user/sven/linux.git/include/asm-generic/futex.h, branch v4.4.232

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50Z

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream. There is code duplicated over all architecture's headers for futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr, and comparison of the result. Remove this duplication and leave up to the arches only the needed assembly which is now in arch_futex_atomic_op_inuser. This effectively distributes the Will Deacon's arm64 fix for undefined behaviour reported by UBSAN to all architectures. The fix was done in commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump. And as suggested by Thomas, check for negative oparg too, because it was also reported to cause undefined behaviour report. Note that s390 removed access_ok check in d12a29703 ("s390/uaccess: remove pointless access_ok() checks") as access_ok there returns true. We introduce it back to the helper for the sake of simplicity (it gets optimized away anyway). Signed-off-by: Jiri Slaby Signed-off-by: Thomas Gleixner Acked-by: Russell King Acked-by: Michael Ellerman (powerpc) Acked-by: Heiko Carstens [s390] Acked-by: Chris Metcalf [for tile] Reviewed-by: Darren Hart (VMware) Reviewed-by: Will Deacon [core/arm64] Cc: linux-mips@linux-mips.org Cc: Rich Felker Cc: linux-ia64@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: peterz@infradead.org Cc: Benjamin Herrenschmidt Cc: Max Filippov Cc: Paul Mackerras Cc: sparclinux@vger.kernel.org Cc: Jonas Bonn Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Yoshinori Sato Cc: linux-hexagon@vger.kernel.org Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Catalin Marinas Cc: Matt Turner Cc: linux-snps-arc@lists.infradead.org Cc: Fenghua Yu Cc: Arnd Bergmann Cc: linux-xtensa@linux-xtensa.org Cc: Stefan Kristiansson Cc: openrisc@lists.librecores.org Cc: Ivan Kokshaysky Cc: Stafford Horne Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Henderson Cc: Chris Zankel Cc: Michal Simek Cc: Tony Luck Cc: linux-parisc@vger.kernel.org Cc: Vineet Gupta Cc: Ralf Baechle Cc: Richard Kuo Cc: linux-alpha@vger.kernel.org Cc: Martin Schwidefsky Cc: linuxppc-dev@lists.ozlabs.org Cc: "David S. Miller" Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()

2016-05-04T21:48:43Z

commit fba7cd681b6155e2d93e7862fcd6f970336b83c3 upstream. The recent decoupling of pagefault disable and preempt disable added an explicit preempt_disable/enable() pair to the futex_atomic_cmpxchg_inatomic() implementation in asm-generic/futex.h. But it forgot to add preempt_enable() calls to the error handling code pathes, which results in a preemption count imbalance. This is observable on boot when the test for atomic_cmpxchg() is calling futex_atomic_cmpxchg_inatomic() on a NULL pointer. Add the missing preempt_enable() calls to the error handling code pathes. [ tglx: Massaged changelog ] Fixes: d9b9ff8c1889 ("sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly") Signed-off-by: Romain Perier Cc: linux-arch@vger.kernel.org Cc: Thomas Petazzoni Cc: Arnd Bergmann Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1460640963-690-1-git-send-email-romain.perier@free-electrons.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly

2015-05-19T06:39:16Z

Let's explicitly disable/enable preemption in the !CONFIG_SMP version of futex_atomic_cmpxchg_inatomic(), to prepare for pagefault_disable() not touching preemption anymore. This is needed for this function to be callable from both, atomic and non-atomic context. Otherwise we might break mutual exclusion when relying on a get_user()/ put_user() implementation. Reviewed-and-tested-by: Thomas Gleixner Signed-off-by: David Hildenbrand Signed-off-by: Peter Zijlstra (Intel) Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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/1431359540-32227-10-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

sched/preempt, futex: Disable preemption in UP futex_atomic_op_inuser() explicitly

2015-05-19T06:39:16Z

Let's explicitly disable/enable preemption in the !CONFIG_SMP version of futex_atomic_op_inuser, to prepare for pagefault_disable() not touching preemption anymore. Otherwise we might break mutual exclusion when relying on a get_user()/ put_user() implementation. Reviewed-and-tested-by: Thomas Gleixner Signed-off-by: David Hildenbrand Signed-off-by: Peter Zijlstra (Intel) Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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/1431359540-32227-9-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

asm-generic: add generic futex for !CONFIG_SMP

2014-12-08T04:55:48Z

Follow m68k futex implementation for !CONFIG_SMP. Signed-off-by: Ley Foon Tan Acked-by: Arnd Bergmann

futex: Sanitize futex ops argument types

2011-03-11T11:23:31Z

Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic prototypes to use u32 types for the futex as this is the data type the futex core code uses all over the place. Signed-off-by: Michel Lespinasse Cc: Darren Hart Cc: Peter Zijlstra Cc: Matt Turner Cc: Russell King Cc: David Howells Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: "James E.J. Bottomley" Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Linus Torvalds LKML-Reference: <20110311025058.GD26122@google.com> Signed-off-by: Thomas Gleixner

futex: Sanitize cmpxchg_futex_value_locked API

2011-03-11T11:23:08Z

The cmpxchg_futex_value_locked API was funny in that it returned either the original, user-exposed futex value OR an error code such as -EFAULT. This was confusing at best, and could be a source of livelocks in places that retry the cmpxchg_futex_value_locked after trying to fix the issue by running fault_in_user_writeable(). This change makes the cmpxchg_futex_value_locked API more similar to the get_futex_value_locked one, returning an error code and updating the original value through a reference argument. Signed-off-by: Michel Lespinasse Acked-by: Chris Metcalf [tile] Acked-by: Tony Luck [ia64] Acked-by: Thomas Gleixner Tested-by: Michal Simek [microblaze] Acked-by: David Howells [frv] Cc: Darren Hart Cc: Peter Zijlstra Cc: Matt Turner Cc: Russell King Cc: Ralf Baechle Cc: "James E.J. Bottomley" Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Paul Mundt Cc: "David S. Miller" Cc: Linus Torvalds LKML-Reference: <20110311024851.GC26122@google.com> Signed-off-by: Thomas Gleixner

remove KERNEL tests of unexported headers under asm-generic/

2008-04-30T15:29:54Z

Signed-off-by: Robert P. J. Day Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

asm-*/futex.h should include linux/uaccess.h

2008-04-30T15:29:52Z

Lots of asm-*/futex.h call pagefault_enable and pagefault_disable, which are declared in linux/uaccess.h, without including linux/uaccess.h. They all include asm/uaccess.h, so this patch replaces asm/uaccess.h with linux/uaccess.h. Signed-off-by: Jeff Dike Cc: "Luck, Tony" Cc: Ralf Baechle Cc: Kyle McMartin Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Paul Mundt Cc: "David S. Miller" Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] mm: pagefault_{disable,enable}()

2006-12-07T16:39:21Z

Introduce pagefault_{disable,enable}() and use these where previously we did manual preempt increments/decrements to make the pagefault handler do the atomic thing. Currently they still rely on the increased preempt count, but do not rely on the disabled preemption, this might go away in the future. (NOTE: the extra barrier() in pagefault_disable might fix some holes on machines which have too many registers for their own good) [heiko.carstens@de.ibm.com: s390 fix] Signed-off-by: Peter Zijlstra Acked-by: Nick Piggin Cc: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds