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authorWill Deacon <will.deacon@arm.com>2012-03-05 06:49:33 -0500
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 08:42:14 -0400
commit478fcb2cdb2351dcfc3fb23f42d76f4436ee4149 (patch)
treef5d0be182e1ca20a1c539d1632cc27d4d910d5db
parent53631b54c8704fe5de435582c82ddbc0bfabf06a (diff)
arm64: Debugging support
This patch adds ptrace, debug monitors and hardware breakpoints support. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat
-rw-r--r--arch/arm64/include/asm/debug-monitors.h88
-rw-r--r--arch/arm64/include/asm/hw_breakpoint.h137
-rw-r--r--arch/arm64/kernel/debug-monitors.c288
-rw-r--r--arch/arm64/kernel/hw_breakpoint.c880
-rw-r--r--arch/arm64/kernel/ptrace.c1126
-rw-r--r--include/linux/elf.h3
6 files changed, 2522 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
new file mode 100644
index 000000000000..7eaa0b302493
--- /dev/null
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -0,0 +1,88 @@
1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __ASM_DEBUG_MONITORS_H
17#define __ASM_DEBUG_MONITORS_H
18
19#ifdef __KERNEL__
20
21#define DBG_ESR_EVT(x) (((x) >> 27) & 0x7)
22
23/* AArch64 */
24#define DBG_ESR_EVT_HWBP 0x0
25#define DBG_ESR_EVT_HWSS 0x1
26#define DBG_ESR_EVT_HWWP 0x2
27#define DBG_ESR_EVT_BRK 0x6
28
29enum debug_el {
30 DBG_ACTIVE_EL0 = 0,
31 DBG_ACTIVE_EL1,
32};
33
34/* AArch32 */
35#define DBG_ESR_EVT_BKPT 0x4
36#define DBG_ESR_EVT_VECC 0x5
37
38#define AARCH32_BREAK_ARM 0x07f001f0
39#define AARCH32_BREAK_THUMB 0xde01
40#define AARCH32_BREAK_THUMB2_LO 0xf7f0
41#define AARCH32_BREAK_THUMB2_HI 0xa000
42
43#ifndef __ASSEMBLY__
44struct task_struct;
45
46#define local_dbg_save(flags) \
47 do { \
48 typecheck(unsigned long, flags); \
49 asm volatile( \
50 "mrs %0, daif // local_dbg_save\n" \
51 "msr daifset, #8" \
52 : "=r" (flags) : : "memory"); \
53 } while (0)
54
55#define local_dbg_restore(flags) \
56 do { \
57 typecheck(unsigned long, flags); \
58 asm volatile( \
59 "msr daif, %0 // local_dbg_restore\n" \
60 : : "r" (flags) : "memory"); \
61 } while (0)
62
63#define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */
64
65u8 debug_monitors_arch(void);
66
67void enable_debug_monitors(enum debug_el el);
68void disable_debug_monitors(enum debug_el el);
69
70void user_rewind_single_step(struct task_struct *task);
71void user_fastforward_single_step(struct task_struct *task);
72
73void kernel_enable_single_step(struct pt_regs *regs);
74void kernel_disable_single_step(void);
75int kernel_active_single_step(void);
76
77#ifdef CONFIG_HAVE_HW_BREAKPOINT
78int reinstall_suspended_bps(struct pt_regs *regs);
79#else
80static inline int reinstall_suspended_bps(struct pt_regs *regs)
81{
82 return -ENODEV;
83}
84#endif
85
86#endif /* __ASSEMBLY */
87#endif /* __KERNEL__ */
88#endif /* __ASM_DEBUG_MONITORS_H */
diff --git a/arch/arm64/include/asm/hw_breakpoint.h b/arch/arm64/include/asm/hw_breakpoint.h
new file mode 100644
index 000000000000..d064047612b1
--- /dev/null
+++ b/arch/arm64/include/asm/hw_breakpoint.h
@@ -0,0 +1,137 @@
1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __ASM_HW_BREAKPOINT_H
17#define __ASM_HW_BREAKPOINT_H
18
19#ifdef __KERNEL__
20
21struct arch_hw_breakpoint_ctrl {
22 u32 __reserved : 19,
23 len : 8,
24 type : 2,
25 privilege : 2,
26 enabled : 1;
27};
28
29struct arch_hw_breakpoint {
30 u64 address;
31 u64 trigger;
32 struct arch_hw_breakpoint_ctrl ctrl;
33};
34
35static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
36{
37 return (ctrl.len << 5) | (ctrl.type << 3) | (ctrl.privilege << 1) |
38 ctrl.enabled;
39}
40
41static inline void decode_ctrl_reg(u32 reg,
42 struct arch_hw_breakpoint_ctrl *ctrl)
43{
44 ctrl->enabled = reg & 0x1;
45 reg >>= 1;
46 ctrl->privilege = reg & 0x3;
47 reg >>= 2;
48 ctrl->type = reg & 0x3;
49 reg >>= 2;
50 ctrl->len = reg & 0xff;
51}
52
53/* Breakpoint */
54#define ARM_BREAKPOINT_EXECUTE 0
55
56/* Watchpoints */
57#define ARM_BREAKPOINT_LOAD 1
58#define ARM_BREAKPOINT_STORE 2
59#define AARCH64_ESR_ACCESS_MASK (1 << 6)
60
61/* Privilege Levels */
62#define AARCH64_BREAKPOINT_EL1 1
63#define AARCH64_BREAKPOINT_EL0 2
64
65/* Lengths */
66#define ARM_BREAKPOINT_LEN_1 0x1
67#define ARM_BREAKPOINT_LEN_2 0x3
68#define ARM_BREAKPOINT_LEN_4 0xf
69#define ARM_BREAKPOINT_LEN_8 0xff
70
71/* Kernel stepping */
72#define ARM_KERNEL_STEP_NONE 0
73#define ARM_KERNEL_STEP_ACTIVE 1
74#define ARM_KERNEL_STEP_SUSPEND 2
75
76/*
77 * Limits.
78 * Changing these will require modifications to the register accessors.
79 */
80#define ARM_MAX_BRP 16
81#define ARM_MAX_WRP 16
82#define ARM_MAX_HBP_SLOTS (ARM_MAX_BRP + ARM_MAX_WRP)
83
84/* Virtual debug register bases. */
85#define AARCH64_DBG_REG_BVR 0
86#define AARCH64_DBG_REG_BCR (AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
87#define AARCH64_DBG_REG_WVR (AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
88#define AARCH64_DBG_REG_WCR (AARCH64_DBG_REG_WVR + ARM_MAX_WRP)
89
90/* Debug register names. */
91#define AARCH64_DBG_REG_NAME_BVR "bvr"
92#define AARCH64_DBG_REG_NAME_BCR "bcr"
93#define AARCH64_DBG_REG_NAME_WVR "wvr"
94#define AARCH64_DBG_REG_NAME_WCR "wcr"
95
96/* Accessor macros for the debug registers. */
97#define AARCH64_DBG_READ(N, REG, VAL) do {\
98 asm volatile("mrs %0, dbg" REG #N "_el1" : "=r" (VAL));\
99} while (0)
100
101#define AARCH64_DBG_WRITE(N, REG, VAL) do {\
102 asm volatile("msr dbg" REG #N "_el1, %0" :: "r" (VAL));\
103} while (0)
104
105struct task_struct;
106struct notifier_block;
107struct perf_event;
108struct pmu;
109
110extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
111 int *gen_len, int *gen_type);
112extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
113extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
114extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
115 unsigned long val, void *data);
116
117extern int arch_install_hw_breakpoint(struct perf_event *bp);
118extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
119extern void hw_breakpoint_pmu_read(struct perf_event *bp);
120extern int hw_breakpoint_slots(int type);
121
122#ifdef CONFIG_HAVE_HW_BREAKPOINT
123extern void hw_breakpoint_thread_switch(struct task_struct *next);
124extern void ptrace_hw_copy_thread(struct task_struct *task);
125#else
126static inline void hw_breakpoint_thread_switch(struct task_struct *next)
127{
128}
129static inline void ptrace_hw_copy_thread(struct task_struct *task)
130{
131}
132#endif
133
134extern struct pmu perf_ops_bp;
135
136#endif /* __KERNEL__ */
137#endif /* __ASM_BREAKPOINT_H */
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
new file mode 100644
index 000000000000..0c3ba9f51376
--- /dev/null
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -0,0 +1,288 @@
1/*
2 * ARMv8 single-step debug support and mdscr context switching.
3 *
4 * Copyright (C) 2012 ARM Limited
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program 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
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: Will Deacon <will.deacon@arm.com>
19 */
20
21#include <linux/cpu.h>
22#include <linux/debugfs.h>
23#include <linux/hardirq.h>
24#include <linux/init.h>
25#include <linux/ptrace.h>
26#include <linux/stat.h>
27
28#include <asm/debug-monitors.h>
29#include <asm/local.h>
30#include <asm/cputype.h>
31#include <asm/system_misc.h>
32
33/* Low-level stepping controls. */
34#define DBG_MDSCR_SS (1 << 0)
35#define DBG_SPSR_SS (1 << 21)
36
37/* MDSCR_EL1 enabling bits */
38#define DBG_MDSCR_KDE (1 << 13)
39#define DBG_MDSCR_MDE (1 << 15)
40#define DBG_MDSCR_MASK ~(DBG_MDSCR_KDE | DBG_MDSCR_MDE)
41
42/* Determine debug architecture. */
43u8 debug_monitors_arch(void)
44{
45 return read_cpuid(ID_AA64DFR0_EL1) & 0xf;
46}
47
48/*
49 * MDSCR access routines.
