path: root/kernel/compat.c
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2015-06-04compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap()Helge Deller-2/+4
In the functions compat_get_bitmap() and compat_put_bitmap() the variable nr_compat_longs stores how many compat_ulong_t words should be copied in a loop. The copy loop itself is this: if (nr_compat_longs-- > 0) { if (__get_user(um, umask)) return -EFAULT; } else { um = 0; } Since nr_compat_longs gets unconditionally decremented in each loop and since it's type is unsigned this could theoretically lead to out of bounds accesses to userspace if nr_compat_longs wraps around to (unsigned)(-1). Although the callers currently do not trigger out-of-bounds accesses, we should better implement the loop in a safe way to completely avoid such warp-arounds. Signed-off-by: Helge Deller <> Cc: Linus Torvalds <> Cc: Al Viro <>
2015-02-12all arches, signal: move restart_block to struct task_structAndy Lutomirski-3/+2
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [ metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <> Cc: Thomas Gleixner <> Cc: Al Viro <> Cc: "H. Peter Anvin" <> Cc: Ingo Molnar <> Cc: Kees Cook <> Cc: David Miller <> Acked-by: Richard Weinberger <> Cc: Richard Henderson <> Cc: Ivan Kokshaysky <> Cc: Matt Turner <> Cc: Vineet Gupta <> Cc: Russell King <> Cc: Catalin Marinas <> Cc: Will Deacon <> Cc: Haavard Skinnemoen <> Cc: Hans-Christian Egtvedt <> Cc: Steven Miao <> Cc: Mark Salter <> Cc: Aurelien Jacquiot <> Cc: Mikael Starvik <> Cc: Jesper Nilsson <> Cc: David Howells <> Cc: Richard Kuo <> Cc: "Luck, Tony" <> Cc: Geert Uytterhoeven <> Cc: Michal Simek <> Cc: Ralf Baechle <> Cc: Jonas Bonn <> Cc: "James E.J. Bottomley" <> Cc: Helge Deller <> Cc: Benjamin Herrenschmidt <> Cc: Paul Mackerras <> Acked-by: Michael Ellerman <> (powerpc) Tested-by: Michael Ellerman <> (powerpc) Cc: Martin Schwidefsky <> Cc: Heiko Carstens <> Cc: Chen Liqin <> Cc: Lennox Wu <> Cc: Chris Metcalf <> Cc: Guan Xuetao <> Cc: Chris Zankel <> Cc: Max Filippov <> Cc: Oleg Nesterov <> Cc: Guenter Roeck <> Signed-off-by: James Hogan <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2014-09-06compat: nanosleep: Clarify error handlingThomas Gleixner-3/+21
The error handling in compat_sys_nanosleep() is correct, but completely non obvious. Document it and restrict it to the -ERESTART_RESTARTBLOCK return value for clarity. Reported-by: Kees Cook <> Signed-off-by: Thomas Gleixner <>
2014-06-04kernel/compat.c: use sizeof() instead of sizeofFabian Frederick-4/+4
Fix 4 checkpatch warnings WARNING: sizeof *tv should be sizeof(*tv) Signed-off-by: Fabian Frederick <> Cc: "H. Peter Anvin" <> Cc: Arnd Bergmann <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2014-04-02Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds-56/+56
git:// Pull compat time conversion changes from Peter Anvin: "Despite the branch name this is really neither an x86 nor an x32-specific patchset, although it the implementation of the discussions that followed the x32 security hole a few months ago. This removes get/put_compat_timespec/val() and replaces them with compat_get/put_timespec/val() which are savvy as to the current status of COMPAT_USE_64BIT_TIME. It removes several unused and/or incorrect/misleading functions (like compat_put_timeval_convert which doesn't in fact do any conversion) and also replaces several open-coded implementations what is now called compat_convert_timespec() with that function" * 'x86-x32-for-linus' of git:// compat: Fix sparse address space warnings compat: Get rid of (get|put)_compat_time(val|spec)
2014-03-06mm/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter typesHeiko Carstens-5/+5
In order to allow the COMPAT_SYSCALL_DEFINE macro generate code that performs proper zero and sign extension convert all 64 bit parameters to their corresponding 32 bit compat counterparts. Signed-off-by: Heiko Carstens <>
2014-03-06kernel/compat: convert to COMPAT_SYSCALL_DEFINEHeiko Carstens-45/+45
Convert all compat system call functions where all parameter types have a size of four or less than four bytes, or are pointer types to COMPAT_SYSCALL_DEFINE. The implicit casts within COMPAT_SYSCALL_DEFINE will perform proper zero and sign extension to 64 bit of all parameters if needed. Signed-off-by: Heiko Carstens <>
2014-02-02compat: Fix sparse address space warningsH. Peter Anvin-2/+2
