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/**
* @file common.c
*
* @remark Copyright 2004 Oprofile Authors
* @remark Copyright 2010 ARM Ltd.
* @remark Read the file COPYING
*
* @author Zwane Mwaikambo
* @author Will Deacon [move to perf]
*/
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/oprofile.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/stacktrace.h>
#include <linux/uaccess.h>
#include <asm/perf_event.h>
#include <asm/ptrace.h>
#ifdef CONFIG_HW_PERF_EVENTS
/*
* OProfile has a curious naming scheme for the ARM PMUs, but they are
* part of the user ABI so we need to map from the perf PMU name for
* supported PMUs.
*/
static struct op_perf_name {
char *perf_name;
char *op_name;
} op_perf_name_map[] = {
{ "armv5_xscale1", "arm/xscale1" },
{ "armv5_xscale2", "arm/xscale2" },
{ "armv6_1136", "arm/armv6" },
{ "armv6_1156", "arm/armv6" },
{ "armv6_1176", "arm/armv6" },
{ "armv6_11mpcore", "arm/mpcore" },
{ "armv7_cortex_a8", "arm/armv7" },
{ "armv7_cortex_a9", "arm/armv7-ca9" },
};
char *op_name_from_perf_id(void)
{
int i;
struct op_perf_name names;
const char *perf_name = perf_pmu_name();
for (i = 0; i < ARRAY_SIZE(op_perf_name_map); ++i) {
names = op_perf_name_map[i];
if (!strcmp(names.perf_name, perf_name))
return names.op_name;
}
return NULL;
}
#endif
static int report_trace(struct stackframe *frame, void *d)
{
unsigned int *depth = d;
if (*depth) {
oprofile_add_trace(frame->pc);
(*depth)--;
}
return *depth == 0;
}
/*
* The registers we're interested in are at the end of the variable
* length saved register structure. The fp points at the end of this
* structure so the address of this struct is:
* (struct frame_tail *)(xxx->fp)-1
*/
struct frame_tail {
struct frame_tail *fp;
unsigned long sp;
unsigned long lr;
} __attribute__((packed));
static struct frame_tail* user_backtrace(struct frame_tail *tail)
{
struct frame_tail buftail[2];
/* Also check accessibility of one struct frame_tail beyond */
if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
return NULL;
if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
return NULL;
oprofile_add_trace(buftail[0].lr);
/* frame pointers should strictly progress back up the stack
* (towards higher addresses) */
if (tail + 1 >= buftail[0].fp)
return NULL;
return buftail[0].fp-1;
}
static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
{
struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
if (!user_mode(regs)) {
struct stackframe frame;
arm_get_current_stackframe(regs, &frame);
walk_stackframe(&frame, report_trace, &depth);
return;
}
while (depth-- && tail && !((unsigned long) tail & 3))
tail = user_backtrace(tail);
}
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
/* provide backtrace support also in timer mode: */
ops->backtrace = arm_backtrace;
return oprofile_perf_init(ops);
}
void oprofile_arch_exit(void)
{
oprofile_perf_exit();
}
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