50 */
51static void mdscr_write(u32 mdscr)
52{
53 unsigned long flags;
54 local_dbg_save(flags);
55 asm volatile("msr mdscr_el1, %0" :: "r" (mdscr));
56 local_dbg_restore(flags);
57}
58
59static u32 mdscr_read(void)
60{
61 u32 mdscr;
62 asm volatile("mrs %0, mdscr_el1" : "=r" (mdscr));
63 return mdscr;
64}
65
66/*
67 * Allow root to disable self-hosted debug from userspace.
68 * This is useful if you want to connect an external JTAG debugger.
69 */
70static u32 debug_enabled = 1;
71
72static int create_debug_debugfs_entry(void)
73{
74 debugfs_create_bool("debug_enabled", 0644, NULL, &debug_enabled);
75 return 0;
76}
77fs_initcall(create_debug_debugfs_entry);
78
79static int __init early_debug_disable(char *buf)
80{
81 debug_enabled = 0;
82 return 0;
83}
84
85early_param("nodebugmon", early_debug_disable);
86
87/*
88 * Keep track of debug users on each core.
89 * The ref counts are per-cpu so we use a local_t type.
90 */
91static DEFINE_PER_CPU(local_t, mde_ref_count);
92static DEFINE_PER_CPU(local_t, kde_ref_count);
93
94void enable_debug_monitors(enum debug_el el)
95{
96 u32 mdscr, enable = 0;
97
98 WARN_ON(preemptible());
99
100 if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
101 enable = DBG_MDSCR_MDE;
102
103 if (el == DBG_ACTIVE_EL1 &&
104 local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
105 enable |= DBG_MDSCR_KDE;
106
107 if (enable && debug_enabled) {
108 mdscr = mdscr_read();
109 mdscr |= enable;
110 mdscr_write(mdscr);
111 }
112}
113
114void disable_debug_monitors(enum debug_el el)
115{
116 u32 mdscr, disable = 0;
117
118 WARN_ON(preemptible());
119
120 if (local_dec_and_test(&__get_cpu_var(mde_ref_count)))
121 disable = ~DBG_MDSCR_MDE;
122
123 if (el == DBG_ACTIVE_EL1 &&
124 local_dec_and_test(&__get_cpu_var(kde_ref_count)))
125 disable &= ~DBG_MDSCR_KDE;
126
127 if (disable) {
128 mdscr = mdscr_read();
129 mdscr &= disable;
130 mdscr_write(mdscr);
131 }
132}
133
134/*
135 * OS lock clearing.
136 */
137static void clear_os_lock(void *unused)
138{
139 asm volatile("msr mdscr_el1, %0" : : "r" (0));
140 isb();
141 asm volatile("msr oslar_el1, %0" : : "r" (0));
142 isb();
143}
144
145static int __cpuinit os_lock_notify(struct notifier_block *self,
146 unsigned long action, void *data)
147{
148 int cpu = (unsigned long)data;
149 if (action == CPU_ONLINE)
150 smp_call_function_single(cpu, clear_os_lock, NULL, 1);
151 return NOTIFY_OK;
152}
153
154static struct notifier_block __cpuinitdata os_lock_nb = {
155 .notifier_call = os_lock_notify,
156};
157
158static int __cpuinit debug_monitors_init(void)
159{
160 /* Clear the OS lock. */
161 smp_call_function(clear_os_lock, NULL, 1);
162 clear_os_lock(NULL);
163
164 /* Register hotplug handler. */
165 register_cpu_notifier(&os_lock_nb);
166 return 0;
167}
168postcore_initcall(debug_monitors_init);
169
170/*
171 * Single step API and exception handling.
172 */
173static void set_regs_spsr_ss(struct pt_regs *regs)
174{
175 unsigned long spsr;
176
177 spsr = regs->pstate;
178 spsr &= ~DBG_SPSR_SS;
179 spsr |= DBG_SPSR_SS;
180 regs->pstate = spsr;
181}
182
183static void clear_regs_spsr_ss(struct pt_regs *regs)
184{
185 unsigned long spsr;
186
187 spsr = regs->pstate;
188 spsr &= ~DBG_SPSR_SS;
189 regs->pstate = spsr;
190}
191
192static int single_step_handler(unsigned long addr, unsigned int esr,
193 struct pt_regs *regs)
194{
195 siginfo_t info;
196
197 /*
198 * If we are stepping a pending breakpoint, call the hw_breakpoint
199 * handler first.
200 */
201 if (!reinstall_suspended_bps(regs))
202 return 0;
203
204 if (user_mode(regs)) {
205 info.si_signo = SIGTRAP;
206 info.si_errno = 0;
207 info.si_code = TRAP_HWBKPT;
208 info.si_addr = (void __user *)instruction_pointer(regs);
209 force_sig_info(SIGTRAP, &info, current);
210
211 /*
212 * ptrace will disable single step unless explicitly
213 * asked to re-enable it. For other clients, it makes
214 * sense to leave it enabled (i.e. rewind the controls
215 * to the active-not-pending state).
216 */
217 user_rewind_single_step(current);
218 } else {
219 /* TODO: route to KGDB */
220 pr_warning("Unexpected kernel single-step exception at EL1\n");
221 /*
222 * Re-enable stepping since we know that we will be
223 * returning to regs.
224 */
225 set_regs_spsr_ss(regs);
226 }
227
228 return 0;
229}
230
231static int __init single_step_init(void)
232{
233 hook_debug_fault_code(DBG_ESR_EVT_HWSS, single_step_handler, SIGTRAP,
234 TRAP_HWBKPT, "single-step handler");
235 return 0;
236}
237arch_initcall(single_step_init);
238
239/* Re-enable single step for syscall restarting. */
240void user_rewind_single_step(struct task_struct *task)
241{
242 /*
243 * If single step is active for this thread, then set SPSR.SS
244 * to 1 to avoid returning to the active-pending state.
245 */
246 if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
247 set_regs_spsr_ss(task_pt_regs(task));
248}
249
250void user_fastforward_single_step(struct task_struct *task)
251{
252 if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
253 clear_regs_spsr_ss(task_pt_regs(task));
254}
255
256/* Kernel API */
257void kernel_enable_single_step(struct pt_regs *regs)
258{
259 WARN_ON(!irqs_disabled());
260 set_regs_spsr_ss(regs);
261 mdscr_write(mdscr_read() | DBG_MDSCR_SS);
262 enable_debug_monitors(DBG_ACTIVE_EL1);
263}
264
265void kernel_disable_single_step(void)
266{
267 WARN_ON(!irqs_disabled());
268 mdscr_write(mdscr_read() & ~DBG_MDSCR_SS);
269 disable_debug_monitors(DBG_ACTIVE_EL1);
270}
271
272int kernel_active_single_step(void)
273{
274 WARN_ON(!irqs_disabled());
275 return mdscr_read() & DBG_MDSCR_SS;
276}
277
278/* ptrace API */
279void user_enable_single_step(struct task_struct *task)
280{
281 set_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
282 set_regs_spsr_ss(task_pt_regs(task));
283}
284
285void user_disable_single_step(struct task_struct *task)
286{
287 clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
288}
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
new file mode 100644
index 000000000000..5ab825c59db9
--- /dev/null
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -0,0 +1,880 @@
1/*
2 * HW_breakpoint: a unified kernel/user-space hardware breakpoint facility,
3 * using the CPU's debug registers.
4 *
5 * Copyright (C) 2012 ARM Limited
6 * Author: Will Deacon <will.deacon@arm.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
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
21#define pr_fmt(fmt) "hw-breakpoint: " fmt
22
23#include <linux/errno.h>
24#include <linux/hw_breakpoint.h>
25#include <linux/perf_event.h>
26#include <linux/ptrace.h>
27#include <linux/smp.h>
28
29#include <asm/compat.h>
30#include <asm/current.h>
31#include <asm/debug-monitors.h>
32#include <asm/hw_breakpoint.h>
33#include <asm/kdebug.h>
34#include <asm/traps.h>
35#include <asm/cputype.h>
36#include <asm/system_misc.h>
37
38/* Breakpoint currently in use for each BRP. */
39static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]);
40
41/* Watchpoint currently in use for each WRP. */
42static DEFINE_PER_CPU(struct perf_event *, wp_on_reg[ARM_MAX_WRP]);
43
44/* Currently stepping a per-CPU kernel breakpoint. */
45static DEFINE_PER_CPU(int, stepping_kernel_bp);
46
47/* Number of BRP/WRP registers on this CPU. */
48static int core_num_brps;
49static int core_num_wrps;
50
51/* Determine number of BRP registers available. */
52static int get_num_brps(void)
53{
54 return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1;
55}
56
57/* Determine number of WRP registers available. */
58static int get_num_wrps(void)
59{
60 return ((read_cpuid(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1;
61}
62
63int hw_breakpoint_slots(int type)
64{
65 /*
66 * We can be called early, so don't rely on
67 * our static variables being initialised.
