linux/kernel
KOSAKI Motohiro fa9dc265ac cpumask: fix compat getaffinity
Commit a45185d2d "cpumask: convert kernel/compat.c" broke libnuma, which
abuses sched_getaffinity to find out NR_CPUS in order to parse
/sys/devices/system/node/node*/cpumap.

On NUMA systems with less than 32 possibly CPUs, the current
compat_sys_sched_getaffinity now returns '4' instead of the actual
NR_CPUS/8, which makes libnuma bail out when parsing the cpumap.

The libnuma call sched_getaffinity(0, bitmap, 4096) at first.  It mean
the libnuma expect the return value of sched_getaffinity() is either len
argument or NR_CPUS.  But it doesn't expect to return nr_cpu_ids.

Strictly speaking, userland requirement are

1) Glibc assume the return value mean the lengh of initialized
   of mask argument. E.g. if sched_getaffinity(1024) return 128,
   glibc make zero fill rest 896 byte.
2) Libnuma assume the return value can be used to guess NR_CPUS
   in kernel. It assume len-arg<NR_CPUS makes -EINVAL. But
   it try len=4096 at first and 4096 is always bigger than
   NR_CPUS. Then, if we remove strange min_length normalization,
   we never hit -EINVAL case.

sched_getaffinity() already solved this issue.  This patch adapts
compat_sys_sched_getaffinity() to match the non-compat case.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ken Werner <ken.werner@web.de>
Cc: stable@kernel.org
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-19 11:48:18 -07:00
..
gcov
irq Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-04-06 13:03:22 -07:00
power PM / Hibernate: user.c, fix SNAPSHOT_SET_SWAP_AREA handling 2010-04-10 22:28:56 +02:00
time sched: Intoduce get_cpu_iowait_time_us() 2010-05-09 19:35:27 +02:00
trace Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:35:04 -07:00
.gitignore
acct.c bsdacct: use del_timer_sync() in acct_exit_ns() 2010-05-11 17:33:42 -07:00
async.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit_tree.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit_watch.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.h
auditfilter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
auditsc.c audit: preface audit printk with audit 2010-04-05 13:19:45 -07:00
backtracetest.c
bounds.c
capability.c sched: Remove remaining USER_SCHED code 2010-04-02 20:12:00 +02:00
cgroup_freezer.c rcu: Fix RCU lockdep splat on freezer_fork path 2010-04-30 12:03:17 +02:00
cgroup.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
compat.c cpumask: fix compat getaffinity 2010-05-19 11:48:18 -07:00
configs.c
cpu.c stop_machine: reimplement using cpu_stop 2010-05-06 18:49:20 +02:00
cpuset.c sched: Make select_fallback_rq() cpuset friendly 2010-04-02 20:12:03 +02:00
cred.c Merge commit 'v2.6.34-rc6' into sched/core 2010-05-07 11:27:54 +02:00
delayacct.c
dma.c
early_res.c x86: Do not free zero sized per cpu areas 2010-03-29 18:55:40 +02:00
elfcore.c elf coredump: add extended numbering support 2010-03-06 11:26:46 -08:00
exec_domain.c
exit.c Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
extable.c
fork.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:19:03 -07:00
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c
hung_task.c
hw_breakpoint.c hw_breakpoints: Fix percpu build failure 2010-05-04 08:39:36 +02:00
itimer.c
kallsyms.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kexec: fix OOPS in crash_kernel_shrink 2010-05-11 17:33:42 -07:00
kfifo.c
kgdb.c kgdb: Turn off tracing while in the debugger 2010-04-02 14:58:19 -05:00
kmod.c
kprobes.c kprobes: Move enable/disable_kprobe() out from debugfs code 2010-05-08 18:08:30 +02:00
ksysfs.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
kthread.c cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node 2010-03-24 16:31:21 -07:00
latencytop.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
lockdep_internals.h lockdep: No need to disable preemption in debug atomic ops 2010-05-04 05:38:16 +02:00
lockdep_proc.c lockstat: Make lockstat counting per cpu 2010-04-06 00:15:37 +02:00
lockdep_states.h
lockdep.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:19:03 -07:00
Makefile cpu_stop: add dummy implementation for UP 2010-05-08 17:12:33 +02:00
module.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
ns_cgroup.c
nsproxy.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
padata.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
panic.c panic: fix panic_timeout accuracy when running on a hypervisor 2010-03-06 11:26:33 -08:00
params.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
perf_event.c perf: Fix exit() vs event-groups 2010-05-11 17:08:24 +02:00
pid_namespace.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pid.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-13 14:43:01 -08:00
pm_qos_params.c
posix-cpu-timers.c Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-26 15:10:38 -07:00
posix-timers.c
printk.c printk: avoid warning when CONFIG_PRINTK is disabled 2010-03-06 11:26:33 -08:00
profile.c profile: fix stats and data leakage 2010-05-14 19:45:06 -07:00
ptrace.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:19:03 -07:00
range.c
rcupdate.c rcu: slim down rcutiny by removing rcu_scheduler_active and friends 2010-05-10 11:08:34 -07:00
rcutiny_plugin.h rcu: slim down rcutiny by removing rcu_scheduler_active and friends 2010-05-10 11:08:34 -07:00
rcutiny.c rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutorture.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
rcutree_plugin.h rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutree_trace.c rcu: reduce the number of spurious RCU_SOFTIRQ invocations 2010-05-10 11:08:35 -07:00
rcutree.c rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutree.h rcu: reduce the number of spurious RCU_SOFTIRQ invocations 2010-05-10 11:08:35 -07:00
relay.c splice: comparing unsigned int < 0 2010-03-06 11:26:32 -08:00
res_counter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
resource.c resources: add interfaces that return conflict information 2010-03-23 13:33:50 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c
sched_cpupri.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sched_cpupri.h
sched_debug.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
sched_fair.c sched: replace migration_thread with cpu_stop 2010-05-06 18:49:21 +02:00
sched_features.h sched: Remove ASYM_GRAN feature 2010-03-11 18:32:53 +01:00
sched_idletask.c sched: Cure load average vs NO_HZ woes 2010-04-23 11:02:02 +02:00
sched_rt.c sched: Add enqueue/dequeue flags 2010-04-02 20:12:05 +02:00
sched_stats.h
sched.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
seccomp.c
semaphore.c
signal.c kernel core: use helpers for rlimits 2010-03-06 11:26:33 -08:00
slow-work-debugfs.c
slow-work.c slow-work: use get_ref wrapper instead of directly calling get_ref 2010-03-29 09:13:30 -07:00
slow-work.h SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG 2010-03-29 09:14:47 -07:00
smp.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
softirq.c rcu: refactor RCU's context-switch handling 2010-05-10 11:08:33 -07:00
softlockup.c softlockup: Stop spurious softlockup messages due to overflow 2010-03-21 19:30:13 +01:00
spinlock.c
srcu.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
stacktrace.c
stop_machine.c stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback() 2010-05-18 00:17:44 +02:00
sys_ni.c Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
sys.c kernel/sys.c: fix compat uname machine 2010-04-24 11:31:24 -07:00
sysctl_binary.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sysctl_check.c
sysctl.c [S390] debug: enable exception-trace debug facility 2010-05-17 10:00:17 +02:00
taskstats.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
test_kprobes.c
time.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
timeconst.pl
timer.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tracepoint.c
tsacct.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c sched: Remove a stale comment 2010-05-10 08:48:39 +02:00
utsname_sysctl.c
utsname.c
wait.c
workqueue.c workqueue: flush_delayed_work: keep the original workqueue for re-queueing 2010-04-30 07:24:51 +02:00