HIGHMEM pages may not be mapped so we must kmap them before accessing.
This resolves a random OOPs error that was showing up during OpenSSL SHA tests.

Signed-off-by: Joel Fernandes <redacted>
---
 drivers/crypto/omap-sham.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 8bdde57..fcf6562 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c

@@ -636,11 +636,21 @@ static size_t omap_sham_append_buffer(struct omap_sham_reqctx *ctx,
 static size_t omap_sham_append_sg(struct omap_sham_reqctx *ctx)
 {
 	size_t count;
+	const u8 *vaddr;
 
 	while (ctx->sg) {
+		if (PageHighMem(sg_page(ctx->sg)))
+			vaddr = kmap_atomic(sg_page(ctx->sg));
+		else
+			vaddr = sg_virt(ctx->sg);
+
 		count = omap_sham_append_buffer(ctx,
-				sg_virt(ctx->sg) + ctx->offset,
+				vaddr + ctx->offset,
 				ctx->sg->length - ctx->offset);
+
+		if (PageHighMem(sg_page(ctx->sg)))
+			kunmap_atomic((void *)vaddr);
+
 		if (!count)
 			break;
 		ctx->offset += count;