68 */
69 switch (type) {
70 case TYPE_INST:
71 return get_num_brps();
72 case TYPE_DATA:
73 return get_num_wrps();
74 default:
75 pr_warning("unknown slot type: %d\n", type);
76 return 0;
77 }
78}
79
80#define READ_WB_REG_CASE(OFF, N, REG, VAL) \
81 case (OFF + N): \
82 AARCH64_DBG_READ(N, REG, VAL); \
83 break
84
85#define WRITE_WB_REG_CASE(OFF, N, REG, VAL) \
86 case (OFF + N): \
87 AARCH64_DBG_WRITE(N, REG, VAL); \
88 break
89
90#define GEN_READ_WB_REG_CASES(OFF, REG, VAL) \
91 READ_WB_REG_CASE(OFF, 0, REG, VAL); \
92 READ_WB_REG_CASE(OFF, 1, REG, VAL); \
93 READ_WB_REG_CASE(OFF, 2, REG, VAL); \
94 READ_WB_REG_CASE(OFF, 3, REG, VAL); \
95 READ_WB_REG_CASE(OFF, 4, REG, VAL); \
96 READ_WB_REG_CASE(OFF, 5, REG, VAL); \
97 READ_WB_REG_CASE(OFF, 6, REG, VAL); \
98 READ_WB_REG_CASE(OFF, 7, REG, VAL); \
99 READ_WB_REG_CASE(OFF, 8, REG, VAL); \
100 READ_WB_REG_CASE(OFF, 9, REG, VAL); \
101 READ_WB_REG_CASE(OFF, 10, REG, VAL); \
102 READ_WB_REG_CASE(OFF, 11, REG, VAL); \
103 READ_WB_REG_CASE(OFF, 12, REG, VAL); \
104 READ_WB_REG_CASE(OFF, 13, REG, VAL); \
105 READ_WB_REG_CASE(OFF, 14, REG, VAL); \
106 READ_WB_REG_CASE(OFF, 15, REG, VAL)
107
108#define GEN_WRITE_WB_REG_CASES(OFF, REG, VAL) \
109 WRITE_WB_REG_CASE(OFF, 0, REG, VAL); \
110 WRITE_WB_REG_CASE(OFF, 1, REG, VAL); \
111 WRITE_WB_REG_CASE(OFF, 2, REG, VAL); \
112 WRITE_WB_REG_CASE(OFF, 3, REG, VAL); \
113 WRITE_WB_REG_CASE(OFF, 4, REG, VAL); \
114 WRITE_WB_REG_CASE(OFF, 5, REG, VAL); \
115 WRITE_WB_REG_CASE(OFF, 6, REG, VAL); \
116 WRITE_WB_REG_CASE(OFF, 7, REG, VAL); \
117 WRITE_WB_REG_CASE(OFF, 8, REG, VAL); \
118 WRITE_WB_REG_CASE(OFF, 9, REG, VAL); \
119 WRITE_WB_REG_CASE(OFF, 10, REG, VAL); \
120 WRITE_WB_REG_CASE(OFF, 11, REG, VAL); \
121 WRITE_WB_REG_CASE(OFF, 12, REG, VAL); \
122 WRITE_WB_REG_CASE(OFF, 13, REG, VAL); \
123 WRITE_WB_REG_CASE(OFF, 14, REG, VAL); \
124 WRITE_WB_REG_CASE(OFF, 15, REG, VAL)
125
126static u64 read_wb_reg(int reg, int n)
127{
128 u64 val = 0;
129
130 switch (reg + n) {
131 GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_BVR, AARCH64_DBG_REG_NAME_BVR, val);
132 GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_BCR, AARCH64_DBG_REG_NAME_BCR, val);
133 GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_WVR, AARCH64_DBG_REG_NAME_WVR, val);
134 GEN_READ_WB_REG_CASES(AARCH64_DBG_REG_WCR, AARCH64_DBG_REG_NAME_WCR, val);
135 default:
136 pr_warning("attempt to read from unknown breakpoint register %d\n", n);
137 }
138
139 return val;
140}
141
142static void write_wb_reg(int reg, int n, u64 val)
143{
144 switch (reg + n) {
145 GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_BVR, AARCH64_DBG_REG_NAME_BVR, val);
146 GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_BCR, AARCH64_DBG_REG_NAME_BCR, val);
147 GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_WVR, AARCH64_DBG_REG_NAME_WVR, val);
148 GEN_WRITE_WB_REG_CASES(AARCH64_DBG_REG_WCR, AARCH64_DBG_REG_NAME_WCR, val);
149 default:
150 pr_warning("attempt to write to unknown breakpoint register %d\n", n);
151 }
152 isb();
153}
154
155/*
156 * Convert a breakpoint privilege level to the corresponding exception
157 * level.
158 */
159static enum debug_el debug_exception_level(int privilege)
160{
161 switch (privilege) {
162 case AARCH64_BREAKPOINT_EL0:
163 return DBG_ACTIVE_EL0;
164 case AARCH64_BREAKPOINT_EL1:
165 return DBG_ACTIVE_EL1;
166 default:
167 pr_warning("invalid breakpoint privilege level %d\n", privilege);
168 return -EINVAL;
169 }
170}
171
172/*
173 * Install a perf counter breakpoint.
174 */
175int arch_install_hw_breakpoint(struct perf_event *bp)
176{
177 struct arch_hw_breakpoint *info = counter_arch_bp(bp);
178 struct perf_event **slot, **slots;
179 struct debug_info *debug_info = &current->thread.debug;
180 int i, max_slots, ctrl_reg, val_reg, reg_enable;
181 u32 ctrl;
182
183 if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
184 /* Breakpoint */
185 ctrl_reg = AARCH64_DBG_REG_BCR;
186 val_reg = AARCH64_DBG_REG_BVR;
187 slots = __get_cpu_var(bp_on_reg);
188 max_slots = core_num_brps;
189 reg_enable = !debug_info->bps_disabled;
190 } else {
191 /* Watchpoint */
192 ctrl_reg = AARCH64_DBG_REG_WCR;
193 val_reg = AARCH64_DBG_REG_WVR;
194 slots = __get_cpu_var(wp_on_reg);
195 max_slots = core_num_wrps;
196 reg_enable = !debug_info->wps_disabled;
197 }
198
199 for (i = 0; i < max_slots; ++i) {
200 slot = &slots[i];
201
202 if (!*slot) {
203 *slot = bp;
204 break;
205 }
206 }
207
208 if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
209 return -ENOSPC;
210
211 /* Ensure debug monitors are enabled at the correct exception level. */
212 enable_debug_monitors(debug_exception_level(info->ctrl.privilege));
213
214 /* Setup the address register. */
215 write_wb_reg(val_reg, i, info->address);
216
217 /* Setup the control register. */
218 ctrl = encode_ctrl_reg(info->ctrl);
219 write_wb_reg(ctrl_reg, i, reg_enable ? ctrl | 0x1 : ctrl & ~0x1);
220
221 return 0;
222}
223
224void arch_uninstall_hw_breakpoint(struct perf_event *bp)
225{
226 struct arch_hw_breakpoint *info = counter_arch_bp(bp);
227 struct perf_event **slot, **slots;
228 int i, max_slots, base;
229
230 if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
231 /* Breakpoint */
232 base = AARCH64_DBG_REG_BCR;
233 slots = __get_cpu_var(bp_on_reg);
234 max_slots = core_num_brps;
235 } else {
236 /* Watchpoint */
237 base = AARCH64_DBG_REG_WCR;
238 slots = __get_cpu_var(wp_on_reg);
239 max_slots = core_num_wrps;
240 }
241
242 /* Remove the breakpoint. */
243 for (i = 0; i < max_slots; ++i) {
244 slot = &slots[i];
245
246 if (*slot == bp) {
247 *slot = NULL;
248 break;
249 }
250 }
251
252 if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
253 return;
254
255 /* Reset the control register. */
256 write_wb_reg(base, i, 0);
257
258 /* Release the debug monitors for the correct exception level. */
259 disable_debug_monitors(debug_exception_level(info->ctrl.privilege));
260}
261
262static int get_hbp_len(u8 hbp_len)
263{
264 unsigned int len_in_bytes = 0;
265
266 switch (hbp_len) {
267 case ARM_BREAKPOINT_LEN_1:
268 len_in_bytes = 1;
269 break;
270 case ARM_BREAKPOINT_LEN_2:
271 len_in_bytes = 2;
272 break;
273 case ARM_BREAKPOINT_LEN_4:
274 len_in_bytes = 4;
275 break;
276 case ARM_BREAKPOINT_LEN_8:
277 len_in_bytes = 8;
278 break;
279 }
280
281 return len_in_bytes;
282}
283
284/*
285 * Check whether bp virtual address is in kernel space.
286 */
287int arch_check_bp_in_kernelspace(struct perf_event *bp)
288{
289 unsigned int len;
290 unsigned long va;
291 struct arch_hw_breakpoint *info = counter_arch_bp(bp);
292
293 va = info->address;
294 len = get_hbp_len(info->ctrl.len);
295
296 return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
297}
298
299/*
300 * Extract generic type and length encodings from an arch_hw_breakpoint_ctrl.
301 * Hopefully this will disappear when ptrace can bypass the conversion
302 * to generic breakpoint descriptions.
303 */
304int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
305 int *gen_len, int *gen_type)
306{
307 /* Type */
308 switch (ctrl.type) {
309 case ARM_BREAKPOINT_EXECUTE:
310 *gen_type = HW_BREAKPOINT_X;
311 break;
312 case ARM_BREAKPOINT_LOAD:
313 *gen_type = HW_BREAKPOINT_R;
314 break;
315 case ARM_BREAKPOINT_STORE:
316 *gen_type = HW_BREAKPOINT_W;
317 break;
318 case ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE:
319 *gen_type = HW_BREAKPOINT_RW;
320 break;
321 default:
322 return -EINVAL;
323 }
324
325 /* Len */
326 switch (ctrl.len) {
327 case ARM_BREAKPOINT_LEN_1:
328 *gen_len = HW_BREAKPOINT_LEN_1;
329 break;
330 case ARM_BREAKPOINT_LEN_2:
331 *gen_len = HW_BREAKPOINT_LEN_2;
332 break;
333 case ARM_BREAKPOINT_LEN_4:
334 *gen_len = HW_BREAKPOINT_LEN_4;
335 break;
336 case ARM_BREAKPOINT_LEN_8:
337 *gen_len = HW_BREAKPOINT_LEN_8;
338 break;
339 default:
340 return -EINVAL;
341 }
342
343 return 0;
344}
345
346/*
347 * Construct an arch_hw_breakpoint from a perf_event.
