add definition for ability to produce a backtrace

[unix-history] / usr / src / sys / kern / kern_malloc.c

diff --git a/usr/src/sys/kern/kern_malloc.c b/usr/src/sys/kern/kern_malloc.c
index d00d2b7..76d5e1a 100644 (file)
--- a/usr/src/sys/kern/kern_malloc.c
+++ b/usr/src/sys/kern/kern_malloc.c
@@ -1,19 +1,20 @@
 /*
 /*

- * Copyright (c) 1987, 1991 The Regents of the University of California.
- * All rights reserved.
+ * Copyright (c) 1987, 1991, 1993
+ *     The Regents of the University of California.  All rights reserved.

  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)kern_malloc.c       7.25.1.1 (Berkeley) %G%
+ *     @(#)kern_malloc.c       8.3 (Berkeley) %G%

  */
 
  */
 

-#include "param.h"
-#include "proc.h"
-#include "map.h"
-#include "kernel.h"
-#include "malloc.h"
-#include "vm/vm.h"
-#include "vm/vm_kern.h"
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/map.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+
+#include <vm/vm.h>
+#include <vm/vm_kern.h>

 
 struct kmembuckets bucket[MINBUCKET + 16];
 struct kmemstats kmemstats[M_LAST];
 
 struct kmembuckets bucket[MINBUCKET + 16];
 struct kmemstats kmemstats[M_LAST];


@@ -26,6 +27,49 @@ long malloc_reentered;
                        else malloc_reentered = 1;}
 #define OUT (malloc_reentered = 0)
 
                        else malloc_reentered = 1;}
 #define OUT (malloc_reentered = 0)
 

+#ifdef DIAGNOSTIC
+/*
+ * This structure provides a set of masks to catch unaligned frees.
+ */
+long addrmask[] = { 0,
+       0x00000001, 0x00000003, 0x00000007, 0x0000000f,
+       0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
+       0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
+       0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
+};
+
+/*
+ * The WEIRD_ADDR is used as known text to copy into free objects so
+ * that modifications after frees can be detected.
+ */
+#define WEIRD_ADDR     0xdeadbeef
+#define MAX_COPY       32
+
+/*
+ * Normally the first word of the structure is used to hold the list
+ * pointer for free objects. However, when running with diagnostics,
+ * we use the third and fourth fields, so as to catch modifications
+ * in the most commonly trashed first two words.
+ */
+struct freelist {
+       long    spare0;
+       short   type;
+       long    spare1;
+       caddr_t next;
+};
+#else /* !DIAGNOSTIC */
+struct freelist {
+       caddr_t next;
+};
+#endif /* DIAGNOSTIC */
+
+struct uselist {
+       struct  uselist *next;
+       caddr_t mem;
+       long    size;
+       long    type;
+} *listhd;
+

 /*
  * Allocate a block of memory
  */
 /*
  * Allocate a block of memory
  */


@@ -36,7 +80,8 @@ malloc(size, type, flags)
 {
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
 {
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;

-       long indx, npg, alloc, allocsize;
+       register struct freelist *freep;
+       long indx, npg, allocsize;

        int s;
        caddr_t va, cp, rp;
 #ifdef KMEMSTATS
        int s;
        caddr_t va, cp, rp;
 #ifdef KMEMSTATS


@@ -47,7 +92,6 @@ malloc(size, type, flags)
                panic("malloc - bogus type");
        if (type == M_NAMEI)
                curproc->p_spare[0]++;
                panic("malloc - bogus type");
        if (type == M_NAMEI)
                curproc->p_spare[0]++;

-

        indx = BUCKETINDX(size);
        kbp = &bucket[indx];
        s = splimp();
        indx = BUCKETINDX(size);
        kbp = &bucket[indx];
        s = splimp();


@@ -65,8 +109,13 @@ malloc(size, type, flags)
                tsleep((caddr_t)ksp, PSWP+2, memname[type], 0);
                IN;
        }
                tsleep((caddr_t)ksp, PSWP+2, memname[type], 0);
                IN;
        }

