diff options
Diffstat (limited to 'arch/powerpc/kernel/perf_callchain.c')
| -rw-r--r-- | arch/powerpc/kernel/perf_callchain.c | 478 | 
1 files changed, 0 insertions, 478 deletions
diff --git a/arch/powerpc/kernel/perf_callchain.c b/arch/powerpc/kernel/perf_callchain.c deleted file mode 100644 index d05ae4204bb..00000000000 --- a/arch/powerpc/kernel/perf_callchain.c +++ /dev/null @@ -1,478 +0,0 @@ -/* - * 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; - -	if (!__get_user_inatomic(*ret, ptr)) -		return 0; - -	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; - -	if (!__get_user_inatomic(*ret, ptr)) -		return 0; - -	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) -{ -	if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || -	    ((unsigned long)ptr & 3)) -		return -EFAULT; - -	return __get_user_inatomic(*ret, ptr); -} - -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); -}  | 
