4.9-stable patches

added patches:
	kbuild-add-fno-stack-check-to-kernel-build-options.patch

diff --git a/queue-4.9/kbuild-add-fno-stack-check-to-kernel-build-options.patch b/queue-4.9/kbuild-add-fno-stack-check-to-kernel-build-options.patch
new file mode 100644 (file)
index 0000000..144d30d
--- /dev/null
+++ b/queue-4.9/kbuild-add-fno-stack-check-to-kernel-build-options.patch
@@ -0,0 +1,49 @@
+From 3ce120b16cc548472f80cf8644f90eda958cf1b6 Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Fri, 29 Dec 2017 17:34:43 -0800
+Subject: kbuild: add '-fno-stack-check' to kernel build options
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit 3ce120b16cc548472f80cf8644f90eda958cf1b6 upstream.
+
+It appears that hardened gentoo enables "-fstack-check" by default for
+gcc.
+
+That doesn't work _at_all_ for the kernel, because the kernel stack
+doesn't act like a user stack at all: it's much smaller, and it doesn't
+auto-expand on use.  So the extra "probe one page below the stack" code
+generated by -fstack-check just breaks the kernel in horrible ways,
+causing infinite double faults etc.
+
+[ I have to say, that the particular code gcc generates looks very
+  stupid even for user space where it works, but that's a separate
+  issue.  ]
+
+Reported-and-tested-by: Alexander Tsoy <alexander@tsoy.me>
+Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
+Cc: Dave Hansen <dave.hansen@intel.com>
+Cc: Jiri Kosina <jikos@kernel.org>
+Cc: Andy Lutomirski <luto@amacapital.net>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ Makefile |    3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/Makefile
++++ b/Makefile
+@@ -788,6 +788,9 @@ KBUILD_CFLAGS += $(call cc-disable-warni
+ # disable invalid "can't wrap" optimizations for signed / pointers
+ KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
+ 
++# Make sure -fstack-check isn't enabled (like gentoo apparently did)
++KBUILD_CFLAGS  += $(call cc-option,-fno-stack-check,)
++
+ # conserve stack if available
+ KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
+ 

diff --git a/queue-4.9/series b/queue-4.9/series
index feef68fd787c4d20548a3fc9a2c77d0aa402dfde..494e136cbb338079ade8bfd8e85da9d9b843f73e 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -16,3 +16,4 @@ x86-mm-make-flush_tlb_mm_range-more-predictable.patch
 x86-mm-reimplement-flush_tlb_page-using-flush_tlb_mm_range.patch
 x86-mm-remove-the-up-asm-tlbflush.h-code-always-use-the-formerly-smp-code.patch
 x86-mm-disable-pcid-on-32-bit-kernels.patch
+kbuild-add-fno-stack-check-to-kernel-build-options.patch