On 07/14/2018 10:53 PM, Eugeniu Rosca wrote:
> 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.g...@gmx.de>
> Signed-off-by: Eugeniu Rosca <ero...@de.adit-jv.com>
> ---
>
> v2:
> - Replace _SHIFT enum values by ULL defines to match UEFI 2.7 spec
> - Add ELF size comparison to patch description
>
> cmd/efi.c | 22 +++++++++++-----------
> include/efi.h | 24 ++++++++++--------------
> lib/efi_loader/efi_memory.c | 7 +++----
> 3 files changed, 24 insertions(+), 29 deletions(-)
>
> diff --git a/cmd/efi.c b/cmd/efi.c
> index 6c1eb88424be..92a565f71373 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
> diff --git a/include/efi.h b/include/efi.h
> index 0fe15e65c06c..eb2a569fe010 100644
> --- a/include/efi.h
> +++ b/include/efi.h
> @@ -162,20 +162,16 @@ enum efi_mem_type {
> };
>
> /* Attribute values */
> -enum {
> - EFI_MEMORY_UC_SHIFT = 0, /* uncached */
> - EFI_MEMORY_WC_SHIFT = 1, /* write-coalescing */
> - EFI_MEMORY_WT_SHIFT = 2, /* write-through */
> - EFI_MEMORY_WB_SHIFT = 3, /* write-back */
> - EFI_MEMORY_UCE_SHIFT = 4, /* uncached, exported */
> - EFI_MEMORY_WP_SHIFT = 12, /* write-protect */
> - EFI_MEMORY_RP_SHIFT = 13, /* read-protect */
> - EFI_MEMORY_XP_SHIFT = 14, /* execute-protect */
> - EFI_MEMORY_RUNTIME_SHIFT = 63, /* range requires runtime mapping */
> -
> - EFI_MEMORY_RUNTIME = 1ULL << EFI_MEMORY_RUNTIME_SHIFT,
> - EFI_MEM_DESC_VERSION = 1,
> -};
> +#define EFI_MEMORY_UC ((u64)0x0000000000000001ULL) /*
> uncached */
Unsigned long long int (ULL) is at least 64bit wide and unsigned (cf.
https://gcc.gnu.org/onlinedocs/gcc/Long-Long.html). Why do you introduce
the (u64) conversion?
Otherwise
Reviewed-by: Heinrich Schuchardt <xypron.g...@gmx.de>
> +#define EFI_MEMORY_WC ((u64)0x0000000000000002ULL) /*
> write-coalescing */
> +#define EFI_MEMORY_WT ((u64)0x0000000000000004ULL) /*
> write-through */
> +#define EFI_MEMORY_WB ((u64)0x0000000000000008ULL) /*
> write-back */
> +#define EFI_MEMORY_UCE ((u64)0x0000000000000010ULL) /*
> uncached, exported */
> +#define EFI_MEMORY_WP ((u64)0x0000000000001000ULL) /*
> write-protect */
> +#define EFI_MEMORY_RP ((u64)0x0000000000002000ULL) /*
> read-protect */
> +#define EFI_MEMORY_XP ((u64)0x0000000000004000ULL) /*
> execute-protect */
> +#define EFI_MEMORY_RUNTIME ((u64)0x8000000000000000ULL) /* range
> requires runtime mapping */
> +#define EFI_MEM_DESC_VERSION 1
>
> #define EFI_PAGE_SHIFT 12
> #define EFI_PAGE_SIZE (1UL << EFI_PAGE_SHIFT)
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index ec66af98ea8f..233333bf6b18 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -171,14 +171,13 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t
> pages, int memory_type,
> switch (memory_type) {
> case EFI_RUNTIME_SERVICES_CODE:
> case EFI_RUNTIME_SERVICES_DATA:
> - newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
> - (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
> + newlist->desc.attribute = EFI_MEMORY_WB | EFI_MEMORY_RUNTIME;
> break;
> case EFI_MMAP_IO:
> - newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
> + newlist->desc.attribute = EFI_MEMORY_RUNTIME;
> break;
> default:
> - newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
> + newlist->desc.attribute = EFI_MEMORY_WB;
> break;
> }
>
>
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