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
| ||
|
Date: Tue, 16 Jun 2015 15:58:01 +0200 From: Borislav Petkov <bp@...en8.de> To: Enrico Mioso <mrkiko.rs@...il.com> Cc: Michael Matz <matz@...e.de>, linux-kernel@...r.kernel.org, x86-ml <x86@...nel.org> Subject: Re: X86 GIT GCC 5 compilation warning On Tue, Jun 16, 2015 at 02:47:02PM +0200, Michael Matz wrote: > Yeah, building like so on i686 will produce an assembler that warns on > "1<<32". Enrico, try this. --- From: Borislav Petkov <bp@...e.de> Date: Tue, 16 Jun 2015 15:43:27 +0200 Subject: [PATCH] x86/head_32: Fix overflow warning with 32-bit binutils When building the kernel with 32-bit binutils built with support only for the i386 target, we get the following warning: arch/x86/kernel/head_32.S:66: Warning: shift count out of range (32 is not between 0 and 31) The problem is that in that case, binutils' internal type representation is 32-bit wide and the shift range overflows. In order to fix this, manipulate the shift expression which creates the 4GiB constant to not overflow the shift count. Reported-by: Enrico Mioso <mrkiko.rs@...il.com> Suggested-by: Michael Matz <matz@...e.de> Signed-off-by: Borislav Petkov <bp@...e.de> --- arch/x86/kernel/head_32.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 53eeb226657c..c601d1de5ae5 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -63,8 +63,8 @@ #endif /* Number of possible pages in the lowmem region */ -LOWMEM_PAGES = (((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) - +LOWMEM_PAGES = (((2<<31) - __PAGE_OFFSET) >> PAGE_SHIFT) + /* Enough space to fit pagetables for the low memory linear map */ MAPPING_BEYOND_END = PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT -- 2.3.5 -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists