[src/trunk]: src/sys/miscfs/procfs Fix excessive memory usage, and fix handli...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1aef80032418
branches:  trunk
changeset: 472311:1aef80032418
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Tue Apr 27 06:02:09 1999 +0000

description:
Fix excessive memory usage, and fix handling of SZOMB processes.  PR #7164,
Jaromir Dolecek.

diffstat:

 sys/miscfs/procfs/procfs_cmdline.c |  40 ++++++++++++++++++++-----------------
 1 files changed, 22 insertions(+), 18 deletions(-)

diffs (101 lines):

diff -r 989470629d00 -r 1aef80032418 sys/miscfs/procfs/procfs_cmdline.c
--- a/sys/miscfs/procfs/procfs_cmdline.c        Tue Apr 27 05:38:08 1999 +0000
+++ b/sys/miscfs/procfs/procfs_cmdline.c        Tue Apr 27 06:02:09 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: procfs_cmdline.c,v 1.4 1999/03/24 05:51:27 mrg Exp $   */
+/*     $NetBSD: procfs_cmdline.c,v 1.5 1999/04/27 06:02:09 thorpej Exp $       */
 
 /*
  * Copyright (c) 1999 Jaromir Dolecek <dolecek%ics.muni.cz@localhost>
@@ -62,7 +62,8 @@
        struct uio *uio;
 {
        struct ps_strings pss;
-       int xlen, len, count, error;
+       int xlen, count, error, i;
+       size_t len, upper_bound;
        struct uio auio;
        struct iovec aiov;
        vaddr_t argv;
@@ -74,11 +75,8 @@
 
        /*
         * Allocate a temporary buffer to hold the arguments.
-        *
-        * XXX THIS COULD BE HANDLED MUCH MORE INTELLIGENTLY,
-        * XXX WITHOUT REQUIRING A 256k TEMPORARY BUFFER!
         */
-       arg = malloc(ARG_MAX, M_TEMP, M_WAITOK);
+       arg = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
 
        /*
         * Zombies don't have a stack, so we can't read their psstrings.
@@ -86,8 +84,7 @@
         * ps(1) would display.
         */
        if (p->p_stat == SZOMB || (p->p_flag & P_SYSTEM) != 0) {
-               snprintf(arg, sizeof(arg), "(%s)", p->p_comm);
-               len = strlen(arg);      /* exclude last NUL */
+               len = snprintf(arg, PAGE_SIZE, "(%s)", p->p_comm);
                goto doio;
        }
 
@@ -139,19 +136,20 @@
                goto bad;
 
        /*
-        * Now copy in the actual argument vector, one byte at a time,
+        * Now copy in the actual argument vector, one page at a time,
         * since we don't know how long the vector is (though, we do
         * know how many NUL-terminated strings are in the vector).
         */
        len = 0;
        count = pss.ps_nargvstr;
-       while (count && len < ARG_MAX) {
-               aiov.iov_base = &arg[len];
-               aiov.iov_len = 1;
+       upper_bound = round_page(uio->uio_offset + 1);
+       for (; count && len < upper_bound; len += PAGE_SIZE) {
+               aiov.iov_base = arg;
+               aiov.iov_len = PAGE_SIZE;
                auio.uio_iov = &aiov;
                auio.uio_iovcnt = 1;
                auio.uio_offset = argv + len;
-               auio.uio_resid = 1;
+               auio.uio_resid = PAGE_SIZE;
                auio.uio_segflg = UIO_SYSSPACE;
                auio.uio_rw = UIO_READ;
                auio.uio_procp = NULL;
@@ -159,9 +157,16 @@
                if (error)
                        goto bad;
 
-               if (len > 0 && arg[len] == '\0')
-                       count--;        /* one full string */
-               len++;
+               for (i = len; i < (len + PAGE_SIZE) && count != 0; i++) {
+                       if (arg[i] == '\0')
+                               count--;        /* one full string */
+               }
+
+               if (count == 0) {
+                       /* No more argv strings, set up len and break. */
+                       len = i;
+                       break;
+               }
        }
        if (len > 0)
                len--;                  /* exclude last NUL */
@@ -174,11 +179,10 @@
 
  doio:
        xlen = len - uio->uio_offset;
-       xlen = imin(xlen, uio->uio_resid);
        if (xlen <= 0) 
                error = 0;
        else
-               error = uiomove(arg + uio->uio_offset, xlen, uio);
+               error = uiomove(arg + trunc_page(len), xlen, uio);
 
        free(arg, M_TEMP);
        return (error);