top: Prevent integer overflows in procs_re... REVERTED

That patch referenced below is being reverted because:

. By design, no other top macro looks like a function.
Instead, they all contain some minimal capitalization.
The 'grow_by_size' macro stands out like a sore thumb.

. We would need to approach 400+ million tasks for for
the 1st addressed problem to produce integer overflow.

. And a 2nd check against SSIZE_MAX remains a mystery.

Me thinks a system on which top is running will suffer
ENOMEM before we need to worry about integer overflow.

Reference(s):
. original qualys patch
0105-top-Prevent-integer-overflows-in-procs_refresh.patch
commit 131e5e2fe63f29edfc7df04b2b2a1682d93af846

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.c b/top/top.c
index 98400bd7759253176c7307f13105b63f5f408ba9..00a59e5cb4f43a1b7682841bc20a3b4492af68b0 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -22,7 +22,6 @@
 #include <fcntl.h>
 #include <float.h>
 #include <limits.h>
-#include <stdint.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdarg.h>
@@ -2727,15 +2726,6 @@ static inline void hstput (unsigned idx) {
 #undef _HASH_
 #endif
 
-
-#define grow_by_size(nmemb, over, size) do { \
-   if ((nmemb) < 0 || (size_t)(nmemb) >= INT_MAX / 5) \
-      error_exit("integer overflow in procs_refresh"); \
-   (nmemb) = (nmemb) * 5 / 4 + (over); \
-   if ((nmemb) < 0 || (size_t)(nmemb) >= SSIZE_MAX / (size)) \
-      error_exit("integer overflow in procs_refresh"); \
-} while (0)
-
         /*
          * Refresh procs *Helper* function to eliminate yet one more need
          * to loop through our darn proc_t table.  He's responsible for:
@@ -2807,7 +2797,7 @@ static void procs_hlp (proc_t *this) {
    }
 
    if (Frame_maxtask+1 >= HHist_siz) {
-      grow_by_size(HHist_siz, 100, sizeof(HST_t));
+      HHist_siz = HHist_siz * 5 / 4 + 100;
       PHist_sav = alloc_r(PHist_sav, sizeof(HST_t) * HHist_siz);
       PHist_new = alloc_r(PHist_new, sizeof(HST_t) * HHist_siz);
    }
@@ -2869,7 +2859,7 @@ static void procs_refresh (void) {
 
    for (;;) {
       if (n_used == n_alloc) {
-         grow_by_size(n_alloc, 10, sizeof(proc_t*));
+         n_alloc = 10 + ((n_alloc * 5) / 4);     // grow by over 25%
          private_ppt = alloc_r(private_ppt, sizeof(proc_t*) * n_alloc);
          // ensure NULL pointers for the additional memory just acquired
          memset(private_ppt + n_used, 0, sizeof(proc_t*) * (n_alloc - n_used));
@@ -2896,8 +2886,6 @@ static void procs_refresh (void) {
  #undef n_used
 } // end: procs_refresh
 
-#undef grow_by_size
-
 
         /*
          * This serves as our interface to the memory & cpu count (sysinfo)