110 строки
2.7 KiB
C
110 строки
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Performance counter callchain support - powerpc architecture code
|
|
*
|
|
* Copyright © 2009 Paul Mackerras, IBM Corporation.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/perf_event.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/mm.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/sigcontext.h>
|
|
#include <asm/ucontext.h>
|
|
#include <asm/vdso.h>
|
|
#include <asm/pte-walk.h>
|
|
|
|
#include "callchain.h"
|
|
|
|
/*
|
|
* Is sp valid as the address of the next kernel stack frame after prev_sp?
|
|
* The next frame may be in a different stack area but should not go
|
|
* back down in the same stack area.
|
|
*/
|
|
static int valid_next_sp(unsigned long sp, unsigned long prev_sp)
|
|
{
|
|
if (sp & 0xf)
|
|
return 0; /* must be 16-byte aligned */
|
|
if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
|
|
return 0;
|
|
if (sp >= prev_sp + STACK_FRAME_MIN_SIZE)
|
|
return 1;
|
|
/*
|
|
* sp could decrease when we jump off an interrupt stack
|
|
* back to the regular process stack.
|
|
*/
|
|
if ((sp & ~(THREAD_SIZE - 1)) != (prev_sp & ~(THREAD_SIZE - 1)))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
|
|
{
|
|
unsigned long sp, next_sp;
|
|
unsigned long next_ip;
|
|
unsigned long lr;
|
|
long level = 0;
|
|
unsigned long *fp;
|
|
|
|
lr = regs->link;
|
|
sp = regs->gpr[1];
|
|
perf_callchain_store(entry, perf_instruction_pointer(regs));
|
|
|
|
if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
|
|
return;
|
|
|
|
for (;;) {
|
|
fp = (unsigned long *) sp;
|
|
next_sp = fp[0];
|
|
|
|
if (next_sp == sp + STACK_INT_FRAME_SIZE &&
|
|
fp[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
|
|
/*
|
|
* This looks like an interrupt frame for an
|
|
* interrupt that occurred in the kernel
|
|
*/
|
|
regs = (struct pt_regs *)(sp + STACK_FRAME_OVERHEAD);
|
|
next_ip = regs->nip;
|
|
lr = regs->link;
|
|
level = 0;
|
|
perf_callchain_store_context(entry, PERF_CONTEXT_KERNEL);
|
|
|
|
} else {
|
|
if (level == 0)
|
|
next_ip = lr;
|
|
else
|
|
next_ip = fp[STACK_FRAME_LR_SAVE];
|
|
|
|
/*
|
|
* We can't tell which of the first two addresses
|
|
* we get are valid, but we can filter out the
|
|
* obviously bogus ones here. We replace them
|
|
* with 0 rather than removing them entirely so
|
|
* that userspace can tell which is which.
|
|
*/
|
|
if ((level == 1 && next_ip == lr) ||
|
|
(level <= 1 && !kernel_text_address(next_ip)))
|
|
next_ip = 0;
|
|
|
|
++level;
|
|
}
|
|
|
|
perf_callchain_store(entry, next_ip);
|
|
if (!valid_next_sp(next_sp, sp))
|
|
return;
|
|
sp = next_sp;
|
|
}
|
|
}
|
|
|
|
void
|
|
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
|
|
{
|
|
if (!is_32bit_task())
|
|
perf_callchain_user_64(entry, regs);
|
|
else
|
|
perf_callchain_user_32(entry, regs);
|
|
}
|