In compat_sys_old_getrlimit() we pass a kernel pointer to sys_old_getrlimit() inside a set_fs() bracket. This is okay, so we can safely cast the affected pointer to __user. In compat_clock_nanosleep_restart(), the variable "rmtp" holds a user pointer. Annotate it as such. Both of these warnings are ancient, but were reported by Fengguang Wu's test system due to other changes. Signed-off-by: H. Peter Anvin <> Cc: Toyo Abe <> Link:
2014-02-02compat: Get rid of (get|put)_compat_time(val|spec)H. Peter Anvin-54/+54
We have two APIs for compatiblity timespec/val, with confusingly similar names. compat_(get|put)_time(val|spec) *do* handle the case where COMPAT_USE_64BIT_TIME is set, whereas (get|put)_compat_time(val|spec) do not. This is an accident waiting to happen. Clean it up by favoring the full-service version; the limited version is replaced with double-underscore versions static to kernel/compat.c. A common pattern is to convert a struct timespec to kernel format in an allocation on the user stack. Unfortunately it is open-coded in several places. Since this allocation isn't actually needed if COMPAT_USE_64BIT_TIME is true (since user format == kernel format) encapsulate that whole pattern into the function compat_convert_timespec(). An equivalent function should be written for struct timeval if it is needed in the future. Finally, get rid of compat_(get|put)_timeval_convert(): each was only used once, and the latter was not even doing what the function said (no conversion actually was being done.) Moving the conversion into compat_sys_settimeofday() itself makes the code much more similar to sys_settimeofday() itself. v3: Remove unused compat_convert_timeval(). v2: Drop bogus "const" in the destination argument for compat_convert_time*(). Cc: Mauro Carvalho Chehab <> Cc: Alexander Viro <> Cc: Hans Verkuil <> Cc: Andrew Morton <> Cc: Heiko Carstens <> Cc: Manfred Spraul <> Cc: Mateusz Guzik <> Cc: Rafael Aquini <> Cc: Davidlohr Bueso <> Cc: Stephen Rothwell <> Cc: Dan Carpenter <> Cc: Arnd Bergmann <> Cc: Thomas Gleixner <> Cc: Ingo Molnar <> Cc: Linus Torvalds <> Cc: Catalin Marinas <> Cc: Will Deacon <> Tested-by: H.J. Lu <> Signed-off-by: H. Peter Anvin <>
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds-19/+0
git:// Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git:// syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions
2013-04-30kernel/compat.c: make do_sysinfo() staticStephen Rothwell-65/+0
The only use outside of kernel/timer.c was in kernel/compat.c, so move compat_sys_sysinfo() next to sys_sysinfo() in kernel/timer.c. Signed-off-by: Stephen Rothwell <> Cc: Thomas Gleixner <> Cc: Guenter Roeck <> Cc: Al Viro <> Acked-by: Arnd Bergmann <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2013-03-03switch getrusage() to COMPAT_SYSCALL_DEFINEAl Viro-19/+0
Signed-off-by: Al Viro <>
2013-02-23Merge branch 'for-linus' of ↵Linus Torvalds-46/+26
git:// Pull signal handling cleanups from Al Viro: "This is the first pile; another one will come a bit later and will contain SYSCALL_DEFINE-related patches. - a bunch of signal-related syscalls (both native and compat) unified. - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE (fixing several potential problems with missing argument validation, while we are at it) - a lot of now-pointless wrappers killed - a couple of architectures (cris and hexagon) forgot to save altstack settings into sigframe, even though they used the (uninitialized) values in sigreturn; fixed. - microblaze fixes for delivery of multiple signals arriving at once - saner set of helpers for signal delivery introduced, several architectures switched to using those." * 'for-linus' of git:// (143 commits) x86: convert to ksignal sparc: convert to ksignal arm: switch to struct ksignal * passing alpha: pass k_sigaction and siginfo_t using ksignal pointer burying unused conditionals make do_sigaltstack() static arm64: switch to generic old sigaction() (compat-only) arm64: switch to generic compat rt_sigaction() arm64: switch compat to generic old sigsuspend arm64: switch to generic compat rt_sigqueueinfo() arm64: switch to generic compat rt_sigpending() arm64: switch to generic compat rt_sigprocmask() arm64: switch to generic sigaltstack sparc: switch to generic old sigsuspend sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE sparc: kill sign-extending wrappers for native syscalls kill sparc32_open() sparc: switch to use of generic old sigaction sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE mips: switch to generic sys_fork() and sys_clone() ...
