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2012-12-26x32: fix sigtimedwaitAl Viro
It needs 64bit timespec. As it is, we end up truncating the timeout to whole seconds; usually it doesn't matter, but for having all sub-second timeouts truncated to one jiffy is visibly wrong. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26x32: fix waitid()Al Viro
It needs 64bit rusage and 32bit siginfo. glibc never calls it with non-NULL rusage pointer, or we would've seen breakage already... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-26switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINEAl Viro
Strictly speaking, ppc64 needs it for C ABI compliance. Realistically I would be very surprised if e.g. passing 0xffffffff as 'options' argument to waitid() from 32bit task would cause problems, but yes, it puts us into undefined behaviour territory. ppc64 expects int argument to be passed in 64bit register with bits 31..63 containing the same value. SYSCALL_DEFINE on ppc provides a wrapper that normalizes the value passed from userland; so does COMPAT_SYSCALL_DEFINE. Plain declaration of compat_sys_something() with an int argument obviously doesn't. Again, for wait4 and waitid I would be extremely surprised if gcc started to produce code depending on that value having been properly sign-extended - the argument(s) in question end up passed blindly to sys_wait4 and sys_waitid resp. and normalization for native syscalls takes care of their use there. Still, better to use COMPAT_SYSCALL_DEFINE here than worry about nasal daemons... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-17compat: generic compat_sys_sched_rr_get_interval() implementationCatalin Marinas
This function is used by sparc, powerpc tile and arm64 for compat support. The patch adds a generic implementation with a wrapper for PowerPC to do the u32->int sign extension. The reason for a single patch covering powerpc, tile, sparc and arm64 is to keep it bisectable, otherwise kernel building may fail with mismatched function declarations. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile] Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-21new helper: sigsuspend()Al Viro
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-10compat: Fix RT signal mask corruption via sigprocmaskJan Kiszka
compat_sys_sigprocmask reads a smaller signal mask from userspace than sigprogmask accepts for setting. So the high word of blocked.sig[0] will be cleared, releasing any potentially blocked RT signal. This was discovered via userspace code that relies on get/setcontext. glibc's i386 versions of those functions use sigprogmask instead of rt_sigprogmask to save/restore signal mask and caused RT signal unblocking this way. As suggested by Linus, this replaces the sys_sigprocmask based compat version with one that open-codes the required logic, including the merge of the existing blocked set with the new one provided on SIG_SETMASK. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20compat: Add helper functions to read/write struct timeval, timespecH. Peter Anvin
Add helper functions to read and write struct timeval and struct timespec from userspace. We already had helper functions for reading and writing struct compat_timespec; add a set of functions to do the same with struct timeval, and add a second suite of functions which can be sensitive to COMPAT_USE_64BIT_TIME and access either 32- or 64-bit time structures. This also exports these helper functions to modules. Rename the existing inlines for converting between struct compat_timeval and native struct timespec so we can have a saner naming convention for the exported functions. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2011-10-31kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructurePaul Gortmaker
These files were getting <linux/module.h> via an implicit non-obvious path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-30Merge branch 'v4l_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (430 commits) [media] ir-mce_kbd-decoder: include module.h for its facilities [media] ov5642: include module.h for its facilities [media] em28xx: Fix DVB-C maxsize for em2884 [media] tda18271c2dd: Fix saw filter configuration for DVB-C @6MHz [media] v4l: mt9v032: Fix Bayer pattern [media] V4L: mt9m111: rewrite set_pixfmt [media] V4L: mt9m111: fix missing return value check mt9m111_reg_clear [media] V4L: initial driver for ov5642 CMOS sensor [media] V4L: sh_mobile_ceu_camera: fix Oops when USERPTR mapping fails [media] V4L: soc-camera: remove soc-camera bus and devices on it [media] V4L: soc-camera: un-export the soc-camera bus [media] V4L: sh_mobile_csi2: switch away from using the soc-camera bus notifier [media] V4L: add media bus configuration subdev operations [media] V4L: soc-camera: group struct field initialisations together [media] V4L: soc-camera: remove now unused soc-camera specific PM hooks [media] V4L: pxa-camera: switch to using standard PM hooks [media] NetUP Dual DVB-T/C CI RF: force card hardware revision by module param [media] Don't OOPS if videobuf_dvb_get_frontend return NULL [media] NetUP Dual DVB-T/C CI RF: load firmware according card revision [media] omap3isp: Support configurable HS/VS polarities ... Fix up conflicts: - arch/arm/mach-omap2/board-rx51-peripherals.c: cleanup regulator supply definitions in mach-omap2 vs OMAP3: RX-51: define vdds_csib regulator supply - drivers/staging/tm6000/tm6000-alsa.c (trivial)
