[SPARC64]: Fix fault handling in unaligned trap handler.

We were not calling kernel_mna_trap_fault() correctly.
Instead of being fancy, just return 0 vs. -EFAULT from
the assembler stubs, and handle that return value as
appropriate.

Create an "__retl_efault" stub for assembler exception
table entries and use it where possible.

Signed-off-by: David S. Miller <[e-mail]>

arch/sparc64/kernel/head.S

···
 prom_tba:	.xword	0
 tlb_type:	.word	0	/* Must NOT end up in BSS */
 	.section	".fixup",#alloc,#execinstr
-	.globl	__ret_efault
+
+	.globl	__ret_efault, __retl_efault
 __ret_efault:
 	ret
 	 restore %g0, -EFAULT, %o0
-
+__retl_efault:
+	retl
+	 mov	-EFAULT, %o0

arch/sparc64/kernel/sys32.S

···
 	or		%g2, %lo(__socketcall_table_begin), %g2
 	jmpl		%g2 + %o0, %g0
 	 nop
+do_einval:
+	retl
+	 mov		-EINVAL, %o0
 
 	.align		32
 __socketcall_table_begin:
···
 	nop
 	nop
 
-do_einval:
-	retl
-	 mov		-EINVAL, %o0
-do_efault:
-	retl
-	 mov		-EFAULT, %o0
-
 	.section	__ex_table
 	.align		4
-	.word	1b, do_efault, 2b, do_efault, 3b, do_efault, 4b, do_efault
-	.word	5b, do_efault, 6b, do_efault, 7b, do_efault, 8b, do_efault
-	.word	9b, do_efault, 10b, do_efault, 11b, do_efault, 12b, do_efault
-	.word	13b, do_efault, 14b, do_efault, 15b, do_efault, 16b, do_efault
-	.word	17b, do_efault, 18b, do_efault, 19b, do_efault, 20b, do_efault
-	.word	21b, do_efault, 22b, do_efault, 23b, do_efault, 24b, do_efault
-	.word	25b, do_efault, 26b, do_efault, 27b, do_efault, 28b, do_efault
-	.word	29b, do_efault, 30b, do_efault, 31b, do_efault, 32b, do_efault
-	.word	33b, do_efault, 34b, do_efault, 35b, do_efault, 36b, do_efault
-	.word	37b, do_efault, 38b, do_efault, 39b, do_efault, 40b, do_efault
-	.word	41b, do_efault, 42b, do_efault, 43b, do_efault, 44b, do_efault
-	.word	45b, do_efault, 46b, do_efault, 47b, do_efault, 48b, do_efault
-	.word	49b, do_efault, 50b, do_efault, 51b, do_efault, 52b, do_efault
-	.word	53b, do_efault, 54b, do_efault, 55b, do_efault, 56b, do_efault
-	.word	57b, do_efault, 58b, do_efault, 59b, do_efault, 60b, do_efault
-	.word	61b, do_efault, 62b, do_efault
+	.word		1b, __retl_efault, 2b, __retl_efault
+	.word		3b, __retl_efault, 4b, __retl_efault
+	.word		5b, __retl_efault, 6b, __retl_efault
+	.word		7b, __retl_efault, 8b, __retl_efault
+	.word		9b, __retl_efault, 10b, __retl_efault
+	.word		11b, __retl_efault, 12b, __retl_efault
+	.word		13b, __retl_efault, 14b, __retl_efault
+	.word		15b, __retl_efault, 16b, __retl_efault
+	.word		17b, __retl_efault, 18b, __retl_efault
+	.word		19b, __retl_efault, 20b, __retl_efault
+	.word		21b, __retl_efault, 22b, __retl_efault
+	.word		23b, __retl_efault, 24b, __retl_efault
+	.word		25b, __retl_efault, 26b, __retl_efault
+	.word		27b, __retl_efault, 28b, __retl_efault
+	.word		29b, __retl_efault, 30b, __retl_efault
+	.word		31b, __retl_efault, 32b, __retl_efault
+	.word		33b, __retl_efault, 34b, __retl_efault
+	.word		35b, __retl_efault, 36b, __retl_efault
+	.word		37b, __retl_efault, 38b, __retl_efault
+	.word		39b, __retl_efault, 40b, __retl_efault
+	.word		41b, __retl_efault, 42b, __retl_efault
+	.word		43b, __retl_efault, 44b, __retl_efault
+	.word		45b, __retl_efault, 46b, __retl_efault
+	.word		47b, __retl_efault, 48b, __retl_efault
+	.word		49b, __retl_efault, 50b, __retl_efault
+	.word		51b, __retl_efault, 52b, __retl_efault
+	.word		53b, __retl_efault, 54b, __retl_efault
+	.word		55b, __retl_efault, 56b, __retl_efault
+	.word		57b, __retl_efault, 58b, __retl_efault
+	.word		59b, __retl_efault, 60b, __retl_efault
+	.word		61b, __retl_efault, 62b, __retl_efault
 	.previous

