From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
Peter Zijlstra <peterz@infradead.org>,
PaX Team <pageexec@freemail.hu>, Jann Horn <jannh@google.com>,
Eric Biggers <ebiggers3@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
"axboe@kernel.dk" <axboe@kernel.dk>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Elena Reshetova <elena.reshetova@intel.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
David Windsor <dwindsor@gmail.com>,
"x86@kernel.org" <x86@kernel.org>, Ingo Molnar <mingo@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"David S. Miller" <davem@davemloft.net>,
Rik van Riel <riel@redhat.com>,
linux-arch <linux-arch@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: [PATCH v2 1/2] x86, asm: Add suffix macro for GEN_*_RMWcc()
Date: Tue, 25 Apr 2017 15:56:36 -0700 [thread overview]
Message-ID: <1493160997-126108-2-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1493160997-126108-1-git-send-email-keescook@chromium.org>
The coming x86 refcount protection needs to be able to add trailing
instructions to the GEN_*_RMWcc() operations. This extracts the
difference between the goto/non-goto cases so the helper macros
can be defined outside the #ifdef cases. Additionally adds argument
naming to the resulting asm for referencing from suffixed
instructions.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/x86/include/asm/rmwcc.h | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h
index 661dd305694a..3e96f9a56b6d 100644
--- a/arch/x86/include/asm/rmwcc.h
+++ b/arch/x86/include/asm/rmwcc.h
@@ -8,18 +8,15 @@
#define __GEN_RMWcc(fullop, var, cc, ...) \
do { \
asm_volatile_goto (fullop "; j" #cc " %l[cc_label]" \
- : : "m" (var), ## __VA_ARGS__ \
+ : : [counter] "m" (var), ## __VA_ARGS__ \
: "memory" : cc_label); \
return 0; \
cc_label: \
return 1; \
} while (0)
-#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
- __GEN_RMWcc(op " " arg0, var, cc)
+#define __BINARY_RMWcc_ARG " %1, "
-#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
- __GEN_RMWcc(op " %1, " arg0, var, cc, vcon (val))
#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
@@ -29,17 +26,26 @@ cc_label: \
do { \
bool c; \
asm volatile (fullop ";" CC_SET(cc) \
- : "+m" (var), CC_OUT(cc) (c) \
+ : [counter] "+m" (var), CC_OUT(cc) (c) \
: __VA_ARGS__ : "memory"); \
return c; \
} while (0)
+#define __BINARY_RMWcc_ARG " %2, "
+
+#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
+
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
__GEN_RMWcc(op " " arg0, var, cc)
+#define GEN_UNARY_SUFFIXED_RMWcc(op, suffix, var, arg0, cc) \
+ __GEN_RMWcc(op " " arg0 "\n\t" suffix, var, cc)
+
#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
- __GEN_RMWcc(op " %2, " arg0, var, cc, vcon (val))
+ __GEN_RMWcc(op __BINARY_RMWcc_ARG arg0, var, cc, vcon (val))
-#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
+#define GEN_BINARY_SUFFIXED_RMWcc(op, suffix, var, vcon, val, arg0, cc) \
+ __GEN_RMWcc(op __BINARY_RMWcc_ARG arg0 "\n\t" suffix, var, cc, \
+ vcon (val))
#endif /* _ASM_X86_RMWcc */
--
2.7.4
next prev parent reply other threads:[~2017-04-25 22:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-25 22:56 [PATCH v2 0/2] x86, refcount: Implement fast refcount overflow Kees Cook
2017-04-25 22:56 ` Kees Cook [this message]
2017-04-25 22:56 ` [PATCH v2 2/2] x86, refcount: Implement fast refcount overflow protection Kees Cook
2017-04-26 0:25 ` Jann Horn
2017-04-26 3:52 ` Kees Cook
2017-04-27 1:31 ` kbuild test robot
2017-04-27 20:22 ` Kees Cook
2017-05-01 15:54 ` Josh Poimboeuf
2017-05-01 17:28 ` Kees Cook
2017-05-01 22:33 ` Josh Poimboeuf
2017-05-01 16:30 ` Josh Poimboeuf
2017-05-01 17:36 ` Kees Cook
2017-05-01 22:45 ` Josh Poimboeuf
2017-04-26 2:01 ` [PATCH v2 0/2] x86, refcount: Implement fast refcount overflow PaX Team
2017-04-26 3:59 ` Kees Cook
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