watch for signal catchers, and recursive invokations therefrom.

SCCS-vsn: lib/libc/gmon/gmon.c 1.2

diff --git a/usr/src/lib/libc/gmon/gmon.c b/usr/src/lib/libc/gmon/gmon.c
index eeff787..a6a3122 100644 (file)
--- a/usr/src/lib/libc/gmon/gmon.c
+++ b/usr/src/lib/libc/gmon/gmon.c
@@ -1,4 +1,4 @@
-static char *sccsid = "@(#)gmon.c      1.1 (Berkeley) %G%";
+static char *sccsid = "@(#)gmon.c      1.2 (Berkeley) %G%";

 
 #include <stdio.h>
 
 
 #include <stdio.h>
 


@@ -81,7 +81,7 @@ _mcleanup()
     monitor((int (*)())0);
     fd = fopen( "dmon.out" , "w" );
     if ( fd == NULL ) {
     monitor((int (*)())0);
     fd = fopen( "dmon.out" , "w" );
     if ( fd == NULL ) {

-       perror( "mcount: mon.out2" );
+       perror( "mcount: dmon.out" );

        return;
     }
     fwrite( sbuf , ssiz , 1 , fd );
        return;
     }
     fwrite( sbuf , ssiz , 1 , fd );


@@ -113,7 +113,7 @@ mcount()
     register char              *selfpc;        /* r11 */
     register unsigned short    *frompcindex;   /* r10 */
     register struct tostruct   *top;           /* r9 */
     register char              *selfpc;        /* r11 */
     register unsigned short    *frompcindex;   /* r10 */
     register struct tostruct   *top;           /* r9 */

-    /* !!! if you add anything, you have to fix the pushr and popr !!! */
+    static int                 profiling = 0;

 
     asm( "     forgot to run ex script on monitor.s" );
     asm( "#define r11 r5" );
 
     asm( "     forgot to run ex script on monitor.s" );
     asm( "#define r11 r5" );


@@ -124,19 +124,27 @@ mcount()
     frompcindex = 0;
 #else not lint
        /*
     frompcindex = 0;
 #else not lint
        /*

-        *      we've pushed the old r11, r10, and r9,
-        *      so the return address for a plain old jsb
-        *      which should be at 0(sp) is now at 12(sp)
+        *      find the return address for mcount,
+        *      and the return address for mcount's caller.

         */
     asm("      movl (sp), r11");       /* selfpc = ... (jsb frame) */
     asm("      movl 16(fp), r10");     /* frompcindex =     (calls frame) */
 #endif not lint
         */
     asm("      movl (sp), r11");       /* selfpc = ... (jsb frame) */
     asm("      movl 16(fp), r10");     /* frompcindex =     (calls frame) */
 #endif not lint

-    /*
-     * check that we are profiling
-     */
-    if ( tos == 0 ) {
+       /*
+        *      check that we are profiling
+        */
+    if ( profiling || tos == 0 ) {

        goto out;
     }
        goto out;
     }

+    profiling = 1;
+       /*
+        *      check that frompcindex is a reasonable pc value.
+        *      for example:    signal catchers get called from the stack,
+        *                      not from text space.  too bad.
+        */
+    if ( (char *) frompcindex < s_lowpc || (char *) frompcindex > s_highpc ) {
+       goto done;
+    }

     frompcindex = &froms[ ( (long) frompcindex - (long) s_lowpc ) >> 1 ];
     if ( *frompcindex == 0 ) {
        *frompcindex = ++tos[0].link;
     frompcindex = &froms[ ( (long) frompcindex - (long) s_lowpc ) >> 1 ];
     if ( *frompcindex == 0 ) {
        *frompcindex = ++tos[0].link;


@@ -150,10 +158,10 @@ mcount()
     } else {
        top = &tos[ *frompcindex ];
     }
     } else {
        top = &tos[ *frompcindex ];
     }

-    for ( ; /*break*/ ; top = &tos[ top -> link ] ) {
+    for ( ; /* goto done */ ; top = &tos[ top -> link ] ) {

        if ( top -> selfpc == selfpc ) {
            top -> count++;
        if ( top -> selfpc == selfpc ) {
            top -> count++;

-           break;
+           goto done;

        }
        if ( top -> link == 0 ) {
            top -> link = ++tos[0].link;
        }
        if ( top -> link == 0 ) {
            top -> link = ++tos[0].link;


@@ -163,9 +171,12 @@ mcount()
            top -> selfpc = selfpc;
            top -> count = 1;
            top -> link = 0;
            top -> selfpc = selfpc;
            top -> count = 1;
            top -> link = 0;

-           break;
+           goto done;

        }
     }
        }
     }

+done:
+    profiling = 0;
+    /* and fall through */

 out:
     asm( "     rsb" );
     asm( "#undef r11" );
 out:
     asm( "     rsb" );
     asm( "#undef r11" );