2013-02-21compat: return -EFAULT on error in waitid()Dan Carpenter-1/+1
The copy_to_user() call returns the number of bytes remaining but we want to return -EFAULT on error. Fixes "x32: fix waitid()" Signed-off-by: Dan Carpenter <> Cc: Al Viro <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2013-02-03switch compat_sys_sched_rr_get_interval to COMPAT_SYSCALL_DEFINEAl Viro-4/+3
... and make it unconditional - we want the sucker on all biarch platforms, really. All kinds of wrappers and private implementations can go now; fortunately, they don't cause name conflicts, so we can do that one first without any bisect hazards. Signed-off-by: Al Viro <>
2013-02-03switch rt_tgsigqueueinfo to COMPAT_SYSCALL_DEFINEAl Viro-11/+0
C ABI violations on sparc, ppc and mips Signed-off-by: Al Viro <>
2013-02-03switch compat_sys_sigprocmask to COMPAT_SYSCALL_DEFINEAl Viro-3/+3
In principle, C ABI violation on ppc and mips... Signed-off-by: Al Viro <>
2013-02-03switch compat_sys_rt_sigtimedwait to COMPAT_SYSCALL_DEFINEAl Viro-5/+3
Signed-off-by: Al Viro <>
2013-02-03generic compat_sys_rt_sigprocmask()Al Viro-1/+12
conditional on GENERIC_COMPAT_RT_SIGPROCMASK; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <>
2013-02-03consolidate rt_sigsuspend()Al Viro-17/+0
* pull compat version alongside with the native one * make little-endian compat variant just call the native * don't bother with separate conditional for compat (both native and compat are going to become unconditional very soon). Signed-off-by: Al Viro <>
2013-02-03switch compat_sys_[gs]etitimer(2) to COMPAT_SYSCALL_DEFINEAl Viro-5/+5
again, strictly speaking we are in nasal daemon territory on ppc and mips - we need to sign-extend int arguments. Signed-off-by: Al Viro <>
2012-12-26x32: fix sigtimedwaitAl Viro-1/+1
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 <>
2012-12-26x32: fix waitid()Al Viro-1/+5
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 <>
2012-12-26switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINEAl Viro-6/+9
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 <>
2012-12-17compat: generic compat_sys_sched_rr_get_interval() implementationCatalin Marinas-0/+17
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 <> Acked-by: Chris Metcalf <> [for tile] Acked-by: David S. Miller <> Acked-by: Arnd Bergmann <> Cc: Benjamin Herrenschmidt <> Cc: Paul Mackerras <> Cc: Alexander Viro <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2012-05-21new helper: sigsuspend()Al Viro-9/+1
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by: Al Viro <>
2012-05-10compat: Fix RT signal mask corruption via sigprocmaskJan Kiszka-17/+46
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 <> Signed-off-by: Linus Torvalds <>
2012-02-20compat: Add helper functions to read/write struct timeval, timespecH. Peter Anvin-8/+60
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 <> Signed-off-by: H. Peter Anvin <>
2011-10-31kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructurePaul Gortmaker-0/+1
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 <>
2011-07-30Merge branch 'v4l_for_linus' of ↵Linus Torvalds-0/+1
git:// * 'v4l_for_linus' of git:// (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-0/+1
Signed-off-by: Hans Verkuil <> Signed-off-by: Mauro Carvalho Chehab <>
2011-07-27signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()Oleg Nesterov-4/+1
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 <> Reviewed-by: Matt Fleming <> Acked-by: Tejun Heo <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2011-07-12KVM: Add compat ioctl for KVM_SET_SIGNAL_MASKAlexander Graf-0/+1
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 <> Signed-off-by: Avi Kivity <>
2011-05-25Merge git:// Torvalds-0/+8
* git:// (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-0/+8
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 <> Signed-off-by: Chris Metcalf <>
