat.h"
38#include "inf-ptrace.h"
39
40#if __FreeBSD_version >= 1400005
41#define HAVE_DBREG
42
43#include <unordered_set>
44#endif
45
46#ifdef HAVE_DBREG
47struct aarch64_fbsd_nat_target final
48 : public aarch64_nat_target<fbsd_nat_target>
49#else
51#endif
52{
53 void fetch_registers (struct regcache *, int) override;
54 void store_registers (struct regcache *, int) override;
55
56 const struct target_desc *read_description () override;
57
58#ifdef HAVE_DBREG
59 /* Hardware breakpoints and watchpoints. */
60 bool stopped_by_watchpoint () override;
61 bool stopped_data_address (CORE_ADDR *) override;
62 bool stopped_by_hw_breakpoint () override;
63 bool supports_stopped_by_hw_breakpoint () override;
64
65 void post_startup_inferior (ptid_t) override;
66 void post_attach (int pid) override;
67
68 void low_new_fork (ptid_t parent, pid_t child) override;
69 void low_delete_thread (thread_info *) override;
70 void low_prepare_to_resume (thread_info *) override;
71
72private:
73 void probe_debug_regs (int pid);
74 static bool debug_regs_probed;
75#endif
76};
77
79
80/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
81 for all registers. */
82
83void
85 int regnum)
86{
87 fetch_register_set<struct reg> (regcache, regnum, PT_GETREGS,
89 fetch_register_set<struct fpreg> (regcache, regnum, PT_GETFPREGS,
91
93 aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
94 if (tdep->has_tls ())
95 fetch_regset<uint64_t> (regcache, regnum, NT_ARM_TLS,
97}
98
99/* Store register REGNUM back into the inferior. If REGNUM is -1, do
100 this for all registers. */
101
102void
104 int regnum)
105{
106 store_register_set<struct reg> (regcache, regnum, PT_GETREGS, PT_SETREGS,
108 store_register_set<struct fpreg> (regcache, regnum, PT_GETFPREGS,
109 PT_SETFPREGS, &aarch64_fbsd_fpregset);
110
112 aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
113 if (tdep->has_tls ())
114 store_regset<uint64_t> (regcache, regnum, NT_ARM_TLS,
116}
117
118/* Implement the target read_description method. */
119
120const struct target_desc *
122{
123 aarch64_features features;
124 features.tls = have_regset (inferior_ptid, NT_ARM_TLS)? 1 : 0;
125 return aarch64_read_description (features);
126}
127
128#ifdef HAVE_DBREG
129bool aarch64_fbsd_nat_target::debug_regs_probed;
130
131/* Set of threads which need to update debug registers on next resume. */
132
133static std::unordered_set<lwpid_t> aarch64_debug_pending_threads;
134
135/* Implement the "stopped_data_address" target_ops method. */
136
137bool
139{
140 siginfo_t siginfo;
141 struct aarch64_debug_reg_state *state;
142
143 if (!fbsd_nat_get_siginfo (inferior_ptid, &siginfo))
144 return false;
145
146 /* This must be a hardware breakpoint. */
147 if (siginfo.si_signo != SIGTRAP
148 || siginfo.si_code != TRAP_TRACE
149 || siginfo.si_trapno != EXCP_WATCHPT_EL0)
150 return false;
151
152 const CORE_ADDR addr_trap = (CORE_ADDR) siginfo.si_addr;
153
154 /* Check if the address matches any watched address. */
156 return aarch64_stopped_data_address (state, addr_trap, addr_p);
157}
158
159/* Implement the "stopped_by_watchpoint" target_ops method. */
160
161bool
163{
164 CORE_ADDR addr;
165
166 return stopped_data_address (&addr);
167}
168
169/* Implement the "stopped_by_hw_breakpoint" target_ops method. */
170
171bool
173{
174 siginfo_t siginfo;
175 struct aarch64_debug_reg_state *state;
176
