Alexey Dobriyan 81243eacfa cred: simpler, 1D supplementary groups ... Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-10-07 18:46:30 -07:00
..
bpf	bpf: allow access into map value arrays	2016-09-29 01:35:35 -04:00
configs	KVM updates for v4.9-rc1	2016-10-06 10:49:01 -07:00
debug	mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings	2016-02-22 08:51:37 +01:00
events	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2016-10-05 10:11:24 -07:00
gcov	gcov: add support for gcc version >= 6	2016-07-15 14:54:27 +09:00
irq	genirq: Make function __irq_do_set_handler() static	2016-09-25 16:46:52 -04:00
livepatch	livepatch/module: make TAINT_LIVEPATCH module-specific	2016-08-26 14:42:08 +02:00
locking	locking/lglock: Remove lglock implementation	2016-09-22 15:25:56 +02:00
power	oom, suspend: fix oom_killer_disable vs. pm suspend properly	2016-10-07 18:46:27 -07:00
printk	printk/nmi: avoid direct printk()-s from __printk_nmi_flush()	2016-09-01 17:52:01 -07:00
rcu	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 12:15:00 -07:00
sched	nmi_backtrace: generate one-line reports for idle cpus	2016-10-07 18:46:30 -07:00
time	tick/nohz: Prevent stopping the tick on an offline CPU	2016-09-13 17:53:52 +02:00
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2016-10-07 12:24:08 -07:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	userns: Add per user namespace sysctls.	2016-08-08 13:18:58 -05:00
acct.c	…
async.c	async: export current_is_async()	2015-11-19 17:51:48 +01:00
audit.c	Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit	2016-10-04 14:21:41 -07:00
audit.h	Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit	2016-07-29 17:54:17 -07:00
audit_fsnotify.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
audit_tree.c	audit: cleanup prune_tree_thread	2016-04-04 09:46:47 -04:00
audit_watch.c	Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit	2016-09-01 15:55:56 -07:00
auditfilter.c	audit: add fields to exclude filter by reusing user filter	2016-06-27 11:01:00 -04:00
auditsc.c	Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit	2016-10-04 14:21:41 -07:00
backtracetest.c	…
bounds.c	…
capability.c	kernel: Add noaudit variant of ns_capable()	2016-06-06 20:16:18 +10:00
cgroup.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2016-10-06 09:52:23 -07:00
cgroup_freezer.c	cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends	2015-12-03 10:24:08 -05:00
cgroup_pids.c	cgroup: Use lld instead of ld when printing pids controller events_limit	2016-06-21 15:03:36 -04:00
compat.c	…
configs.c	…
context_tracking.c	context_tracking: Switch to new static_branch API	2015-11-24 09:56:43 +01:00
cpu.c	Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 19:43:08 -07:00
cpu_pm.c	…
cpuset.c	cpuset: fix non static symbol warning	2016-09-16 11:31:17 -04:00
crash_dump.c	…
cred.c	cred: Reject inodes with invalid ids in set_create_file_as()	2016-06-30 18:05:09 -05:00
delayacct.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	mm, oom: enforce exit_oom_victim on current task	2016-10-07 18:46:28 -07:00
extable.c	…
fork.c	thp: reduce usage of huge zero page's atomic counter	2016-10-07 18:46:28 -07:00
freezer.c	freezer, oom: check TIF_MEMDIE on the correct task	2016-07-28 16:07:41 -07:00
futex.c	futex: Add some more function commentry	2016-09-05 17:20:18 +02:00
futex_compat.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
groups.c	cred: simpler, 1D supplementary groups	2016-10-07 18:46:30 -07:00
hung_task.c	locking/hung_task: Show all locks	2016-08-24 12:16:13 +02:00
irq_work.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
jump_label.c	powerpc updates for 4.8 #2	2016-08-05 09:00:54 -04:00
kallsyms.c	kallsyms: add support for relative offsets in kallsyms address table	2016-03-15 16:55:16 -07:00
kcmp.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
kcov.c	kernel/kcov: unproxify debugfs file's fops	2016-06-15 04:56:35 -07:00
