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2015-10-19um: Fix kernel mode fault conditionRichard Weinberger
We have to exclude memory locations <= PAGE_SIZE from the condition and let the kernel mode fault path catch it. Otherwise a kernel NULL pointer exception will be reported as a kernel user space access. Fixes: d2313084e2c (um: Catch unprotected user memory access) Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19um: Fix waitpid() usage in helper codeRichard Weinberger
If UML is executing a helper program it is using waitpid() with the __WCLONE flag to wait for the program as the helper is executed from a clone()'ed thread. While using __WCLONE is perfectly fine for clone()'ed childs it won't detect terminated childs if the helper has issued an execve(). We have to use __WALL to wait for both clone()'ed and regular childs to detect the termination before and after an execve(). Reported-and-tested-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19um: Fix out-of-tree buildRichard Weinberger
Commit 30b11ee9a (um: Remove copy&paste code from init.h) uncovered an issue wrt. out-of-tree builds. For out-of-tree builds, we must not rely on relative paths. Before 30b11ee9a it worked by chance as no host code included generated header files. Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-04Merge branch 'strscpy' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull strscpy string copy function implementation from Chris Metcalf. Chris sent this during the merge window, but I waffled back and forth on the pull request, which is why it's going in only now. The new "strscpy()" function is definitely easier to use and more secure than either strncpy() or strlcpy(), both of which are horrible nasty interfaces that have serious and irredeemable problems. strncpy() has a useless return value, and doesn't NUL-terminate an overlong result. To make matters worse, it pads a short result with zeroes, which is a performance disaster if you have big buffers. strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking the insane NUL padding, but having a differently broken return value which returns the original length of the source string. Which means that it will read characters past the count from the source buffer, and you have to trust the source to be properly terminated. It also makes error handling fragile, since the test for overflow is unnecessarily subtle. strscpy() avoids both these problems, guaranteeing the NUL termination (but not excessive padding) if the destination size wasn't zero, and making the overflow condition very obvious by returning -E2BIG. It also doesn't read past the size of the source, and can thus be used for untrusted source data too. So why did I waffle about this for so long? Every time we introduce a new-and-improved interface, people start doing these interminable series of trivial conversion patches. And every time that happens, somebody does some silly mistake, and the conversion patch to the improved interface actually makes things worse. Because the patch is mindnumbing and trivial, nobody has the attention span to look at it carefully, and it's usually done over large swatches of source code which means that not every conversion gets tested. So I'm pulling the strscpy() support because it *is* a better interface. But I will refuse to pull mindless conversion patches. Use this in places where it makes sense, but don't do trivial patches to fix things that aren't actually known to be broken. * 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: use global strscpy() rather than private copy string: provide strscpy() Make asm/word-at-a-time.h available on all architectures
2015-09-01Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Rather large, but nothing exiting: - new range check for settimeofday() to prevent that boot time becomes negative. - fix for file time rounding - a few simplifications of the hrtimer code - fix for the proc/timerlist code so the output of clock realtime timers is accurate - more y2038 work - tree wide conversion of clockevent drivers to the new callbacks" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits) hrtimer: Handle failure of tick_init_highres() gracefully hrtimer: Unconfuse switch_hrtimer_base() a bit hrtimer: Simplify get_target_base() by returning current base hrtimer: Drop return code of hrtimer_switch_to_hres() time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64() time: Introduce current_kernel_time64() time: Introduce struct itimerspec64 time: Add the common weak version of update_persistent_clock() time: Always make sure wall_to_monotonic isn't positive time: Fix nanosecond file time rounding in timespec_trunc() timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers cris/time: Migrate to new 'set-state' interface kernel: broadcast-hrtimer: Migrate to new 'set-state' interface xtensa/time: Migrate to new 'set-state' interface unicore/time: Migrate to new 'set-state' interface um/time: Migrate to new 'set-state' interface sparc/time: Migrate to new 'set-state' interface sh/localtimer: Migrate to new 'set-state' interface score/time: Migrate to new 'set-state' interface s390/time: Migrate to new 'set-state' interface ...