arch/sparc64/kernel/una_asm.S

···
 
 	.text
 
-kernel_unaligned_trap_fault:
-	call	kernel_mna_trap_fault
-	 nop
-	retl
-	 nop
-	.size	kern_unaligned_trap_fault, .-kern_unaligned_trap_fault
-
 	.globl	__do_int_store
 __do_int_store:
 	rd	%asi, %o4
···
 0:
 	wr	%o4, 0x0, %asi
 	retl
-	 nop
+	 mov	0, %o0
 	.size	__do_int_store, .-__do_int_store
 
 	.section	__ex_table
-	.word		4b, kernel_unaligned_trap_fault
-	.word		5b, kernel_unaligned_trap_fault
-	.word		6b, kernel_unaligned_trap_fault
-	.word		7b, kernel_unaligned_trap_fault
-	.word		8b, kernel_unaligned_trap_fault
-	.word		9b, kernel_unaligned_trap_fault
-	.word		10b, kernel_unaligned_trap_fault
-	.word		11b, kernel_unaligned_trap_fault
-	.word		12b, kernel_unaligned_trap_fault
-	.word		13b, kernel_unaligned_trap_fault
-	.word		14b, kernel_unaligned_trap_fault
-	.word		15b, kernel_unaligned_trap_fault
-	.word		16b, kernel_unaligned_trap_fault
-	.word		17b, kernel_unaligned_trap_fault
+	.word		4b, __retl_efault
+	.word		5b, __retl_efault
+	.word		6b, __retl_efault
+	.word		7b, __retl_efault
+	.word		8b, __retl_efault
+	.word		9b, __retl_efault
+	.word		10b, __retl_efault
+	.word		11b, __retl_efault
+	.word		12b, __retl_efault
+	.word		13b, __retl_efault
+	.word		14b, __retl_efault
+	.word		15b, __retl_efault
+	.word		16b, __retl_efault
+	.word		17b, __retl_efault
 	.previous
 
 	.globl	do_int_load
···
 0:
 	wr	%o5, 0x0, %asi
 	retl
-	 nop
+	 mov	0, %o0
 	.size	__do_int_load, .-__do_int_load
 
 	.section	__ex_table
-	.word		4b, kernel_unaligned_trap_fault
-	.word		5b, kernel_unaligned_trap_fault
-	.word		6b, kernel_unaligned_trap_fault
-	.word		7b, kernel_unaligned_trap_fault
-	.word		8b, kernel_unaligned_trap_fault
-	.word		9b, kernel_unaligned_trap_fault
-	.word		10b, kernel_unaligned_trap_fault
-	.word		11b, kernel_unaligned_trap_fault
-	.word		12b, kernel_unaligned_trap_fault
-	.word		13b, kernel_unaligned_trap_fault
-	.word		14b, kernel_unaligned_trap_fault
-	.word		15b, kernel_unaligned_trap_fault
-	.word		16b, kernel_unaligned_trap_fault
+	.word		4b, __retl_efault
+	.word		5b, __retl_efault
+	.word		6b, __retl_efault
+	.word		7b, __retl_efault
+	.word		8b, __retl_efault
+	.word		9b, __retl_efault
+	.word		10b, __retl_efault
+	.word		11b, __retl_efault
+	.word		12b, __retl_efault
+	.word		13b, __retl_efault
+	.word		14b, __retl_efault
+	.word		15b, __retl_efault
+	.word		16b, __retl_efault
 	.previous

arch/sparc64/kernel/unaligned.c

···
 	die_if_kernel(str, regs);
 }
 
-extern void do_int_load(unsigned long *dest_reg, int size,
-			unsigned long *saddr, int is_signed, int asi);
+extern int do_int_load(unsigned long *dest_reg, int size,
+		       unsigned long *saddr, int is_signed, int asi);
 	
-extern void __do_int_store(unsigned long *dst_addr, int size,
-			   unsigned long src_val, int asi);
+extern int __do_int_store(unsigned long *dst_addr, int size,
+			  unsigned long src_val, int asi);
 
-static inline void do_int_store(int reg_num, int size, unsigned long *dst_addr,
-				struct pt_regs *regs, int asi, int orig_asi)
+static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
+			       struct pt_regs *regs, int asi, int orig_asi)
 {
 	unsigned long zero = 0;
 	unsigned long *src_val_p = &zero;
···
 			break;
 		};
 	}
-	__do_int_store(dst_addr, size, src_val, asi);
+	return __do_int_store(dst_addr, size, src_val, asi);
 }
 
 static inline void advance(struct pt_regs *regs)
···
 	return !floating_point_load_or_store_p(insn);
 }
 
-void kernel_mna_trap_fault(void)
+static void kernel_mna_trap_fault(void)
 {
 	struct pt_regs *regs = current_thread_info()->kern_una_regs;
 	unsigned int insn = current_thread_info()->kern_una_insn;
···
 		kernel_mna_trap_fault();
 	} else {
 		unsigned long addr, *reg_addr;
-		int orig_asi, asi;
+		int orig_asi, asi, err;
 
 		addr = compute_effective_address(regs, insn,
 						 ((insn >> 25) & 0x1f));
···
 		switch (dir) {
 		case load:
 			reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
-			do_int_load(reg_addr, size, (unsigned long *) addr,
-				    decode_signedness(insn), asi);
-			if (unlikely(asi != orig_asi)) {
+			err = do_int_load(reg_addr, size,
+					  (unsigned long *) addr,
+					  decode_signedness(insn), asi);
+			if (likely(!err) && unlikely(asi != orig_asi)) {
 				unsigned long val_in = *reg_addr;
 				switch (size) {
 				case 2:
···
 			break;
 
 		case store:
-			do_int_store(((insn>>25)&0x1f), size,
-				     (unsigned long *) addr, regs,
-				     asi, orig_asi);
+			err = do_int_store(((insn>>25)&0x1f), size,
+					   (unsigned long *) addr, regs,
+					   asi, orig_asi);
 			break;
 
 		default:
 			panic("Impossible kernel unaligned trap.");
 			/* Not reached... */
 		}
-		advance(regs);
+		if (unlikely(err))
+			kernel_mna_trap_fault();
+		else
+			advance(regs);
 	}
 }
 

arch/sparc64/lib/strncpy_from_user.S

···
 	 add	%o2, %o3, %o0
 	.size	__strncpy_from_user, .-__strncpy_from_user
 
-	.section .fixup,#alloc,#execinstr
-	.align	4
-4:	retl
-	 mov	-EFAULT, %o0
-
 	.section __ex_table,#alloc
 	.align	4
-	.word	60b, 4b
-	.word	61b, 4b
-	.word	62b, 4b
-	.word	63b, 4b
-	.word	64b, 4b
+	.word	60b, __retl_efault
+	.word	61b, __retl_efault
+	.word	62b, __retl_efault
+	.word	63b, __retl_efault
+	.word	64b, __retl_efault
+	.previous

include/asm-sparc64/uaccess.h

···
 };
 
 extern void __ret_efault(void);
+extern void __retl_efault(void);
 
 /* Uh, these should become the main single-value transfer routines..
  * They automatically use the right size if we just have the right