use tolimit for data structure initialization checks;

some speedups in mcount;
better recovery in the face of running out of tos[] space.

SCCS-vsn: lib/libc/gmon/gmon.c 1.6

diff --git a/usr/src/lib/libc/gmon/gmon.c b/usr/src/lib/libc/gmon/gmon.c
index 1007afa..c695b0e 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      1.5 (Berkeley) %G%";
+static char *sccsid = "@(#)gmon.c      1.6 (Berkeley) %G%";

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


@@ -87,6 +87,7 @@ static struct tostruct        *tos = 0;
 static unsigned short  tolimit = 0;
 static char            *s_lowpc = 0;
 static char            *s_highpc = 0;
 static unsigned short  tolimit = 0;
 static char            *s_lowpc = 0;
 static char            *s_highpc = 0;

+static unsigned long   s_textsize = 0;

 
 static int     ssiz;
 static int     *sbuf;
 
 static int     ssiz;
 static int     *sbuf;


@@ -97,35 +98,41 @@ _mstartup(lowpc, highpc)
     char       *lowpc;
     char       *highpc;
 {
     char       *lowpc;
     char       *highpc;
 {

-    int                monsize;
-    char       *buffer;
-    int                textsize;
-    char       *sbrk();
+    int                        monsize;
+    char               *buffer;
+    char               *sbrk();
+    unsigned long      limit;

 
     s_lowpc = lowpc;
     s_highpc = highpc;
 
     s_lowpc = lowpc;
     s_highpc = highpc;

-    textsize = ( (char *) highpc - (char *) lowpc );
-    monsize = textsize + sizeof(struct phdr);
+    s_textsize = highpc - lowpc;
+    monsize = s_textsize + sizeof(struct phdr);

     buffer = sbrk( monsize );
     if ( buffer == (char *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        return;
     }
     buffer = sbrk( monsize );
     if ( buffer == (char *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        return;
     }

-    froms = (unsigned short *) sbrk( textsize );
+    froms = (unsigned short *) sbrk( s_textsize );

     if ( froms == (unsigned short *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        return;
     }
     if ( froms == (unsigned short *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        return;
     }

-    tos = (struct tostruct *) sbrk(textsize);
+    tos = (struct tostruct *) sbrk(s_textsize);

     if ( tos == (struct tostruct *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        tos = 0;
        return;
     }
     if ( tos == (struct tostruct *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        tos = 0;
        return;
     }

-    tolimit = textsize / sizeof(struct tostruct);

     tos[0].link = 0;
     tos[0].link = 0;

+    limit = s_textsize / sizeof(struct tostruct);
+       /*
+        *      tolimit is what mcount checks to see if
+        *      all the data structures are ready!!!
+        *      make sure it won't overflow.
+        */
+    tolimit = limit > 65534 ? 65534 : limit;

     monitor( lowpc , highpc , buffer , monsize );
 }
 
     monitor( lowpc , highpc , buffer , monsize );
 }
 


@@ -135,7 +142,6 @@ _mcleanup()
     int                fromindex;
     char       *frompc;
     int                toindex;
     int                fromindex;
     char       *frompc;
     int                toindex;

-    int                textsize;

 
     monitor( (int (*)()) 0 );
     fd = fopen( "gmon.out" , "w" );
 
     monitor( (int (*)()) 0 );
     fd = fopen( "gmon.out" , "w" );


@@ -147,8 +153,7 @@ _mcleanup()
        fprintf( stderr , "[mcleanup] sbuf 0x%x ssiz %d\n" , sbuf , ssiz );
 #   endif DEBUG
     fwrite( sbuf , 1 , ssiz , fd );
        fprintf( stderr , "[mcleanup] sbuf 0x%x ssiz %d\n" , sbuf , ssiz );
 #   endif DEBUG
     fwrite( sbuf , 1 , ssiz , fd );

-    textsize = s_highpc - s_lowpc;
-    for ( fromindex = 0 ; fromindex < textsize>>1 ; fromindex++ ) {
+    for ( fromindex = 0 ; fromindex < s_textsize>>1 ; fromindex++ ) {

        if ( froms[fromindex] == 0 ) {
            continue;
        }
        if ( froms[fromindex] == 0 ) {
            continue;
        }


@@ -197,7 +202,7 @@ mcount()
         *      check that we are profiling
         *      and that we aren't recursively invoked.
         */
         *      check that we are profiling
         *      and that we aren't recursively invoked.
         */

-    if ( tos == 0 ) {
+    if ( tolimit == 0 ) {

        goto out;
     }
     if ( profiling ) {
        goto out;
     }
     if ( profiling ) {


@@ -209,10 +214,11 @@ mcount()
         *      for example:    signal catchers get called from the stack,
         *                      not from text space.  too bad.
         */
         *      for example:    signal catchers get called from the stack,
         *                      not from text space.  too bad.
         */

-    if ( (char *) frompcindex < s_lowpc || (char *) frompcindex > s_highpc ) {
+    frompcindex = (unsigned short *) ( (long) frompcindex - (long) s_lowpc );
+    if ( (unsigned long) frompcindex > s_textsize ) {

        goto done;
     }
        goto done;
     }

-    frompcindex = &froms[ ( (long) frompcindex - (long) s_lowpc ) >> 1 ];
+    frompcindex = &froms[ ( (long) frompcindex ) >> 1 ];

     if ( *frompcindex == 0 ) {
        *frompcindex = ++tos[0].link;
        if ( *frompcindex >= tolimit ) {
     if ( *frompcindex == 0 ) {
        *frompcindex = ++tos[0].link;
        if ( *frompcindex >= tolimit ) {


@@ -252,10 +258,9 @@ out:
     asm( "#undef _mcount");
 
 overflow:
     asm( "#undef _mcount");
 
 overflow:

+    tolimit = 0;

 #   define     TOLIMIT "mcount: tos overflow\n"
     write( 2 , TOLIMIT , sizeof( TOLIMIT ) );
 #   define     TOLIMIT "mcount: tos overflow\n"
     write( 2 , TOLIMIT , sizeof( TOLIMIT ) );

-    tos = 0;
-    froms = 0;

     goto out;
 }
 
     goto out;
 }