2015-08-10um/time: Migrate to new 'set-state' interfaceViresh Kumar
Migrate um driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-07-31Merge branch 'x86/urgent' into x86/asm, before applying dependent patchesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-17mm: clean up per architecture MM hook header filesLaurent Dufour
Commit 2ae416b142b6 ("mm: new mm hook framework") introduced an empty header file (mm-arch-hooks.h) for every architecture, even those which doesn't need to define mm hooks. As suggested by Geert Uytterhoeven, this could be cleaned through the use of a generic header file included via each per architecture asm/include/Kbuild file. The PowerPC architecture is not impacted here since this architecture has to defined the arch_remap MM hook. Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Vineet Gupta <vgupta@synopsys.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-08Make asm/word-at-a-time.h available on all architecturesChris Metcalf
Added the x86 implementation of word-at-a-time to the generic version, which previously only supported big-endian. Omitted the x86-specific load_unaligned_zeropad(), which in any case is also not present for the existing BE-only implementation of a word-at-a-time, and is only used under CONFIG_DCACHE_WORD_ACCESS. Added as a "generic-y" to the Kbuilds of all architectures that didn't previously have it. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-07-07um: Fix do_signal() prototypeIngo Molnar
Once x86 exports its do_signal(), the prototypes will clash. Fix the clash and also improve the code a bit: remove the unnecessary kern_do_signal() indirection. This allows interrupt_end() to share the 'regs' parameter calculation. Also remove the unused return code to match x86. Minimally build and boot tested. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard.weinberger@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/67c57eac09a589bac3c6c5ff22f9623ec55a184a.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-06-28Merge branch 'for-linus-4.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - remove hppfs ("HonePot ProcFS") - initial support for musl libc - uaccess cleanup - random cleanups and bug fixes all over the place * 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (21 commits) um: Don't pollute kernel namespace with uapi um: Include sys/types.h for makedev(), major(), minor() um: Do not use stdin and stdout identifiers for struct members um: Do not use __ptr_t type for stack_t's .ss pointer um: Fix mconsole dependency um: Handle tracehook_report_syscall_entry() result um: Remove copy&paste code from init.h um: Stop abusing __KERNEL__ um: Catch unprotected user memory access um: Fix warning in setup_signal_stack_si() um: Rework uaccess code um: Add uaccess.h to ldt.c um: Add uaccess.h to syscalls_64.c um: Add asm/elf.h to vma.c um: Cleanup mem_32/64.c headers um: Remove hppfs um: Move syscall() declaration into os.h um: kernel: ksyms: Export symbol syscall() for fixing modpost issue um/os-Linux: Use char[] for syscall_stub declarations um: Use char[] for linker script address declarations ...
2015-06-26Merge tag 'char-misc-4.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here's the big char/misc driver pull request for 4.2-rc1. Lots of mei, extcon, coresight, uio, mic, and other driver updates in here. Full details in the shortlog. All of these have been in linux-next for some time with no reported problems" * tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (176 commits) mei: me: wait for power gating exit confirmation mei: reset flow control on the last client disconnection MAINTAINERS: mei: add mei_cl_bus.h to maintained file list misc: sram: sort and clean up included headers misc: sram: move reserved block logic out of probe function misc: sram: add private struct device and virt_base members misc: sram: report correct SRAM pool size misc: sram: bump error message level on unclean driver unbinding misc: sram: fix device node reference leak on error misc: sram: fix enabled clock leak on error path misc: mic: Fix reported static checker warning misc: mic: Fix randconfig build error by including errno.h uio: pruss: Drop depends on ARCH_DAVINCI_DA850 from config uio: pruss: Add CONFIG_HAS_IOMEM dependence uio: pruss: Include <linux/sizes.h> extcon: Redefine the unique id of supported external connectors without 'enum extcon' type char:xilinx_hwicap:buffer_icap - change 1/0 to true/false for bool type variable in function buffer_icap_set_configuration(). Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion parport: check exclusive access before register w1: use correct lock on error in w1_seq_show() ...