2011-07-27[media] v4l2-compat-ioctl32: add VIDIOC_DQEVENT supportHans Verkuil
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()Oleg Nesterov
sys_ssetmask(), sys_rt_sigsuspend() and compat_sys_rt_sigsuspend() change ->blocked directly. This is not correct, see the changelog in e6fa16ab "signal: sigprocmask() should do retarget_shared_pending()" Change them to use set_current_blocked(). Another change is that now we are doing ->saved_sigmask = ->blocked lockless, it doesn't make any sense to do this under ->siglock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-12KVM: Add compat ioctl for KVM_SET_SIGNAL_MASKAlexander Graf
KVM has an ioctl to define which signal mask should be used while running inside VCPU_RUN. At least for big endian systems, this mask is different on 32-bit and 64-bit systems (though the size is identical). Add a compat wrapper that converts the mask to whatever the kernel accepts, allowing 32-bit kvm user space to set signal masks. This patch fixes qemu with --enable-io-thread on ppc64 hosts when running 32-bit user land. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (26 commits) arch/tile: prefer "tilepro" as the name of the 32-bit architecture compat: include aio_abi.h for aio_context_t arch/tile: cleanups for tilegx compat mode arch/tile: allocate PCI IRQs later in boot arch/tile: support signal "exception-trace" hook arch/tile: use better definitions of xchg() and cmpxchg() include/linux/compat.h: coding-style fixes tile: add an RTC driver for the Tilera hypervisor arch/tile: finish enabling support for TILE-Gx 64-bit chip compat: fixes to allow working with tile arch arch/tile: update defconfig file to something more useful tile: do_hardwall_trap: do not play with task->sighand tile: replace mm->cpu_vm_mask with mm_cpumask() tile,mn10300: add device parameter to dma_cache_sync() audit: support the "standard" <asm-generic/unistd.h> arch/tile: clarify flush_buffer()/finv_buffer() function names arch/tile: kernel-related cleanups from removing static page size arch/tile: various header improvements for building drivers arch/tile: disable GX prefetcher during cache flush arch/tile: tolerate disabling CONFIG_BLK_DEV_INITRD ...
2011-05-12compat: fixes to allow working with tile archChris Metcalf
The existing <asm-generic/unistd.h> mechanism doesn't really provide enough to create the 64-bit "compat" ABI properly in a generic way, since the compat ABI is a mix of things were you can re-use the 64-bit versions of syscalls and things where you need a compat wrapper. To provide this in the most direct way possible, I added two new macros to go along with the existing __SYSCALL and __SC_3264 macros: __SC_COMP and SC_COMP_3264. These macros take an additional argument, typically a "compat_sys_xxx" function, which is passed to __SYSCALL if you define __SYSCALL_COMPAT when including the header, resulting in a pointer to the compat function being placed in the generated syscall table. The change also adds some missing definitions to <linux/compat.h> so that it actually has declarations for all the compat syscalls, since the "[nr] = ##call" approach requires proper C declarations for all the functions included in the syscall table. Finally, compat.c defines compat_sys_sigpending() and compat_sys_sigprocmask() even if the underlying architecture doesn't request it, which tries to pull in undefined compat_old_sigset_t defines. We need to guard those compat syscall definitions with appropriate __ARCH_WANT_SYS_xxx ifdefs. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-04-28signal: introduce do_sigtimedwait() to factor out compat/native codeOleg Nesterov
Factor out the common code in sys_rt_sigtimedwait/compat_sys_rt_sigtimedwait to the new helper, do_sigtimedwait(). Add the comment to document the extra tick we add to timespec_to_jiffies(ts), thanks to Linus who explained this to me. Perhaps it would be better to move compat_sys_rt_sigtimedwait() into signal.c under CONFIG_COMPAT, then we can make do_sigtimedwait() static. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
2011-04-28signal: sys_rt_sigtimedwait: simplify the timeout logicOleg Nesterov
No functional changes, cleanup compat_sys_rt_sigtimedwait() and sys_rt_sigtimedwait(). Calculate the timeout before we take ->siglock, this simplifies and lessens the code. Use timespec_valid() to check the timespec. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
2011-02-02posix-timers: Introduce a syscall for clock tuning.Richard Cochran
