kernel/linux.git/lib, branch v4.9.21

lib/syscall: Clear return values when no stack

2017-04-08T07:30:35+00:00

commit 854fbd6e5f60fe99e8e3a569865409fca378f143 upstream. Commit: aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") ... added logic to handle a process stack not existing, but left sp and pc uninitialized, which can be later reported via /proc/$pid/syscall for zombie processes, potentially exposing kernel memory to userspace. Zombie /proc/$pid/syscall before: -1 0xffffffff9a060100 0xffff92f42d6ad900 Zombie /proc/$pid/syscall after: -1 0x0 0x0 Reported-by: Robert Święcki Signed-off-by: Kees Cook Reviewed-by: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()") Link: http://lkml.kernel.org/r/20170323224616.GA92694@beast Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

swiotlb: Add swiotlb=noforce debug option

2017-01-26T07:24:44+00:00

commit fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 upstream. On architectures like arm64, swiotlb is tied intimately to the core architecture DMA support. In addition, ZONE_DMA cannot be disabled. To aid debugging and catch devices not supporting DMA to memory outside the 32-bit address space, add a kernel command line option "swiotlb=noforce", which disables the use of bounce buffers. If specified, trying to map memory that cannot be used with DMA will fail, and a rate-limited warning will be printed. Note that io_tlb_nslabs is set to 1, which is the minimal supported value. Signed-off-by: Geert Uytterhoeven Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

swiotlb: Convert swiotlb_force from int to enum

2017-01-26T07:24:44+00:00

commit ae7871be189cb41184f1e05742b4a99e2c59774d upstream. Convert the flag swiotlb_force from an int to an enum, to prepare for the advent of more possible values. Suggested-by: Konrad Rzeszutek Wilk Signed-off-by: Geert Uytterhoeven Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

fix a fencepost error in pipe_advance()

2017-01-19T19:18:02+00:00

commit b9dc6f65bc5e232d1c05fe34b5daadc7e8bbf1fb upstream. The logics in pipe_advance() used to release all buffers past the new position failed in cases when the number of buffers to release was equal to pipe->buffers. If that happened, none of them had been released, leaving pipe full. Worse, it was trivial to trigger and we end up with pipe full of uninitialized pages. IOW, it's an infoleak. Reported-by: "Alan J. Wylie" Tested-by: "Alan J. Wylie" Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

Revert "radix tree test suite: fix compilation"

2016-12-09T18:41:42+00:00

This reverts commit 53855d10f4567a0577360b6448d52a863929775b. It shouldn't have come in yet - it depends on the changes in linux-next that will come in during the next merge window. As Matthew Wilcox says, the test suite is broken with the current state without the revert. Requested-by: Matthew Wilcox Cc: Andrew Morton Signed-off-by: Linus Torvalds

radix tree test suite: fix compilation

2016-12-08T01:10:00+00:00

Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test suite as it adds a call to cpuhp_setup_state_nocalls() which is not currently emulated in the test suite. Add it, and delete the emulation of the old CPU hotplug mechanism. Link: http://lkml.kernel.org/r/1480369871-5271-36-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox Tested-by: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Ross Zwisler Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-07T19:27:33+00:00

Pull locking fixes from Ingo Molnar: "Two rtmutex race fixes (which miraculously never triggered, that we know of), plus two lockdep printk formatting regression fixes" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Fix report formatting locking/rtmutex: Use READ_ONCE() in rt_mutex_owner() locking/rtmutex: Prevent dequeue vs. unlock race locking/selftest: Fix output since KERN_CONT changes

kasan: support use-after-scope detection

2016-12-01T00:32:52+00:00

Gcc revision 241896 implements use-after-scope detection. Will be available in gcc 7. Support it in KASAN. Gcc emits 2 new callbacks to poison/unpoison large stack objects when they go in/out of scope. Implement the callbacks and add a test. [dvyukov@google.com: v3] Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov Acked-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: [4.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/debugobjects: export for use in modules

2016-12-01T00:32:52+00:00

Drivers, or other modules, that use a mixture of objects (especially objects embedded within other objects) would like to take advantage of the debugobjects facilities to help catch misuse. Currently, the debugobjects interface is only available to builtin drivers and requires a set of EXPORT_SYMBOL_GPL for use by modules. I am using the debugobjects in i915.ko to try and catch some invalid operations on embedded objects. The problem currently only presents itself across module unload so forcing i915 to be builtin is not an option. Link: http://lkml.kernel.org/r/20161122143039.6433-1-chris@chris-wilson.co.uk Signed-off-by: Chris Wilson Cc: "Du, Changbin" Cc: Thomas Gleixner Cc: Christian Borntraeger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locking/selftest: Fix output since KERN_CONT changes

2016-11-25T06:12:19+00:00

Since the KERN_CONT changes the locking-selftest output is messed up, eg: ---------------------------------------------------------------------------- | spin |wlock |rlock |mutex | wsem | rsem | -------------------------------------------------------------------------- A-A deadlock: ok | ok | ok | ok | ok | ok | Use pr_cont() to get it looking normal again: ---------------------------------------------------------------------------- | spin |wlock |rlock |mutex | wsem | rsem | -------------------------------------------------------------------------- A-A deadlock: ok | ok | ok | ok | ok | ok | Reported-by: Christian Kujau Signed-off-by: Michael Ellerman Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/1480027528-934-1-git-send-email-mpe@ellerman.id.au Signed-off-by: Ingo Molnar