FreeBSD/Linux Kernel Cross Reference
sys/dev/hwpmc/hwpmc_arm.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2005, Joseph Koshy
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/pmc.h>
    #include <sys/proc.h>
    #include <sys/systm.h>
    
    #include <machine/cpu.h>
    #include <machine/md_var.h>
    #include <machine/pmc_mdep.h>
    #include <machine/stack.h>
    
    #include <vm/vm.h>
    #include <vm/vm_param.h>
    #include <vm/pmap.h>
    
    /* XXX: Userland code compiled with gcc will need an heuristic
     * to be correctly detected. 
     */
    #ifdef __clang__
    #define PC_OFF 1
    #define FP_OFF 0
    #else
    #define PC_OFF -1
    #define FP_OFF -3
    #endif
    
    struct pmc_mdep *
    pmc_md_initialize(void)
    {
    #ifdef CPU_CORTEXA
            if (cpu_class == CPU_CLASS_CORTEXA)
                    return pmc_armv7_initialize();
    #endif
            return NULL;
    }
    
    void
    pmc_md_finalize(struct pmc_mdep *md)
    {
    #ifdef CPU_CORTEXA
            if (cpu_class == CPU_CLASS_CORTEXA)
                    pmc_armv7_finalize(md);
    #endif
    }
    
    int
    pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
        struct trapframe *tf)
    {
            uintptr_t pc, r, stackstart, stackend, fp;
            struct thread *td;
            int count;
    
            KASSERT(TRAPF_USERMODE(tf) == 0,("[arm,%d] not a kernel backtrace",
                __LINE__));
    
            td = curthread;
            pc = PMC_TRAPFRAME_TO_PC(tf);
            *cc++ = pc;
    
            if (maxsamples <= 1)
                    return (1);
    
            stackstart = (uintptr_t) td->td_kstack;
            stackend = (uintptr_t) td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
            fp = PMC_TRAPFRAME_TO_FP(tf);
    
            if (!PMC_IN_KERNEL(pc) ||
               !PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
                   return (1);
   
           for (count = 1; count < maxsamples; count++) {
                   /* Use saved lr as pc. */
                   r = fp + PC_OFF * sizeof(uintptr_t);
                   if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
                           break;
                   pc = *(uintptr_t *)r;
                   if (!PMC_IN_KERNEL(pc))
                           break;
   
                   *cc++ = pc;
   
                   /* Switch to next frame up */
                   r = fp + FP_OFF * sizeof(uintptr_t);
                   if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
                           break;
                   fp = *(uintptr_t *)r;
                   if (!PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
                           break;
           }
   
           return (count);
   }
   
   int
   pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
       struct trapframe *tf)
   {
           uintptr_t pc, r, oldfp, fp;
           int count;
   
           KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
               __LINE__, (void *) tf));
   
           pc = PMC_TRAPFRAME_TO_PC(tf);
           *cc++ = pc;
   
           if (maxsamples <= 1)
                   return (1);
   
           oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
   
           if (!PMC_IN_USERSPACE(pc) ||
               !PMC_IN_USERSPACE(fp))
                   return (1);
   
           for (count = 1; count < maxsamples; count++) {
                   /* Use saved lr as pc. */
                   r = fp + PC_OFF * sizeof(uintptr_t);
                   if (copyin((void *)r, &pc, sizeof(pc)) != 0)
                           break;
                   if (!PMC_IN_USERSPACE(pc))
                           break;
   
                   *cc++ = pc;
   
                   /* Switch to next frame up */
                   oldfp = fp;
                   r = fp + FP_OFF * sizeof(uintptr_t);
                   if (copyin((void *)r, &fp, sizeof(fp)) != 0)
                           break;
                   if (fp < oldfp || !PMC_IN_USERSPACE(fp))
                           break;
           }
   
           return (count);
   }

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