[SPARC64]: Unaligned accesses to userspace are hard errors.

Userspace is forbidden from making unaligned loads and
stores.  So if we get an unaligned trap due to a
{get,put}_user(), signal a fault and run the exception
handler.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc64/kernel/unaligned.c b/arch/sparc64/kernel/unaligned.c
index a9b765271b85f9da4546c846f446ab383cecd781..bc18d480dd1cb958fe4010acef75aa8e8a43a766 100644 (file)
--- a/arch/sparc64/kernel/unaligned.c
+++ b/arch/sparc64/kernel/unaligned.c
@@ -243,7 +243,7 @@ static inline int ok_for_kernel(unsigned int insn)
        return !floating_point_load_or_store_p(insn);
 }
 
-static void kernel_mna_trap_fault(void)
+static void kernel_mna_trap_fault(int fixup_tstate_asi)
 {
        struct pt_regs *regs = current_thread_info()->kern_una_regs;
        unsigned int insn = current_thread_info()->kern_una_insn;
@@ -274,18 +274,15 @@ static void kernel_mna_trap_fault(void)
        regs->tpc = entry->fixup;
        regs->tnpc = regs->tpc + 4;
 
-       regs->tstate &= ~TSTATE_ASI;
-       regs->tstate |= (ASI_AIUS << 24UL);
+       if (fixup_tstate_asi) {
+               regs->tstate &= ~TSTATE_ASI;
+               regs->tstate |= (ASI_AIUS << 24UL);
+       }
 }
 
-asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+static void log_unaligned(struct pt_regs *regs)
 {
        static unsigned long count, last_time;
-       enum direction dir = decode_direction(insn);
-       int size = decode_access_size(insn);
-
-       current_thread_info()->kern_una_regs = regs;
-       current_thread_info()->kern_una_insn = insn;
 
        if (jiffies - last_time > 5 * HZ)
                count = 0;
@@ -295,6 +292,28 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                printk("Kernel unaligned access at TPC[%lx] ", regs->tpc);
                print_symbol("%s\n", regs->tpc);
        }
+}
+
+asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+{
+       enum direction dir = decode_direction(insn);
+       int size = decode_access_size(insn);
+       int orig_asi, asi;
+
+       current_thread_info()->kern_una_regs = regs;
+       current_thread_info()->kern_una_insn = insn;
+
+       orig_asi = asi = decode_asi(insn, regs);
+
+       /* If this is a {get,put}_user() on an unaligned userspace pointer,
+        * just signal a fault and do not log the event.
+        */
+       if (asi == ASI_AIUS) {
+               kernel_mna_trap_fault(0);
+               return;
+       }
+
+       log_unaligned(regs);
 
        if (!ok_for_kernel(insn) || dir == both) {
                printk("Unsupported unaligned load/store trap for kernel "
@@ -302,10 +321,10 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                unaligned_panic("Kernel does fpu/atomic "
                                "unaligned load/store.", regs);
 
-               kernel_mna_trap_fault();
+               kernel_mna_trap_fault(0);
        } else {
                unsigned long addr, *reg_addr;
-               int orig_asi, asi, err;
+               int err;
 
                addr = compute_effective_address(regs, insn,
                                                 ((insn >> 25) & 0x1f));
@@ -315,7 +334,6 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                       regs->tpc, dirstrings[dir], addr, size,
                       regs->u_regs[UREG_RETPC]);
 #endif
-               orig_asi = asi = decode_asi(insn, regs);
                switch (asi) {
                case ASI_NL:
                case ASI_AIUPL:
@@ -365,7 +383,7 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                        /* Not reached... */
                }
                if (unlikely(err))
-                       kernel_mna_trap_fault();
+                       kernel_mna_trap_fault(1);
                else
                        advance(regs);
        }