This is the mail archive of the mailing list for the binutils project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [committed, PATCH] Add -mshared option to x86 ELF assembler

On 2015.05.15 at 03:34 -0700, H.J. Lu wrote:
> This patch adds -mshared option to x86 ELF assembler.  By default,
> assembler will optimize out non-PLT relocations against defined non-weak
> global branch targets with default visibility.  The -mshared option tells
> the assembler to generate code which may go into a shared library
> where all non-weak global branch targets with default visibility can
> be preempted.  The resulting code is slightly bigger.  This option
> only affects the handling of branch instructions.
> This Linux kernel patch is needed to create a working x86 Linux kernel if
> it hasn't been applied:
> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index ae6588b..b91a00c 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -339,8 +339,8 @@ early_idt_handlers:
>  	i = i + 1
>  	.endr
> -/* This is global to keep gas from relaxing the jumps */
> -ENTRY(early_idt_handler)
> +/* This is weak to keep gas from relaxing the jumps */
> +WEAK(early_idt_handler)
>  	cld

Have you posted the patch to LKML already? 
(I hit this issue today and it took me a while to figure out the cause.)


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]