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/param.h>
31 #include <sys/systm.h>
32 #include <sys/pmc.h>
33
34 #include <vm/vm.h>
35 #include <vm/pmap.h>
36
37 #include <machine/cpu.h>
38 #include <machine/md_var.h>
39 #include <machine/pmc_mdep.h>
40 #include <machine/stack.h>
41 #include <machine/vmparam.h>
42
43 /* XXX: Userland code compiled with gcc will need an heuristic
44 * to be correctly detected.
45 */
46 #ifdef __clang__
47 #define PC_OFF 1
48 #define FP_OFF 0
49 #else
50 #define PC_OFF -1
51 #define FP_OFF -3
52 #endif
53
54 struct pmc_mdep *
pmc_md_initialize(void)55 pmc_md_initialize(void)
56 {
57 #ifdef CPU_CORTEXA
58 if (cpu_class == CPU_CLASS_CORTEXA)
59 return pmc_armv7_initialize();
60 #endif
61 return NULL;
62 }
63
64 void
pmc_md_finalize(struct pmc_mdep * md)65 pmc_md_finalize(struct pmc_mdep *md)
66 {
67 #ifdef CPU_CORTEXA
68 if (cpu_class == CPU_CLASS_CORTEXA)
69 pmc_armv7_finalize(md);
70 #endif
71 }
72
73 int
pmc_save_kernel_callchain(uintptr_t * cc,int maxsamples,struct trapframe * tf)74 pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
75 struct trapframe *tf)
76 {
77 uintptr_t pc, ra, fp;
78 int count;
79
80 KASSERT(TRAPF_USERMODE(tf) == 0,("[arm,%d] not a kernel backtrace",
81 __LINE__));
82
83 pc = PMC_TRAPFRAME_TO_PC(tf);
84 *cc++ = pc;
85
86 if (maxsamples <= 1)
87 return (1);
88
89 fp = PMC_TRAPFRAME_TO_FP(tf);
90 if (!PMC_IN_KERNEL(pc) || !PMC_IN_KERNEL_STACK(fp))
91 return (1);
92
93 for (count = 1; count < maxsamples; count++) {
94 /* Use saved lr as pc. */
95 ra = fp + PC_OFF * sizeof(uintptr_t);
96 if (!PMC_IN_KERNEL_STACK(ra))
97 break;
98 pc = *(uintptr_t *)ra;
99 if (!PMC_IN_KERNEL(pc))
100 break;
101
102 *cc++ = pc;
103
104 /* Switch to next frame up */
105 ra = fp + FP_OFF * sizeof(uintptr_t);
106 if (!PMC_IN_KERNEL_STACK(ra))
107 break;
108 fp = *(uintptr_t *)ra;
109 if (!PMC_IN_KERNEL_STACK(fp))
110 break;
111 }
112
113 return (count);
114 }
115
116 int
pmc_save_user_callchain(uintptr_t * cc,int maxsamples,struct trapframe * tf)117 pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
118 struct trapframe *tf)
119 {
120 uintptr_t pc, r, oldfp, fp;
121 int count;
122
123 KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
124 __LINE__, (void *) tf));
125
126 pc = PMC_TRAPFRAME_TO_PC(tf);
127 *cc++ = pc;
128
129 if (maxsamples <= 1)
130 return (1);
131
132 oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
133
134 if (!PMC_IN_USERSPACE(pc) ||
135 !PMC_IN_USERSPACE(fp))
136 return (1);
137
138 for (count = 1; count < maxsamples; count++) {
139 /* Use saved lr as pc. */
140 r = fp + PC_OFF * sizeof(uintptr_t);
141 if (copyin((void *)r, &pc, sizeof(pc)) != 0)
142 break;
143 if (!PMC_IN_USERSPACE(pc))
144 break;
145
146 *cc++ = pc;
147
148 /* Switch to next frame up */
149 oldfp = fp;
150 r = fp + FP_OFF * sizeof(uintptr_t);
151 if (copyin((void *)r, &fp, sizeof(fp)) != 0)
152 break;
153 if (fp < oldfp || !PMC_IN_USERSPACE(fp))
154 break;
155 }
156
157 return (count);
158 }
159