x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm

commit b9e705ef7cfaf22db0daab91ad3cd33b0fa32eb9 upstream.

Where an ALTERNATIVE is used in the middle of an inline asm block, this
would otherwise lead to the following instruction being appended directly
to the trailing ".popsection", and a failed compile.

Fixes: 9cebed423c84 ("x86, alternative: Use .pushsection/.popsection")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: ak@linux.intel.com
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180104143710.8961-8-dwmw@amazon.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 999d4f1961fa002bda138ddfe9119965421f85da)
Orabug: 27477743
CVE: CVE-2017-5715
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 7d2e9a5175d0d3cd3d938f649542fb1660f7ba47..5ed0d04177b841d90ccbc956d1345145e2595a4f 100644 (file)
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -132,7 +132,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
        ".popsection\n"                                                 \
        ".pushsection .altinstr_replacement, \"ax\"\n"                  \
        ALTINSTR_REPLACEMENT(newinstr, feature, 1)                      \
-       ".popsection"
+       ".popsection\n"
 
 #define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\
        OLDINSTR_2(oldinstr, 1, 2)                                      \
@@ -143,7 +143,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
        ".pushsection .altinstr_replacement, \"ax\"\n"                  \
        ALTINSTR_REPLACEMENT(newinstr1, feature1, 1)                    \
        ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)                    \
-       ".popsection"
+       ".popsection\n"
 
 /*
  * This must be included *after* the definition of ALTERNATIVE due to