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From: Kees Cook <keescook@chromium.org>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Richard Weinberger <richard.weinberger@gmail.com>,
	Richard Weinberger <richard@nod.at>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Prasad Sodagudi <psodagud@codeaurora.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Amit Daniel Kachhap <amit.kachhap@arm.com>,
	"open list:KERNEL SELFTEST FRAMEWORK" 
	<linux-kselftest@vger.kernel.org>,
	clang-built-linux@googlegroups.com,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH drivers/misc 0/4] lkdtm: Various clean ups
Date: Wed, 24 Jun 2020 23:06:18 -0700	[thread overview]
Message-ID: <202006242300.145D555@keescook> (raw)
In-Reply-To: <80f501f4-d4fb-1f22-5603-57b5490a695d@infradead.org>

On Wed, Jun 24, 2020 at 06:45:47PM -0700, Randy Dunlap wrote:
> Looks like lkdtm/bugs.c needs to get/use arch/x86/include/asm/processor.h
> but it actually uses arch/x86/um/asm/processor*.h, which does not have the
> needed structs etc.

Should I just test for !UML in bugs.c? (This is all for the
lkdtm_DOUBLE_FAULT() test.) I already do those kinds of checks for the
lkdtm_UNSET_SMEP() test. e.g.:


diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 736675f0a246..f3e7040a7739 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -13,7 +13,7 @@
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 
-#ifdef CONFIG_X86_32
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
 #include <asm/desc.h>
 #endif
 
@@ -419,7 +419,7 @@ void lkdtm_UNSET_SMEP(void)
 
 void lkdtm_DOUBLE_FAULT(void)
 {
-#ifdef CONFIG_X86_32
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
 	/*
 	 * Trigger #DF by setting the stack limit to zero.  This clobbers
 	 * a GDT TLS slot, which is okay because the current task will die

-- 
Kees Cook

  reply	other threads:[~2020-06-25  6:06 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-29 20:03 [PATCH drivers/misc 0/4] lkdtm: Various clean ups Kees Cook
2020-05-29 20:03 ` [PATCH 1/4] lkdtm: Avoid more compiler optimizations for bad writes Kees Cook
2020-05-29 20:10   ` Nick Desaulniers
2020-05-29 20:03 ` [PATCH 2/4] lkdtm/heap: Avoid edge and middle of slabs Kees Cook
2020-05-29 20:03 ` [PATCH 3/4] selftests/lkdtm: Reset WARN_ONCE to avoid false negatives Kees Cook
2020-05-29 20:22   ` Shuah Khan
2020-05-29 20:03 ` [PATCH 4/4] lkdtm: Make arch-specific tests always available Kees Cook
2020-06-23 23:10 ` [PATCH drivers/misc 0/4] lkdtm: Various clean ups Kees Cook
2020-06-23 23:32   ` Randy Dunlap
2020-06-24  0:01     ` Kees Cook
2020-06-24  7:23     ` Richard Weinberger
2020-06-24 20:36       ` Kees Cook
2020-06-24 21:29         ` Randy Dunlap
2020-06-24 22:01           ` Richard Weinberger
2020-06-24 22:23             ` Randy Dunlap
2020-06-24 22:35               ` Randy Dunlap
2020-06-25  1:45                 ` Randy Dunlap
2020-06-25  6:06                   ` Kees Cook [this message]
2020-06-25  6:24                     ` Richard Weinberger
2020-06-25 15:24                       ` Randy Dunlap
2020-06-24  6:13   ` Greg Kroah-Hartman

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