3 files changed, 51 insertions, 25 deletions

diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c
index 0203baefb5c0..d4a7df2205b8 100644
--- a/arch/x86/math-emu/fpu_entry.c
+++ b/arch/x86/math-emu/fpu_entry.c
@@ -147,7 +147,7 @@ void math_emulate(struct math_emu_info *info)
 		}
 
 		code_descriptor = FPU_get_ldt_descriptor(FPU_CS);
-		if (SEG_D_SIZE(code_descriptor)) {
+		if (code_descriptor.d) {
 			/* The above test may be wrong, the book is not clear */
 			/* Segmented 32 bit protected mode */
 			addr_modes.default_mode = SEG32;
@@ -155,11 +155,10 @@ void math_emulate(struct math_emu_info *info)
 			/* 16 bit protected mode */
 			addr_modes.default_mode = PM16;
 		}
-		FPU_EIP += code_base = SEG_BASE_ADDR(code_descriptor);
-		code_limit = code_base
-		    + (SEG_LIMIT(code_descriptor) +
-		       1) * SEG_GRANULARITY(code_descriptor)
-		    - 1;
+		FPU_EIP += code_base = seg_get_base(&code_descriptor);
+		code_limit = seg_get_limit(&code_descriptor) + 1;
+		code_limit *= seg_get_granularity(&code_descriptor);
+		code_limit += code_base - 1;
 		if (code_limit < code_base)
 			code_limit = 0xffffffff;
 	}
diff --git a/arch/x86/math-emu/fpu_system.h b/arch/x86/math-emu/fpu_system.h
index a179254a5122..2319a257ec32 100644
--- a/arch/x86/math-emu/fpu_system.h
+++ b/arch/x86/math-emu/fpu_system.h
@@ -34,17 +34,43 @@ static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg)
 	return ret;
 }
 
-#define SEG_D_SIZE(x)		((x).b & (3 << 21))
-#define SEG_G_BIT(x)		((x).b & (1 << 23))
-#define SEG_GRANULARITY(x)	(((x).b & (1 << 23)) ? 4096 : 1)
-#define SEG_286_MODE(x)		((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
-#define SEG_BASE_ADDR(s)	(((s).b & 0xff000000) \
-				 | (((s).b & 0xff) << 16) | ((s).a >> 16))
-#define SEG_LIMIT(s)		(((s).b & 0xff0000) | ((s).a & 0xffff))
-#define SEG_EXECUTE_ONLY(s)	(((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
-#define SEG_WRITE_PERM(s)	(((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
-#define SEG_EXPAND_DOWN(s)	(((s).b & ((1 << 11) | (1 << 10))) \
-				 == (1 << 10))
+#define SEG_TYPE_WRITABLE	(1U << 1)
+#define SEG_TYPE_EXPANDS_DOWN	(1U << 2)
+#define SEG_TYPE_EXECUTE	(1U << 3)
+#define SEG_TYPE_EXPAND_MASK	(SEG_TYPE_EXPANDS_DOWN | SEG_TYPE_EXECUTE)
+#define SEG_TYPE_EXECUTE_MASK	(SEG_TYPE_WRITABLE | SEG_TYPE_EXECUTE)
+
+static inline unsigned long seg_get_base(struct desc_struct *d)
+{
+	unsigned long base = (unsigned long)d->base2 << 24;
+
+	return base | ((unsigned long)d->base1 << 16) | d->base0;
+}
+
+static inline unsigned long seg_get_limit(struct desc_struct *d)
+{
+	return ((unsigned long)d->limit << 16) | d->limit0;
+}
+
+static inline unsigned long seg_get_granularity(struct desc_struct *d)
+{
+	return d->g ? 4096 : 1;
+}
+
+static inline bool seg_expands_down(struct desc_struct *d)
+{
+	return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN;
+}
+
+static inline bool seg_execute_only(struct desc_struct *d)
+{
+	return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE;
+}
+
+static inline bool seg_writable(struct desc_struct *d)
+{
+	return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE;
+}
 
 #define I387			(&current->thread.fpu.state)
 #define FPU_info		(I387->soft.info)
diff --git a/arch/x86/math-emu/get_address.c b/arch/x86/math-emu/get_address.c
index b8ef9f9d2ffc..c48967c6a0e2 100644
--- a/arch/x86/math-emu/get_address.c
+++ b/arch/x86/math-emu/get_address.c
@@ -159,17 +159,18 @@ static long pm_address(u_char FPU_modrm, u_char segment,
 	}
 
 	descriptor = FPU_get_ldt_descriptor(addr->selector);
-	base_address = SEG_BASE_ADDR(descriptor);
+	base_address = seg_get_base(&descriptor);
 	address = base_address + offset;
-	limit = base_address
-	    + (SEG_LIMIT(descriptor) + 1) * SEG_GRANULARITY(descriptor) - 1;
+	limit = seg_get_limit(&descriptor) + 1;
+	limit *= seg_get_granularity(&descriptor);
+	limit += base_address - 1;
 	if (limit < base_address)
 		limit = 0xffffffff;
 
-	if (SEG_EXPAND_DOWN(descriptor)) {
-		if (SEG_G_BIT(descriptor))
+	if (seg_expands_down(&descriptor)) {
+		if (descriptor.g) {
 			seg_top = 0xffffffff;
-		else {
+		} else {
 			seg_top = base_address + (1 << 20);
 			if (seg_top < base_address)
 				seg_top = 0xffffffff;
@@ -182,8 +183,8 @@ static long pm_address(u_char FPU_modrm, u_char segment,
 		    (address > limit) || (address < base_address) ? 0 :
 		    ((limit - address) >= 254 ? 255 : limit - address + 1);
 	}
-	if (SEG_EXECUTE_ONLY(descriptor) ||
-	    (!SEG_WRITE_PERM(descriptor) && (FPU_modrm & FPU_WRITE_BIT))) {
+	if (seg_execute_only(&descriptor) ||
+	    (!seg_writable(&descriptor) && (FPU_modrm & FPU_WRITE_BIT))) {
 		access_limit = 0;
 	}
 	return address;