lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 2 Jul 2014 17:56:35 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Kees Cook <kees@...flux.net>
Cc:	Andi Kleen <ak@...ux.intel.com>,
	Randy Dunlap <rdunlap@...radead.org>,
	linux-kernel@...r.kernel.org, linux-next@...r.kernel.org,
	sfr@...b.auug.org.au, mhocko@...e.cz
Subject: Re: mmotm 2014-07-02-15-07 uploaded (stack protector)

On Wed, 2 Jul 2014 17:51:00 -0700 Kees Cook <kees@...flux.net> wrote:

> > It's hard to tell what the original author wanted, perhaps they wanted
> > it to error out. It looks intentional. Clearly they didn't think of randconfig
> > though.
> 
> The problem is that if you make kbuild hard-fail when selecting this missing
> compiler option, you can never switch it back because "make menuconfig" will
> refuse to build since the compiler option would be missing. Being silent
> about the missing option (and/or falling back to other options) means that
> you could get two different kernel features selection with the same CONFIG_*
> set, depending on the kernel, which is extremely bad ("I selected
> stack-protector-strong but it built without it?!").
> 
> So, the middle ground was to warn about it during the kbuild logic so
> you could find the source of the problem, but ultimately fail the build
> when the compiler doesn't support it so there weren't any silent failure
> modes.

--- a/Makefile~a
+++ a/Makefile
@@ -630,6 +630,9 @@ KBUILD_CFLAGS += $(call cc-option,-Wfram
 endif
 
 # Handle stack protector mode.
+#
+# This space reserved for Kees
+#
 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
   stackp-flag := -fstack-protector
   ifeq ($(call cc-option, $(stackp-flag)),)
_

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists