android_kernel_msm-6.1_noth.../include
Will Deacon 784e0300fe rseq: Avoid infinite recursion when delivering SIGSEGV
When delivering a signal to a task that is using rseq, we call into
__rseq_handle_notify_resume() so that the registers pushed in the
sigframe are updated to reflect the state of the restartable sequence
(for example, ensuring that the signal returns to the abort handler if
necessary).

However, if the rseq management fails due to an unrecoverable fault when
accessing userspace or certain combinations of RSEQ_CS_* flags, then we
will attempt to deliver a SIGSEGV. This has the potential for infinite
recursion if the rseq code continuously fails on signal delivery.

Avoid this problem by using force_sigsegv() instead of force_sig(), which
is explicitly designed to reset the SEGV handler to SIG_DFL in the case
of a recursive fault. In doing so, remove rseq_signal_deliver() from the
internal rseq API and have an optional struct ksignal * parameter to
rseq_handle_notify_resume() instead.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: peterz@infradead.org
Cc: paulmck@linux.vnet.ibm.com
Cc: boqun.feng@gmail.com
Link: https://lkml.kernel.org/r/1529664307-983-1-git-send-email-will.deacon@arm.com
2018-06-22 19:04:22 +02:00
..
acpi Additional ACPI updates for 4.18-rc1 2018-06-13 07:32:10 -07:00
asm-generic int-ll64.h: define u{8,16,32,64} and s{8,16,32,64} based on uapi header 2018-06-07 17:34:38 -07:00
clocksource
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-06-05 15:51:21 -07:00
drm drm for v4.18-rc1 2018-06-06 08:16:33 -07:00
dt-bindings ARM: SoC driver updates 2018-06-11 18:15:22 -07:00
keys docs: Fix some broken references 2018-06-15 18:10:01 -03:00
kvm
linux rseq: Avoid infinite recursion when delivering SIGSEGV 2018-06-22 19:04:22 +02:00
math-emu
media
memory
misc ocxl: Expose the thread_id needed for wait on POWER9 2018-06-03 20:40:32 +10:00
net net/ipv6: respect rcu grace period before freeing fib6_info 2018-06-20 07:57:23 +09:00
pcmcia
ras
rdma 4.18-rc 2018-06-21 07:22:30 +09:00
scsi SCSI misc on 20180610 2018-06-10 13:01:12 -07:00
soc ARM: SoC: late updates 2018-06-11 18:19:45 -07:00
sound sound updates for 4.18 2018-06-06 09:08:38 -07:00
target
trace NFS client updates for Linux 4.18 2018-06-12 10:09:03 -07:00
uapi Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
video fbdev changes for v4.18: 2018-06-17 05:00:24 +09:00
xen docs: Fix some broken references 2018-06-15 18:10:01 -03:00