kexec.c	kexec: allow architectures to override boot mapping	2016-08-02 19:35:27 -04:00
kexec_core.c	kexec: add restriction on kexec_load() segment sizes	2016-08-02 19:35:31 -04:00
kexec_file.c	kexec: fix double-free when failing to relocate the purgatory	2016-09-01 17:52:01 -07:00
kexec_internal.h	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kmod.c	…
kprobes.c	…
ksysfs.c	kexec: add a kexec_crash_loaded() function	2016-08-02 19:35:30 -04:00
kthread.c	kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function	2016-09-16 09:18:53 +02:00
latencytop.c	sched/debug: Make schedstats a runtime tunable that is disabled by default	2016-02-09 11:54:23 +01:00
membarrier.c	…
memremap.c	mm: fix cache mode of dax pmd mappings	2016-09-09 17:34:46 -07:00
module-internal.h	…
module.c	livepatch/module: make TAINT_LIVEPATCH module-specific	2016-08-26 14:42:08 +02:00
module_signing.c	KEYS: Move the point of trust determination to __key_link()	2016-04-11 22:43:43 +01:00
notifier.c	…
nsproxy.c	cgroup: introduce cgroup namespaces	2016-02-16 13:04:58 -05:00
padata.c	padata: Convert to hotplug state machine	2016-09-19 21:44:30 +02:00
panic.c	kexec: use core_param for crash_kexec_post_notifiers boot option	2016-08-02 19:35:29 -04:00
params.c	Nothing exciting, minor tweaks and cleanups.	2015-11-09 15:53:39 -08:00
pid.c	remove lots of IS_ERR_VALUE abuses	2016-05-27 15:26:11 -07:00
pid_namespace.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
profile.c	profile: Convert to hotplug state machine	2016-07-15 10:41:42 +02:00
ptrace.c	tree-wide: replace config_enabled() with IS_ENABLED()	2016-08-04 08:50:07 -04:00
range.c	…
reboot.c	…
relay.c	relayfs: Convert to hotplug state machine	2016-09-06 18:30:20 +02:00
resource.c	/proc/iomem: only expose physical resource addresses to privileged users	2016-04-14 12:56:09 -07:00
seccomp.c	seccomp: Fix tracer exit notifications during fatal signals	2016-08-30 16:12:46 -07:00
signal.c	x86/signal: Add SA_{X32,IA32}_ABI sa_flags	2016-09-14 21:28:11 +02:00
smp.c	smp: Allocate smp_call_on_cpu() workqueue on stack too	2016-09-22 14:49:10 +02:00
smpboot.c	sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn()	2016-09-22 12:28:00 +02:00
smpboot.h	cpu/hotplug: Create hotplug threads	2016-03-01 20:36:56 +01:00
softirq.c	Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 19:43:08 -07:00
stacktrace.c	…
stop_machine.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 13:39:00 -07:00
sys.c	prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable	2016-05-23 17:04:14 -07:00
sys_ni.c	vfs: add copy_file_range syscall and vfs helper	2015-12-01 14:00:53 -05:00
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2016-10-06 09:52:23 -07:00
sysctl_binary.c	kernel/sysctl_binary.c: use generic UUID library	2016-05-20 17:58:30 -07:00
task_work.c	task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works	2016-08-02 19:35:02 -04:00
taskstats.c	taskstats: use the libnl API to align nlattr on 64-bit	2016-04-23 20:13:25 -04:00
test_kprobes.c	…
torture.c	torture: Convert torture_shutdown() to hrtimer	2016-08-22 10:01:49 -07:00
tracepoint.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
tsacct.c	time, acct: Drop irq save & restore from __acct_update_integrals()	2016-02-29 09:53:09 +01:00
ucount.c	mntns: Add a limit on the number of mount namespaces.	2016-08-31 07:28:35 -05:00
uid16.c	cred: simpler, 1D supplementary groups	2016-10-07 18:46:30 -07:00
up.c	smp: Add function to execute a function synchronously on a CPU	2016-09-05 13:52:39 +02:00
user-return-notifier.c	…
user.c	…
user_namespace.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
utsname.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
utsname_sysctl.c	…
watchdog.c	Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86"	2016-07-10 20:58:36 +02:00
workqueue.c	Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-07-29 13:55:30 -07:00
workqueue_internal.h	sched/core: Get rid of 'cpu' argument in wq_worker_sleeping()	2016-03-02 10:28:47 -05:00