A new syscall is introduced that allows tuning of a POSIX clock. The new call, clock_adjtime, takes two parameters, the clock ID and a pointer to a struct timex. Any ADJTIMEX(2) operation may be requested via this system call, but various POSIX clocks may or may not support tuning. [ tglx: Adapted to the posix-timer cleanup series. Avoid copy_to_user in the error case ] Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134419.869804645@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-02time: Splitout compat timex accessorsRichard Cochran
Split out the compat timex accessors into separate functions. Preparatory patch for a new syscall. [ tglx: Split that patch from Richards "posix-timers: Introduce a syscall for clock tuning.". Keeps the changes strictly separate ] Originally-from: Richard Cochran <richardcochran@gmail.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20110201134419.772343089@linutronix.de>
2010-09-14compat: Make compat_alloc_user_space() incorporate the access_ok()H. Peter Anvin
compat_alloc_user_space() expects the caller to independently call access_ok() to verify the returned area. A missing call could introduce problems on some architectures. This patch incorporates the access_ok() check into compat_alloc_user_space() and also adds a sanity check on the length. The existing compat_alloc_user_space() implementations are renamed arch_compat_alloc_user_space() and are used as part of the implementation of the new global function. This patch assumes NULL will cause __get_user()/__put_user() to either fail or access userspace on all architectures. This should be followed by checking the return value of compat_access_user_space() for NULL in the callers, at which time the access_ok() in the callers can also be removed. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@kernel.org>
2010-07-16rlimits: switch more rlimit syscalls to do_prlimitJiri Slaby
After we added more generic do_prlimit, switch sys_getrlimit to that. Also switch compat handling, so we can get rid of ugly __user casts and avoid setting process' address limit to kernel data and back. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2010-05-19cpumask: fix compat getaffinityKOSAKI Motohiro
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>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-04-30signals: implement sys_rt_tgsigqueueinfoThomas Gleixner
sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is missing a thread directed counterpart. Such an interface is important for migrating applications from other OSes which have the per thread delivery implemented. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: Ulrich Drepper <drepper@redhat.com>
2009-01-06Allow times and time system calls to return small negative valuesPaul Mackerras
At the moment, the times() system call will appear to fail for a period shortly after boot, while the value it want to return is between -4095 and -1. The same thing will also happen for the time() system call on 32-bit platforms some time in 2106 or so. On some platforms, such as x86, this is unavoidable because of the system call ABI, but other platforms such as powerpc have a separate error indication from the return value, so system calls can in fact return small negative values without indicating an error. On those platforms, force_successful_syscall_return() provides a way to indicate that the system call return value should not be treated as an error even if it is in the range which would normally be taken as a negative error number. This adds a force_successful_syscall_return() call to the time() and times() system calls plus their 32-bit compat versions, so that they don't erroneously indicate an error on those platforms whose system call ABI has a separate error indication. This will not affect anything on other platforms. Joakim Tjernlund added the fix for time() and the compat versions of time() and times(), after I did the fix for times(). Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-01cpumask: convert kernel/compat.cRusty Russell
Impact: Reduce stack usage, use new cpumask API. Straightforward conversion; cpumasks' size is given by cpumask_size() (now a variable rather than fixed) and on-stack cpu masks use cpumask_var_t. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-10-20Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', ↵Thomas Gleixner
'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
2008-10-16compat: generic compat get/settimeofdayChristoph Hellwig
Nothing arch specific in get/settimeofday. The details of the timeval conversion varied a little from arch to arch, but all with the same results. Also add an extern declaration for sys_tz to linux/time.h because externs in .c files are fowned upon. I'll kill the externs in various other files in a sparate patch. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ] Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-14timers: fix itimer/many thread hangFrank Mayhar
Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-01ntp: support for TAIRoman Zippel
This adds support for setting the TAI value (International Atomic Time). The value is reported back to userspace via timex (as we don't have a ntp_gettime() syscall). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: add set_restore_sigmaskRoland McGrath
This adds the set_restore_sigmask() inline in <linux/thread_info.h> and replaces every set_thread_flag(TIF_RESTORE_SIGMASK) with a call to it. No change, but abstracts the details of the flag protocol from all the calls. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-19generic: reduce stack pressure in sched_affinityMike Travis
* Modify sched_affinity functions to pass cpumask_t variables by reference instead of by value. * Use new set_cpus_allowed_ptr function. Depends on: [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: Paul Jackson <pj@sgi.com> Cc: Cliff Wickman <cpw@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17hrtimer: use nanosleep specific restart_block fieldsThomas Gleixner
Convert all the nanosleep related users of restart_block to the new nanosleep specific restart_block fields. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-10hrtimer: don't modify restart_block->fn in restart functionsOleg Nesterov
hrtimer_nanosleep_restart() clears/restores restart_block->fn. This is pointless and complicates its usage. Note that if sys_restart_syscall() doesn't actually happen, we have a bogus "pending" restart->fn anyway, this is harmless. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Pavel Emelyanov <xemul@sw.ru> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Toyo Abe <toyoa@mvista.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-10hrtimer: fix *rmtp/restarts handling in compat_sys_nanosleep()Oleg Nesterov
Spotted by Pavel Emelyanov and Alexey Dobriyan. compat_sys_nanosleep() implicitly uses hrtimer_nanosleep_restart(), this can't work. Make a suitable compat_nanosleep_restart() helper. Introduced by commit c70878b4e0b6cf8d2f1e46319e48e821ef4a8aba hrtimer: hook compat_sys_nanosleep up to high res timer code Also, set ->addr_limit = KERNEL_DS before doing hrtimer_nanosleep(), this func was changed by the previous patch and now takes the "__user *" parameter. Thanks to Ingo Molnar for fixing the bug in this patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Pavel Emelyanov <xemul@sw.ru> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Toyo Abe <toyoa@mvista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-18Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrtLinus Torvalds
* ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: hrtimer: hook compat_sys_nanosleep up to high res timer code hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier
2007-10-18whitespace fixes: compat syscallsDaniel Walker
Signed-off-by: Daniel Walker <dwalker@mvista.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18hrtimer: hook compat_sys_nanosleep up to high res timer codeAnton Blanchard
Now we have high res timers on ppc64 I thought Id test them. It turns out compat_sys_nanosleep hasnt been converted to the hrtimer code and so is limited to HZ resolution. The follow patch converts compat_sys_nanosleep to use high res timers. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-05-11signal/timer/event: timerfd compat codeDavide Libenzi
This patch implements the necessary compat code for the timerfd system call. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Common compat_sys_sysinfoKyle McMartin
I noticed that almost all architectures implemented exactly the same sys32_sysinfo... except parisc, where a bug was to be found in handling of the uptime. So let's remove a whole whack of code for fun and profit. Cribbed compat_sys_sysinfo from x86_64's implementation, since I figured it would be the best tested. This patch incorporates Arnd's suggestion of not using set_fs/get_fs, but instead extracting out the common code from sys_sysinfo. Cc: Christoph Hellwig <hch@infradead.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-11-03[PATCH] Create compat_sys_migrate_pagesStephen Rothwell
This is needed on bigendian 64bit architectures. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28[PATCH] Constify compat_get_bitmap argumentStephen Rothwell
This means we can call it when the bitmap we want to fetch is declared const. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] BLOCK: Revert patch to hack around undeclared sigset_t in linux/compat.hDavid Howells
Revert Andrew Morton's patch to temporarily hack around the lack of a declaration of sigset_t in linux/compat.h to make the block-disablement patches build on IA64. This got accidentally pushed to Linus and should be fixed in a different manner. Also make linux/compat.h #include asm/signal.h to gain a definition of sigset_t so that it can externally declare sigset_from_compat(). This has been compile-tested for i386, x86_64, ia64, mips, mips64, frv, ppc and ppc64 and run-tested on frv. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-30[PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6]David Howells