+       ksp->ks_size |= 1 << indx;
+#endif
+#ifdef DIAGNOSTIC
+       copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY;

 #endif
        if (kbp->kb_next == NULL) {
 #endif
        if (kbp->kb_next == NULL) {

+               kbp->kb_last = NULL;

                if (size > MAXALLOCSAVE)
                        allocsize = roundup(size, CLBYTES);
                else
                if (size > MAXALLOCSAVE)
                        allocsize = roundup(size, CLBYTES);
                else


@@ -104,7 +153,6 @@ malloc(size, type, flags)
                 */
                savedlist = kbp->kb_next;
                rp = kbp->kb_next; /* returned while blocked in vmemall */
                 */
                savedlist = kbp->kb_next;
                rp = kbp->kb_next; /* returned while blocked in vmemall */

-               kbp->kb_next = va + (npg * NBPG) - allocsize;

                for (cp = kbp->kb_next; cp >= va; cp -= allocsize) {
                        ((caddr_t *)cp)[2] = (cp > va ? cp - allocsize : rp);
                        if (indx == 7) {
                for (cp = kbp->kb_next; cp >= va; cp -= allocsize) {
                        ((caddr_t *)cp)[2] = (cp > va ? cp - allocsize : rp);
                        if (indx == 7) {


@@ -138,6 +186,14 @@ out:
 #else
 out:
 #endif
 #else
 out:
 #endif

+       if (size > 64 && size <= 128) {
+               mlp = (struct uselist *)malloc(sizeof(*mlp), M_TEMP, M_WAITOK);
+               mlp->type = type;
+               mlp->size = size;
+               mlp->mem = va;
+               mlp->next = listhd;
+               listhd = mlp;
+       }

        OUT;
        splx(s);
        return ((void *) va);
        OUT;
        splx(s);
        return ((void *) va);


@@ -152,15 +208,6 @@ long addrmask[] = { 0x00000000,
 };
 #endif /* DIAGNOSTIC */
 
 };
 #endif /* DIAGNOSTIC */
 

-#ifdef DIAGNOSTIC
-long addrmask[] = { 0x00000000,
-       0x00000001, 0x00000003, 0x00000007, 0x0000000f,
-       0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
-       0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
-       0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
-};
-#endif /* DIAGNOSTIC */
-

 /*
  * Free a block of memory allocated by malloc.
  */
 /*
  * Free a block of memory allocated by malloc.
  */


@@ -171,8 +218,13 @@ free(addr, type)
 {
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;
 {
        register struct kmembuckets *kbp;
        register struct kmemusage *kup;

-       long alloc, size;
+       register struct freelist *freep;
+       long size;

        int s;
        int s;

+#ifdef DIAGNOSTIC
+       caddr_t cp;
+       long *end, *lp, alloc, copysize;
+#endif

 #ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];
 #endif
 #ifdef KMEMSTATS
        register struct kmemstats *ksp = &kmemstats[type];
 #endif


@@ -191,21 +243,42 @@ free(addr, type)
        }
 #endif /* DIAGNOSTIC */
        size = 1 << kup->ku_indx;
        }
 #endif /* DIAGNOSTIC */
        size = 1 << kup->ku_indx;

+       kbp = &bucket[kup->ku_indx];
+       s = splimp();
+       if (size == 128) {
+               struct uselist *mlp, *pmlp;
+
+               mlp = listhd;
+               if (mlp->mem == addr)
+                       listhd = mlp->next;
+               else for (pmlp = mlp, mlp = mlp->next ; mlp; mlp = mlp->next) {
+                       if (mlp->mem == addr) {
+                               pmlp->next = mlp->next;
+                               break;
+                       }
+                       pmlp = mlp;
+               }
+               if (mlp == NULL)
+                       printf("free: lost type %s size %d\n", memname[type],
+                           size);
+               else
+                       free(mlp, M_TEMP);
+       }

