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2009-05-08sched: account system time properlyEric Dumazet
commit f5f293a4e3d0a0c52cec31de6762c95050156516 upstream. Andrew Gallatin reported that IRQ and SOFTIRQ times were sometime not reported correctly on recent kernels, and even bisected to commit 457533a7d3402d1d91fbc125c8bd1bd16dcd3cd4 ([PATCH] fix scaled & unscaled cputime accounting) as the first bad commit. Further analysis pointed that commit 79741dd35713ff4f6fd0eafd59fa94e8a4ba922d ([PATCH] idle cputime accounting) was the real cause of the problem. account_process_tick() was not taking into account timer IRQ interrupting the idle task servicing a hard or soft irq. On mostly idle cpu, irqs were thus not accounted and top or mpstat could tell user/admin that cpu was 100 % idle, 0.00 % irq, 0.00 % softirq, while it was not. [ Impact: fix occasionally incorrect CPU statistics in top/mpstat ] Reported-by: Andrew Gallatin <gallatin@myri.com> Re-reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: rick.jones2@hp.com Cc: brice@myri.com Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <49F84BC1.7080602@cosmosbay.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08clockevents: prevent endless loop in tick_handle_periodic()john stultz
commit 74a03b69d1b5ce00a568e142ca97e76b7f5239c6 upstream. tick_handle_periodic() can lock up hard when a one shot clock event device is used in combination with jiffies clocksource. Avoid an endless loop issue by requiring that a highres valid clocksource be installed before we call tick_periodic() in a loop when using ONESHOT mode. The result is we will only increment jiffies once per interrupt until a continuous hardware clocksource is available. Without this, we can run into a endless loop, where each cycle through the loop, jiffies is updated which increments time by tick_period or more (due to clock steering), which can cause the event programming to think the next event was before the newly incremented time and fail causing tick_periodic() to be called again and the whole process loops forever. [ Impact: prevent hard lock up ] Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08New locking/refcounting for fs_structAl Viro
commit 498052bba55ecaff58db6a1436b0e25bfd75a7ff upstream. * all changes of current->fs are done under task_lock and write_lock of old fs->lock * refcount is not atomic anymore (same protection) * its decrements are done when removing reference from current; at the same time we decide whether to free it. * put_fs_struct() is gone * new field - ->in_exec. Set by check_unsafe_exec() if we are trying to do execve() and only subthreads share fs_struct. Cleared when finishing exec (success and failure alike). Makes CLONE_FS fail with -EAGAIN if set. * check_unsafe_exec() may fail with -EAGAIN if another execve() from subthread is in progress. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08Take fs_struct handling to new file (fs/fs_struct.c)Al Viro
commit 3e93cd671813e204c258f1e6c797959920cf7772 upstream. Pure code move; two new helper functions for nfsd and daemonize (unshare_fs_struct() and daemonize_fs_struct() resp.; for now - the same code as used to be in callers). unshare_fs_struct() exported (for nfsd, as copy_fs_struct()/exit_fs() used to be), copy_fs_struct() and exit_fs() don't need exports anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08Kill unsharing fs_struct in __set_personality()Al Viro
commit 11d06b2a1e5658f448a308aa3beb97bacd64a940 upstream. That's a rudiment of altroot support. I.e. it should've been buried a long time ago. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08ptrace: ptrace_attach: fix the usage of ->cred_exec_mutexOleg Nesterov
commit cad81bc2529ab8c62b6fdc83a1c0c7f4a87209eb upstream. ptrace_attach() needs task->cred_exec_mutex, not current->cred_exec_mutex. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08exit_notify: kill the wrong capable(CAP_KILL) check (CVE-2009-1337)Oleg Nesterov
CVE-2009-1337 commit 432870dab85a2f69dc417022646cb9a70acf7f94 upstream. The CAP_KILL check in exit_notify() looks just wrong, kill it. Whatever logic we have to reset ->exit_signal, the malicious user can bypass it if it execs the setuid application before exiting. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-27hrtimer: fix rq->lock inversion (again)Peter Zijlstra
upstream commit: 7f1e2ca9f04b02794597f60e7b1d43f0a1317939 It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27posix-timers: fix RLIMIT_CPU && setitimer(CPUCLOCK_PROF)Oleg Nesterov
upstream commit: 8f2e586567b1bad72dac7c3810fe9a2ef7117506 update_rlimit_cpu() tries to optimize out set_process_cpu_timer() in case when we already have CPUCLOCK_PROF timer which should expire first. But it uses cputime_lt() instead of cputime_gt(). Test case: int main(void) { struct itimerval it = { .it_value = { .tv_sec = 1000 }, }; assert(!setitimer(ITIMER_PROF, &it, NULL)); struct rlimit rl = { .rlim_cur = 1, .rlim_max = 1, }; assert(!setrlimit(RLIMIT_CPU, &rl)); for (;;) ; return 0; } Without this patch, the task is not killed as RLIMIT_CPU demands. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Peter Lojkin <ia6432@inbox.ru> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org LKML-Reference: <20090327000610.GA10108@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27posix-timers: fix RLIMIT_CPU && fork()Oleg Nesterov
upstream commit: 6279a751fe096a21dc7704e918d570d3ff06e769 See http://bugzilla.kernel.org/show_bug.cgi?id=12911 copy_signal() copies signal->rlim, but RLIMIT_CPU is "lost". Because posix_cpu_timers_init_group() sets cputime_expires.prof_exp = 0 and thus fastpath_timer_check() returns false unless we have other expired cpu timers. Change copy_signal() to set cputime_expires.prof_exp if we have RLIMIT_CPU. Also, set cputimer.running = 1 in that case. This is not strictly necessary, but imho makes sense. Reported-by: Peter Lojkin <ia6432@inbox.ru> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Peter Lojkin <ia6432@inbox.ru> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org LKML-Reference: <20090327000607.GA10104@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27posixtimers, sched: Fix posix clock monotonicityHidetoshi Seto
upstream commit: c5f8d99585d7b5b7e857fabf8aefd0174903a98c Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27kprobes: Fix locking imbalance in kretprobesAnanth N Mavinakayanahalli
upstream commit: f02b8624fedca39886b0eef770dca70c2f0749b3 Fix locking imbalance in kretprobes: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- kthreadd/2 is trying to release lock (&rp->lock) at: [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 but there are no more locks to release! other info that might help us debug this: 1 lock held by kthreadd/2: #0: (rcu_read_lock){..--}, at: [<c06b2b24>] __atomic_notifier_call_chain+0x0/0x5a stack backtrace: Pid: 2, comm: kthreadd Not tainted 2.6.29-rc8 #1 Call Trace: [<c06ae498>] ? printk+0xf/0x17 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044ce6c>] print_unlock_inbalance_bug+0xc3/0xce [<c0444d4b>] ? clocksource_read+0x7/0xa [<c04450a4>] ? getnstimeofday+0x5f/0xf6 [<c044a9ca>] ? register_lock_class+0x17/0x293 [<c044b72c>] ? mark_lock+0x1e/0x30b [<c0448956>] ? tick_dev_program_event+0x4a/0xbc [<c0498100>] ? __slab_alloc+0xa5/0x415 [<c06b2fbe>] ? pre_handler_kretprobe+0x28/0xf4 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044cf1b>] lock_release_non_nested+0xa4/0x1a5 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044d15d>] lock_release+0x141/0x166 [<c06b07dd>] _spin_unlock_irqrestore+0x19/0x50 [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 [<c06b20b5>] kprobe_exceptions_notify+0x1c9/0x43e [<c06b2b02>] notifier_call_chain+0x26/0x48 [<c06b2b5b>] __atomic_notifier_call_chain+0x37/0x5a [<c06b2b24>] ? __atomic_notifier_call_chain+0x0/0x5a [<c06b2b8a>] atomic_notifier_call_chain+0xc/0xe [<c0442d0d>] notify_die+0x2d/0x2f [<c06b0f9c>] do_int3+0x1f/0x71 [<c06b0e84>] int3+0x2c/0x34 [<c042d476>] ? do_fork+0x1/0x288 [<c040221b>] ? kernel_thread+0x71/0x79 [<c043ed1b>] ? kthread+0x0/0x60 [<c043ed1b>] ? kthread+0x0/0x60 [<c04040b8>] ? kernel_thread_helper+0x0/0x10 [<c043ec7f>] kthreadd+0xac/0x148 [<c043ebd3>] ? kthreadd+0x0/0x148 [<c04040bf>] kernel_thread_helper+0x7/0x10 Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> [2.6.29.x, 2.6.28.x, 2.6.27.x] LKML-Reference: <20090318113621.GB4129@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27sysctl: fix suid_dumpable and lease-break-time sysctlsMatthew Wilcox