348 */
349static int arch_build_bp_info(struct perf_event *bp)
350{
351 struct arch_hw_breakpoint *info = counter_arch_bp(bp);
352
353 /* Type */
354 switch (bp->attr.bp_type) {
355 case HW_BREAKPOINT_X:
356 info->ctrl.type = ARM_BREAKPOINT_EXECUTE;
357 break;
358 case HW_BREAKPOINT_R:
359 info->ctrl.type = ARM_BREAKPOINT_LOAD;
360 break;
361 case HW_BREAKPOINT_W:
362 info->ctrl.type = ARM_BREAKPOINT_STORE;
363 break;
364 case HW_BREAKPOINT_RW:
365 info->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;
366 break;
367 default:
368 return -EINVAL;
369 }
370
371 /* Len */
372 switch (bp->attr.bp_len) {
373 case HW_BREAKPOINT_LEN_1:
374 info->ctrl.len = ARM_BREAKPOINT_LEN_1;
375 break;
376 case HW_BREAKPOINT_LEN_2:
377 info->ctrl.len = ARM_BREAKPOINT_LEN_2;
378 break;
379 case HW_BREAKPOINT_LEN_4:
380 info->ctrl.len = ARM_BREAKPOINT_LEN_4;
381 break;
382 case HW_BREAKPOINT_LEN_8:
383 info->ctrl.len = ARM_BREAKPOINT_LEN_8;
384 break;
385 default:
386 return -EINVAL;
387 }
388
389 /*
390 * On AArch64, we only permit breakpoints of length 4, whereas
391 * AArch32 also requires breakpoints of length 2 for Thumb.
392 * Watchpoints can be of length 1, 2, 4 or 8 bytes.
393 */
394 if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
395 if (is_compat_task()) {
396 if (info->ctrl.len != ARM_BREAKPOINT_LEN_2 &&
397 info->ctrl.len != ARM_BREAKPOINT_LEN_4)
398 return -EINVAL;
399 } else if (info->ctrl.len != ARM_BREAKPOINT_LEN_4) {
400 /*
401 * FIXME: Some tools (I'm looking at you perf) assume
402 * that breakpoints should be sizeof(long). This
403 * is nonsense. For now, we fix up the parameter
404 * but we should probably return -EINVAL instead.
405 */
406 info->ctrl.len = ARM_BREAKPOINT_LEN_4;
407 }
408 }
409
410 /* Address */
411 info->address = bp->attr.bp_addr;
412
413 /*
414 * Privilege
415 * Note that we disallow combined EL0/EL1 breakpoints because
416 * that would complicate the stepping code.
417 */
418 if (arch_check_bp_in_kernelspace(bp))
419 info->ctrl.privilege = AARCH64_BREAKPOINT_EL1;
420 else
421 info->ctrl.privilege = AARCH64_BREAKPOINT_EL0;
422
423 /* Enabled? */
424 info->ctrl.enabled = !bp->attr.disabled;
425
426 return 0;
427}
428
429/*
430 * Validate the arch-specific HW Breakpoint register settings.
431 */
432int arch_validate_hwbkpt_settings(struct perf_event *bp)
433{
434 struct arch_hw_breakpoint *info = counter_arch_bp(bp);
435 int ret;
436 u64 alignment_mask, offset;
437
438 /* Build the arch_hw_breakpoint. */
439 ret = arch_build_bp_info(bp);
440 if (ret)
441 return ret;
442
443 /*
444 * Check address alignment.
445 * We don't do any clever alignment correction for watchpoints
446 * because using 64-bit unaligned addresses is deprecated for
447 * AArch64.
448 *
449 * AArch32 tasks expect some simple alignment fixups, so emulate
450 * that here.
451 */
452 if (is_compat_task()) {
453 if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
454 alignment_mask = 0x7;
455 else
456 alignment_mask = 0x3;
457 offset = info->address & alignment_mask;
458 switch (offset) {
459 case 0:
460 /* Aligned */
461 break;
462 case 1:
463 /* Allow single byte watchpoint. */
464 if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
465 break;
466 case 2:
467 /* Allow halfword watchpoints and breakpoints. */
468 if (info->ctrl.len == ARM_BREAKPOINT_LEN_2)
469 break;
470 default:
471 return -EINVAL;
472 }
473
474 info->address &= ~alignment_mask;
475 info->ctrl.len <<= offset;
476 } else {
477 if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE)
478 alignment_mask = 0x3;
479 else
480 alignment_mask = 0x7;
481 if (info->address & alignment_mask)
482 return -EINVAL;
483 }
484
485 /*
486 * Disallow per-task kernel breakpoints since these would
487 * complicate the stepping code.
488 */
489 if (info->ctrl.privilege == AARCH64_BREAKPOINT_EL1 && bp->hw.bp_target)
490 return -EINVAL;
491
492 return 0;
493}
494
495/*
496 * Enable/disable all of the breakpoints active at the specified
497 * exception level at the register level.
498 * This is used when single-stepping after a breakpoint exception.
499 */
500static void toggle_bp_registers(int reg, enum debug_el el, int enable)
501{
502 int i, max_slots, privilege;
503 u32 ctrl;
504 struct perf_event **slots;
505
506 switch (reg) {
507 case AARCH64_DBG_REG_BCR:
508 slots = __get_cpu_var(bp_on_reg);
509 max_slots = core_num_brps;
510 break;
511 case AARCH64_DBG_REG_WCR:
512 slots = __get_cpu_var(wp_on_reg);
513 max_slots = core_num_wrps;
514 break;
515 default:
516 return;
517 }
518
519 for (i = 0; i < max_slots; ++i) {
520 if (!slots[i])
521 continue;
522
523 privilege = counter_arch_bp(slots[i])->ctrl.privilege;
524 if (debug_exception_level(privilege) != el)
525 continue;
526
527 ctrl = read_wb_reg(reg, i);
528 if (enable)
529 ctrl |= 0x1;
530 else
531 ctrl &= ~0x1;
532 write_wb_reg(reg, i, ctrl);
533 }
534}
535
536/*
537 * Debug exception handlers.
538 */
539static int breakpoint_handler(unsigned long unused, unsigned int esr,
540 struct pt_regs *regs)
541{
542 int i, step = 0, *kernel_step;
543 u32 ctrl_reg;
544 u64 addr, val;
545 struct perf_event *bp, **slots;
546 struct debug_info *debug_info;
547 struct arch_hw_breakpoint_ctrl ctrl;
548
549 slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
550 addr = instruction_pointer(regs);
551 debug_info = &current->thread.debug;
552
553 for (i = 0; i < core_num_brps; ++i) {
554 rcu_read_lock();
555
556 bp = slots[i];
557
558 if (bp == NULL)
559 goto unlock;
560
561 /* Check if the breakpoint value matches. */
562 val = read_wb_reg(AARCH64_DBG_REG_BVR, i);
563 if (val != (addr & ~0x3))
564 goto unlock;
565
566 /* Possible match, check the byte address select to confirm. */
567 ctrl_reg = read_wb_reg(AARCH64_DBG_REG_BCR, i);
568 decode_ctrl_reg(ctrl_reg, &ctrl);
569 if (!((1 << (addr & 0x3)) & ctrl.len))
570 goto unlock;
571
572 counter_arch_bp(bp)->trigger = addr;
573 perf_bp_event(bp, regs);
574
575 /* Do we need to handle the stepping? */
576 if (!bp->overflow_handler)
577 step = 1;
578unlock:
579 rcu_read_unlock();
580 }
581
582 if (!step)
583 return 0;
584
585 if (user_mode(regs)) {
586 debug_info->bps_disabled = 1;
587 toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL0, 0);
588
589 /* If we're already stepping a watchpoint, just return. */
590 if (debug_info->wps_disabled)
591 return 0;
592
593 if (test_thread_flag(TIF_SINGLESTEP))
594 debug_info->suspended_step = 1;
595 else
596 user_enable_single_step(current);
597 } else {
598 toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 0);
599 kernel_step = &__get_cpu_var(stepping_kernel_bp);
600
601 if (*kernel_step != ARM_KERNEL_STEP_NONE)
602 return 0;
603
604 if (kernel_active_single_step()) {
605 *kernel_step = ARM_KERNEL_STEP_SUSPEND;
606 } else {
607 *kernel_step = ARM_KERNEL_STEP_ACTIVE;
608 kernel_enable_single_step(regs);
609 }
610 }
611
612 return 0;
613}
614
615static int watchpoint_handler(unsigned long addr, unsigned int esr,
616 struct pt_regs *regs)
617{
618 int i, step = 0, *kernel_step, access;
619 u32 ctrl_reg;
620 u64 val, alignment_mask;
621 struct perf_event *wp, **slots;
622 struct debug_info *debug_info;
623 struct arch_hw_breakpoint *info;
624 struct arch_hw_breakpoint_ctrl ctrl;
625
626 slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
627 debug_info = &current->thread.debug;
628
629 for (i = 0; i < core_num_wrps; ++i) {
630 rcu_read_lock();
631
632 wp = slots[i];
633
634 if (wp == NULL)
635 goto unlock;
636
637 info = counter_arch_bp(wp);
638 /* AArch32 watchpoints are either 4 or 8 bytes aligned. */
639 if (is_compat_task()) {
640 if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
641 alignment_mask = 0x7;
642 else
643 alignment_mask = 0x3;
644 } else {
645 alignment_mask = 0x7;
646 }
647
648 /* Check if the watchpoint value matches. */
649 val = read_wb_reg(AARCH64_DBG_REG_WVR, i);
650 if (val != (addr & ~alignment_mask))
651 goto unlock;
652
653 /* Possible match, check the byte address select to confirm. */
654 ctrl_reg = read_wb_reg(AARCH64_DBG_REG_WCR, i);
655 decode_ctrl_reg(ctrl_reg, &ctrl);
656 if (!((1 << (addr & alignment_mask)) & ctrl.len))
657 goto unlock;
658
659 /*
660 * Check that the access type matches.
