Commit-ID: ac180540b04d7ffaf8ba6f13bf628c4f50dc9820
Gitweb: https://git.kernel.org/tip/ac180540b04d7ffaf8ba6f13bf628c4f50dc9820
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Wed, 19 Dec 2018 11:23:14 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 19 Dec 2018 12:00:09 +0100
Revert "x86/refcount: Work around GCC inlining bug"
This reverts commit 9e1725b410594911cc5981b6c7b4cea4ec054ca8.
See this commit for details about the revert:
e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")
The conflict resolution for interaction with:
288e4521f0f6: ("x86/asm: 'Simplify' GEN_*_RMWcc() macros")
was provided by Masahiro Yamada.
Conflicts:
arch/x86/include/asm/refcount.h
Reported-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Richard Biener <rguenther@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/refcount.h | 81 +++++++++++++++++------------------------
arch/x86/kernel/macros.S | 1 -
2 files changed, 33 insertions(+), 49 deletions(-)
diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h
index a8b5e1e13319..dbaed55c1c24 100644
--- a/arch/x86/include/asm/refcount.h
+++ b/arch/x86/include/asm/refcount.h
@@ -4,41 +4,6 @@
* x86-specific implementation of refcount_t. Based on PAX_REFCOUNT from
* PaX/grsecurity.
*/
-
-#ifdef __ASSEMBLY__
-
-#include <asm/asm.h>
-#include <asm/bug.h>
-
-.macro REFCOUNT_EXCEPTION counter:req
- .pushsection .text..refcount
-111: lea \counter, %_ASM_CX
-112: ud2
- ASM_UNREACHABLE
- .popsection
-113: _ASM_EXTABLE_REFCOUNT(112b, 113b)
-.endm
-
-/* Trigger refcount exception if refcount result is negative. */
-.macro REFCOUNT_CHECK_LT_ZERO counter:req
- js 111f
- REFCOUNT_EXCEPTION counter="\counter"
-.endm
-
-/* Trigger refcount exception if refcount result is zero or negative. */
-.macro REFCOUNT_CHECK_LE_ZERO counter:req
- jz 111f
- REFCOUNT_CHECK_LT_ZERO counter="\counter"
-.endm
-
-/* Trigger refcount exception unconditionally. */
-.macro REFCOUNT_ERROR counter:req
- jmp 111f
- REFCOUNT_EXCEPTION counter="\counter"
-.endm
-
-#else /* __ASSEMBLY__ */
-
#include <linux/refcount.h>
#include <asm/bug.h>
@@ -50,12 +15,35 @@
* central refcount exception. The fixup address for the exception points
* back to the regular execution flow in .text.
*/
+#define _REFCOUNT_EXCEPTION \
+ ".pushsection .text..refcount\n" \
+ "111:\tlea %[var], %%" _ASM_CX "\n" \
+ "112:\t" ASM_UD2 "\n" \
+ ASM_UNREACHABLE \
+ ".popsection\n" \
+ "113:\n" \
+ _ASM_EXTABLE_REFCOUNT(112b, 113b)
+
+/* Trigger refcount exception if refcount result is negative. */
+#define REFCOUNT_CHECK_LT_ZERO \
+ "js 111f\n\t" \
+ _REFCOUNT_EXCEPTION
+
+/* Trigger refcount exception if refcount result is zero or negative. */
+#define REFCOUNT_CHECK_LE_ZERO \
+ "jz 111f\n\t" \
+ REFCOUNT_CHECK_LT_ZERO
+
+/* Trigger refcount exception unconditionally. */
+#define REFCOUNT_ERROR \
+ "jmp 111f\n\t" \
+ _REFCOUNT_EXCEPTION
static __always_inline void refcount_add(unsigned int i, refcount_t *r)
{
asm volatile(LOCK_PREFIX "addl %1,%0\n\t"
- "REFCOUNT_CHECK_LT_ZERO counter=\"%[counter]\""
- : [counter] "+m" (r->refs.counter)
+ REFCOUNT_CHECK_LT_ZERO
+ : [var] "+m" (r->refs.counter)
: "ir" (i)
: "cc", "cx");
}
@@ -63,32 +51,31 @@ static __always_inline void refcount_add(unsigned int i, refcount_t *r)
static __always_inline void refcount_inc(refcount_t *r)
{
asm volatile(LOCK_PREFIX "incl %0\n\t"
- "REFCOUNT_CHECK_LT_ZERO counter=\"%[counter]\""
- : [counter] "+m" (r->refs.counter)
+ REFCOUNT_CHECK_LT_ZERO
+ : [var] "+m" (r->refs.counter)
: : "cc", "cx");
}
static __always_inline void refcount_dec(refcount_t *r)
{
asm volatile(LOCK_PREFIX "decl %0\n\t"
- "REFCOUNT_CHECK_LE_ZERO counter=\"%[counter]\""
- : [counter] "+m" (r->refs.counter)
+ REFCOUNT_CHECK_LE_ZERO
+ : [var] "+m" (r->refs.counter)
: : "cc", "cx");
}
static __always_inline __must_check
bool refcount_sub_and_test(unsigned int i, refcount_t *r)
{
-
return GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl",
- "REFCOUNT_CHECK_LT_ZERO counter=\"%[var]\"",
+ REFCOUNT_CHECK_LT_ZERO,
r->refs.counter, e, "er", i, "cx");
}
static __always_inline __must_check bool refcount_dec_and_test(refcount_t *r)
{
return GEN_UNARY_SUFFIXED_RMWcc(LOCK_PREFIX "decl",
- "REFCOUNT_CHECK_LT_ZERO counter=\"%[var]\"",
+ REFCOUNT_CHECK_LT_ZERO,
r->refs.counter, e, "cx");
}
@@ -106,8 +93,8 @@ bool refcount_add_not_zero(unsigned int i, refcount_t *r)
/* Did we try to increment from/to an undesirable state? */
if (unlikely(c < 0 || c == INT_MAX || result < c)) {
- asm volatile("REFCOUNT_ERROR counter=\"%[counter]\""
- : : [counter] "m" (r->refs.counter)
+ asm volatile(REFCOUNT_ERROR
+ : : [var] "m" (r->refs.counter)
: "cc", "cx");
break;
}
@@ -122,6 +109,4 @@ static __always_inline __must_check bool refcount_inc_not_zero(refcount_t *r)
return refcount_add_not_zero(1, r);
}
-#endif /* __ASSEMBLY__ */
-
#endif
diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
index f1fe1d570365..cee28c3246dc 100644
--- a/arch/x86/kernel/macros.S
+++ b/arch/x86/kernel/macros.S
@@ -7,4 +7,3 @@
*/
#include <linux/compiler.h>
-#include <asm/refcount.h>
|