memcheck/tests/wrap8.c

   1 #include <unistd.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include "valgrind.h"
   5
   6 /* This is the same as wrap5.c, except that the recursion depth is 16.
   7    This is intended to check that on ppc64-linux, which uses a
   8    16-entry per-thread stack, the resulting stack overflow is caught.
   9    (Undetected overflows in redirection stacks are very bad news; they
  10    cause guest code to fail in all sorts of strange ways.)
  11
  12    Hence this test has two expected outcomes:
  13    - on ppc64-linux, a stack overflow is caught, and V aborts.
  14    - on everything else, it runs successfully to completion.
  15    Note, pre() and post() used so as to avoid printf, which messes
  16    up the call stacks on ppc64-linux due to intercept of mempcpy.
  17 */
  18 typedef
  19    struct _Lard {
  20       struct _Lard* next;
  21       char stuff[999];
  22    }
  23    Lard;
  24 Lard* lard = NULL;
  25 static int ctr = 0;
  26
  27 void addMoreLard ( void )
  28 {
  29    Lard* p;
  30    ctr++;
  31    if ((ctr % 3) == 1) {
  32       p = malloc(sizeof(Lard));
  33       p->next = lard;
  34       lard = p;
  35    }
  36 }
  37 static void post ( char* s, int n, int r );
  38 static void pre ( char* s, int n );
  39 static int fact1 ( int n );
  40 static int fact2 ( int n );
  41
  42 /* This is needed to stop gcc4 turning 'fact' into a loop */
  43 __attribute__((noinline))
  44 int mul ( int x, int y ) { return x * y; }
  45
  46 int fact1 ( int n )
  47 {
  48    addMoreLard();
  49    if (n == 0) return 1; else return mul(n, fact2(n-1));
  50 }
  51 int fact2 ( int n )
  52 {
  53    addMoreLard();
  54    if (n == 0) return 1; else return mul(n, fact1(n-1));
  55 }
  56
  57
  58 int I_WRAP_SONAME_FNNAME_ZU(NONE,fact1) ( int n )
  59 {
  60    int    r;
  61    OrigFn fn;
  62    VALGRIND_GET_ORIG_FN(fn);
  63    pre("wrapper1", n);
  64    addMoreLard();
  65    CALL_FN_W_W(r, fn, n);
  66    addMoreLard();
  67    post("wrapper1", n, r);
  68    if (n >= 3) r += fact2(2);
  69    return r;
  70 }
  71
  72 int I_WRAP_SONAME_FNNAME_ZU(NONE,fact2) ( int n )
  73 {
  74    int    r;
  75    OrigFn fn;
  76    VALGRIND_GET_ORIG_FN(fn);
  77    pre("wrapper2", n);
  78    addMoreLard();
  79    CALL_FN_W_W(r, fn, n);
  80    addMoreLard();
  81    post("wrapper2", n, r);
  82    return r;
  83 }
  84
  85 /* --------------- */
  86
  87 int main ( void )
  88 {
  89    int r, n = 15; /* 14 succeeds on ppc64-linux, >= 15 fails */
  90    Lard *p, *p_next;
  91    printf("computing fact1(%d)\n", n); fflush(stdout);
  92    r = fact1(n);
  93    printf("fact1(%d) = %d\n", n, r); fflush(stdout);
  94
  95    printf("allocated %d Lards\n", ctr); fflush(stdout);
  96    for (p = lard; p; p = p_next) {
  97       p_next = p->next;
  98       free(p);
  99    }
 100
 101    return 0;
 102 }
 103
 104 static void send ( char* s )
 105 {
 106   while (*s) {
 107     write(1, s, 1);
 108     s++;
 109   }
 110 }
 111
 112 static void pre ( char* s, int n )
 113 {
 114   char buf[50];
 115   fflush(stdout);
 116   sprintf(buf,"%d", n);
 117   send("in ");
 118   send(s);
 119   send("-pre:  fact(");
 120   send(buf);
 121   send(")\n");
 122   fflush(stdout);
 123 }
 124
 125 static void post ( char* s, int n, int r )
 126 {
 127   char buf[50];
 128   fflush(stdout);
 129   sprintf(buf,"%d", n);
 130   send("in ");
 131   send(s);
 132   send("-post: fact(");
 133   send(buf);
 134   send(") = ");
 135   sprintf(buf,"%d", r);
 136   send(buf);
 137   send("\n");
 138   fflush(stdout);
 139 }