Iulia Manda 2813893f8b kernel: conditionally support non-root users, groups and capabilities ... There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-04-15 16:35:22 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-04-15 09:00:47 -07:00
configs	x86: Add "make tinyconfig" to configure the tiniest possible kernel	2014-08-08 16:30:24 -07:00
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-04-15 09:00:47 -07:00
gcov	kbuild,gcov: simplify kernel/gcov/Makefile more	2015-01-09 17:25:44 +01:00
irq	irqchip core change for v4.1 (round 3)	2015-04-11 11:17:28 +02:00
livepatch	Merge branch 'for-4.1/core-noarch' into for-linus	2015-04-13 23:57:20 +02:00
locking	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-13 10:27:28 -07:00
power	Merge back earlier suspend/hibernate material for v4.1.	2015-04-10 12:01:59 +02:00
printk	Merge branch 'iocb' into for-next	2015-04-11 22:24:41 -04:00
rcu	Merge branches 'doc.2015.02.26a', 'earlycb.2015.03.03a', 'fixes.2015.03.03a', 'gpexp.2015.02.26a', 'hotplug.2015.03.20a', 'sysidle.2015.02.26b' and 'tiny.2015.02.26a' into HEAD	2015-03-20 08:31:01 -07:00
sched	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 13:58:48 -07:00
time	timers/PM: Drop unnecessary braces from tick_freeze()	2015-04-03 15:15:52 +02:00
trace	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 14:37:47 -07:00
.gitignore
acct.c	new fs_pin killing logics	2015-01-25 23:17:28 -05:00
async.c	kernel/async.c: switch to pr_foo()	2014-10-09 22:26:04 -04:00
audit_tree.c	fsnotify: unify inode and mount marks handling	2014-12-13 12:42:53 -08:00
audit_watch.c	audit: invalid op= values for rules	2014-09-23 16:37:53 -04:00
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-12-30 10:45:47 -08:00
audit.h	audit: replace getname()/putname() hacks with reference counters	2015-01-23 00:23:58 -05:00
auditfilter.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-02-11 20:07:47 -08:00
auditsc.c	Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-02-17 15:27:47 -08:00
backtracetest.c
bounds.c	page-cgroup: get rid of NR_PCG_FLAGS	2014-08-08 15:57:18 -07:00
capability.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
cgroup_freezer.c
cgroup.c	memcg: zap mem_cgroup_lookup()	2015-04-15 16:35:16 -07:00
compat.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
configs.c
context_tracking.c	context_tracking: Export context_tracking_user_enter/exit	2015-03-09 15:43:00 +01:00
cpu_pm.c
cpu.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 13:36:04 -07:00
cpuset.c	kernel, cpuset: remove exception for __GFP_THISNODE	2015-04-14 16:49:03 -07:00
crash_dump.c	crash_dump: Make is_kdump_kernel() accessible from modules	2014-08-25 15:42:19 -07:00
cred.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
delayacct.c	delayacct: Remove braindamaged type conversions	2014-07-23 10:18:06 -07:00
dma.c
elfcore.c
exec_domain.c
exit.c	oom, PM: make OOM detection in the freezer path raceless	2015-02-11 17:06:03 -08:00
extable.c	ftrace/x86/extable: Add is_ftrace_trampoline() function	2014-11-19 15:25:26 -05:00
fork.c	mm: do not use mm->nr_pmds on !MMU configurations	2015-02-12 18:54:10 -08:00
freezer.c	freezer: remove obsolete comments in __thaw_task()	2014-10-21 23:44:20 +02:00
futex_compat.c
futex.c	Linux 34.0-rc1	2015-02-24 08:41:07 +01:00
groups.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
hung_task.c
irq_work.c	percpu: Convert remaining __get_cpu_var uses in 3.18-rcX	2014-10-29 11:18:18 -04:00
jump_label.c
kallsyms.c	kernel/kallsyms.c: use __seq_open_private()	2014-10-14 02:18:16 +02:00
kcmp.c	kcmp: fix standard comparison bug	2014-09-10 15:42:12 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/mcs: Better differentiate between MCS variants	2015-01-14 15:07:32 +01:00
Kconfig.preempt
kexec.c	kexec: simplify conditional	2015-02-17 14:34:51 -08:00
kmod.c	usermodehelper: kill the kmod_thread_locker logic	2014-12-10 17:41:17 -08:00
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c	kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations")	2014-10-09 22:25:51 -04:00
latencytop.c
Makefile	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
module_signing.c
module-internal.h
module.c	Some clean ups and small fixes, but the biggest change is the addition	2015-04-14 10:49:03 -07:00
notifier.c	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
nsproxy.c	bury struct proc_ns in fs/proc	2014-12-04 14:34:54 -05:00
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
params.c	param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC	2015-01-20 11:38:31 +10:30
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: remove linux/compat.h inclusion under CONFIG_COMPAT	2015-02-17 14:34:51 -08:00
range.c	kernel: avoid overflow in cmp_range	2015-01-17 10:02:23 +13:00
reboot.c	kernel: add support for kernel restart handler call chain	2014-09-26 00:00:06 -07:00
relay.c
resource.c	resources: Move struct resource_list_entry from ACPI into resource core	2015-02-05 15:09:25 +01:00
seccomp.c	seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO	2015-02-17 14:34:55 -08:00
signal.c	signal: use current->state helpers	2015-02-17 14:34:51 -08:00
smp.c	Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2014-10-15 07:48:18 +02:00
smpboot.c	smpboot: Add common code for notification from dying CPU	2015-03-11 13:20:25 -07:00
smpboot.h
softirq.c	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-09 15:24:03 -08:00
stacktrace.c	stacktrace: introduce snprint_stack_trace for buffer output	2014-12-13 12:42:48 -08:00
stop_machine.c
sys_ni.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
sys.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
sysctl_binary.c	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
sysctl.c	mm: allow compaction of unevictable pages	2015-04-15 16:35:17 -07:00
system_certificates.S
system_keyring.c	KEYS: validate certificate trust only with builtin keys	2014-07-17 09:35:17 -04:00
task_work.c
taskstats.c	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
test_kprobes.c	kernel/test_kprobes.c: use current logging functions	2014-08-08 15:57:18 -07:00
torture.c	torture: Address race in module cleanup	2014-09-16 13:41:06 -07:00
tracepoint.c
tsacct.c	sched: Make task->start_time nanoseconds based	2014-07-23 10:18:05 -07:00
uid16.c	groups: Consolidate the setgroups permission checks	2014-12-05 17:19:27 -06:00
up.c
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
user-return-notifier.c	scheduler: Replace __get_cpu_var with this_cpu_ptr	2014-08-26 13:45:45 -04:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
utsname_sysctl.c
utsname.c	copy address of proc_ns_ops into ns_common	2014-12-04 14:34:47 -05:00
watchdog.c	Merge branch 'akpm' (patches from Andrew)	2015-04-14 16:49:17 -07:00
workqueue_internal.h
workqueue.c	workqueue: Reorder sysfs code	2015-04-06 11:16:04 -04:00