[PATCH] Cygwin: Have gmondump support ssp-generated gmon.out

[Mark Geisert]

Cygwin tool ssp generates gmon.out files with different address
resolution than other tools do. Two address bytes per bucket rather than
the usual four address bytes. Gprof can deal with the difference but
gmondump can't because the latter's gmon.out header validation fails.

- Remove the offending portion of the header validation code.
- Make sure all code can handle differing address resolutions.
- Display address resolution in verbose data dumps.
- Change "rawarc" to "struct rawarc" in certain sizeof expressions to
  avoid buffer overrun faults.
- When "-v" (verbose) is specified, note when there is missing bucket
  data or rawarc data.

---
 winsup/utils/gmondump.c | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/winsup/utils/gmondump.c b/winsup/utils/gmondump.c
index 2d29e826d..16b99594a 100644
--- a/winsup/utils/gmondump.c
+++ b/winsup/utils/gmondump.c
@@ -103,6 +103,7 @@ error (int geterrno, const char *fmt, ...)
 void
 gmondump1 (char *filename)
 {
+  int        addrincr;
   ushort    *bucket = NULL;
   int        fd;
   struct gmonhdr hdr;
@@ -134,16 +135,15 @@ gmondump1 (char *filename)
   if (hdr.lpc >= hdr.hpc)
     goto notgmon;
   numbuckets = (hdr.ncnt - sizeof (hdr)) / sizeof (short);
-  if (numbuckets != (hdr.hpc - hdr.lpc) / 4)
-    goto notgmon;
+  addrincr = (hdr.hpc - hdr.lpc) / numbuckets;
   numrawarcs = 0;
   if (stat.st_size != hdr.ncnt)
     {
       numrawarcs = stat.st_size - hdr.ncnt;
-      if (numrawarcs !=
-          (int) sizeof (rawarc) * (numrawarcs / (int) sizeof (rawarc)))
+      if (numrawarcs != (int) sizeof (struct rawarc) *
+                        (numrawarcs / (int) sizeof (struct rawarc)))
         goto notgmon;
-      numrawarcs /= (int) sizeof (rawarc);
+      numrawarcs /= (int) sizeof (struct rawarc);
     }
 
   /* Looks good, so read and display the profiling info. */
@@ -162,7 +162,8 @@ gmondump1 (char *filename)
 
   note ("file %s, gmon version 0x%x, sample rate %d\n",
         filename, hdr.version, hdr.profrate);
-  note ("  address range %p..%p\n", hdr.lpc, hdr.hpc);
+  note ("  address range %p..%p, address increment %d/bucket\n",
+        hdr.lpc, hdr.hpc, addrincr);
   note ("  numbuckets %d, hitbuckets %d, hitcount %d, numrawarcs %d\n",
         numbuckets, hitbuckets, hitcount, numrawarcs);
 
@@ -171,27 +172,31 @@ gmondump1 (char *filename)
     {
       if (hitbuckets)
         note ("  bucket data follows...\n");
+      else
+        note ("  no bucket data present\n");
       char *addr = (char *) hdr.lpc;
-      int   incr = (hdr.hpc - hdr.lpc) / numbuckets;
-      for (res = 0; res < numbuckets; ++bucket, ++res, addr += incr)
+      for (res = 0; res < numbuckets; ++bucket, ++res, addr += addrincr)
         if (*bucket)
           note ("    address %p, hitcount %d\n", addr, *bucket);
       bucket -= numbuckets;
 
       if (numrawarcs)
         {
-          rawarc = (struct rawarc *) calloc (numrawarcs, sizeof (rawarc));
-          res = read (fd, rawarc, numrawarcs * (int) sizeof (rawarc));
-          if (res != numrawarcs * (int) sizeof (rawarc))
+          rawarc = (struct rawarc *) calloc (numrawarcs,
+                                             sizeof (struct rawarc));
+          res = read (fd, rawarc, numrawarcs * (int) sizeof (struct rawarc));
+          if (res != numrawarcs * (int) sizeof (struct rawarc))
             error (0, "unable to read rawarc data");
           note ("  rawarc data follows...\n");
           for (res = 0; res < numrawarcs; ++rawarc, ++res)
             note ("    from %p, self %p, count %d\n",
                   rawarc->raw_frompc, rawarc->raw_selfpc, rawarc->raw_count);
+          rawarc -= numrawarcs;
         }
+      else
+        note ("  no rawarc data present\n");
     }
 
-  note ("\n");
   if (0)
     {
 notgmon:
@@ -261,7 +266,11 @@ main(int argc, char **argv)
     usage1 (ofile);
 
   for (int i = optind; i < argc; i++)
-    gmondump1 (argv[i]);
+    {
+      gmondump1 (argv[i]);
+      if ((i + 1) < argc)
+        note ("\n");
+    }
 
   return 0;
 }
-- 
2.36.1