[kvm-unit-tests PATCH v2 7/8] efi: fix load_options_size conversion to character count

[Giacomo Mazzola <gmazz@amazon.de>]

load_options_size is in bytes, but options_chars is used as the
iteration count over the u16 load options array.  Divide by
sizeof(u16) to convert from bytes to UTF-16 code units; without
this, the loop reads past the end of the load options buffer.

The original Linux kernel code (drivers/firmware/efi/libstub/
efi-stub-helper.c) from which this function was adapted performs
the same conversion:

    options_chars = options_size / sizeof(efi_char16_t);

This was lost when the function was ported to KUT.

Fixes: 85c3c524 ("lib/efi: Add support for getting the cmdline")
Signed-off-by: Giacomo Mazzola <gmazz@amazon.de>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
---
 lib/efi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/efi.c b/lib/efi.c
index f396bd71..d1be2bfc 100644
--- a/lib/efi.c
+++ b/lib/efi.c
@@ -134,7 +134,7 @@ static char *efi_convert_cmdline(struct efi_loaded_image_64 *image, int *cmd_lin
 {
 	const u16 *s2;
 	unsigned long cmdline_addr = 0;
-	int options_chars = image->load_options_size;
+	int options_chars = image->load_options_size / sizeof(u16);
 	const u16 *options = image->load_options;
 	int options_bytes = 0, safe_options_bytes = 0;  /* UTF-8 bytes */
 	bool in_quote = false;
-- 
2.47.3