You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
492 lines
12 KiB
492 lines
12 KiB
/*
|
|
* Performance counter callchain support - powerpc architecture code
|
|
*
|
|
* Copyright © 2009 Paul Mackerras, IBM Corporation.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
#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/pgtable.h>
|
|
#include <asm/sigcontext.h>
|
|
#include <asm/ucontext.h>
|
|
#include <asm/vdso.h>
|
|
#ifdef CONFIG_PPC64
|
|
#include "ppc32.h"
|
|
#endif
|
|
|
|
|
|
/*
|
|
* 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_OVERHEAD)
|
|
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 *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, regs->nip);
|
|
|
|
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(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;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_PPC64
|
|
/*
|
|
* On 64-bit we don't want to invoke hash_page on user addresses from
|
|
* interrupt context, so if the access faults, we read the page tables
|
|
* to find which page (if any) is mapped and access it directly.
|
|
*/
|
|
static int read_user_stack_slow(void __user *ptr, void *ret, int nb)
|
|
{
|
|
pgd_t *pgdir;
|
|
pte_t *ptep, pte;
|
|
unsigned shift;
|
|
unsigned long addr = (unsigned long) ptr;
|
|
unsigned long offset;
|
|
unsigned long pfn;
|
|
void *kaddr;
|
|
|
|
pgdir = current->mm->pgd;
|
|
if (!pgdir)
|
|
return -EFAULT;
|
|
|
|
ptep = find_linux_pte_or_hugepte(pgdir, addr, &shift);
|
|
if (!shift)
|
|
shift = PAGE_SHIFT;
|
|
|
|
/* align address to page boundary */
|
|
offset = addr & ((1UL << shift) - 1);
|
|
addr -= offset;
|
|
|
|
if (ptep == NULL)
|
|
return -EFAULT;
|
|
pte = *ptep;
|
|
if (!pte_present(pte) || !(pte_val(pte) & _PAGE_USER))
|
|
return -EFAULT;
|
|
pfn = pte_pfn(pte);
|
|
if (!page_is_ram(pfn))
|
|
return -EFAULT;
|
|
|
|
/* no highmem to worry about here */
|
|
kaddr = pfn_to_kaddr(pfn);
|
|
memcpy(ret, kaddr + offset, nb);
|
|
return 0;
|
|
}
|
|
|
|
static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret)
|
|
{
|
|
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned long) ||
|
|
((unsigned long)ptr & 7))
|
|
return -EFAULT;
|
|
|
|
pagefault_disable();
|
|
if (!__get_user_inatomic(*ret, ptr)) {
|
|
pagefault_enable();
|
|
return 0;
|
|
}
|
|
pagefault_enable();
|
|
|
|
return read_user_stack_slow(ptr, ret, 8);
|
|
}
|
|
|
|
static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
|
|
{
|
|
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
|
|
((unsigned long)ptr & 3))
|
|
return -EFAULT;
|
|
|
|
pagefault_disable();
|
|
if (!__get_user_inatomic(*ret, ptr)) {
|
|
pagefault_enable();
|
|
return 0;
|
|
}
|
|
pagefault_enable();
|
|
|
|
return read_user_stack_slow(ptr, ret, 4);
|
|
}
|
|
|
|
static inline int valid_user_sp(unsigned long sp, int is_64)
|
|
{
|
|
if (!sp || (sp & 7) || sp > (is_64 ? TASK_SIZE : 0x100000000UL) - 32)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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 (vdso64_rt_sigtramp && current->mm->context.vdso_base &&
|
|
nip == current->mm->context.vdso_base + vdso64_rt_sigtramp)
|
|
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;
|
|
}
|
|
|
|
static void perf_callchain_user_64(struct perf_callchain_entry *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 = regs->nip;
|
|
lr = regs->link;
|
|
sp = regs->gpr[1];
|
|
perf_callchain_store(entry, next_ip);
|
|
|
|
for (;;) {
|
|
fp = (unsigned long __user *) sp;
|
|
if (!valid_user_sp(sp, 1) || 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(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;
|
|
}
|
|
}
|
|
|
|
static inline int current_is_64bit(void)
|
|
{
|
|
/*
|
|
* We can't use test_thread_flag() here because we may be on an
|
|
* interrupt stack, and the thread flags don't get copied over
|
|
* from the thread_info on the main stack to the interrupt stack.
|
|
*/
|
|
return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
|
|
}
|
|
|
|
#else /* CONFIG_PPC64 */
|
|
/*
|
|
* On 32-bit we just access the address and let hash_page create a
|
|
* HPTE if necessary, so there is no need to fall back to reading
|
|
* the page tables. Since this is called at interrupt level,
|
|
* do_page_fault() won't treat a DSI as a page fault.
