Re: [PATCH] x86: Dynamically relocate the compat vdso

2014-03-11 Thread H. Peter Anvin
On 03/11/2014 02:33 PM, Andy Lutomirski wrote: > diff --git a/arch/x86/include/asm/pgtable_types.h > b/arch/x86/include/asm/pgtable_types.h > index 1aa9ccd..943f166 100644 > --- a/arch/x86/include/asm/pgtable_types.h > +++ b/arch/x86/include/asm/pgtable_types.h > @@ -214,13 +214,8 @@ > #ifdef CON

[PATCH] x86: Dynamically relocate the compat vdso

2014-03-11 Thread Andy Lutomirski
This removes the compat vdso from the fixmap and instead relocates it each time it's mapped. It also documents the reason for the compat vDSO. Before this patch, using the compat vDSO partially defeated ASLR. With this patch, ASLR is left alone, but starting a 32-bit process with the compat vDSO