[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 <davem@davemloft.net>

6 files changed, 95 insertions, 87 deletions

diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index ecc748fb9ad7..89406f9649a9 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -540,8 +540,11 @@ bootup_user_stack_end:
 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
diff --git a/arch/sparc64/kernel/sys32.S b/arch/sparc64/kernel/sys32.S
index 4fb99e0bc7c3..9cd272ac3ac1 100644
--- a/arch/sparc64/kernel/sys32.S
+++ b/arch/sparc64/kernel/sys32.S
@@ -157,6 +157,9 @@ sys32_socketcall:	/* %o0=call, %o1=args */
         or              %g2, %lo(__socketcall_table_begin), %g2
         jmpl            %g2 + %o0, %g0
          nop
+do_einval:
+        retl
+         mov            -EINVAL, %o0
 
         .align          32
 __socketcall_table_begin:
@@ -316,29 +319,37 @@ do_sys_recvmsg: /* compat_sys_recvmsg(int, struct compat_msghdr *, unsigned int)
         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
diff --git a/arch/sparc64/kernel/una_asm.S b/arch/sparc64/kernel/una_asm.S
index da48400bcc95..1f5b5b708ce7 100644
--- a/arch/sparc64/kernel/una_asm.S
+++ b/arch/sparc64/kernel/una_asm.S
@@ -6,13 +6,6 @@
 
         .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
@@ -51,24 +44,24 @@ __do_int_store:
 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
@@ -133,21 +126,21 @@ 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
diff --git a/arch/sparc64/kernel/unaligned.c b/arch/sparc64/kernel/unaligned.c
index 9d6be20f4125..70faf630603b 100644
--- a/arch/sparc64/kernel/unaligned.c
+++ b/arch/sparc64/kernel/unaligned.c
@@ -180,14 +180,14 @@ static void __attribute_used__ unaligned_panic(char *str, struct pt_regs *regs)
         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;
@@ -219,7 +219,7 @@ static inline void do_int_store(int reg_num, int size, unsigned long *dst_addr,
                         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)
@@ -242,7 +242,7 @@ static inline int ok_for_kernel(unsigned int insn)
         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;
@@ -294,7 +294,7 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn, u
                 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));
@@ -319,9 +319,10 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn, u
                 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:
@@ -343,16 +344,19 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn, u
                         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);
         }
 }
 
diff --git a/arch/sparc64/lib/strncpy_from_user.S b/arch/sparc64/lib/strncpy_from_user.S
index 09cbbaa0ebf4..e1264650ca7a 100644
--- a/arch/sparc64/lib/strncpy_from_user.S
+++ b/arch/sparc64/lib/strncpy_from_user.S
@@ -125,15 +125,11 @@ __strncpy_from_user:
          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
diff --git a/include/asm-sparc64/uaccess.h b/include/asm-sparc64/uaccess.h
index c099aa339784..bc8ddbb1cbed 100644
--- a/include/asm-sparc64/uaccess.h
+++ b/include/asm-sparc64/uaccess.h
@@ -77,6 +77,7 @@ struct exception_table_entry {
 };
 
 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