upstream commit: 8e654fba4a376f436bdfe361fc5cdbc87ac09b35 Arne de Bruijn points out that commit 76fdbb25f963de5dc1e308325f0578a2f92b1c2d ("coredump masking: bound suid_dumpable sysctl") mistakenly limits lease-break-time instead of suid_dumpable. Signed-off-by: Matthew Wilcox <matthew@wil.cx> Reported-by: Arne de Bruijn <kernelbt@arbruijn.dds.nl> Cc: Kawai, Hidehiro <hidehiro.kawai.ez@hitachi.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-04-27tracing/core: fix early free of cpumasksFrederic Weisbecker
upstream commit: 2fc1dfbe17e7705c55b7a99da995fa565e26f151 Impact: fix crashes when tracing cpumasks While ring-buffer allocation, the cpumasks are allocated too, including the tracing cpumask and the per-cpu file mask handler. But these cpumasks are freed accidentally just after. Fix it. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1237164303-11476-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2009-03-23fix ptrace slownessMiklos Szeredi
This patch fixes bug #12208: Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12208 Subject : uml is very slow on 2.6.28 host This turned out to be not a scheduler regression, but an already existing problem in ptrace being triggered by subtle scheduler changes. The problem is this: - task A is ptracing task B - task B stops on a trace event - task A is woken up and preempts task B - task A calls ptrace on task B, which does ptrace_check_attach() - this calls wait_task_inactive(), which sees that task B is still on the runq - task A goes to sleep for a jiffy - ... Since UML does lots of the above sequences, those jiffies quickly add up to make it slow as hell. This patch solves this by not rescheduling in read_unlock() after ptrace_stop() has woken up the tracer. Thanks to Oleg Nesterov and Ingo Molnar for the feedback. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-18module: fix refptr allocation and release orderMasami Hiramatsu
Impact: fix ref-after-free crash on failed module load Fix refptr bug: Change refptr allocation and release order not to access a module data structure pointed by 'mod' after freeing mod->module_core. This bug will cause kernel panic(e.g. failed to find undefined symbols). This bug was reported on systemtap bugzilla. http://sources.redhat.com/bugzilla/show_bug.cgi?id=9927 Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-10kernel/user.c: fix a memory leak when freeing up non-init usernamespaces usersDhaval Giani
We were returning early in the sysfs directory cleanup function if the user belonged to a non init usernamespace. Due to this a lot of the cleanup was not done and we were left with a leak. Fix the leak. Reported-by: Serge Hallyn <serue@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-09copy_process: fix CLONE_PARENT && parent_exec_id interactionOleg Nesterov
CLONE_PARENT can fool the ->self_exec_id/parent_exec_id logic. If we re-use the old parent, we must also re-use ->parent_exec_id to make sure exit_notify() sees the right ->xxx_exec_id's when the CLONE_PARENT'ed task exits. Also, move down the "p->parent_exec_id = p->self_exec_id" thing, to place two different cases together. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Howells <dhowells@redhat.com> Cc: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-09Fix fixpoint divide exception in acct_update_integralsHeiko Carstens
