x86: cpa: ensure page alignment

the cpa API is page aligned - warn about any weird alignments.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index bd61ed13f9c..5d2259468d3 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -688,6 +688,15 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
 	if (!pgprot_val(mask_set) && !pgprot_val(mask_clr))
 		return 0;
 
+	/* Ensure we are PAGE_SIZE aligned */
+	if (addr & ~PAGE_MASK) {
+		addr &= PAGE_MASK;
+		/*
+		 * People should not be passing in unaligned addresses:
+		 */
+		WARN_ON_ONCE(1);
+	}
+
 	cpa.vaddr = addr;
 	cpa.numpages = numpages;
 	cpa.mask_set = mask_set;