2015-06-25Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull asm/scatterlist.h removal from Jens Axboe: "We don't have any specific arch scatterlist anymore, since parisc finally switched over. Kill the include" * 'for-4.2/sg' of git://git.kernel.dk/linux-block: remove scatterlist.h generation from arch Kbuild files remove <asm/scatterlist.h>
2015-06-25um: Don't pollute kernel namespace with uapiRichard Weinberger
Don't include ptrace uapi stuff in arch headers, it will pollute the kernel namespace and conflict with existing stuff. In this case it fixes clashes with common names like R8. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Include sys/types.h for makedev(), major(), minor()Hans-Werner Hilse
The functions in question are not part of the POSIX standard, documentation however hints that the corresponding header shall be sys/types.h. C libraries other than glibc, namely musl, did not include that header via other ways and complained. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Do not use stdin and stdout identifiers for struct membersHans-Werner Hilse
stdin, stdout and stderr are macros according to C89/C99. Thus do not use them as struct member identifiers to avoid bad results from macro expansion. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Do not use __ptr_t type for stack_t's .ss pointerHans-Werner Hilse
__ptr_t type is a glibc-specific type, while the generally documented type is a void*. That's what other C libraries use, too. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-24mm: new mm hook frameworkLaurent Dufour
CRIU is recreating the process memory layout by remapping the checkpointee memory area on top of the current process (criu). This includes remapping the vDSO to the place it has at checkpoint time. However some architectures like powerpc are keeping a reference to the vDSO base address to build the signal return stack frame by calling the vDSO sigreturn service. So once the vDSO has been moved, this reference is no more valid and the signal frame built later are not usable. This patch serie is introducing a new mm hook framework, and a new arch_remap hook which is called when mremap is done and the mm lock still hold. The next patch is adding the vDSO remap and unmap tracking to the powerpc architecture. This patch (of 3): This patch introduces a new set of header file to manage mm hooks: - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h) - a generic header (include/linux/mm-arch-hooks.h) The architecture which need to overwrite a hook as to redefine it in its header file, while architecture which doesn't need have nothing to do. The default hooks are defined in the generic header and are used in the case the architecture is not defining it. In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should be moved here. Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-23module: add per-module param_lockDan Streetman
Add a "param_lock" mutex to each module, and update params.c to use the correct built-in or module mutex while locking kernel params. Remove the kparam_block_sysfs_r/w() macros, replace them with direct calls to kernel_param_[un]lock(module). The kernel param code currently uses a single mutex to protect modification of any and all kernel params. While this generally works, there is one specific problem with it; a module callback function cannot safely load another module, i.e. with request_module() or even with indirect calls such as crypto_has_alg(). If the module to be loaded has any of its params configured (e.g. with a /etc/modprobe.d/* config file), then the attempt will result in a deadlock between the first module param callback waiting for modprobe, and modprobe trying to lock the single kernel param mutex to set the new module's param. This fixes that by using per-module mutexes, so that each individual module is protected against concurrent changes in its own kernel params, but is not blocked by changes to other module params. All built-in modules continue to use the built-in mutex, since they will always be loaded at runtime and references (e.g. request_module(), crypto_has_alg()) to them will never cause load-time param changing. This also simplifies the interface used by modules to block sysfs access to their params; while there are currently functions to block and unblock sysfs param access which are split up by read and write and expect a single kernel param to be passed, their actual operation is identical and applies to all params, not just the one passed to them; they simply lock and unlock the global param mutex. They are replaced with direct calls to kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or if the module is built-in, it locks the built-in mutex. Suggested-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-31um: Fix mconsole dependencyRichard Weinberger
mconsole depends on CONFIG_PROC_FS. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Handle tracehook_report_syscall_entry() resultRichard Weinberger
tracehook_report_syscall_entry() is allowed to fail, in case of failure we have to abort the current syscall. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Remove copy&paste code from init.hRichard Weinberger
As we got rid of the __KERNEL__ abuse, we can directly include linux/compiler.h now. This also allows gcc 5 to build UML. Reported-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Stop abusing __KERNEL__Richard Weinberger
Currently UML is abusing __KERNEL__ to distinguish between kernel and host code (os-Linux). It is better to use a custom define such that existing users of __KERNEL__ don't get confused. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Catch unprotected user memory accessRichard Weinberger
