library: lift 1024 byte restriction on control groups

The control group hierarchies for any particular task
could conceivably grow quite large.  However, the
library might impose an arbitrary limit of 1024 bytes
via fill_cgroup_cvt.

Two utility buffers of 128 KiB each were already
available for command line use.  This commit simply
trades the smaller 1024 byte stack based buffers for
those much larger existing ones.  Thus, truncation
can be avoided with no additional run-time costs.

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

diff --git a/proc/readproc.c b/proc/readproc.c
index 9ef587bfaa8976f8fcfad62b96980d3ae168f311..1e9d3414b0045b9fff1b66aca5048dabf19e28c0 100644 (file)
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -654,14 +654,13 @@ static char** vectorize_this_str (const char* src) {
     // It is similar to file2strvec except we filter and concatenate
     // the data into a single string represented as a single vector.
 static void fill_cgroup_cvt (const char* directory, proc_t *restrict p) {
- #define vMAX ( sizeof(dbuf) - (int)(dst - dbuf) )
-    char sbuf[1024], dbuf[1024];
+ #define vMAX ( MAX_BUFSZ - (int)(dst - dst_buffer) )
     char *src, *dst, *grp, *eob;
-    int tot, x, whackable_int = sizeof(dbuf);
+    int tot, x, whackable_int = MAX_BUFSZ;
 
-    *(dst = dbuf) = '\0';                        // empty destination
-    tot = read_unvectored(sbuf, sizeof(sbuf), directory, "cgroup", '\0');
-    for (src = sbuf, eob = sbuf + tot; src < eob; src += x) {
+    *(dst = dst_buffer) = '\0';                  // empty destination
+    tot = read_unvectored(src_buffer, MAX_BUFSZ, directory, "cgroup", '\0');
+    for (src = src_buffer, eob = src_buffer + tot; src < eob; src += x) {
         x = 1;                                   // loop assist
         if (!*src) continue;
         x = strlen((grp = src));
@@ -669,10 +668,10 @@ static void fill_cgroup_cvt (const char* directory, proc_t *restrict p) {
 #if 0
         grp += strspn(grp, "0123456789:");       // jump past group number
 #endif
-        dst += snprintf(dst, vMAX, "%s", (dst > dbuf) ? "," : "");
+        dst += snprintf(dst, vMAX, "%s", (dst > dst_buffer) ? "," : "");
         dst += escape_str(dst, grp, vMAX, &whackable_int);
     }
-    p->cgroup = vectorize_this_str(dbuf[0] ? dbuf : "-");
+    p->cgroup = vectorize_this_str(dst_buffer[0] ? dst_buffer : "-");
  #undef vMAX
 }