WSL2-Linux-Kernel/include
Linus Torvalds fee7e49d45 mm: propagate error from stack expansion even for guard page
Jay Foad reports that the address sanitizer test (asan) sometimes gets
confused by a stack pointer that ends up being outside the stack vma
that is reported by /proc/maps.

This happens due to an interaction between RLIMIT_STACK and the guard
page: when we do the guard page check, we ignore the potential error
from the stack expansion, which effectively results in a missing guard
page, since the expected stack expansion won't have been done.

And since /proc/maps explicitly ignores the guard page (commit
d7824370e263: "mm: fix up some user-visible effects of the stack guard
page"), the stack pointer ends up being outside the reported stack area.

This is the minimal patch: it just propagates the error.  It also
effectively makes the guard page part of the stack limit, which in turn
measn that the actual real stack is one page less than the stack limit.

Let's see if anybody notices.  We could teach acct_stack_growth() to
allow an extra page for a grow-up/grow-down stack in the rlimit test,
but I don't want to add more complexity if it isn't needed.

Reported-and-tested-by: Jay Foad <jay.foad@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-06 13:00:05 -08:00
..
acpi Merge branches 'acpi-scan', 'acpi-utils' and 'acpi-pm' 2014-12-18 18:42:56 +01:00
asm-generic ARM: SoC/iommu configuration for 3.19 2014-12-16 14:53:01 -08:00
clocksource
crypto
drm Revert "drm/gem: Warn on illegal use of the dumb buffer interface v2" 2014-12-24 13:13:22 +10:00
dt-bindings Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal into thermal-soc 2014-12-21 22:49:12 +08:00
keys
kvm arm/arm64: KVM: Require in-kernel vgic for the arch timers 2014-12-15 11:50:42 +01:00
linux mm: propagate error from stack expansion even for guard page 2015-01-06 13:00:05 -08:00
math-emu
media
memory
misc
net netlink/genetlink: pass network namespace to bind/unbind 2014-12-27 03:07:50 -05:00
pcmcia
ras
rdma IB/core: Implement support for MMU notifiers regarding on demand paging regions 2014-12-15 18:13:36 -08:00
rxrpc
scsi SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
soc
sound ALSA: pcm: Fix kerneldoc for params_*() functions 2014-12-30 16:41:11 +01:00
target SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
trace SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
uapi vhost: virtio 1.0 bugfix 2015-01-02 12:07:50 -08:00
video
xen
Kbuild