2011-04-28signal: introduce do_sigtimedwait() to factor out compat/native codeOleg Nesterov-34/+7
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 <> Acked-by: Tejun Heo <> Reviewed-by: Matt Fleming <>
2011-04-28signal: sys_rt_sigtimedwait: simplify the timeout logicOleg Nesterov-24/+18
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 <> Acked-by: Tejun Heo <> Reviewed-by: Matt Fleming <>
2011-02-02posix-timers: Introduce a syscall for clock tuning.Richard Cochran-0/+23
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 <> Acked-by: John Stultz <> LKML-Reference: <> Signed-off-by: Thomas Gleixner <>
2011-02-02time: Splitout compat timex accessorsRichard Cochran-48/+65
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 <> Acked-by: John Stultz <> Signed-off-by: Thomas Gleixner <> LKML-Reference: <>
2010-09-14compat: Make compat_alloc_user_space() incorporate the access_ok()H. Peter Anvin-0/+21
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 <> Signed-off-by: H. Peter Anvin <> Acked-by: Benjamin Herrenschmidt <> Acked-by: Chris Metcalf <> Acked-by: David S. Miller <> Acked-by: Ingo Molnar <> Acked-by: Thomas Gleixner <> Acked-by: Tony Luck <> Cc: Andrew Morton <> Cc: Arnd Bergmann <> Cc: Fenghua Yu <> Cc: H. Peter Anvin <> Cc: Heiko Carstens <> Cc: Helge Deller <> Cc: James Bottomley <> Cc: Kyle McMartin <> Cc: Martin Schwidefsky <> Cc: Paul Mackerras <> Cc: Ralf Baechle <> Cc: <>
2010-07-16rlimits: switch more rlimit syscalls to do_prlimitJiri Slaby-14/+3
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 <>
2010-05-19cpumask: fix compat getaffinityKOSAKI Motohiro-14/+11
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 <> Acked-by: Rusty Russell <> Acked-by: Arnd Bergmann <> Reported-by: Ken Werner <> Cc: Cc: Andi Kleen <> Signed-off-by: Linus Torvalds <>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo-0/+1
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. 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 <> Guess-its-ok-by: Christoph Lameter <> Cc: Ingo Molnar <> Cc: Lee Schermerhorn <>
2009-04-30signals: implement sys_rt_tgsigqueueinfoThomas Gleixner-0/+11
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 <> Reviewed-by: Oleg Nesterov <> Acked-by: Roland McGrath <> Acked-by: Ulrich Drepper <>
2009-01-06Allow times and time system calls to return small negative valuesPaul Mackerras-1/+4
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 <> Signed-off-by: Paul Mackerras <> Acked-by: David S. Miller <> Cc: Ingo Molnar <> Cc: Thomas Gleixner <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2009-01-01cpumask: convert kernel/compat.cRusty Russell-19/+30
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 <>
2008-10-20Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', ↵Thomas Gleixner-39/+72
'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
2008-10-16compat: generic compat get/settimeofdayChristoph Hellwig-0/+58
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. [ coding-style fixes] Signed-off-by: Christoph Hellwig <> Acked-by: David S. Miller <> [ sparc bits ] Cc: "Luck, Tony" <> Cc: Ralf Baechle <> Acked-by: Kyle McMartin <> Cc: Matthew Wilcox <> Cc: Grant Grundler <> Cc: Paul Mackerras <> Cc: Benjamin Herrenschmidt <> Cc: Martin Schwidefsky <> Cc: Heiko Carstens <> Cc: Ingo Molnar <> Cc: Thomas Gleixner <> Cc: "H. Peter Anvin" <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2008-09-14timers: fix itimer/many thread hangFrank Mayhar-39/+14
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 <> Cc: Roland McGrath <> Cc: Alexey Dobriyan <> Cc: Andrew Morton <> Signed-off-by: Ingo Molnar <>
2008-05-01ntp: support for TAIRoman Zippel-1/+2
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 <> Cc: john stultz <> Cc: Thomas Gleixner <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>