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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-26 22:24:09 +08:00
linux-next/arch/arm64
Mark Rutland 289d07a2dc arm64: mm: abort uaccess retries upon fatal signal
When there's a fatal signal pending, arm64's do_page_fault()
implementation returns 0. The intent is that we'll return to the
faulting userspace instruction, delivering the signal on the way.

However, if we take a fatal signal during fixing up a uaccess, this
results in a return to the faulting kernel instruction, which will be
instantly retried, resulting in the same fault being taken forever. As
the task never reaches userspace, the signal is not delivered, and the
task is left unkillable. While the task is stuck in this state, it can
inhibit the forward progress of the system.

To avoid this, we must ensure that when a fatal signal is pending, we
apply any necessary fixup for a faulting kernel instruction. Thus we
will return to an error path, and it is up to that code to make forward
progress towards delivering the fatal signal.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-08-22 18:15:42 +01:00
..
boot Allwinner fixes for 4.13, round 2 2017-08-18 11:55:44 +02:00
configs arm64: defconfig: enable missing HWSPINLOCK 2017-07-27 23:09:54 -05:00
crypto crypto: arm64/sha - avoid non-standard inline asm tricks 2017-05-18 13:19:52 +08:00
include Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:34:24 -07:00
kernel arm64: fpsimd: Prevent registers leaking across exec 2017-08-22 18:15:42 +01:00
kvm KVM: arm/arm64: PMU: Fix overflow interrupt injection 2017-07-25 14:18:01 +01:00
lib arm64/lib: copy_page: use consistent prefetch stride 2017-07-25 10:04:42 +01:00
mm arm64: mm: abort uaccess retries upon fatal signal 2017-08-22 18:15:42 +01:00
net arm64 updates for 4.13: 2017-07-05 17:09:27 -07:00
xen xen/privcmd: Add IOCTL_PRIVCMD_DM_OP 2017-02-14 15:13:43 -05:00
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00
Kconfig.debug arm64: relocation testing module 2017-04-04 17:03:32 +01:00
Kconfig.platforms ARM: SoC 64-bit changes 2017-07-04 14:53:26 -07:00
Makefile arm64: pass endianness info to sparse 2017-06-26 10:15:06 +01:00