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-rw-r--r--zfs/lib/libumem/getpcstack.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/zfs/lib/libumem/getpcstack.c b/zfs/lib/libumem/getpcstack.c
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+++ b/zfs/lib/libumem/getpcstack.c
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License"). You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * Portions Copyright 2006 OmniTI, Inc.
+ */
+
+/* #pragma ident "@(#)getpcstack.c 1.5 05/06/08 SMI" */
+
+#include "config.h"
+#include "misc.h"
+
+#if HAVE_UCONTEXT_H
+#include <ucontext.h>
+#endif
+
+#if HAVE_SYS_FRAME_H
+#include <sys/frame.h>
+#endif
+#if HAVE_SYS_STACK_H
+#include <sys/stack.h>
+#endif
+
+#include <stdio.h>
+
+#if defined(__MACH__)
+/*
+ * Darwin doesn't have any exposed frame info, so give it some space.
+ */
+#define UMEM_FRAMESIZE (2 * sizeof(long long))
+
+#elif defined(__sparc) || defined(__sparcv9)
+extern void flush_windows(void);
+#define UMEM_FRAMESIZE MINFRAME
+
+#elif defined(__i386) || defined(__amd64)
+/*
+ * On x86, MINFRAME is defined to be 0, but we want to be sure we can
+ * dereference the entire frame structure.
+ */
+#define UMEM_FRAMESIZE (sizeof (struct frame))
+
+#elif !defined(EC_UMEM_DUMMY_PCSTACK)
+#error needs update for new architecture
+#endif
+
+/*
+ * Get a pc-only stacktrace. Used for kmem_alloc() buffer ownership tracking.
+ * Returns MIN(current stack depth, pcstack_limit).
+ */
+/*ARGSUSED*/
+int
+getpcstack(uintptr_t *pcstack, int pcstack_limit, int check_signal)
+{
+#ifdef EC_UMEM_DUMMY_PCSTACK
+ return 0;
+#else
+ struct frame *fp;
+ struct frame *nextfp, *minfp;
+ int depth = 0;
+ uintptr_t base = 0;
+ size_t size = 0;
+#ifndef UMEM_STANDALONE
+ int on_altstack = 0;
+ uintptr_t sigbase = 0;
+ size_t sigsize = 0;
+
+ stack_t st;
+
+ if (stack_getbounds(&st) != 0) {
+ if (thr_stksegment(&st) != 0 ||
+ (uintptr_t)st.ss_sp < st.ss_size) {
+ return (0); /* unable to get stack bounds */
+ }
+ /*
+ * thr_stksegment(3C) has a slightly different interface than
+ * stack_getbounds(3C) -- correct it
+ */
+ st.ss_sp = (void *)(((uintptr_t)st.ss_sp) - st.ss_size);
+ st.ss_flags = 0; /* can't be on-stack */
+ }
+ on_altstack = (st.ss_flags & SS_ONSTACK);
+
+ if (st.ss_size != 0) {
+ base = (uintptr_t)st.ss_sp;
+ size = st.ss_size;
+ } else {
+ /*
+ * If size == 0, then ss_sp is the *top* of the stack.
+ *
+ * Since we only allow increasing frame pointers, and we
+ * know our caller set his up correctly, we can treat ss_sp
+ * as an upper bound safely.
+ */
+ base = 0;
+ size = (uintptr_t)st.ss_sp;
+ }
+
+ if (check_signal != 0) {
+ void (*sigfunc)() = NULL;
+ int sigfuncsize = 0;
+ extern void thr_sighndlrinfo(void (**)(), int *);
+
+ thr_sighndlrinfo(&sigfunc, &sigfuncsize);
+ sigbase = (uintptr_t)sigfunc;
+ sigsize = sigfuncsize;
+ }
+#else /* UMEM_STANDALONE */
+ base = (uintptr_t)umem_min_stack;
+ size = umem_max_stack - umem_min_stack;
+#endif
+
+ /*
+ * shorten size so that fr_savfp and fr_savpc will be within the stack
+ * bounds.
+ */
+ if (size >= UMEM_FRAMESIZE - 1)
+ size -= (UMEM_FRAMESIZE - 1);
+ else
+ size = 0;
+
+#if defined(__sparc) || defined(__sparcv9)
+ flush_windows();
+#endif
+
+ /* LINTED alignment */
+ fp = (struct frame *)((caddr_t)getfp() + STACK_BIAS);
+
+ minfp = fp;
+
+ if (((uintptr_t)fp - base) >= size)
+ return (0); /* the frame pointer isn't in our stack */
+
+ while (depth < pcstack_limit) {
+ uintptr_t tmp;
+
+ /* LINTED alignment */
+ nextfp = (struct frame *)((caddr_t)fp->fr_savfp + STACK_BIAS);
+ tmp = (uintptr_t)nextfp;
+
+ /*
+ * Check nextfp for validity. It must be properly aligned,
+ * increasing compared to the last %fp (or the top of the
+ * stack we just switched to), and it must be inside
+ * [base, base + size).
+ */
+ if (tmp != SA(tmp))
+ break;
+ else if (nextfp <= minfp || (tmp - base) >= size) {
+#ifndef UMEM_STANDALONE
+ if (tmp == NULL || !on_altstack)
+ break;
+ /*
+ * If we're on an alternate signal stack, try jumping
+ * to the main thread stack.
+ *
+ * If the main thread stack has an unlimited size, we
+ * punt, since we don't know where the frame pointer's
+ * been.
+ *
+ * (thr_stksegment() returns the *top of stack*
+ * in ss_sp, not the bottom)
+ */
+ if (thr_stksegment(&st) == 0) {
+ if (st.ss_size >= (uintptr_t)st.ss_sp ||
+ st.ss_size < UMEM_FRAMESIZE - 1)
+ break;
+
+ on_altstack = 0;
+ base = (uintptr_t)st.ss_sp - st.ss_size;
+ size = st.ss_size - (UMEM_FRAMESIZE - 1);
+ minfp = (struct frame *)base;
+ continue; /* try again */
+ }
+#endif
+ break;
+ }
+
+#ifndef UMEM_STANDALONE
+ if (check_signal && (fp->fr_savpc - sigbase) <= sigsize)
+ umem_panic("called from signal handler");
+#endif
+ pcstack[depth++] = fp->fr_savpc;
+ fp = nextfp;
+ minfp = fp;
+ }
+ return (depth);
+#endif
+}