|
|
*/
|
|
static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret)
|
|
{
|
|
int rc;
|
|
|
|
if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) ||
|
|
((unsigned long)ptr & 3))
|
|
return -EFAULT;
|
|
|
|
pagefault_disable();
|
|
rc = __get_user_inatomic(*ret, ptr);
|
|
pagefault_enable();
|
|
|
|
return rc;
|
|
}
|
|
|
|
static inline void perf_callchain_user_64(struct perf_callchain_entry *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
}
|
|
|
|
static inline int current_is_64bit(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int valid_user_sp(unsigned long sp, int is_64)
|
|
{
|
|
if (!sp || (sp & 7) || sp > TASK_SIZE - 32)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE
|
|
#define sigcontext32 sigcontext
|
|
#define mcontext32 mcontext
|
|
#define ucontext32 ucontext
|
|
#define compat_siginfo_t struct siginfo
|
|
|
|
#endif /* CONFIG_PPC64 */
|
|
|
|
/*
|
|
* Layout for non-RT signal frames
|
|
*/
|
|
struct signal_frame_32 {
|
|
char dummy[__SIGNAL_FRAMESIZE32];
|
|
struct sigcontext32 sctx;
|
|
struct mcontext32 mctx;
|
|
int abigap[56];
|
|
};
|
|
|
|
/*
|
|
* Layout for RT signal frames
|
|
*/
|
|
struct rt_signal_frame_32 {
|
|
char dummy[__SIGNAL_FRAMESIZE32 + 16];
|
|
compat_siginfo_t info;
|
|
struct ucontext32 uc;
|
|
int abigap[56];
|
|
};
|
|
|
|
static int is_sigreturn_32_address(unsigned int nip, unsigned int fp)
|
|
{
|
|
if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad))
|
|
return 1;
|
|
if (vdso32_sigtramp && current->mm->context.vdso_base &&
|
|
nip == current->mm->context.vdso_base + vdso32_sigtramp)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int is_rt_sigreturn_32_address(unsigned int nip, unsigned int fp)
|
|
{
|
|
if (nip == fp + offsetof(struct rt_signal_frame_32,
|
|
uc.uc_mcontext.mc_pad))
|
|
return 1;
|
|
if (vdso32_rt_sigtramp && current->mm->context.vdso_base &&
|
|
nip == current->mm->context.vdso_base + vdso32_rt_sigtramp)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int sane_signal_32_frame(unsigned int sp)
|
|
{
|
|
struct signal_frame_32 __user *sf;
|
|
unsigned int regs;
|
|
|
|
sf = (struct signal_frame_32 __user *) (unsigned long) sp;
|
|
if (read_user_stack_32((unsigned int __user *) &sf->sctx.regs, ®s))
|
|
return 0;
|
|
return regs == (unsigned long) &sf->mctx;
|
|
}
|
|
|
|
static int sane_rt_signal_32_frame(unsigned int sp)
|
|
{
|
|
struct rt_signal_frame_32 __user *sf;
|
|
unsigned int regs;
|
|
|
|
sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp;
|
|
if (read_user_stack_32((unsigned int __user *) &sf->uc.uc_regs, ®s))
|
|
return 0;
|
|
return regs == (unsigned long) &sf->uc.uc_mcontext;
|
|
}
|
|
|
|
static unsigned int __user *signal_frame_32_regs(unsigned int sp,
|
|
unsigned int next_sp, unsigned int next_ip)
|
|
{
|
|
struct mcontext32 __user *mctx = NULL;
|
|
struct signal_frame_32 __user *sf;
|
|
struct rt_signal_frame_32 __user *rt_sf;
|
|
|
|
/*
|
|
* Note: the next_sp - sp >= signal frame size check
|
|
* is true when next_sp < sp, for example, when
|
|
* transitioning from an alternate signal stack to the
|
|
* normal stack.
|
|
*/
|
|
if (next_sp - sp >= sizeof(struct signal_frame_32) &&
|
|
is_sigreturn_32_address(next_ip, sp) &&
|
|
sane_signal_32_frame(sp)) {
|
|
sf = (struct signal_frame_32 __user *) (unsigned long) sp;
|
|
mctx = &sf->mctx;
|
|
}
|
|
|
|
if (!mctx && next_sp - sp >= sizeof(struct rt_signal_frame_32) &&
|
|
is_rt_sigreturn_32_address(next_ip, sp) &&
|
|
sane_rt_signal_32_frame(sp)) {
|
|
rt_sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp;
|
|
mctx = &rt_sf->uc.uc_mcontext;
|
|
}
|
|
|
|
if (!mctx)
|
|
return NULL;
|
|
return mctx->mc_gregs;
|
|
}
|
|
|
|
static void perf_callchain_user_32(struct perf_callchain_entry *entry,
|
|
struct pt_regs *regs)
|
|
{
|
|
unsigned int sp, next_sp;
|
|
unsigned int next_ip;
|
|
unsigned int lr;
|
|
long level = 0;
|
|
unsigned int __user *fp, *uregs;
|
|
|
|
next_ip = regs->nip;
|
|
lr = regs->link;
|
|
sp = regs->gpr[1];
|
|
perf_callchain_store(entry, next_ip);
|
|
|
|
while (entry->nr < PERF_MAX_STACK_DEPTH) {
|
|
fp = (unsigned int __user *) (unsigned long) sp;
|
|
if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp))
|
|
return;
|
|
if (level > 0 && read_user_stack_32(&fp[1], &next_ip))
|
|
return;
|
|
|
|
uregs = signal_frame_32_regs(sp, next_sp, next_ip);
|
|
if (!uregs && level <= 1)
|
|
uregs = signal_frame_32_regs(sp, next_sp, lr);
|
|
if (uregs) {
|
|
/*
|
|
* This looks like an signal frame, so restart
|
|
* the stack trace with the values in it.
|
|
*/
|
|
if (read_user_stack_32(&uregs[PT_NIP], &next_ip) ||
|
|
read_user_stack_32(&uregs[PT_LNK], &lr) ||
|
|
read_user_stack_32(&uregs[PT_R1], &sp))
|
|
return;
|
|
level = 0;
|
|
perf_callchain_store(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;
|
|
}
|
|
}
|
|
|
|
void
|
|
perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
|
|
{
|
|
if (current_is_64bit())
|
|
perf_callchain_user_64(entry, regs);
|
|
else
|
|
perf_callchain_user_32(entry, regs);
|
|
}
|
|
|