diff options
Diffstat (limited to 'arch/powerpc/kernel/perf_callchain.c')
-rw-r--r-- | arch/powerpc/kernel/perf_callchain.c | 492 |
1 files changed, 0 insertions, 492 deletions
diff --git a/arch/powerpc/kernel/perf_callchain.c b/arch/powerpc/kernel/perf_callchain.c deleted file mode 100644 index 564c1d8..0000000 --- a/arch/powerpc/kernel/perf_callchain.c +++ /dev/null @@ -1,492 +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; - - 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); -} |