Frans Pop reported the crash below when running an s390 kernel under Hercules: Kernel BUG at 000738b4 verbose debug info unavailable! fixpoint divide exception: 0009 #1! SMP Modules linked in: nfs lockd nfs_acl sunrpc ctcm fsm tape_34xx cu3088 tape ccwgroup tape_class ext3 jbd mbcache dm_mirror dm_log dm_snapshot dm_mod dasd_eckd_mod dasd_mod CPU: 0 Not tainted 2.6.27.19 #13 Process awk (pid: 2069, task: 0f9ed9b8, ksp: 0f4f7d18) Krnl PSW : 070c1000 800738b4 (acct_update_integrals+0x4c/0x118) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 Krnl GPRS: 00000000 000007d0 7fffffff fffff830 00000000 ffffffff 00000002 0f9ed9b8 00000000 00008ca0 00000000 0f9ed9b8 0f9edda4 8007386e 0f4f7ec8 0f4f7e98 Krnl Code: 800738aa: a71807d0 lhi %r1,2000 800738ae: 8c200001 srdl %r2,1 800738b2: 1d21 dr %r2,%r1 >800738b4: 5810d10e l %r1,270(%r13) 800738b8: 1823 lr %r2,%r3 800738ba: 4130f060 la %r3,96(%r15) 800738be: 0de1 basr %r14,%r1 800738c0: 5800f060 l %r0,96(%r15) Call Trace: ( <000000000004fdea>! blocking_notifier_call_chain+0x1e/0x2c) <0000000000038502>! do_exit+0x106/0x7c0 <0000000000038c36>! do_group_exit+0x7a/0xb4 <0000000000038c8e>! SyS_exit_group+0x1e/0x30 <0000000000021c28>! sysc_do_restart+0x12/0x16 <0000000077e7e924>! 0x77e7e924 Reason for this is that cpu time accounting usually only happens from interrupt context, but acct_update_integrals gets also called from process context with interrupts enabled. So in acct_update_integrals we may end up with the following scenario: Between reading tsk->stime/tsk->utime and tsk->acct_timexpd an interrupt happens which updates accouting values. This causes acct_timexpd to be greater than the former stime + utime. The subsequent calculation of dtime = cputime_sub(time, tsk->acct_timexpd); will be negative and the division performed by cputime_to_jiffies(dtime) will generate an exception since the result won't fit into a 32 bit register. In order to fix this just always disable interrupts while accessing any of the accounting values. Reported by: Frans Pop <elendil@planet.nl> Tested by: Frans Pop <elendil@planet.nl> Cc: stable@kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-04rcu: increment quiescent state counter in ksoftirqd()Eric Dumazet
If a machine is flooded by network frames, a cpu can loop 100% of its time inside ksoftirqd() without calling schedule(). This can delay RCU grace period to insane values. Adding rcu_qsctr_inc() call in ksoftirqd() solves this problem. Paul: "This regression was a result of the recent change from "schedule()" to "cond_resched()", which got rid of that quiescent state in the common case where a reschedule is not needed". Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-03Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: don't allow setuid to succeed if the user does not have rt bandwidth sched_rt: don't start timer when rt bandwidth disabled
2009-03-03Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Teach RCU that idle task is not quiscent state at boot
2009-03-02x86-64: seccomp: fix 32/64 syscall holeRoland McGrath
On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with ljmp, and then use the "syscall" instruction to make a 64-bit system call. A 64-bit process make a 32-bit system call with int $0x80. In both these cases under CONFIG_SECCOMP=y, secure_computing() will use the wrong system call number table. The fix is simple: test TS_COMPAT instead of TIF_IA32. Here is an example exploit: /* test case for seccomp circumvention on x86-64 There are two failure modes: compile with -m64 or compile with -m32. The -m64 case is the worst one, because it does "chmod 777 ." (could be any chmod call). The -m32 case demonstrates it was able to do stat(), which can glean information but not harm anything directly. A buggy kernel will let the test do something, print, and exit 1; a fixed kernel will make it exit with SIGKILL before it does anything. */ #define _GNU_SOURCE #include <assert.h> #include <inttypes.h> #include <stdio.h> #include <linux/prctl.h> #include <sys/stat.h> #include <unistd.h> #include <asm/unistd.h> int main (int argc, char **argv) { char buf[100]; static const char dot[] = "."; long ret; unsigned st[24]; if (prctl (PR_SET_SECCOMP, 1, 0, 0, 0) != 0) perror ("prctl(PR_SET_SECCOMP) -- not compiled into kernel?"); #ifdef __x86_64__ assert ((uintptr_t) dot < (1UL << 32)); asm ("int $0x80 # %0 <- %1(%2 %3)" : "=a" (ret) : "0" (15), "b" (dot), "c" (0777)); ret = snprintf (buf, sizeof buf, "result %ld (check mode on .!)