661 * 0 => load, otherwise => store
662 */
663 access = (esr & AARCH64_ESR_ACCESS_MASK) ? HW_BREAKPOINT_W :
664 HW_BREAKPOINT_R;
665 if (!(access & hw_breakpoint_type(wp)))
666 goto unlock;
667
668 info->trigger = addr;
669 perf_bp_event(wp, regs);
670
671 /* Do we need to handle the stepping? */
672 if (!wp->overflow_handler)
673 step = 1;
674
675unlock:
676 rcu_read_unlock();
677 }
678
679 if (!step)
680 return 0;
681
682 /*
683 * We always disable EL0 watchpoints because the kernel can
684 * cause these to fire via an unprivileged access.
685 */
686 toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 0);
687
688 if (user_mode(regs)) {
689 debug_info->wps_disabled = 1;
690
691 /* If we're already stepping a breakpoint, just return. */
692 if (debug_info->bps_disabled)
693 return 0;
694
695 if (test_thread_flag(TIF_SINGLESTEP))
696 debug_info->suspended_step = 1;
697 else
698 user_enable_single_step(current);
699 } else {
700 toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 0);
701 kernel_step = &__get_cpu_var(stepping_kernel_bp);
702
703 if (*kernel_step != ARM_KERNEL_STEP_NONE)
704 return 0;
705
706 if (kernel_active_single_step()) {
707 *kernel_step = ARM_KERNEL_STEP_SUSPEND;
708 } else {
709 *kernel_step = ARM_KERNEL_STEP_ACTIVE;
710 kernel_enable_single_step(regs);
711 }
712 }
713
714 return 0;
715}
716
717/*
718 * Handle single-step exception.
719 */
720int reinstall_suspended_bps(struct pt_regs *regs)
721{
722 struct debug_info *debug_info = &current->thread.debug;
723 int handled_exception = 0, *kernel_step;
724
725 kernel_step = &__get_cpu_var(stepping_kernel_bp);
726
727 /*
728 * Called from single-step exception handler.
729 * Return 0 if execution can resume, 1 if a SIGTRAP should be
730 * reported.
731 */
732 if (user_mode(regs)) {
733 if (debug_info->bps_disabled) {
734 debug_info->bps_disabled = 0;
735 toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL0, 1);
736 handled_exception = 1;
737 }
738
739 if (debug_info->wps_disabled) {
740 debug_info->wps_disabled = 0;
741 toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 1);
742 handled_exception = 1;
743 }
744
745 if (handled_exception) {
746 if (debug_info->suspended_step) {
747 debug_info->suspended_step = 0;
748 /* Allow exception handling to fall-through. */
749 handled_exception = 0;
750 } else {
751 user_disable_single_step(current);
752 }
753 }
754 } else if (*kernel_step != ARM_KERNEL_STEP_NONE) {
755 toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 1);
756 toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 1);
757
758 if (!debug_info->wps_disabled)
759 toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 1);
760
761 if (*kernel_step != ARM_KERNEL_STEP_SUSPEND) {
762 kernel_disable_single_step();
763 handled_exception = 1;
764 } else {
765 handled_exception = 0;
766 }
767
768 *kernel_step = ARM_KERNEL_STEP_NONE;
769 }
770
771 return !handled_exception;
772}
773
774/*
775 * Context-switcher for restoring suspended breakpoints.
776 */
777void hw_breakpoint_thread_switch(struct task_struct *next)
778{
779 /*
780 * current next
781 * disabled: 0 0 => The usual case, NOTIFY_DONE
782 * 0 1 => Disable the registers
783 * 1 0 => Enable the registers
784 * 1 1 => NOTIFY_DONE. per-task bps will
785 * get taken care of by perf.
786 */
787
788 struct debug_info *current_debug_info, *next_debug_info;
789
790 current_debug_info = &current->thread.debug;
791 next_debug_info = &next->thread.debug;
792
793 /* Update breakpoints. */
794 if (current_debug_info->bps_disabled != next_debug_info->bps_disabled)
795 toggle_bp_registers(AARCH64_DBG_REG_BCR,
796 DBG_ACTIVE_EL0,
797 !next_debug_info->bps_disabled);
798
799 /* Update watchpoints. */
800 if (current_debug_info->wps_disabled != next_debug_info->wps_disabled)
801 toggle_bp_registers(AARCH64_DBG_REG_WCR,
802 DBG_ACTIVE_EL0,
803 !next_debug_info->wps_disabled);
804}
805
806/*
807 * CPU initialisation.
808 */
809static void reset_ctrl_regs(void *unused)
810{
811 int i;
812
813 for (i = 0; i < core_num_brps; ++i) {
814 write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
815 write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
816 }
817
818 for (i = 0; i < core_num_wrps; ++i) {
819 write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
820 write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
821 }
822}
823
824static int __cpuinit hw_breakpoint_reset_notify(struct notifier_block *self,
825 unsigned long action,
826 void *hcpu)
827{
828 int cpu = (long)hcpu;
829 if (action == CPU_ONLINE)
830 smp_call_function_single(cpu, reset_ctrl_regs, NULL, 1);
831 return NOTIFY_OK;
832}
833
834static struct notifier_block __cpuinitdata hw_breakpoint_reset_nb = {
835 .notifier_call = hw_breakpoint_reset_notify,
836};
837
838/*
839 * One-time initialisation.
840 */
841static int __init arch_hw_breakpoint_init(void)
842{
843 core_num_brps = get_num_brps();
844 core_num_wrps = get_num_wrps();
845
846 pr_info("found %d breakpoint and %d watchpoint registers.\n",
847 core_num_brps, core_num_wrps);
848
849 /*
850 * Reset the breakpoint resources. We assume that a halting
851 * debugger will leave the world in a nice state for us.
852 */
853 smp_call_function(reset_ctrl_regs, NULL, 1);
854 reset_ctrl_regs(NULL);
855
856 /* Register debug fault handlers. */
857 hook_debug_fault_code(DBG_ESR_EVT_HWBP, breakpoint_handler, SIGTRAP,
858 TRAP_HWBKPT, "hw-breakpoint handler");
859 hook_debug_fault_code(DBG_ESR_EVT_HWWP, watchpoint_handler, SIGTRAP,
860 TRAP_HWBKPT, "hw-watchpoint handler");
861
862 /* Register hotplug notifier. */
863 register_cpu_notifier(&hw_breakpoint_reset_nb);
864
865 return 0;
866}
867arch_initcall(arch_hw_breakpoint_init);
868
869void hw_breakpoint_pmu_read(struct perf_event *bp)
870{
871}
872
873/*
874 * Dummy function to register with die_notifier.
875 */
876int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
877 unsigned long val, void *data)
878{
879 return NOTIFY_DONE;
880}
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
new file mode 100644
index 000000000000..490f7537a270
--- /dev/null
+++ b/arch/arm64/kernel/ptrace.c
@@ -0,0 +1,1126 @@
1/*
2 * Based on arch/arm/kernel/ptrace.c
3 *
4 * By Ross Biro 1/23/92
5 * edited by Linus Torvalds
6 * ARM modifications Copyright (C) 2000 Russell King
7 * Copyright (C) 2012 ARM Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/kernel.h>
23#include <linux/sched.h>
24#include <linux/mm.h>
25#include <linux/smp.h>
26#include <linux/ptrace.h>
27#include <linux/user.h>
28#include <linux/security.h>
29#include <linux/init.h>
30#include <linux/signal.h>
31#include <linux/uaccess.h>
32#include <linux/perf_event.h>
33#include <linux/hw_breakpoint.h>
34#include <linux/regset.h>
35#include <linux/tracehook.h>
36#include <linux/elf.h>
37
38#include <asm/compat.h>
39#include <asm/debug-monitors.h>
40#include <asm/pgtable.h>
41#include <asm/traps.h>
42#include <asm/system_misc.h>
43
44/*
45 * TODO: does not yet catch signals sent when the child dies.
46 * in exit.c or in signal.c.
47 */
48
49/*
50 * Called by kernel/ptrace.c when detaching..
51 */
52void ptrace_disable(struct task_struct *child)
53{
54}
55
56/*
57 * Handle hitting a breakpoint.
58 */
59static int ptrace_break(struct pt_regs *regs)
60{
61 siginfo_t info = {
62 .si_signo = SIGTRAP,
63 .si_errno = 0,
64 .si_code = TRAP_BRKPT,
65 .si_addr = (void __user *)instruction_pointer(regs),
66 };
67
68 force_sig_info(SIGTRAP, &info, current);
69 return 0;
70}
71
72static int arm64_break_trap(unsigned long addr, unsigned int esr,
73 struct pt_regs *regs)
74{
75 return ptrace_break(regs);
76}
77
78#ifdef CONFIG_HAVE_HW_BREAKPOINT
79/*
80 * Handle hitting a HW-breakpoint.
81 */
82static void ptrace_hbptriggered(struct perf_event *bp,
83 struct perf_sample_data *data,
84 struct pt_regs *regs)
85{
86 struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
87 siginfo_t info = {
88 .si_signo = SIGTRAP,
89 .si_errno = 0,
90 .si_code = TRAP_HWBKPT,
91 .si_addr = (void __user *)(bkpt->trigger),
92 };
93
94#ifdef CONFIG_COMPAT
95 int i;
96
97 if (!is_compat_task())
98 goto send_sig;
99
100 for (i = 0; i < ARM_MAX_BRP; ++i) {
101 if (current->thread.debug.hbp_break[i] == bp) {
102 info.si_errno = (i << 1) + 1;
103 break;
104 }
105 }
106 for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
107 if (current->thread.debug.hbp_watch[i] == bp) {
108 info.si_errno = -((i << 1) + 1);
109 break;
110 }
111 }
112
113send_sig:
114#endif
115 force_sig_info(SIGTRAP, &info, current);
116}
117
118/*
119 * Unregister breakpoints from this task and reset the pointers in
120 * the thread_struct.
