freebsd-dev/sys/dev/hwpmc/hwpmc_x86.c
Pedro F. Giffuni 718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00

281 lines
7.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005,2008 Joseph Koshy
* Copyright (c) 2007 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by A. Joseph Koshy under
* sponsorship from the FreeBSD Foundation and Google, Inc.
*
* 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/bus.h>
#include <sys/pmc.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <machine/cpu.h>
#include <machine/cputypes.h>
#include <machine/intr_machdep.h>
#if (__FreeBSD_version >= 1100000)
#include <x86/apicvar.h>
#else
#include <machine/apicvar.h>
#endif
#include <machine/pmc_mdep.h>
#include <machine/md_var.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include "hwpmc_soft.h"
/*
* Attempt to walk a user call stack using a too-simple algorithm.
* In the general case we need unwind information associated with
* the executable to be able to walk the user stack.
*
* We are handed a trap frame laid down at the time the PMC interrupt
* was taken. If the application is using frame pointers, the saved
* PC value could be:
* a. at the beginning of a function before the stack frame is laid
* down,
* b. just before a 'ret', after the stack frame has been taken off,
* c. somewhere else in the function with a valid stack frame being
* present,
*
* If the application is not using frame pointers, this algorithm will
* fail to yield an interesting call chain.
*
* TODO: figure out a way to use unwind information.
*/
int
pmc_save_user_callchain(uintptr_t *cc, int nframes, struct trapframe *tf)
{
int n;
uint32_t instr;
uintptr_t fp, oldfp, pc, r, sp;
KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
__LINE__, (void *) tf));
pc = PMC_TRAPFRAME_TO_PC(tf);
oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
sp = PMC_TRAPFRAME_TO_USER_SP(tf);
*cc++ = pc; n = 1;
r = fp + sizeof(uintptr_t); /* points to return address */
if (!PMC_IN_USERSPACE(pc))
return (n);
if (copyin((void *) pc, &instr, sizeof(instr)) != 0)
return (n);
if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) ||
PMC_AT_FUNCTION_EPILOGUE_RET(instr)) { /* ret */
if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
return (n);
} else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) {
sp += sizeof(uintptr_t);
if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
return (n);
} else if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
copyin((void *) fp, &fp, sizeof(fp)) != 0)
return (n);
for (; n < nframes;) {
if (pc == 0 || !PMC_IN_USERSPACE(pc))
break;
*cc++ = pc; n++;
if (fp < oldfp)
break;
r = fp + sizeof(uintptr_t); /* address of return address */
oldfp = fp;
if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
copyin((void *) fp, &fp, sizeof(fp)) != 0)
break;
}
return (n);
}
/*
* Walking the kernel call stack.
*
* We are handed the trap frame laid down at the time the PMC
* interrupt was taken. The saved PC could be:
* a. in the lowlevel trap handler, meaning that there isn't a C stack
* to traverse,
* b. at the beginning of a function before the stack frame is laid
* down,
* c. just before a 'ret', after the stack frame has been taken off,
* d. somewhere else in a function with a valid stack frame being
* present.
*
* In case (d), the previous frame pointer is at [%ebp]/[%rbp] and
* the return address is at [%ebp+4]/[%rbp+8].
*
* For cases (b) and (c), the return address is at [%esp]/[%rsp] and
* the frame pointer doesn't need to be changed when going up one
* level in the stack.
*
* For case (a), we check if the PC lies in low-level trap handling
* code, and if so we terminate our trace.
*/
int
pmc_save_kernel_callchain(uintptr_t *cc, int nframes, struct trapframe *tf)
{
int n;
uint32_t instr;
uintptr_t fp, pc, r, sp, stackstart, stackend;
struct thread *td;
KASSERT(TRAPF_USERMODE(tf) == 0,("[x86,%d] not a kernel backtrace",
__LINE__));
td = curthread;
pc = PMC_TRAPFRAME_TO_PC(tf);
fp = PMC_TRAPFRAME_TO_FP(tf);
sp = PMC_TRAPFRAME_TO_KERNEL_SP(tf);
*cc++ = pc;
r = fp + sizeof(uintptr_t); /* points to return address */
if (nframes <= 1)
return (1);
stackstart = (uintptr_t) td->td_kstack;
stackend = (uintptr_t) td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
if (PMC_IN_TRAP_HANDLER(pc) ||
!PMC_IN_KERNEL(pc) ||
!PMC_IN_KERNEL_STACK(r, stackstart, stackend) ||
!PMC_IN_KERNEL_STACK(sp, stackstart, stackend) ||
!PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
return (1);
instr = *(uint32_t *) pc;
/*
* Determine whether the interrupted function was in the
* processing of either laying down its stack frame or taking
* it off.
*
* If we haven't started laying down a stack frame, or are
* just about to return, then our caller's address is at
* *sp, and we don't have a frame to unwind.
*/
if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) ||
PMC_AT_FUNCTION_EPILOGUE_RET(instr))
pc = *(uintptr_t *) sp;
else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) {
/*
* The code was midway through laying down a frame.
* At this point sp[0] has a frame back pointer,
* and the caller's address is therefore at sp[1].
*/
sp += sizeof(uintptr_t);
if (!PMC_IN_KERNEL_STACK(sp, stackstart, stackend))
return (1);
pc = *(uintptr_t *) sp;
} else {
/*
* Not in the function prologue or epilogue.
*/
pc = *(uintptr_t *) r;
fp = *(uintptr_t *) fp;
}
for (n = 1; n < nframes; n++) {
*cc++ = pc;
if (PMC_IN_TRAP_HANDLER(pc))
break;
r = fp + sizeof(uintptr_t);
if (!PMC_IN_KERNEL_STACK(fp, stackstart, stackend) ||
!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
break;
pc = *(uintptr_t *) r;
fp = *(uintptr_t *) fp;
}
return (n);
}
/*
* Machine dependent initialization for x86 class platforms.
*/
struct pmc_mdep *
pmc_md_initialize()
{
int i;
struct pmc_mdep *md;
/* determine the CPU kind */
if (cpu_vendor_id == CPU_VENDOR_AMD)
md = pmc_amd_initialize();
else if (cpu_vendor_id == CPU_VENDOR_INTEL)
md = pmc_intel_initialize();
else
return (NULL);
/* disallow sampling if we do not have an LAPIC */
if (md != NULL && !lapic_enable_pmc())
for (i = 0; i < md->pmd_nclass; i++) {
if (i == PMC_CLASS_INDEX_SOFT)
continue;
md->pmd_classdep[i].pcd_caps &= ~PMC_CAP_INTERRUPT;
}
return (md);
}
void
pmc_md_finalize(struct pmc_mdep *md)
{
lapic_disable_pmc();
if (cpu_vendor_id == CPU_VENDOR_AMD)
pmc_amd_finalize(md);
else if (cpu_vendor_id == CPU_VENDOR_INTEL)
pmc_intel_finalize(md);
else
KASSERT(0, ("[x86,%d] Unknown vendor", __LINE__));
}