\n", ret); #elif defined __i386__ asm (".code32\n" "pushl %%cs\n" "pushl $2f\n" "ljmpl $0x33, $1f\n" ".code64\n" "1: syscall # %0 <- %1(%2 %3)\n" "lretl\n" ".code32\n" "2:" : "=a" (ret) : "0" (4), "D" (dot), "S" (&st)); if (ret == 0) ret = snprintf (buf, sizeof buf, "stat . -> st_uid=%u\n", st[7]); else ret = snprintf (buf, sizeof buf, "result %ld\n", ret); #else # error "not this one" #endif write (1, buf, ret); syscall (__NR_exit, 1); return 2; } Signed-off-by: Roland McGrath <roland@redhat.com> [ I don't know if anybody actually uses seccomp, but it's enabled in at least both Fedora and SuSE kernels, so maybe somebody is. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-27Fix recursive lock in free_uid()/free_user_ns()David Howells
free_uid() and free_user_ns() are corecursive when CONFIG_USER_SCHED=n, but free_user_ns() is called from free_uid() by way of uid_hash_remove(), which requires uidhash_lock to be held. free_user_ns() then calls free_uid() to complete the destruction. Fix this by deferring the destruction of the user_namespace. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-27sched: don't allow setuid to succeed if the user does not have rt bandwidthDhaval Giani
Impact: fix hung task with certain (non-default) rt-limit settings Corey Hickey reported that on using setuid to change the uid of a rt process, the process would be unkillable and not be running. This is because there was no rt runtime for that user group. Add in a check to see if a user can attach an rt task to its task group. On failure, return EINVAL, which is also returned in CONFIG_CGROUP_SCHED. Reported-by: Corey Hickey <bugfood-ml@fatooh.org> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26sched_rt: don't start timer when rt bandwidth disabledHiroshi Shimamoto
Impact: fix incorrect condition check No need to start rt bandwidth timer when rt bandwidth is disabled. If this timer starts, it may stop at sched_rt_period_timer() on the first time. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26rcu: Teach RCU that idle task is not quiscent state at bootPaul E. McKenney
This patch fixes a bug located by Vegard Nossum with the aid of kmemcheck, updated based on review comments from Nick Piggin, Ingo Molnar, and Andrew Morton. And cleans up the variable-name and function-name language. ;-) The boot CPU runs in the context of its idle thread during boot-up. During this time, idle_cpu(0) will always return nonzero, which will fool Classic and Hierarchical RCU into deciding that a large chunk of the boot-up sequence is a big long quiescent state. This in turn causes RCU to prematurely end grace periods during this time. This patch changes the rcutree.c and rcuclassic.c rcu_check_callbacks() function to ignore the idle task as a quiescent state until the system has started up the scheduler in rest_init(), introducing a new non-API function rcu_idle_now_means_idle() to inform RCU of this transition. RCU maintains an internal rcu_idle_cpu_truthful variable to track this state, which is then used by rcu_check_callback() to determine if it should believe idle_cpu(). Because this patch has the effect of disallowing RCU grace periods during long stretches of the boot-up sequence, this patch also introduces Josh Triplett's UP-only optimization that makes synchronize_rcu() be a no-op if num_online_cpus() returns 1. This allows boot-time code that calls synchronize_rcu() to proceed normally. Note, however, that RCU callbacks registered by call_rcu() will likely queue up until later in the boot sequence. Although rcuclassic and rcutree can also use this same optimization after boot completes, rcupreempt must restrict its use of this optimization to the portion of the boot