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authorDavid S. Miller <davem@sunset.davemloft.net>2006-11-28 20:18:05 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2006-12-10 02:39:39 -0800
commitc449c38b5df1fad556ea210deb6cff3b27323e49 (patch)
tree1469b4334e0f620586c875bd1e622b606b196d8d /arch/sparc64/kernel/unaligned.c
parent6e7726e16fb5e8f1169dbfcb75e321ac871af827 (diff)
[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>
Diffstat (limited to 'arch/sparc64/kernel/unaligned.c')
-rw-r--r--arch/sparc64/kernel/unaligned.c44
1 files changed, 31 insertions, 13 deletions
diff --git a/arch/sparc64/kernel/unaligned.c b/arch/sparc64/kernel/unaligned.c
index a9b765271b8..bc18d480dd1 100644
--- 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);
}