177 if (!fbsd_nat_get_siginfo (inferior_ptid, &siginfo))
178 return false;
179
180 /* This must be a hardware breakpoint. */
181 if (siginfo.si_signo != SIGTRAP
182 || siginfo.si_code != TRAP_TRACE
183 || siginfo.si_trapno != EXCP_WATCHPT_EL0)
184 return false;
185
186 return !stopped_by_watchpoint();
187}
188
189/* Implement the "supports_stopped_by_hw_breakpoint" target_ops method. */
190
191bool
193{
194 return true;
195}
196
197/* Fetch the hardware debug register capability information. */
198
199void
200aarch64_fbsd_nat_target::probe_debug_regs (int pid)
201{
202 if (!debug_regs_probed)
203 {
204 struct dbreg reg;
205
206 debug_regs_probed = true;
209
210 if (ptrace(PT_GETDBREGS, pid, (PTRACE_TYPE_ARG3) &reg, 0) == 0)
211 {
212 switch (reg.db_debug_ver)
213 {
218 break;
219 default:
220 return;
221 }
222
223 aarch64_num_bp_regs = reg.db_nbkpts;
225 {
226 warning (_("Unexpected number of hardware breakpoint registers"
227 " reported by ptrace, got %d, expected %d."),
230 }
231 aarch64_num_wp_regs = reg.db_nwtpts;
233 {
234 warning (_("Unexpected number of hardware watchpoint registers"
235 " reported by ptrace, got %d, expected %d."),
238 }
239 }
240 }
241}
242
243/* Implement the virtual inf_ptrace_target::post_startup_inferior method. */
244
245void
247{
248 aarch64_remove_debug_reg_state (ptid.pid ());
249 probe_debug_regs (ptid.pid ());
251}
252
253/* Implement the "post_attach" target_ops method. */
254
255void
257{
259 probe_debug_regs (pid);
261}
262
263/* Implement the virtual fbsd_nat_target::low_new_fork method. */
264
265void
266aarch64_fbsd_nat_target::low_new_fork (ptid_t parent, pid_t child)
267{
268 struct aarch64_debug_reg_state *parent_state, *child_state;
269
270 /* If there is no parent state, no watchpoints nor breakpoints have
271 been set, so there is nothing to do. */
272 parent_state = aarch64_lookup_debug_reg_state (parent.pid ());
273 if (parent_state == nullptr)
274 return;
275
276 /* The kernel clears debug registers in the new child process after
277 fork, but GDB core assumes the child inherits the watchpoints/hw
278 breakpoints of the parent, and will remove them all from the
279 forked off process. Copy the debug registers mirrors into the
280 new process so that all breakpoints and watchpoints can be
281 removed together. */
282
283 child_state = aarch64_get_debug_reg_state (child);
284 *child_state = *parent_state;
285}
286
287/* Mark debug register state "dirty" for all threads belonging to the
288 current inferior. */
289
290void
292 int is_watchpoint, unsigned int idx)
293{
294 for (thread_info *tp : current_inferior ()->non_exited_threads ())
295 {
296 if (tp->ptid.lwp_p ())
297 aarch64_debug_pending_threads.emplace (tp->ptid.lwp ());
298 }
299}
300
301/* Implement the virtual fbsd_nat_target::low_delete_thread method. */
302
303void
305{
306 gdb_assert(tp->ptid.lwp_p ());
307 aarch64_debug_pending_threads.erase (tp->ptid.lwp ());
308}
309
310/* Implement the virtual fbsd_nat_target::low_prepare_to_resume method. */
311
312void
314{
315 gdb_assert(tp->ptid.lwp_p ());
316
317 if (aarch64_debug_pending_threads.erase (tp->ptid.lwp ()) == 0)
318 return;
319
320 struct aarch64_debug_reg_state *state =
322 gdb_assert(state != nullptr);
323
324 struct dbreg reg;
325 memset (&reg, 0, sizeof(reg));
326 for (int i = 0; i < aarch64_num_bp_regs; i++)
327 {
328 reg.db_breakregs[i].dbr_addr = state->dr_addr_bp[i];
