diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/refcount.h | 81 | ||||
| -rw-r--r-- | 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> |