Пример #1
0
static unsigned long __store_trace(struct perf_callchain_entry *entry,
				   unsigned long sp,
				   unsigned long low, unsigned long high)
{
	struct stack_frame *sf;
	struct pt_regs *regs;

	while (1) {
		sp = sp & PSW_ADDR_INSN;
		if (sp < low || sp > high - sizeof(*sf))
			return sp;
		sf = (struct stack_frame *) sp;
		perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
		/*                       */
		while (1) {
			low = sp;
			sp = sf->back_chain & PSW_ADDR_INSN;
			if (!sp)
				break;
			if (sp <= low || sp > high - sizeof(*sf))
				return sp;
			sf = (struct stack_frame *) sp;
			perf_callchain_store(entry,
					     sf->gprs[8] & PSW_ADDR_INSN);
		}
		/*                                                     */
		sp = (unsigned long) (sf + 1);
		if (sp <= low || sp > high - sizeof(*regs))
			return sp;
		regs = (struct pt_regs *) sp;
		perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
		low = sp;
		sp = regs->gprs[15];
	}
}
Пример #2
0
struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
{
	int rctx;
	struct perf_callchain_entry *entry;


	entry = get_callchain_entry(&rctx);
	if (rctx == -1)
		return NULL;

	if (!entry)
		goto exit_put;

	entry->nr = 0;

	if (!user_mode(regs)) {
		perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
		perf_callchain_kernel(entry, regs);
		if (current->mm)
			regs = task_pt_regs(current);
		else
			regs = NULL;
	}

	if (regs) {
		perf_callchain_store(entry, PERF_CONTEXT_USER);
		perf_callchain_user(entry, regs);
	}

exit_put:
	put_callchain_entry(rctx);

	return entry;
}
Пример #3
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;
	}
}
Пример #4
0
struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
	int rctx;
	struct perf_callchain_entry *entry;

	int kernel = !event->attr.exclude_callchain_kernel;
	int user   = !event->attr.exclude_callchain_user;

	if (!kernel && !user)
		return NULL;

	entry = get_callchain_entry(&rctx);
	if (rctx == -1)
		return NULL;

	if (!entry)
		goto exit_put;

	entry->nr = 0;

	if (kernel && !user_mode(regs)) {
		perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
		perf_callchain_kernel(entry, regs);
	}

	if (user) {
		if (!user_mode(regs)) {
			if  (current->mm)
				regs = task_pt_regs(current);
			else
				regs = NULL;
		}

		if (regs) {
			/*
			 * Disallow cross-task user callchains.
			 */
			if (event->ctx->task && event->ctx->task != current)
				goto exit_put;

			perf_callchain_store(entry, PERF_CONTEXT_USER);
			perf_callchain_user(entry, regs);
		}
	}

exit_put:
	put_callchain_entry(rctx);

	return entry;
}
static struct compat_frame_tail __user *
compat_user_backtrace(struct compat_frame_tail __user *tail,
		      struct perf_callchain_entry_ctx *entry)
{
	struct compat_frame_tail buftail;
	unsigned long err;

	/* Also check accessibility of one struct frame_tail beyond */
	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
		return NULL;

	pagefault_disable();
	err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
	pagefault_enable();

	if (err)
		return NULL;

	perf_callchain_store(entry, buftail.lr);

	/*
	 * Frame pointers should strictly progress back up the stack
	 * (towards higher addresses).
	 */
	if (tail + 1 >= (struct compat_frame_tail __user *)
			compat_ptr(buftail.fp))
		return NULL;

	return (struct compat_frame_tail __user *)compat_ptr(buftail.fp) - 1;
}
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
			 struct pt_regs *regs)
{
	if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
		/* We don't support guest os callchain now */
		return;
	}

	perf_callchain_store(entry, regs->pc);

	if (!compat_user_mode(regs)) {
		/* AARCH64 mode */
		struct frame_tail __user *tail;

		tail = (struct frame_tail __user *)regs->regs[29];

		while (entry->nr < entry->max_stack &&
		       tail && !((unsigned long)tail & 0xf))
			tail = user_backtrace(tail, entry);
	} else {
#ifdef CONFIG_COMPAT
		/* AARCH32 compat mode */
		struct compat_frame_tail __user *tail;

		tail = (struct compat_frame_tail __user *)regs->compat_fp - 1;

		while ((entry->nr < entry->max_stack) &&
			tail && !((unsigned long)tail & 0x3))
			tail = compat_user_backtrace(tail, entry);
#endif
	}
}
Пример #7
0
static int __perf_callchain_kernel(void *data, unsigned long address)
{
	struct perf_callchain_entry_ctx *entry = data;

	perf_callchain_store(entry, address);
	return 0;
}
Пример #8
0
struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
		   bool crosstask, bool add_mark)
{
	struct perf_callchain_entry *entry;
	int rctx;

	entry = get_callchain_entry(&rctx);
	if (rctx == -1)
		return NULL;

	if (!entry)
		goto exit_put;

	entry->nr = init_nr;

	if (kernel && !user_mode(regs)) {
		if (add_mark)
			perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
		perf_callchain_kernel(entry, regs);
	}

	if (user) {
		if (!user_mode(regs)) {
			if  (current->mm)
				regs = task_pt_regs(current);
			else
				regs = NULL;
		}

		if (regs) {
			if (crosstask)
				goto exit_put;

			if (add_mark)
				perf_callchain_store(entry, PERF_CONTEXT_USER);
			perf_callchain_user(entry, regs);
		}
	}

exit_put:
	put_callchain_entry(rctx);

	return entry;
}
/*
 * Gets called by walk_stackframe() for every stackframe. This will be called
 * whist unwinding the stackframe and is like a subroutine return so we use
 * the PC.
 */
static int callchain_trace(struct stackframe *frame, void *data)
{
	struct perf_callchain_entry_ctx *entry = data;
	perf_callchain_store(entry, frame->pc);
	return 0;
}