121 */
122void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
123{
124 int i;
125 struct thread_struct *t = &tsk->thread;
126
127 for (i = 0; i < ARM_MAX_BRP; i++) {
128 if (t->debug.hbp_break[i]) {
129 unregister_hw_breakpoint(t->debug.hbp_break[i]);
130 t->debug.hbp_break[i] = NULL;
131 }
132 }
133
134 for (i = 0; i < ARM_MAX_WRP; i++) {
135 if (t->debug.hbp_watch[i]) {
136 unregister_hw_breakpoint(t->debug.hbp_watch[i]);
137 t->debug.hbp_watch[i] = NULL;
138 }
139 }
140}
141
142void ptrace_hw_copy_thread(struct task_struct *tsk)
143{
144 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
145}
146
147static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
148 struct task_struct *tsk,
149 unsigned long idx)
150{
151 struct perf_event *bp = ERR_PTR(-EINVAL);
152
153 switch (note_type) {
154 case NT_ARM_HW_BREAK:
155 if (idx < ARM_MAX_BRP)
156 bp = tsk->thread.debug.hbp_break[idx];
157 break;
158 case NT_ARM_HW_WATCH:
159 if (idx < ARM_MAX_WRP)
160 bp = tsk->thread.debug.hbp_watch[idx];
161 break;
162 }
163
164 return bp;
165}
166
167static int ptrace_hbp_set_event(unsigned int note_type,
168 struct task_struct *tsk,
169 unsigned long idx,
170 struct perf_event *bp)
171{
172 int err = -EINVAL;
173
174 switch (note_type) {
175 case NT_ARM_HW_BREAK:
176 if (idx < ARM_MAX_BRP) {
177 tsk->thread.debug.hbp_break[idx] = bp;
178 err = 0;
179 }
180 break;
181 case NT_ARM_HW_WATCH:
182 if (idx < ARM_MAX_WRP) {
183 tsk->thread.debug.hbp_watch[idx] = bp;
184 err = 0;
185 }
186 break;
187 }
188
189 return err;
190}
191
192static struct perf_event *ptrace_hbp_create(unsigned int note_type,
193 struct task_struct *tsk,
194 unsigned long idx)
195{
196 struct perf_event *bp;
197 struct perf_event_attr attr;
198 int err, type;
199
200 switch (note_type) {
201 case NT_ARM_HW_BREAK:
202 type = HW_BREAKPOINT_X;
203 break;
204 case NT_ARM_HW_WATCH:
205 type = HW_BREAKPOINT_RW;
206 break;
207 default:
208 return ERR_PTR(-EINVAL);
209 }
210
211 ptrace_breakpoint_init(&attr);
212
213 /*
214 * Initialise fields to sane defaults
215 * (i.e. values that will pass validation).
216 */
217 attr.bp_addr = 0;
218 attr.bp_len = HW_BREAKPOINT_LEN_4;
219 attr.bp_type = type;
220 attr.disabled = 1;
221
222 bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
223 if (IS_ERR(bp))
224 return bp;
225
226 err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
227 if (err)
228 return ERR_PTR(err);
229
230 return bp;
231}
232
233static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
234 struct arch_hw_breakpoint_ctrl ctrl,
235 struct perf_event_attr *attr)
236{
237 int err, len, type;
238
239 err = arch_bp_generic_fields(ctrl, &len, &type);
240 if (err)
241 return err;
242
243 switch (note_type) {
244 case NT_ARM_HW_BREAK:
245 if ((type & HW_BREAKPOINT_X) != type)
246 return -EINVAL;
247 break;
248 case NT_ARM_HW_WATCH:
249 if ((type & HW_BREAKPOINT_RW) != type)
250 return -EINVAL;
251 break;
252 default:
253 return -EINVAL;
254 }
255
256 attr->bp_len = len;
257 attr->bp_type = type;
258 attr->disabled = !ctrl.enabled;
259
260 return 0;
261}
262
263static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
264{
265 u8 num;
266 u32 reg = 0;
267
268 switch (note_type) {
269 case NT_ARM_HW_BREAK:
270 num = hw_breakpoint_slots(TYPE_INST);
271 break;
272 case NT_ARM_HW_WATCH:
273 num = hw_breakpoint_slots(TYPE_DATA);
274 break;
275 default:
276 return -EINVAL;
277 }
278
279 reg |= debug_monitors_arch();
280 reg <<= 8;
281 reg |= num;
282
283 *info = reg;
284 return 0;
285}
286
287static int ptrace_hbp_get_ctrl(unsigned int note_type,
288 struct task_struct *tsk,
289 unsigned long idx,
290 u32 *ctrl)
291{
292 struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
293
294 if (IS_ERR(bp))
295 return PTR_ERR(bp);
296
297 *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
298 return 0;
299}
300
301static int ptrace_hbp_get_addr(unsigned int note_type,
302 struct task_struct *tsk,
303 unsigned long idx,
304 u64 *addr)
305{
306 struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
307
308 if (IS_ERR(bp))
309 return PTR_ERR(bp);
310
311 *addr = bp ? bp->attr.bp_addr : 0;
312 return 0;
313}
314
315static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
316 struct task_struct *tsk,
317 unsigned long idx)
318{
319 struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
320
321 if (!bp)
322 bp = ptrace_hbp_create(note_type, tsk, idx);
323
324 return bp;
325}
326
327static int ptrace_hbp_set_ctrl(unsigned int note_type,
328 struct task_struct *tsk,
329 unsigned long idx,
330 u32 uctrl)
331{
332 int err;
333 struct perf_event *bp;
334 struct perf_event_attr attr;
335 struct arch_hw_breakpoint_ctrl ctrl;
336
337 bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
338 if (IS_ERR(bp)) {
339 err = PTR_ERR(bp);
340 return err;
341 }
342
343 attr = bp->attr;
344 decode_ctrl_reg(uctrl, &ctrl);
345 err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
346 if (err)
347 return err;
348
349 return modify_user_hw_breakpoint(bp, &attr);
350}
351
352static int ptrace_hbp_set_addr(unsigned int note_type,
353 struct task_struct *tsk,
354 unsigned long idx,
355 u64 addr)
356{
357 int err;
358 struct perf_event *bp;
359 struct perf_event_attr attr;
360
361 bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
362 if (IS_ERR(bp)) {
363 err = PTR_ERR(bp);
364 return err;
365 }
366
367 attr = bp->attr;
368 attr.bp_addr = addr;
369 err = modify_user_hw_breakpoint(bp, &attr);
370 return err;
371}
372
373#define PTRACE_HBP_ADDR_SZ sizeof(u64)
374#define PTRACE_HBP_CTRL_SZ sizeof(u32)
375#define PTRACE_HBP_REG_OFF sizeof(u32)
376
377static int hw_break_get(struct task_struct *target,
378 const struct user_regset *regset,
379 unsigned int pos, unsigned int count,
380 void *kbuf, void __user *ubuf)
381{
382 unsigned int note_type = regset->core_note_type;
383 int ret, idx = 0, offset = PTRACE_HBP_REG_OFF, limit;
384 u32 info, ctrl;
385 u64 addr;
386
387 /* Resource info */
388 ret = ptrace_hbp_get_resource_info(note_type, &info);
389 if (ret)
390 return ret;
391
392 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0, 4);
393 if (ret)
394 return ret;
395
396 /* (address, ctrl) registers */
397 limit = regset->n * regset->size;
398 while (count && offset < limit) {
399 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
400 if (ret)
401 return ret;
402 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
403 offset, offset + PTRACE_HBP_ADDR_SZ);
404 if (ret)
405 return ret;
406 offset += PTRACE_HBP_ADDR_SZ;
407
408 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
409 if (ret)
410 return ret;
411 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
412 offset, offset + PTRACE_HBP_CTRL_SZ);
413 if (ret)
414 return ret;
415 offset += PTRACE_HBP_CTRL_SZ;
416 idx++;
417 }
418
419 return 0;
420}
421
422static int hw_break_set(struct task_struct *target,
423 const struct user_regset *regset,
424 unsigned int pos, unsigned int count,
425 const void *kbuf, const void __user *ubuf)
426{
427 unsigned int note_type = regset->core_note_type;
428 int ret, idx = 0, offset = PTRACE_HBP_REG_OFF, limit;
429 u32 ctrl;
430 u64 addr;
431
432 /* Resource info */
433 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4);
434 if (ret)
435 return ret;
436
437 /* (address, ctrl) registers */
438 limit = regset->n * regset->size;
439 while (count && offset < limit) {
440 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
441 offset, offset + PTRACE_HBP_ADDR_SZ);
442 if (ret)
443 return ret;
444 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
445 if (ret)
446 return ret;
447 offset += PTRACE_HBP_ADDR_SZ;
448
449 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
450 offset, offset + PTRACE_HBP_CTRL_SZ);
451 if (ret)
452 return ret;
453 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
454 if (ret)
455 return ret;
456 offset += PTRACE_HBP_CTRL_SZ;
457 idx++;
458 }
459
460 return 0;
461}
462#endif /* CONFIG_HAVE_HW_BREAKPOINT */
463
464static int gpr_get(struct task_struct *target,
465 const struct user_regset *regset,
466 unsigned int pos, unsigned int count,
467 void *kbuf, void __user *ubuf)
468{
469 struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
470 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
471}
472
473static int gpr_set(struct task_struct *target, const struct user_regset *regset,
474 unsigned int pos, unsigned int count,
475 const void *kbuf, const void __user *ubuf)
476{
477 int ret;
478 struct user_pt_regs newregs;
479
480 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
481 if (ret)
482 return ret;
483
484 if (!valid_user_regs(&newregs))
485 return -EINVAL;
486
487 task_pt_regs(target)->user_regs = newregs;
488 return 0;
489}
490
491/*
492 * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
493 */
494static int fpr_get(struct task_struct *target, const struct user_regset *regset,
495 unsigned int pos, unsigned int count,
496 void *kbuf, void __user *ubuf)
497{
498 struct user_fpsimd_state *uregs;
499 uregs = &target->thread.fpsimd_state.user_fpsimd;
500 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
501}
502
503static int fpr_set(struct task_struct *target, const struct user_regset *regset,
504 unsigned int pos, unsigned int count,
505 const void *kbuf, const void __user *ubuf)
506{
507 int ret;
508 struct user_fpsimd_state newstate;
509
510 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
511 if (ret)
512 return ret;
513
514 target->thread.fpsimd_state.user_fpsimd = newstate;
515 return ret;
516}
517
518static int tls_get(struct task_struct *target, const struct user_regset *regset,
519 unsigned int pos, unsigned int count,
520 void *kbuf, void __user *ubuf)
521{
522 unsigned long *tls = &target->thread.tp_value;
523 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
524}
525
526static int tls_set(struct task_struct *target, const struct user_regset *regset,
527 unsigned int pos, unsigned int count,
528 const void *kbuf, const void __user *ubuf)
529{
530 int ret;
531 unsigned long tls;
532
533 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
534 if (ret)
535 return ret;
536
537 target->thread.tp_value = tls;
538 return ret;
539}
540
541enum aarch64_regset {
542 REGSET_GPR,
543 REGSET_FPR,
544 REGSET_TLS,
545#ifdef CONFIG_HAVE_HW_BREAKPOINT
546 REGSET_HW_BREAK,
547 REGSET_HW_WATCH,
548#endif
549};
550
551static const struct user_regset aarch64_regsets[] = {
552 [REGSET_GPR] = {
553 .core_note_type = NT_PRSTATUS,
554 .n = sizeof(struct user_pt_regs) / sizeof(u64),
555 .size = sizeof(u64),
556 .align = sizeof(u64),
557 .get = gpr_get,
558 .set = gpr_set
559 },
560 [REGSET_FPR] = {
561 .core_note_type = NT_PRFPREG,
562 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
563 /*
564 * We pretend we have 32-bit registers because the fpsr and
565 * fpcr are 32-bits wide.