 #ifdef DIAGNOSTIC
 #ifdef DIAGNOSTIC

+       /*
+        * Check for returns of data that do not point to the
+        * beginning of the allocation.
+        */

        if (type == M_NAMEI)
                curproc->p_spare[0]--;
        if (size > NBPG * CLSIZE)
                alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)];
        else
                alloc = addrmask[kup->ku_indx];
        if (type == M_NAMEI)
                curproc->p_spare[0]--;
        if (size > NBPG * CLSIZE)
                alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)];
        else
                alloc = addrmask[kup->ku_indx];

-       if (((u_long)addr & alloc) != 0) {
-               printf("free: unaligned addr 0x%x, size %d, type %d, mask %d\n",
-                       addr, size, type, alloc);
-               panic("free: unaligned addr");
-       }
+       if (((u_long)addr & alloc) != 0)
+               panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n",
+                       addr, size, memname[type], alloc);

 #endif /* DIAGNOSTIC */
 #endif /* DIAGNOSTIC */

-       kbp = &bucket[kup->ku_indx];
-       s = splimp();

        IN;
        if (size > MAXALLOCSAVE) {
                kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt));
        IN;
        if (size > MAXALLOCSAVE) {
                kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt));


@@ -223,6 +296,32 @@ free(addr, type)
                splx(s);
                return;
        }
                splx(s);
                return;
        }

+       freep = (struct freelist *)addr;
+#ifdef DIAGNOSTIC
+       /*
+        * Check for multiple frees. Use a quick check to see if
+        * it looks free before laboriously searching the freelist.
+        */
+       if (freep->spare0 == WEIRD_ADDR) {
+               for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) {
+                       if (addr != cp)
+                               continue;
+                       printf("multiply freed item 0x%x\n", addr);
+                       panic("free: duplicated free");
+               }
+       }
+       /*
+        * Copy in known text to detect modification after freeing
+        * and to make it look free. Also, save the type being freed
+        * so we can list likely culprit if modification is detected
+        * when the object is reallocated.
+        */
+       copysize = size < MAX_COPY ? size : MAX_COPY;
+       end = (long *)&((caddr_t)addr)[copysize];
+       for (lp = (long *)addr; lp < end; lp++)
+               *lp = WEIRD_ADDR;
+       freep->type = type;
+#endif /* DIAGNOSTIC */

        if (size == 128) {
                long *lp = (long *)addr;
                lp[0] = lp[1] = lp[3] = lp[4] = -1;
        if (size == 128) {
                long *lp = (long *)addr;
                lp[0] = lp[1] = lp[3] = lp[4] = -1;


@@ -241,8 +340,12 @@ free(addr, type)
                wakeup((caddr_t)ksp);
        ksp->ks_inuse--;
 #endif
                wakeup((caddr_t)ksp);
        ksp->ks_inuse--;
 #endif

-       ((caddr_t *)addr)[2] = kbp->kb_next;
-       kbp->kb_next = addr;
+       if (kbp->kb_next == NULL)
+               kbp->kb_next = addr;
+       else
+               ((struct freelist *)kbp->kb_last)->next = addr;
+       freep->next = NULL;
+       kbp->kb_last = addr;

        OUT;
        splx(s);
 }
        OUT;
        splx(s);
 }


@@ -267,8 +370,8 @@ kmeminit()
        npg = VM_KMEM_SIZE/ NBPG;
        kmemusage = (struct kmemusage *) kmem_alloc(kernel_map,
                (vm_size_t)(npg * sizeof(struct kmemusage)));
        npg = VM_KMEM_SIZE/ NBPG;
        kmemusage = (struct kmemusage *) kmem_alloc(kernel_map,
                (vm_size_t)(npg * sizeof(struct kmemusage)));

-       kmem_map = kmem_suballoc(kernel_map, (vm_offset_t)&kmembase,
-               (vm_offset_t)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE);
+       kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase,
+               (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE);

 #ifdef KMEMSTATS
        for (indx = 0; indx < MINBUCKET + 16; indx++) {
                if (1 << indx >= CLBYTES)
 #ifdef KMEMSTATS
        for (indx = 0; indx < MINBUCKET + 16; indx++) {
                if (1 << indx >= CLBYTES)