setarch: add support for '-R' (disable randomization)

This commit adds support for the -R flag of setarch, which disables
randomization of the virtual address space.

function                                             old     new   delta
setarch_main                                         115     150     +35
packed_usage                                       30664   30651     -13

Signed-off-by: Jan Heylen <heyleke@gmail.com>
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/include/applets.src.h b/include/applets.src.h
index 5b597202e6a5e28dc333075b030ff13329b5e914..6e1b02fc399c6e9deb868fe2a6dd76ed91a8306d 100644 (file)
--- a/include/applets.src.h
+++ b/include/applets.src.h
@@ -192,8 +192,6 @@ IF_KILLALL5(APPLET_ODDNAME(killall5, kill, BB_DIR_USR_SBIN, BB_SUID_DROP, killal
 IF_LAST(APPLET(last, BB_DIR_USR_BIN, BB_SUID_DROP))
 //IF_LENGTH(APPLET_NOFORK(length, length, BB_DIR_USR_BIN, BB_SUID_DROP, length))
 IF_LESS(APPLET(less, BB_DIR_USR_BIN, BB_SUID_DROP))
-IF_SETARCH(APPLET_ODDNAME(linux32, setarch, BB_DIR_BIN, BB_SUID_DROP, linux32))
-IF_SETARCH(APPLET_ODDNAME(linux64, setarch, BB_DIR_BIN, BB_SUID_DROP, linux64))
 IF_LN(APPLET_NOEXEC(ln, ln, BB_DIR_BIN, BB_SUID_DROP, ln))
 IF_LOAD_POLICY(APPLET(load_policy, BB_DIR_USR_SBIN, BB_SUID_DROP))
 IF_LOADFONT(APPLET(loadfont, BB_DIR_USR_SBIN, BB_SUID_DROP))
@@ -274,7 +272,6 @@ IF_SELINUXENABLED(APPLET(selinuxenabled, BB_DIR_USR_SBIN, BB_SUID_DROP))
 IF_SENDMAIL(APPLET(sendmail, BB_DIR_USR_SBIN, BB_SUID_DROP))
 IF_SEQ(APPLET_NOFORK(seq, seq, BB_DIR_USR_BIN, BB_SUID_DROP, seq))
 IF_SESTATUS(APPLET(sestatus, BB_DIR_USR_SBIN, BB_SUID_DROP))
-IF_SETARCH(APPLET(setarch, BB_DIR_BIN, BB_SUID_DROP))
 IF_SETCONSOLE(APPLET(setconsole, BB_DIR_SBIN, BB_SUID_DROP))
 IF_SETENFORCE(APPLET(setenforce, BB_DIR_USR_SBIN, BB_SUID_DROP))
 IF_SETFILES(APPLET(setfiles, BB_DIR_SBIN, BB_SUID_DROP))

diff --git a/util-linux/Config.src b/util-linux/Config.src
index 854b3682e0f757a849c5179a7bb84090524c22d8..922cabdb83dc05bd3115fc60eb148d317cedca97 100644 (file)
--- a/util-linux/Config.src
+++ b/util-linux/Config.src
@@ -489,16 +489,6 @@ config SCRIPTREPLAY
          This program replays a typescript, using timing information
          given by script -t.
 
-config SETARCH
-       bool "setarch"
-       default y
-       select PLATFORM_LINUX
-       help
-         The linux32 utility is used to create a 32bit environment for the
-         specified program (usually a shell). It only makes sense to have
-         this util on a system that supports both 64bit and 32bit userland
-         (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...).
-
 config SWAPONOFF
        bool "swaponoff"
        default y

diff --git a/util-linux/Kbuild.src b/util-linux/Kbuild.src
index 468fc6bc12f8a7339b9712d2f8b6a151d8dbe6e6..0b87c52aca5b59e6dba97178c31d1176ea755141 100644 (file)
--- a/util-linux/Kbuild.src
+++ b/util-linux/Kbuild.src
@@ -40,7 +40,6 @@ lib-$(CONFIG_READPROFILE)       += readprofile.o
 lib-$(CONFIG_RTCWAKE)           += rtcwake.o
 lib-$(CONFIG_SCRIPT)            += script.o
 lib-$(CONFIG_SCRIPTREPLAY)      += scriptreplay.o
-lib-$(CONFIG_SETARCH)           += setarch.o
 lib-$(CONFIG_SWAPONOFF)         += swaponoff.o
 lib-$(CONFIG_SWITCH_ROOT)       += switch_root.o
 lib-$(CONFIG_UMOUNT)            += umount.o

