From: David S. Miller <davem@davemloft.net>
Date: Fri, 12 Feb 2010 20:03:45 +0000 (-0800)
Subject: sparc64: Tighten checks in kstack_valid().
X-Git-Tag: firefly_0821_release~9833^2~3139^2~5
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=232486e1e9f34889424b68ee6270440b554479a2;p=firefly-linux-kernel-4.4.55.git

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 4248d969272f..5247283d1c03 100644
--- 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;