Create a new header file, fs/internal.h, for common definitions local to the sources in the fs/ directory. Move extern definitions that should be in header files from fs/*.c to fs/internal.h or other main header files where they span directories. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-29[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining ↵Toyo Abe
time in compatibility mode The clock_nanosleep() function does not return the time remaining when the sleep is interrupted by a signal. This patch creates a new call out, compat_clock_nanosleep_restart(), which handles returning the remaining time after a sleep is interrupted. This patch revives clock_nanosleep_restart(). It is now accessed via the new call out. The compat_clock_nanosleep_restart() is used for compatibility access. Since this is implemented in compatibility mode the normal path is virtually unaffected - no real performance impact. Signed-off-by: Toyo Abe <toyoa@mvista.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] N32 sigset and __COMPAT_ENDIAN_SWAP__akpm@osdl.org
I'm testing glibc on MIPS64, little-endian, N32, O32 and N64 multilibs. Among the NPTL test failures seen are some arising from sigsuspend problems for N32: it blocks the wrong signals, so SIGCANCEL (SIGRTMIN) is blocked despite glibc's carefully excluding it from sets of signals to block. Specifically, testing suggests it blocks signal N^32 instead of signal N, so (in the example tested) blocking SIGUSR1 (17) blocks signal 49 instead. glibc's sigset_t uses an array of unsigned long, as does the kernel. In both cases, signal N+1 is represented as (1UL << (N % (8 * sizeof (unsigned long)))) in word number (N / (8 * sizeof (unsigned long))). Thus the N32 glibc uses an array of 32-bit words and the N64 kernel uses an array of 64-bit words. For little-endian, the layout is the same, with signals 1-32 in the first 4 bytes, signals 33-64 in the second, etc.; for big-endian, userspace has that layout while in the kernel each 8 bytes have the two halves swapped from the userspace layout. The N32 sigsuspend syscall uses sigset_from_compat to convert the userspace sigset to kernel format. If __COMPAT_ENDIAN_SWAP__ is *not* set, this uses logic of the form set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 ) to convert the userspace sigset to a kernel one. This looks correct to me for both big and little endian, given that in userspace compat->sig[1] will represent signals 33-64, and so will the high 32 bits of set->sig[0] in the kernel. If however __COMPAT_ENDIAN_SWAP__ *is* set, as it is for __MIPSEL__, it uses set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 ); which seems incorrect for both big and little endian, and would explain the observed symptoms. This code is the only use of __COMPAT_ENDIAN_SWAP__, so if incorrect then that macro serves no purpose, in which case something like the following patch would seem appropriate to remove it. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] move_pages: fix 32 -> 64 bit compat functionChristoph Lameter
The definition of the third parameter is a pointer to an array of virtual addresses which give us some trouble. The existing code calculated the wrong address in the array since I used void to avoid having to specify a type. I now use the correct type "compat_uptr_t __user *" in the definition of the function in kernel/compat.c. However, I used __u32 in syscalls.h. Would have to include compat.h there in order to provide the same definition which would generate an ugly include situation. On both ia64 and x86_64 compat_uptr_t is u32. So this works although parameter declarations differ. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] sys_move_pages: 32bit support (i386, x86_64)Christoph Lameter
sys_move_pages() support for 32bit (i386 plus x86_64 compat layer) Add support for move_pages() on i386 and also add the compat functions necessary to run 32 bit binaries on x86_64. Add compat_sys_move_pages to the x86_64 32bit binary layer. Note that it is not up to date so I added the missing pieces. Not sure if this is done the right way. [akpm@osdl.org: compile fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] lightweight robust futexes: compatIngo Molnar
32-bit syscall compatibility support. (This patch also moves all futex related compat functionality into kernel/futex_compat.c.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Acked-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26[PATCH] consolidate sys32/compat_adjtimexStephen Rothwell
Create compat_sys_adjtimex and use it an all appropriate places. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07[PATCH] remove bogus asm/bug.h includes.Al Viro
A bunch of asm/bug.h includes are both not needed (since it will get pulled anyway) and bogus (since they are done too early). Removed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>