1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2005, Joseph Koshy
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/pmc.h>
34
35 #include <vm/vm.h>
36 #include <vm/pmap.h>
37
38 #include <machine/cpu.h>
39 #include <machine/md_var.h>
40 #include <machine/pmc_mdep.h>
41 #include <machine/stack.h>
42 #include <machine/vmparam.h>
43
44 /* XXX: Userland code compiled with gcc will need an heuristic
45 * to be correctly detected.
46 */
47 #ifdef __clang__
48 #define PC_OFF 1
49 #define FP_OFF 0
50 #else
51 #define PC_OFF -1
52 #define FP_OFF -3
53 #endif
54
55 struct pmc_mdep *
pmc_md_initialize(void)56 pmc_md_initialize(void)
57 {
58 #ifdef CPU_CORTEXA
59 if (cpu_class == CPU_CLASS_CORTEXA)
60 return pmc_armv7_initialize();
61 #endif
62 return NULL;
63 }
64
65 void
pmc_md_finalize(struct pmc_mdep * md)66 pmc_md_finalize(struct pmc_mdep *md)
67 {
68 #ifdef CPU_CORTEXA
69 if (cpu_class == CPU_CLASS_CORTEXA)
70 pmc_armv7_finalize(md);
71 #endif
72 }
73
74 int
pmc_save_kernel_callchain(uintptr_t * cc,int maxsamples,struct trapframe * tf)75 pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
76 struct trapframe *tf)
77 {
78 uintptr_t pc, ra, fp;
79 int count;
80
81 KASSERT(TRAPF_USERMODE(tf) == 0,("[arm,%d] not a kernel backtrace",
82 __LINE__));
83
84 pc = PMC_TRAPFRAME_TO_PC(tf);
85 *cc++ = pc;
86
87 if (maxsamples <= 1)
88 return (1);
89
90 fp = PMC_TRAPFRAME_TO_FP(tf);
91 if (!PMC_IN_KERNEL(pc) || !PMC_IN_KERNEL_STACK(fp))
92 return (1);
93
94 for (count = 1; count < maxsamples; count++) {
95 /* Use saved lr as pc. */
96 ra = fp + PC_OFF * sizeof(uintptr_t);
97 if (!PMC_IN_KERNEL_STACK(ra))
98 break;
99 pc = *(uintptr_t *)ra;
100 if (!PMC_IN_KERNEL(pc))
101 break;
102
103 *cc++ = pc;
104
105 /* Switch to next frame up */
106 ra = fp + FP_OFF * sizeof(uintptr_t);
107 if (!PMC_IN_KERNEL_STACK(ra))
108 break;
109 fp = *(uintptr_t *)ra;
110 if (!PMC_IN_KERNEL_STACK(fp))
111 break;
112 }
113
114 return (count);
115 }
116
117 int
pmc_save_user_callchain(uintptr_t * cc,int maxsamples,struct trapframe * tf)118 pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
119 struct trapframe *tf)
120 {
121 uintptr_t pc, r, oldfp, fp;
122 int count;
123
124 KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
125 __LINE__, (void *) tf));
126
127 pc = PMC_TRAPFRAME_TO_PC(tf);
128 *cc++ = pc;
129
130 if (maxsamples <= 1)
131 return (1);
132
133 oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
134
135 if (!PMC_IN_USERSPACE(pc) ||
136 !PMC_IN_USERSPACE(fp))
137 return (1);
138
139 for (count = 1; count < maxsamples; count++) {
140 /* Use saved lr as pc. */
141 r = fp + PC_OFF * sizeof(uintptr_t);
142 if (copyin((void *)r, &pc, sizeof(pc)) != 0)
143 break;
144 if (!PMC_IN_USERSPACE(pc))
145 break;
146
147 *cc++ = pc;
148
149 /* Switch to next frame up */
150 oldfp = fp;
151 r = fp + FP_OFF * sizeof(uintptr_t);
152 if (copyin((void *)r, &fp, sizeof(fp)) != 0)
153 break;
154 if (fp < oldfp || !PMC_IN_USERSPACE(fp))
155 break;
156 }
157
158 return (count);
159 }
160