efi: Fix truncation of constant value

Starting with commit 867a6ac86dd8 ("efi: Add start-up library code"),
sparse constantly complains about truncated constant value in efi.h:

include/efi.h:176:35: warning: cast truncates bits from constant value (8000000000000000 becomes 0)

This can get quite noisy, preventing real issues to be noticed:

$ make defconfig
*** Default configuration is based on 'sandbox_defconfig'
$ make C=2 -j12 2>&1 | grep truncates | wc -l
441

After the patch is applied:
$ make C=2 -j12 2>&1 | grep truncates | wc -l
0
$ sparse --version
v0.5.2

Following the suggestion of Heinrich Schuchardt, instead of only
fixing the root-cause, I replaced the whole enum of _SHIFT values
by ULL defines. This matches both the UEFI 2.7 spec and the Linux
kernel implementation.

Some ELF size comparison before and after the patch (gcc 7.3.0):

efi-x86_payload64_defconfig:
text    data    bss     dec       hex   filename
407174  29432   278676  715282    aea12 u-boot.old
407152  29464   278676  715292    aea1c u-boot.new
-22     +32     0       +10

efi-x86_payload32_defconfig:
text    data    bss     dec       hex   filename
447075  30308   280076  757459    b8ed3 u-boot.old
447053  30340   280076  757469    b8edd u-boot.new
-22     +32     0       +10

Fixes: 867a6ac86dd8 ("efi: Add start-up library code")
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 11 insertions, 11 deletions

diff --git a/cmd/efi.c b/cmd/efi.c
index 6c1eb88424..92a565f713 100644
--- a/cmd/efi.c
+++ b/cmd/efi.c
@@ -28,18 +28,18 @@ static const char *const type_name[] = {
 };
 
 static struct attr_info {
-	int shift;
+	u64 val;
 	const char *name;
 } mem_attr[] = {
-	{ EFI_MEMORY_UC_SHIFT, "uncached" },
-	{ EFI_MEMORY_WC_SHIFT, "write-coalescing" },
-	{ EFI_MEMORY_WT_SHIFT, "write-through" },
-	{ EFI_MEMORY_WB_SHIFT, "write-back" },
-	{ EFI_MEMORY_UCE_SHIFT, "uncached & exported" },
-	{ EFI_MEMORY_WP_SHIFT, "write-protect" },
-	{ EFI_MEMORY_RP_SHIFT, "read-protect" },
-	{ EFI_MEMORY_XP_SHIFT, "execute-protect" },
-	{ EFI_MEMORY_RUNTIME_SHIFT, "needs runtime mapping" }
+	{ EFI_MEMORY_UC, "uncached" },
+	{ EFI_MEMORY_WC, "write-coalescing" },
+	{ EFI_MEMORY_WT, "write-through" },
+	{ EFI_MEMORY_WB, "write-back" },
+	{ EFI_MEMORY_UCE, "uncached & exported" },
+	{ EFI_MEMORY_WP, "write-protect" },
+	{ EFI_MEMORY_RP, "read-protect" },
+	{ EFI_MEMORY_XP, "execute-protect" },
+	{ EFI_MEMORY_RUNTIME, "needs runtime mapping" }
 };
 
 /* Maximum different attribute values we can track */
@@ -173,7 +173,7 @@ static void efi_print_mem_table(struct efi_entry_memmap *map,
 		printf("%c%llx: ", attr & EFI_MEMORY_RUNTIME ? 'r' : ' ',
 		       attr & ~EFI_MEMORY_RUNTIME);
 		for (j = 0, first = true; j < ARRAY_SIZE(mem_attr); j++) {
-			if (attr & (1ULL << mem_attr[j].shift)) {
+			if (attr & mem_attr[j].val) {
 				if (first)
 					first = false;
 				else