sequence before the scheduler starts up, given that an rcupreempt RCU read-side critical section may be preeempted. In addition, this patch takes Nick Piggin's suggestion to make the system_state global variable be __read_mostly. Changes since v4: o Changes the name of the introduced function and variable to be less emotional. ;-) Changes since v3: o WARN_ON(nr_context_switches() > 0) to verify that RCU switches out of boot-time mode before the first context switch, as suggested by Nick Piggin. Changes since v2: o Created rcu_blocking_is_gp() internal-to-RCU API that determines whether a call to synchronize_rcu() is itself a grace period. o The definition of rcu_blocking_is_gp() for rcuclassic and rcutree checks to see if but a single CPU is online. o The definition of rcu_blocking_is_gp() for rcupreempt checks to see both if but a single CPU is online and if the system is still in early boot. This allows rcupreempt to again work correctly if running on a single CPU after booting is complete. o Added check to rcupreempt's synchronize_sched() for there being but one online CPU. Tested all three variants both SMP and !SMP, booted fine, passed a short rcutorture test on both x86 and Power. Located-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-22PM: Split up sysdev_[suspend|resume] from device_power_[down|up]Rafael J. Wysocki
Move the sysdev_suspend/resume from the callee to the callers, with no real change in semantics, so that we can rework the disabling of interrupts during suspend/hibernation. This is based on an earlier patch from Linus. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21Merge branch 'hibernate'Linus Torvalds
* hibernate: PM: Fix suspend_console and resume_console to use only one semaphore PM: Wait for console in resume PM: Fix pm_notifiers during user mode hibernation swsusp: clean up shrink_all_zones() swsusp: dont fiddle with swappiness PM: fix build for CONFIG_PM unset PM/hibernate: fix "swap breaks after hibernation failures" PM/resume: wait for device probing to finish Consolidate driver_probe_done() loops into one place
2009-02-21PM: Fix suspend_console and resume_console to use only one semaphoreArve Hjønnevåg
This fixes a race where a thread acquires the console while the console is suspended, and the console is resumed before this thread releases it. In this case, the secondary console semaphore would be left locked, and the primary semaphore would be released twice. This in turn would cause the console switch on suspend or resume to hang forever. Note that suspend_console does not actually lock the console for clients that use acquire_console_sem, it only locks it for clients that use try_acquire_console_sem. If we change suspend_console to fully lock the console, then the kernel may deadlock on suspend. One client of try_acquire_console_sem is acquire_console_semaphore_for_printk, which uses it to prevent printk from using the console while it is suspended. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21PM: Wait for console in resumeArve Hjønnevåg
Avoids later waking up to a blinking cursor if the device woke up and returned to sleep before the console switch happened. Signed-off-by: Brian Swetland <swetland@google.com> Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21PM: Fix pm_notifiers during user mode hibernationAndrey Borzenkov
Snapshot device is opened with O_RDONLY during suspend and O_WRONLY durig resume. Make sure we also call notifiers with correct parameter telling them what we are really doing. Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21PM: fix build for CONFIG_PM unsetRafael J. Wysocki
Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken config dependncies. Fix that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21PM/resume: wait for device probing to finishArjan van de Ven