566 */
567 .size = sizeof(u32),
568 .align = sizeof(u32),
569 .get = fpr_get,
570 .set = fpr_set
571 },
572 [REGSET_TLS] = {
573 .core_note_type = NT_ARM_TLS,
574 .n = 1,
575 .size = sizeof(void *),
576 .align = sizeof(void *),
577 .get = tls_get,
578 .set = tls_set,
579 },
580#ifdef CONFIG_HAVE_HW_BREAKPOINT
581 [REGSET_HW_BREAK] = {
582 .core_note_type = NT_ARM_HW_BREAK,
583 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
584 .size = sizeof(u32),
585 .align = sizeof(u32),
586 .get = hw_break_get,
587 .set = hw_break_set,
588 },
589 [REGSET_HW_WATCH] = {
590 .core_note_type = NT_ARM_HW_WATCH,
591 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
592 .size = sizeof(u32),
593 .align = sizeof(u32),
594 .get = hw_break_get,
595 .set = hw_break_set,
596 },
597#endif
598};
599
600static const struct user_regset_view user_aarch64_view = {
601 .name = "aarch64", .e_machine = EM_AARCH64,
602 .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
603};
604
605#ifdef CONFIG_COMPAT
606#include <linux/compat.h>
607
608enum compat_regset {
609 REGSET_COMPAT_GPR,
610 REGSET_COMPAT_VFP,
611};
612
613static int compat_gpr_get(struct task_struct *target,
614 const struct user_regset *regset,
615 unsigned int pos, unsigned int count,
616 void *kbuf, void __user *ubuf)
617{
618 int ret = 0;
619 unsigned int i, start, num_regs;
620
621 /* Calculate the number of AArch32 registers contained in count */
622 num_regs = count / regset->size;
623
624 /* Convert pos into an register number */
625 start = pos / regset->size;
626
627 if (start + num_regs > regset->n)
628 return -EIO;
629
630 for (i = 0; i < num_regs; ++i) {
631 unsigned int idx = start + i;
632 void *reg;
633
634 switch (idx) {
635 case 15:
636 reg = (void *)&task_pt_regs(target)->pc;
637 break;
638 case 16:
639 reg = (void *)&task_pt_regs(target)->pstate;
640 break;
641 case 17:
642 reg = (void *)&task_pt_regs(target)->orig_x0;
643 break;
644 default:
645 reg = (void *)&task_pt_regs(target)->regs[idx];
646 }
647
648 ret = copy_to_user(ubuf, reg, sizeof(compat_ulong_t));
649
650 if (ret)
651 break;
652 else
653 ubuf += sizeof(compat_ulong_t);
654 }
655
656 return ret;
657}
658
659static int compat_gpr_set(struct task_struct *target,
660 const struct user_regset *regset,
661 unsigned int pos, unsigned int count,
662 const void *kbuf, const void __user *ubuf)
663{
664 struct pt_regs newregs;
665 int ret = 0;
666 unsigned int i, start, num_regs;
667
668 /* Calculate the number of AArch32 registers contained in count */
669 num_regs = count / regset->size;
670
671 /* Convert pos into an register number */
672 start = pos / regset->size;
673
674 if (start + num_regs > regset->n)
675 return -EIO;
676
677 newregs = *task_pt_regs(target);
678
679 for (i = 0; i < num_regs; ++i) {
680 unsigned int idx = start + i;
681 void *reg;
682
683 switch (idx) {
684 case 15:
685 reg = (void *)&newregs.pc;
686 break;
687 case 16:
688 reg = (void *)&newregs.pstate;
689 break;
690 case 17:
691 reg = (void *)&newregs.orig_x0;
692 break;
693 default:
694 reg = (void *)&newregs.regs[idx];
695 }
696
697 ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t));
698
699 if (ret)
700 goto out;
701 else
702 ubuf += sizeof(compat_ulong_t);
703 }
704
705 if (valid_user_regs(&newregs.user_regs))
706 *task_pt_regs(target) = newregs;
707 else
708 ret = -EINVAL;
709
710out:
711 return ret;
712}
713
714static int compat_vfp_get(struct task_struct *target,
715 const struct user_regset *regset,
716 unsigned int pos, unsigned int count,
717 void *kbuf, void __user *ubuf)
718{
719 struct user_fpsimd_state *uregs;
720 compat_ulong_t fpscr;
721 int ret;
722
723 uregs = &target->thread.fpsimd_state.user_fpsimd;
724
725 /*
726 * The VFP registers are packed into the fpsimd_state, so they all sit
727 * nicely together for us. We just need to create the fpscr separately.
728 */
729 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
730 VFP_STATE_SIZE - sizeof(compat_ulong_t));
731
732 if (count && !ret) {
733 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
734 (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
735 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
736 }
737
738 return ret;
739}
740
741static int compat_vfp_set(struct task_struct *target,
742 const struct user_regset *regset,
743 unsigned int pos, unsigned int count,
744 const void *kbuf, const void __user *ubuf)
745{
746 struct user_fpsimd_state *uregs;
747 compat_ulong_t fpscr;
748 int ret;
749
750 if (pos + count > VFP_STATE_SIZE)
751 return -EIO;
752
753 uregs = &target->thread.fpsimd_state.user_fpsimd;
754
755 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
756 VFP_STATE_SIZE - sizeof(compat_ulong_t));
757
758 if (count && !ret) {
759 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
760 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
761 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
762 }
763
764 return ret;
765}
766
767static const struct user_regset aarch32_regsets[] = {
768 [REGSET_COMPAT_GPR] = {
769 .core_note_type = NT_PRSTATUS,
770 .n = COMPAT_ELF_NGREG,
771 .size = sizeof(compat_elf_greg_t),
772 .align = sizeof(compat_elf_greg_t),
773 .get = compat_gpr_get,
774 .set = compat_gpr_set
775 },
776 [REGSET_COMPAT_VFP] = {
777 .core_note_type = NT_ARM_VFP,
778 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
779 .size = sizeof(compat_ulong_t),
780 .align = sizeof(compat_ulong_t),
781 .get = compat_vfp_get,
782 .set = compat_vfp_set
783 },
784};
785
786static const struct user_regset_view user_aarch32_view = {
787 .name = "aarch32", .e_machine = EM_ARM,
788 .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
789};
790
791int aarch32_break_trap(struct pt_regs *regs)
792{
793 unsigned int instr;
794 bool bp = false;
795 void __user *pc = (void __user *)instruction_pointer(regs);
796
797 if (compat_thumb_mode(regs)) {
798 /* get 16-bit Thumb instruction */
799 get_user(instr, (u16 __user *)pc);
800 if (instr == AARCH32_BREAK_THUMB2_LO) {
801 /* get second half of 32-bit Thumb-2 instruction */
802 get_user(instr, (u16 __user *)(pc + 2));
803 bp = instr == AARCH32_BREAK_THUMB2_HI;
804 } else {
805 bp = instr == AARCH32_BREAK_THUMB;
806 }
807 } else {
808 /* 32-bit ARM instruction */
809 get_user(instr, (u32 __user *)pc);
810 bp = (instr & ~0xf0000000) == AARCH32_BREAK_ARM;
811 }
812
813 if (bp)
814 return ptrace_break(regs);
815 return 1;
816}
817
818static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
819 compat_ulong_t __user *ret)
820{
821 compat_ulong_t tmp;
822
823 if (off & 3)
824 return -EIO;
825
826 if (off == PT_TEXT_ADDR)
827 tmp = tsk->mm->start_code;
828 else if (off == PT_DATA_ADDR)
829 tmp = tsk->mm->start_data;
830 else if (off == PT_TEXT_END_ADDR)
831 tmp = tsk->mm->end_code;
832 else if (off < sizeof(compat_elf_gregset_t))
833 return copy_regset_to_user(tsk, &user_aarch32_view,
834 REGSET_COMPAT_GPR, off,
835 sizeof(compat_ulong_t), ret);
836 else if (off >= COMPAT_USER_SZ)
837 return -EIO;
838 else
839 tmp = 0;
840
841 return put_user(tmp, ret);
842}
843
844static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
845 compat_ulong_t val)
846{
847 int ret;
848
849 if (off & 3 || off >= COMPAT_USER_SZ)
850 return -EIO;
851
852 if (off >= sizeof(compat_elf_gregset_t))
853 return 0;
854
855 ret = copy_regset_from_user(tsk, &user_aarch32_view,
856 REGSET_COMPAT_GPR, off,
857 sizeof(compat_ulong_t),
858 &val);
859 return ret;
860}
861
862#ifdef CONFIG_HAVE_HW_BREAKPOINT
863
864/*
865 * Convert a virtual register number into an index for a thread_info
866 * breakpoint array. Breakpoints are identified using positive numbers
867 * whilst watchpoints are negative. The registers are laid out as pairs
868 * of (address, control), each pair mapping to a unique hw_breakpoint struct.