329 reg.db_breakregs[i].dbr_ctrl = state->dr_ctrl_bp[i];
330 }
331 for (int i = 0; i < aarch64_num_wp_regs; i++)
332 {
333 reg.db_watchregs[i].dbw_addr = state->dr_addr_wp[i];
334 reg.db_watchregs[i].dbw_ctrl = state->dr_ctrl_wp[i];
335 }
336 if (ptrace(PT_SETDBREGS, tp->ptid.lwp (), (PTRACE_TYPE_ARG3) &reg, 0) != 0)
337 error (_("Failed to set hardware debug registers"));
338}
339#else
340/* A stub that should never be called. */
341void
343 int is_watchpoint, unsigned int idx)
344{
345 gdb_assert (true);
346}
347#endif
348
350void
352{
353#ifdef HAVE_DBREG
355#endif
357}
static aarch64_fbsd_nat_target the_aarch64_fbsd_nat_target
void aarch64_notify_debug_reg_change(ptid_t ptid, int is_watchpoint, unsigned int idx)
void _initialize_aarch64_fbsd_nat()
const struct regset aarch64_fbsd_fpregset
const struct regset aarch64_fbsd_gregset
const struct regset aarch64_fbsd_tls_regset
int aarch64_num_bp_regs
int aarch64_num_wp_regs
#define AARCH64_HBP_MAX_NUM
#define AARCH64_DEBUG_ARCH_V8_1
#define AARCH64_DEBUG_ARCH_V8_4
#define AARCH64_DEBUG_ARCH_V8
#define AARCH64_HWP_MAX_NUM
#define AARCH64_DEBUG_ARCH_V8_2
void aarch64_initialize_hw_point()
struct aarch64_debug_reg_state * aarch64_lookup_debug_reg_state(pid_t pid)
Definition aarch64-nat.c:39
struct aarch64_debug_reg_state * aarch64_get_debug_reg_state(pid_t pid)
Definition aarch64-nat.c:51
bool aarch64_stopped_data_address(const struct aarch64_debug_reg_state *state, CORE_ADDR addr_trap, CORE_ADDR *addr_p)
void aarch64_remove_debug_reg_state(pid_t pid)
Definition aarch64-nat.c:59
int regnum
const target_desc * aarch64_read_description(const aarch64_features &features)
bool is_watchpoint(const struct breakpoint *bpt)
size_t have_regset(ptid_t ptid, int note)
Definition fbsd-nat.c:1785
virtual void low_new_fork(ptid_t parent, pid_t child)
Definition fbsd-nat.h:115
void post_startup_inferior(ptid_t) override
Definition fbsd-nat.c:1672
virtual void low_delete_thread(thread_info *)
Definition fbsd-nat.h:119
virtual void low_prepare_to_resume(thread_info *)
Definition fbsd-nat.h:123
void post_attach(int) override
Definition fbsd-nat.c:1680
gdbarch * arch() const
Definition regcache.c:230
ptid_t ptid
Definition gdbthread.h:256
bool fbsd_nat_get_siginfo(ptid_t ptid, siginfo_t *siginfo)
Definition fbsd-nat.c:1857
#define ptrace(request, pid, addr, data)
Definition gdb_ptrace.h:141
mach_port_t mach_port_t name mach_port_t mach_port_t name kern_return_t int int rusage_t pid_t pid
Definition gnu-nat.c:1792
void add_inf_child_target(inf_child_target *target)
Definition inf-child.c:418
ptid_t inferior_ptid
Definition infcmd.c:91
struct inferior * current_inferior(void)
Definition inferior.c:54
#define PTRACE_TYPE_ARG3
CORE_ADDR dr_addr_bp[AARCH64_HBP_MAX_NUM]
unsigned int dr_ctrl_wp[AARCH64_HWP_MAX_NUM]
CORE_ADDR dr_addr_wp[AARCH64_HWP_MAX_NUM]
unsigned int dr_ctrl_bp[AARCH64_HBP_MAX_NUM]
void store_registers(struct regcache *, int) override
void fetch_registers(struct regcache *, int) override
const struct target_desc * read_description() override
uint8_t tls
Definition aarch64.h:38
virtual bool stopped_by_watchpoint() TARGET_DEFAULT_RETURN(false)
virtual bool stopped_data_address(CORE_ADDR *) TARGET_DEFAULT_RETURN(false)
virtual bool stopped_by_hw_breakpoint() TARGET_DEFAULT_RETURN(false)
virtual bool supports_stopped_by_hw_breakpoint() TARGET_DEFAULT_RETURN(false)