the resume code does not currently wait for device probing to finish. Even without async function calls this is dicey and not correct, but with async function calls during the boot sequence this is going to get hit more... This patch adds the synchronization using the newly introduced helper. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Acked-by: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-19Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: limit the number of loops the ring buffer self test can make tracing: have function trace select kallsyms tracing: disable tracing while testing ring buffer tracing/function-graph-tracer: trace the idle tasks
2009-02-18tracing: limit the number of loops the ring buffer self test can makeSteven Rostedt
Impact: prevent deadlock if ring buffer gets corrupted This patch adds a paranoid check to make sure the ring buffer consumer does not go into an infinite loop. Since the ring buffer has been set to read only, the consumer should not loop for more than the ring buffer size. A check is added to make sure the consumer does not loop more than the ring buffer size. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-18tracing: have function trace select kallsymsSteven Rostedt
Impact: fix output of function tracer to be useful The function tracer is pretty useless if KALLSYMS is not configured. Unless you are good at reading hex values, the function tracer should select the KALLSYMS configuration. Also, the dynamic function tracer will fail its self test if KALLSYMS is not selected. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-18tracing: disable tracing while testing ring bufferSteven Rostedt
Impact: fix to prevent hard lockup on self tests If one of the tracers are broken and is constantly filling the ring buffer while the test of the ring buffer is running, it will hang the box. The reason is that the test is a consumer that will not stop till the ring buffer is empty. But if the tracer is broken and is constantly producing input to the buffer, this test will never end. The result is a lockup of the box. This happened when KALLSYMS was not defined and the dynamic ftrace test constantly filled the ring buffer, because the filter failed and all functions were being traced. Something was being called that constantly filled the buffer. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-18Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list block: fix booting from partitioned md array block: revert part of 18ce3751ccd488c78d3827e9f6bf54e6322676fb cciss: PCI power management reset for kexec paride/pg.c: xs(): &&/|| confusion fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free block: fix bad definition of BIO_RW_SYNC bsg: Fix sense buffer bug in SG_IO
2009-02-18pm: fix build for CONFIG_PM unsetRafael J. Wysocki
Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken config dependncies. Fix that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18cgroups: fix possible use after freeLi Zefan
In cgroup_kill_sb(), root is freed before sb is detached from the list, so another sget() may find this sb and call cgroup_test_super(), which will access the root that has been freed. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18block: fix bad definition of BIO_RW_SYNCJens Axboe
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-17Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: cpu hotplug fix
2009-02-17Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: more consistently use clock vs timer
2009-02-17Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: doc: mmiotrace.txt, buffer size control change trace: mmiotrace to the tracer menu in Kconfig mmiotrace: count events lost due to not recording
2009-02-17Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: iommu: fix Intel IOMMU write-buffer flushing futex: fix reference leak Trivial conflicts fixed manually in drivers/pci/intel-iommu.c
2009-02-17tracing/function-graph-tracer: trace the idle tasksFrederic Weisbecker
