Re: [RFC] [PATCH 0/5 V2] Huge page backed user-space stacks

Eric B Munson
2008-07-30T15:08:28Z

[-- Attachment #1: Type: text/plain, Size: 2985 bytes --]

/***************************************************************************
* User front end for using huge pages Copyright (C) 2008, IBM *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the Lesser GNU General Public License as *
* published by the Free Software Foundation; either version 2.1 of the *
* License, or at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the Lesser GNU General Public *
* License along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

#define _GNU_SOURCE /* for getopt_long */
#include <unistd.h>
#include <getopt.h>
#include <sys/personality.h>

/* Peronsality bit for huge page backed stack */
#ifndef HUGETLB_STACK
#define HUGETLB_STACK 0x0020000
#endif

extern int errno;
extern int optind;
extern char *optarg;

void print_usage()
{
fprintf(stderr, "hugectl [options] target\n");
fprintf(stderr, "options:\n");
fprintf(stderr, " --help, -h Prints this message.\n");
fprintf(stderr,
" --stack, -s Attempts to execute target program with a hugtlb page backed stack.\n");
}

void set_huge_stack()
{
char * err;
unsigned long curr_per = personality(0xffffffff);
if (personality(curr_per | HUGETLB_STACK) == -1) {
err = strerror(errno);
fprintf(stderr,
"Error setting HUGE_STACK personality flag: '%s'\n",
err);
exit(-1);
}
}

int main(int argc, char** argv)
{
char opts [] = "+hs";
int ret = 0, index = 0;
struct option long_opts [] = {
{"help", 0, 0, 'h'},
{"stack", 0, 0, 's'},
{0, 0, 0, 0},
};

if (argc < 2) {
print_usage();
return 0;
}

while (ret != -1) {
ret = getopt_long(argc, argv, opts, long_opts, &index);
switch (ret) {
case 's':
set_huge_stack();
break;

case '?':
case 'h':
print_usage();
return 0;

case -1:
break;

default:
ret = -1;
break;
}
}
index = optind;

if (execvp(argv[index], &argv[index]) == -1) {
ret = errno;
fprintf(stderr, "Error calling execvp: '%s'\n", strerror(ret));
return ret;
}

return 0;
}

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 189 bytes --]