sys/dev/hwpmc/hwpmc_arm.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   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 __FBSDID("$FreeBSD$");
  32
  33 #include <sys/param.h>
  34 #include <sys/pmc.h>
  35 #include <sys/proc.h>
  36 #include <sys/systm.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
  43 #include <vm/vm.h>
  44 #include <vm/vm_param.h>
  45 #include <vm/pmap.h>
  46
  47 /* XXX: Userland code compiled with gcc will need an heuristic
  48  * to be correctly detected.
  49  */
  50 #ifdef __clang__
  51 #define PC_OFF 1
  52 #define FP_OFF 0
  53 #else
  54 #define PC_OFF -1
  55 #define FP_OFF -3
  56 #endif
  57
  58 struct pmc_mdep *
  59 pmc_md_initialize()
  60 {
  61 #ifdef CPU_CORTEXA
  62         if (cpu_class == CPU_CLASS_CORTEXA)
  63                 return pmc_armv7_initialize();
  64 #endif
  65         return NULL;
  66 }
  67
  68 void
  69 pmc_md_finalize(struct pmc_mdep *md)
  70 {
  71 #ifdef CPU_CORTEXA
  72         if (cpu_class == CPU_CLASS_CORTEXA)
  73                 pmc_armv7_finalize(md);
  74 #endif
  75 }
  76
  77 int
  78 pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
  79     struct trapframe *tf)
  80 {
  81         uintptr_t pc, r, stackstart, stackend, fp;
  82         struct thread *td;
  83         int count;
  84
  85         KASSERT(TRAPF_USERMODE(tf) == 0,("[arm,%d] not a kernel backtrace",
  86             __LINE__));
  87
  88         td = curthread;
  89         pc = PMC_TRAPFRAME_TO_PC(tf);
  90         *cc++ = pc;
  91
  92         if (maxsamples <= 1)
  93                 return (1);
  94
  95         stackstart = (uintptr_t) td->td_kstack;
  96         stackend = (uintptr_t) td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
  97         fp = PMC_TRAPFRAME_TO_FP(tf);
  98
  99         if (!PMC_IN_KERNEL(pc) ||
 100             !PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
 101                 return (1);
 102
 103         for (count = 1; count < maxsamples; count++) {
 104                 /* Use saved lr as pc. */
 105                 r = fp + PC_OFF * sizeof(uintptr_t);
 106                 if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
 107                         break;
 108                 pc = *(uintptr_t *)r;
 109                 if (!PMC_IN_KERNEL(pc))
 110                         break;
 111
 112                 *cc++ = pc;
 113
 114                 /* Switch to next frame up */
 115                 r = fp + FP_OFF * sizeof(uintptr_t);
 116                 if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
 117                         break;
 118                 fp = *(uintptr_t *)r;
 119                 if (!PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
 120                         break;
 121         }
 122
 123         return (count);
 124 }
 125
 126 int
 127 pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
 128     struct trapframe *tf)
 129 {
 130         uintptr_t pc, r, oldfp, fp;
 131         struct thread *td;
 132         int count;
 133
 134         KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
 135             __LINE__, (void *) tf));
 136
 137         td = curthread;
 138         pc = PMC_TRAPFRAME_TO_PC(tf);
 139         *cc++ = pc;
 140
 141         if (maxsamples <= 1)
 142                 return (1);
 143
 144         oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
 145
 146         if (!PMC_IN_USERSPACE(pc) ||
 147             !PMC_IN_USERSPACE(fp))
 148                 return (1);
 149
 150         for (count = 1; count < maxsamples; count++) {
 151                 /* Use saved lr as pc. */
 152                 r = fp + PC_OFF * sizeof(uintptr_t);
 153                 if (copyin((void *)r, &pc, sizeof(pc)) != 0)
 154                         break;
 155                 if (!PMC_IN_USERSPACE(pc))
 156                         break;
 157
 158                 *cc++ = pc;
 159
 160                 /* Switch to next frame up */
 161                 oldfp = fp;
 162                 r = fp + FP_OFF * sizeof(uintptr_t);
 163                 if (copyin((void *)r, &fp, sizeof(fp)) != 0)
 164                         break;
 165                 if (fp < oldfp || !PMC_IN_USERSPACE(fp))
 166                         break;
 167         }
 168
 169         return (count);
 170 }