When the function graph tracer is activated, it iterates over the task_list to allocate a stack to store the return addresses. But the per cpu idle tasks are not iterated by using do_each_thread / while_each_thread. So we have to iterate on them manually. This fixes somes weirdness in the traces and many losses of traces. Examples on two cpus: 0) Xorg-4287 | 2.906 us | } 0) Xorg-4287 | 3.965 us | } 0) Xorg-4287 | 5.302 us | } ------------------------------------------ 0) Xorg-4287 => <idle>-0 ------------------------------------------ 0) <idle>-0 | 2.861 us | } 0) <idle>-0 | 0.526 us | set_normalized_timespec(); 0) <idle>-0 | 7.201 us | } 0) <idle>-0 | 8.214 us | } 0) <idle>-0 | | clockevents_program_event() { 0) <idle>-0 | | lapic_next_event() { 0) <idle>-0 | 0.510 us | native_apic_mem_write(); 0) <idle>-0 | 1.546 us | } 0) <idle>-0 | 2.583 us | } 0) <idle>-0 | + 12.435 us | } 0) <idle>-0 | + 13.470 us | } 0) <idle>-0 | 0.608 us | _spin_unlock_irqrestore(); 0) <idle>-0 | + 23.270 us | } 0) <idle>-0 | + 24.336 us | } 0) <idle>-0 | + 25.417 us | } 0) <idle>-0 | 0.593 us | _spin_unlock(); 0) <idle>-0 | + 41.869 us | } 0) <idle>-0 | + 42.906 us | } 0) <idle>-0 | + 95.035 us | } 0) <idle>-0 | 0.540 us | menu_reflect(); 0) <idle>-0 | ! 100.404 us | } 0) <idle>-0 | 0.564 us | mce_idle_callback(); 0) <idle>-0 | | enter_idle() { 0) <idle>-0 | 0.526 us | mce_idle_callback(); 0) <idle>-0 | 1.757 us | } 0) <idle>-0 | | cpuidle_idle_call() { 0) <idle>-0 | | menu_select() { 0) <idle>-0 | 0.525 us | pm_qos_requirement(); 0) <idle>-0 | 0.518 us | tick_nohz_get_sleep_length(); 0) <idle>-0 | 2.621 us | } [...] 1) <idle>-0 | 0.518 us | touch_softlockup_watchdog(); 1) <idle>-0 | + 14.355 us | } 1) <idle>-0 | + 22.840 us | } 1) <idle>-0 | + 25.949 us | } 1) <idle>-0 | | handle_irq() { 1) <idle>-0 | 0.511 us | irq_to_desc(); 1) <idle>-0 | | handle_edge_irq() { 1) <idle>-0 | 0.638 us | _spin_lock(); 1) <idle>-0 | | ack_apic_edge() { 1) <idle>-0 | 0.510 us | irq_to_desc(); 1) <idle>-0 | | move_native_irq() { 1) <idle>-0 | 0.510 us | irq_to_desc(); 1) <idle>-0 | 1.532 us | } 1) <idle>-0 | 0.511 us | native_apic_mem_write(); ------------------------------------------ 1) <idle>-0 => cat-5073 ------------------------------------------ 1) cat-5073 | 3.731 us | } 1) cat-5073 | | run_local_timers() { 1) cat-5073 | 0.533 us | hrtimer_run_queues(); 1) cat-5073 | | raise_softirq() { 1) cat-5073 | | __raise_softirq_irqoff() { 1) cat-5073 | | /* nr: 1 */ 1) cat-5073 | 2.718 us | } 1) cat-5073 | 3.814 us | } Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15trace: mmiotrace to the tracer menu in KconfigPekka Paalanen
Impact: cosmetic change in Kconfig menu layout This patch was originally suggested by Peter Zijlstra, but seems it was forgotten. CONFIG_MMIOTRACE and CONFIG_MMIOTRACE_TEST were selectable directly under the Kernel hacking / debugging menu in the kernel configuration system. They were present only for x86 and x86_64. Other tracers that use the ftrace tracing framework are in their own sub-menu. This patch moves the mmiotrace configuration options there. Since the Kconfig file, where the tracer menu is, is not architecture specific, HAVE_MMIOTRACE_SUPPORT is introduced and provided only by x86/x86_64. CONFIG_MMIOTRACE now depends on it. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15mmiotrace: count events lost due to not recordingPekka Paalanen
Impact: enhances lost events counting in mmiotrace The tracing framework, or the ring buffer facility it uses, has a switch to stop recording data. When recording is off, the trace events will be lost. The framework does not count these, so mmiotrace has to count them itself. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13User namespaces: Only put the userns when we unhash the uidSerge E. Hallyn
uids in namespaces other than init don't get a sysfs entry. For those in the init namespace, while we're waiting to remove the sysfs entry for the uid the uid is still hashed, and alloc_uid() may re-grab that uid without getting a new reference to the user_ns, which we've already put in free_user before scheduling remove_user_sysfs_dir(). Reported-and-tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>