If the kernel tries to access user memory without copy_from_user() a trap will happen as kernel and userspace run in different processes on the host side. Currently this special page fault cannot be resolved and will happen over and over again. As result UML will lockup. This patch allows the page fault code to detect that situation and causes a panic() such that the root cause of the unprotected memory access can be found and fixed. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Rework uaccess codeRichard Weinberger
Rework UML's uaccess code to reuse as much as possible from asm-generic/uaccess.c. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Remove hppfsRichard Weinberger
hppfs (honeypot procfs) was an attempt to use UML as honeypot. It was never stable nor in heavy use. As Al Viro and Christoph Hellwig pointed some major issues out it is better to let it die. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Move syscall() declaration into os.hRichard Weinberger
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: kernel: ksyms: Export symbol syscall() for fixing modpost issueChen Gang
syscall() is implemented in libc.so/a (e.g. for glibc, in "syscall.o"), so for normal ".o" files, it is undefined, neither can be found within kernel wide, so will break modpost. Since ".o" files is OK, can simply export 'syscall' symbol, let modpost know about that, then can fix this issue. The related error (with allmodconfig under um): MODPOST 1205 modules ERROR: "syscall" [fs/hostfs/hostfs.ko] undefined! Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um/os-Linux: Use char[] for syscall_stub declarationsNicolas Iooss
When declaring __syscall_stub_start, use the same type in UML userspace code as in arch/um/include/asm/sections.h. While at it, also declare batch_syscall_stub as char[]. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Use char[] for linker script address declarationsNicolas Iooss
The linker script defines some variables which are declared either with type char[] in include/asm-generic/sections.h or with a meaningless integer type in arch/um/include/asm/sections.h. Fix this inconsistency by declaring every variable char[]. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Create asm/sections.hNicolas Iooss
arch/um/kernel/dyn.lds.S and arch/um/kernel/uml.lds.S define some UML-specific symbols. These symbols are used in the kernel part of UML with extern declarations. Move these declarations to a new header, asm/sections.h, like other architectures do. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-24um,ethertap: use strncpyAlan
[um maintainers appear to be vanished] I can't prove the case pointed out in https://bugzilla.kernel.org/show_bug.cgi?id=82341 is correct so let us play safe. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-19remove scatterlist.h generation from arch Kbuild filesChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19mm/fault, um: Fix compile errorPeter Zijlstra
A missing include file caused build fail. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zijlstra (Intel) <peterz@infradead.org> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Fixes: 70ffdb9393a7 ("mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in ↵David Hildenbrand
the handler Introduce faulthandler_disabled() and use it to check for irq context and disabled pagefaults (via pagefault_disable()) in the pagefault handlers. Please note that we keep the in_atomic() checks in place - to detect whether in irq context (in which case preemption is always properly disabled). In contrast, preempt_disable() should never be used to disable pagefaults. With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt counter, and therefore the result of in_atomic() differs. We validate that condition by using might_fault() checks when calling might_sleep(). Therefore, add a comment to faulthandler_disabled(), describing why this is needed. faulthandler_disabled() and pagefault_disable() are defined in linux/uaccess.h, so let's properly add that include to all relevant files. This patch is based on a patch from Thomas Gleixner. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-15Merge branch 'exec_domain_rip_v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc Pull exec domain removal from Richard Weinberger: "This series removes execution domain support from Linux. The idea behind exec domains was to support different ABIs. The feature was never complete nor stable. Let's rip it out and make the kernel signal handling code less complicated" * 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits) arm64: Removed unused variable sparc: Fix execution domain removal Remove rest of exec domains. arch: Remove exec_domain from remaining archs arc: Remove signal translation and exec_domain xtensa: Remove signal translation and exec_domain xtensa: Autogenerate offsets in struct thread_info x86: Remove signal translation and exec_domain unicore32: Remove signal translation and exec_domain um: Remove signal translation and exec_domain tile: Remove signal translation and exec_domain sparc: Remove signal translation and exec_domain sh: Remove signal translation and exec_domain s390: Remove signal translation and exec_domain mn10300: Remove signal translation and exec_domain microblaze: Remove signal translation and exec_domain m68k: Remove signal translation and exec_domain m32r: Remove signal translation and exec_domain m32r: Autogenerate offsets in struct thread_info frv: Remove signal translation and exec_domain ...