diff --git a/util-linux/setarch.c b/util-linux/setarch.c
index 7b9421af1eefb54debe2affbb4b5fdeb9a2cbdc1..2e989ec2af82ef5ca0e017461387faf493fb02cb 100644 (file)
--- a/util-linux/setarch.c
+++ b/util-linux/setarch.c
@@ -6,13 +6,30 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
+//config:config SETARCH
+//config:      bool "setarch"
+//config:      default y
+//config:      select PLATFORM_LINUX
+//config:      help
+//config:        The linux32 utility is used to create a 32bit environment for the
+//config:        specified program (usually a shell). It only makes sense to have
+//config:        this util on a system that supports both 64bit and 32bit userland
+//config:        (like amd64/x86, ppc64/ppc, sparc64/sparc, etc...).
+
+//applet:IF_SETARCH(APPLET(setarch, BB_DIR_BIN, BB_SUID_DROP))
+//applet:IF_SETARCH(APPLET_ODDNAME(linux32, setarch, BB_DIR_BIN, BB_SUID_DROP, linux32))
+//applet:IF_SETARCH(APPLET_ODDNAME(linux64, setarch, BB_DIR_BIN, BB_SUID_DROP, linux64))
+
+//kbuild:lib-$(CONFIG_SETARCH) += setarch.o
 
 //usage:#define setarch_trivial_usage
-//usage:       "personality PROG ARGS"
+//usage:       "PERSONALITY [-R] PROG ARGS"
 //usage:#define setarch_full_usage "\n\n"
-//usage:       "Personality may be:\n"
-//usage:       "       linux32         Set 32bit uname emulation\n"
-//usage:       "       linux64         Set 64bit uname emulation"
+//usage:       "PERSONALITY may be:"
+//usage:   "\n""       linux32 Set 32bit uname emulation"
+//usage:   "\n""       linux64 Set 64bit uname emulation"
+//usage:   "\n"
+//usage:   "\n""       -R      Disable address space randomization"
 //usage:
 //usage:#define linux32_trivial_usage NOUSAGE_STR
 //usage:#define linux32_full_usage ""
@@ -20,14 +37,18 @@
 //usage:#define linux64_trivial_usage NOUSAGE_STR
 //usage:#define linux64_full_usage ""
 
+#include "libbb.h"
 #include <sys/personality.h>
 
-#include "libbb.h"
+#ifndef ADDR_NO_RANDOMIZE
+# define ADDR_NO_RANDOMIZE       0x0040000
+#endif
 
 int setarch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int setarch_main(int argc UNUSED_PARAM, char **argv)
 {
-       int pers;
+       unsigned opts;
+       unsigned long pers;
 
        /* Figure out what personality we are supposed to switch to ...
         * we can be invoked as either:
@@ -35,7 +56,7 @@ int setarch_main(int argc UNUSED_PARAM, char **argv)
         * argv[0]         == "personality"
         */
        if (ENABLE_SETARCH && applet_name[0] == 's'
-        && argv[1] && strncpy(argv[1], "linux", 5)
+        && argv[1] && is_prefixed_with(argv[1], "linux")
        ) {
                applet_name = argv[1];
                argv++;
@@ -47,15 +68,18 @@ int setarch_main(int argc UNUSED_PARAM, char **argv)
        else
                bb_show_usage();
 
-       argv++;
-       if (argv[0] == NULL)
-               bb_show_usage();
+       opts = getopt32(argv, "+R"); /* '+': stop at first non-option */
+       if (opts)
+               pers |= ADDR_NO_RANDOMIZE;
 
        /* Try to set personality */
-       if (personality(pers) >= 0) {
-               /* Try to execute the program */
-               BB_EXECVP(argv[0], argv);
-       }
+       if (personality(pers) < 0)
+               bb_perror_msg_and_die("personality(0x%lx)", pers);
+
+       argv += optind;
+       if (!argv[0])
+               (--argv)[0] = (char*)"/bin/sh";
 
-       bb_simple_perror_msg_and_die(argv[0]);
+       /* Try to execute the program */
+       BB_EXECVP_or_die(argv);
 }