linux-kernel - [PATCH] x86/efi: Fix EFI memmap pointer size warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Sun, 6 Nov 2016 14:02:54 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Matt Fleming <matt@...eblueprint.co.uk>
Cc:     linux-efi <linux-efi@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86/efi: Fix EFI memmap pointer size warning

Hi Matt,

please doublecheck me on this but I think we're fine using an unsigned
long.

Thanks.

---
From: Borislav Petkov <bp@...e.de>
Date: Sun, 6 Nov 2016 13:49:10 +0100
Subject: [PATCH] x86/efi: Fix EFI memmap pointer size warning
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fix this when building on 32-bit:

  arch/x86/platform/efi/efi.c: In function ‘__efi_enter_virtual_mode’:
  arch/x86/platform/efi/efi.c:911:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
       (efi_memory_desc_t *)pa);
       ^
  arch/x86/platform/efi/efi.c:918:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
       (efi_memory_desc_t *)pa);
       ^

The @pa local variable is declared as phys_addr_t and that is a u64 when
CONFIG_PHYS_ADDR_T_64BIT=y. (The last is enabled on 32-bit on a PAE
build.)

However, its value comes from __pa() which is basically doing pointer
arithmetic and checking, and returns unsigned long as it is the native
pointer width.

So let's use an unsigned long too. It should be fine to do so because
the later users cast it to a pointer too.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Matt Fleming <matt@...eblueprint.co.uk>
---
 arch/x86/platform/efi/efi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index bf99aa7005eb..936a488d6cf6 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -861,7 +861,7 @@ static void __init __efi_enter_virtual_mode(void)
 	int count = 0, pg_shift = 0;
 	void *new_memmap = NULL;
 	efi_status_t status;
-	phys_addr_t pa;
+	unsigned long pa;
 
 	efi.systab = NULL;
 
-- 
2.10.0


-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.