2015-04-15Merge tag 'for-linus-4.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - hostfs saw a face lifting - old/broken stuff was removed (SMP, HIGHMEM, SKAS3/4) - random cleanups and bug fixes * tag 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (26 commits) um: Print minimum physical memory requirement um: Move uml_postsetup in the init_thread stack um: add a kmsg_dumper x86, UML: fix integer overflow in ELF_ET_DYN_BASE um: hostfs: Reduce number of syscalls in readdir um: Remove broken highmem support um: Remove broken SMP support um: Remove SKAS3/4 support um: Remove ppc cruft um: Remove ia64 cruft um: Remove dead code from stacktrace hostfs: No need to box and later unbox the file mode hostfs: Use page_offset() hostfs: Set page flags in hostfs_readpage() correctly hostfs: Remove superfluous initializations in hostfs_open() hostfs: hostfs_open: Reset open flags upon each retry hostfs: Remove superfluous test in hostfs_open() hostfs: Report append flag in ->show_options() hostfs: Use __getname() in follow_link hostfs: Remove open coded strcpy() ...
2015-04-15Merge branch 'kbuild' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: "Here is the first round of kbuild changes for v4.1-rc1: - kallsyms fix for ARM and cleanup - make dep(end) removed (developers have no sense of nostalgia these days...) - include Makefiles by relative path - stop useless rebuilds of asm-offsets.h and bounds.h" * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: Kbuild: kallsyms: drop special handling of pre-3.0 GCC symbols Kbuild: kallsyms: ignore veneers emitted by the ARM linker kbuild: ia64: use $(src)/Makefile.gate rather than particular path kbuild: include $(src)/Makefile rather than $(obj)/Makefile kbuild: use relative path more to include Makefile kbuild: use relative path to include Makefile kbuild: do not add $(bounds-file) and $(offsets-file) to targets kbuild: remove warning about "make depend" kbuild: Don't reset timestamps in include/generated if not needed
2015-04-14um: expose number of page table levelsKirill A. Shutemov
We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Richard Weinberger <richard@nod.at> Cc: Jeff Dike <jdike@addtoit.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-13um: Print minimum physical memory requirementThomas Meyer
Print a more sensible message about the minimum physical memory requirement. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Move uml_postsetup in the init_thread stackThomas Meyer
atomic_notifier_chain_register() and uml_postsetup() do call kernel code that rely on the "current" kernel macro and a valid task_struct resp. thread_info struct. Give those functions a valid stack by moving uml_postsetup() in the init_thread stack. This moves enables a panic() call in this early code to generate a valid stacktrace, instead of crashing. E.g. when an UML kernel is started with an initrd but too few physical memory the panic() call get's actually processed. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: add a kmsg_dumperThomas Meyer
Add a kmsg_dumper, that dumps the kmsg buffer to stdout, when no console is available. This an enables the printing of early panic() calls triggered in uml_postsetup(). When a panic() call happens so early in the UML kernel no earlyprintk/console is available yet, but with a kmsg_dumper in place the kernel message buffer will be outputted to the user, to give a better hint, of what the failure was. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove broken highmem supportRichard Weinberger
Highmem was always buggy and experimental on UML(i386). In times where 64 bit computers are default we can remove that experimental code. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove broken SMP supportRichard Weinberger
At times where UML used the TT mode to operate it had kind of SMP support. It never got finished nor was stable. Let's rip out that cruft and stop confusing developers which do tree-wide SMP cleanups. If someone wants SMP support UML it has do be done from scratch. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove SKAS3/4 supportRichard Weinberger
Before we had SKAS0 UML had two modes of operation TT (tracing thread) and SKAS3/4 (separated kernel address space). TT was known to be insecure and got removed a long time ago. SKAS3/4 required a few (3 or 4) patches on the host side which never went mainline. The last host patch is 10 years old. With SKAS0 mode (separated kernel address space using 0 host patches), default since 2005, SKAS3/4 is obsolete and can be removed. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove ppc cruftRichard Weinberger
That code is a relict from the early days of UML. ppc support was never completed nor worked. Let's rip it out. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove ia64 cruftRichard Weinberger
That code is a relict from the early days of UML. ia64 support was never completed nor worked. Let's rip it out. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13um: Remove dead code from stacktraceRichard Weinberger
Remove left over code from commit 970e51feaddb (um: Add support for CONFIG_STACKTRACE) Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-12um: Remove signal translation and exec_domainRichard Weinberger
As execution domain support is gone we can remove signal translation from the signal code and remove exec_domain from thread_info. Signed-off-by: Richard Weinberger <richard@nod.at>