121 lines
3.2 KiB
C
121 lines
3.2 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"
|
|
|
|
static int read_user_stack_64(const unsigned long __user *ptr, unsigned long *ret)
|
|
{
|
|
return __read_user_stack(ptr, ret, sizeof(*ret));
|
|
}
|
|
|
|
/*
|
|
* 64-bit user processes use the same stack frame for RT and non-RT signals.
|
|
*/
|
|
struct signal_frame_64 {
|
|
char dummy[__SIGNAL_FRAMESIZE];
|
|
struct ucontext uc;
|
|
unsigned long unused[2];
|
|
unsigned int tramp[6];
|
|
struct siginfo *pinfo;
|
|
void *puc;
|
|
struct siginfo info;
|
|
char abigap[288];
|
|
};
|
|
|
|
static int is_sigreturn_64_address(unsigned long nip, unsigned long fp)
|
|
{
|
|
if (nip == fp + offsetof(struct signal_frame_64, tramp))
|
|
return 1;
|
|
if (current->mm->context.vdso &&
|
|
nip == VDSO64_SYMBOL(current->mm->context.vdso, sigtramp_rt64))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Do some sanity checking on the signal frame pointed to by sp.
|
|
* We check the pinfo and puc pointers in the frame.
|
|
*/
|
|
static int sane_signal_64_frame(unsigned long sp)
|
|
{
|
|
struct signal_frame_64 __user *sf;
|
|
unsigned long pinfo, puc;
|
|
|
|
sf = (struct signal_frame_64 __user *) sp;
|
|
if (read_user_stack_64((unsigned long __user *) &sf->pinfo, &pinfo) ||
|
|
read_user_stack_64((unsigned long __user *) &sf->puc, &puc))
|
|
return 0;
|
|
return pinfo == (unsigned long) &sf->info &&
|
|
puc == (unsigned long) &sf->uc;
|
|
}
|
|
|
|
void perf_callchain_user_64(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;
|
|
struct signal_frame_64 __user *sigframe;
|
|
unsigned long __user *fp, *uregs;
|
|
|
|
next_ip = perf_instruction_pointer(regs);
|
|
lr = regs->link;
|
|
sp = regs->gpr[1];
|
|
perf_callchain_store(entry, next_ip);
|
|
|
|
while (entry->nr < entry->max_stack) {
|
|
fp = (unsigned long __user *) sp;
|
|
if (invalid_user_sp(sp) || read_user_stack_64(fp, &next_sp))
|
|
return;
|
|
if (level > 0 && read_user_stack_64(&fp[2], &next_ip))
|
|
return;
|
|
|
|
/*
|
|
* Note: the next_sp - sp >= signal frame size check
|
|
* is true when next_sp < sp, which can happen when
|
|
* transitioning from an alternate signal stack to the
|
|
* normal stack.
|
|
*/
|
|
if (next_sp - sp >= sizeof(struct signal_frame_64) &&
|
|
(is_sigreturn_64_address(next_ip, sp) ||
|
|
(level <= 1 && is_sigreturn_64_address(lr, sp))) &&
|
|
sane_signal_64_frame(sp)) {
|
|
/*
|
|
* This looks like an signal frame
|
|
*/
|
|
sigframe = (struct signal_frame_64 __user *) sp;
|
|
uregs = sigframe->uc.uc_mcontext.gp_regs;
|
|
if (read_user_stack_64(&uregs[PT_NIP], &next_ip) ||
|
|
read_user_stack_64(&uregs[PT_LNK], &lr) ||
|
|
read_user_stack_64(&uregs[PT_R1], &sp))
|
|
return;
|
|
level = 0;
|
|
perf_callchain_store_context(entry, PERF_CONTEXT_USER);
|
|
perf_callchain_store(entry, next_ip);
|
|
continue;
|
|
}
|
|
|
|
if (level == 0)
|
|
next_ip = lr;
|
|
perf_callchain_store(entry, next_ip);
|
|
++level;
|
|
sp = next_sp;
|
|
}
|
|
}
|