869 * Register 0 is reserved for describing resource information.
870 */
871static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
872{
873 return (abs(num) - 1) >> 1;
874}
875
876static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
877{
878 u8 num_brps, num_wrps, debug_arch, wp_len;
879 u32 reg = 0;
880
881 num_brps = hw_breakpoint_slots(TYPE_INST);
882 num_wrps = hw_breakpoint_slots(TYPE_DATA);
883
884 debug_arch = debug_monitors_arch();
885 wp_len = 8;
886 reg |= debug_arch;
887 reg <<= 8;
888 reg |= wp_len;
889 reg <<= 8;
890 reg |= num_wrps;
891 reg <<= 8;
892 reg |= num_brps;
893
894 *kdata = reg;
895 return 0;
896}
897
898static int compat_ptrace_hbp_get(unsigned int note_type,
899 struct task_struct *tsk,
900 compat_long_t num,
901 u32 *kdata)
902{
903 u64 addr = 0;
904 u32 ctrl = 0;
905
906 int err, idx = compat_ptrace_hbp_num_to_idx(num);;
907
908 if (num & 1) {
909 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
910 *kdata = (u32)addr;
911 } else {
912 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
913 *kdata = ctrl;
914 }
915
916 return err;
917}
918
919static int compat_ptrace_hbp_set(unsigned int note_type,
920 struct task_struct *tsk,
921 compat_long_t num,
922 u32 *kdata)
923{
924 u64 addr;
925 u32 ctrl;
926
927 int err, idx = compat_ptrace_hbp_num_to_idx(num);
928
929 if (num & 1) {
930 addr = *kdata;
931 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
932 } else {
933 ctrl = *kdata;
934 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
935 }
936
937 return err;
938}
939
940static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
941 compat_ulong_t __user *data)
942{
943 int ret;
944 u32 kdata;
945 mm_segment_t old_fs = get_fs();
946
947 set_fs(KERNEL_DS);
948 /* Watchpoint */
949 if (num < 0) {
950 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
951 /* Resource info */
952 } else if (num == 0) {
953 ret = compat_ptrace_hbp_get_resource_info(&kdata);
954 /* Breakpoint */
955 } else {
956 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
957 }
958 set_fs(old_fs);
959
960 if (!ret)
961 ret = put_user(kdata, data);
962
963 return ret;
964}
965
966static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
967 compat_ulong_t __user *data)
968{
969 int ret;
970 u32 kdata = 0;
971 mm_segment_t old_fs = get_fs();
972
973 if (num == 0)
974 return 0;
975
976 ret = get_user(kdata, data);
977 if (ret)
978 return ret;
979
980 set_fs(KERNEL_DS);
981 if (num < 0)
982 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
983 else
984 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
985 set_fs(old_fs);
986
987 return ret;
988}
989#endif /* CONFIG_HAVE_HW_BREAKPOINT */
990
991long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
992 compat_ulong_t caddr, compat_ulong_t cdata)
993{
994 unsigned long addr = caddr;
995 unsigned long data = cdata;
996 void __user *datap = compat_ptr(data);
997 int ret;
998
999 switch (request) {
1000 case PTRACE_PEEKUSR:
1001 ret = compat_ptrace_read_user(child, addr, datap);
1002 break;
1003
1004 case PTRACE_POKEUSR:
1005 ret = compat_ptrace_write_user(child, addr, data);
1006 break;
1007
1008 case PTRACE_GETREGS:
1009 ret = copy_regset_to_user(child,
1010 &user_aarch32_view,
1011 REGSET_COMPAT_GPR,
1012 0, sizeof(compat_elf_gregset_t),
1013 datap);
1014 break;
1015
1016 case PTRACE_SETREGS:
1017 ret = copy_regset_from_user(child,
1018 &user_aarch32_view,
1019 REGSET_COMPAT_GPR,
1020 0, sizeof(compat_elf_gregset_t),
1021 datap);
1022 break;
1023
1024 case PTRACE_GET_THREAD_AREA:
1025 ret = put_user((compat_ulong_t)child->thread.tp_value,
1026 (compat_ulong_t __user *)datap);
1027 break;
1028
1029 case PTRACE_SET_SYSCALL:
1030 task_pt_regs(child)->syscallno = data;
1031 ret = 0;
1032 break;
1033
1034 case COMPAT_PTRACE_GETVFPREGS:
1035 ret = copy_regset_to_user(child,
1036 &user_aarch32_view,
1037 REGSET_COMPAT_VFP,
1038 0, VFP_STATE_SIZE,
1039 datap);
1040 break;
1041
1042 case COMPAT_PTRACE_SETVFPREGS:
1043 ret = copy_regset_from_user(child,
1044 &user_aarch32_view,
1045 REGSET_COMPAT_VFP,
1046 0, VFP_STATE_SIZE,
1047 datap);
1048 break;
1049
1050#ifdef CONFIG_HAVE_HW_BREAKPOINT
1051 case PTRACE_GETHBPREGS:
1052 ret = compat_ptrace_gethbpregs(child, addr, datap);
1053 break;
1054
1055 case PTRACE_SETHBPREGS:
1056 ret = compat_ptrace_sethbpregs(child, addr, datap);
1057 break;
1058#endif
1059
1060 default:
1061 ret = compat_ptrace_request(child, request, addr,
1062 data);
1063 break;
1064 }
1065
1066 return ret;
1067}
1068#endif /* CONFIG_COMPAT */
1069
1070const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1071{
1072#ifdef CONFIG_COMPAT
1073 if (is_compat_thread(task_thread_info(task)))
1074 return &user_aarch32_view;
1075#endif
1076 return &user_aarch64_view;
1077}
1078
1079long arch_ptrace(struct task_struct *child, long request,
1080 unsigned long addr, unsigned long data)
1081{
1082 return ptrace_request(child, request, addr, data);
1083}
1084
1085
1086static int __init ptrace_break_init(void)
1087{
1088 hook_debug_fault_code(DBG_ESR_EVT_BRK, arm64_break_trap, SIGTRAP,
1089 TRAP_BRKPT, "ptrace BRK handler");
1090 return 0;
1091}
1092core_initcall(ptrace_break_init);
1093
1094
1095asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
1096{
1097 unsigned long saved_reg;
1098
1099 if (!test_thread_flag(TIF_SYSCALL_TRACE))
1100 return regs->syscallno;
1101
1102 if (is_compat_task()) {
1103 /* AArch32 uses ip (r12) for scratch */
1104 saved_reg = regs->regs[12];
1105 regs->regs[12] = dir;
1106 } else {
1107 /*
1108 * Save X7. X7 is used to denote syscall entry/exit:
1109 * X7 = 0 -> entry, = 1 -> exit
1110 */
1111 saved_reg = regs->regs[7];
1112 regs->regs[7] = dir;
1113 }
1114
1115 if (dir)
1116 tracehook_report_syscall_exit(regs, 0);
1117 else if (tracehook_report_syscall_entry(regs))
1118 regs->syscallno = ~0UL;
1119
1120 if (is_compat_task())
1121 regs->regs[12] = saved_reg;
1122 else
1123 regs->regs[7] = saved_reg;
1124
1125 return regs->syscallno;
1126}
diff --git a/include/linux/elf.h b/include/linux/elf.h
index 999b4f52e8e5..1e935e4c6328 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -388,6 +388,9 @@ typedef struct elf64_shdr {
388#define NT_S390_LAST_BREAK 0x306 /* s390 breaking event address */ 388#define NT_S390_LAST_BREAK 0x306 /* s390 breaking event address */
389#define NT_S390_SYSTEM_CALL 0x307 /* s390 system call restart data */ 389#define NT_S390_SYSTEM_CALL 0x307 /* s390 system call restart data */
390#define NT_ARM_VFP 0x400 /* ARM VFP/NEON registers */ 390#define NT_ARM_VFP 0x400 /* ARM VFP/NEON registers */
391#define NT_ARM_TLS 0x401 /* ARM TLS register */
392#define NT_ARM_HW_BREAK 0x402 /* ARM hardware breakpoint registers */
393#define NT_ARM_HW_WATCH 0x403 /* ARM hardware watchpoint registers */
391 394
392 395
393/* Note header in a PT_NOTE section */ 396/* Note header in a PT_NOTE section */
generated by cgit v1.2.2 (git 2.25.0) at 2026-03-11 17:47:10 -0400