sparc64: Tighten checks in kstack_valid().

The kernel stack pointer is invalid if it is not 16-byte
aligned.

Based upon a report by Meelis Roos <mroos@linux.ee>

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

diff --git a/arch/sparc/kernel/kstack.h b/arch/sparc/kernel/kstack.h
index 4248d969272f1f92a7470a15bc631c72bd628f24..5247283d1c03e57c94d40ebfea4074cdf7db3100 100644 (file)
--- a/arch/sparc/kernel/kstack.h
+++ b/arch/sparc/kernel/kstack.h
@@ -11,6 +11,10 @@ static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
 {
        unsigned long base = (unsigned long) tp;
 
+       /* Stack pointer must be 16-byte aligned.  */
+       if (sp & (16UL - 1))
+               return false;
+
        if (sp >= (base + sizeof(struct thread_info)) &&
            sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
                return true;