On Tue 07-11-17 13:38:04, Kirill A. Shutemov wrote: > On machines with 5-level paging we don't want to allocate mapping above > 47-bit unless user explicitly asked for it. See b569bab78d8d ("x86/mm: > Prepare to expose larger address space to userspace") for details. > > c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base > changes") broke the behaviour. After the commit elf binary and heap got > mapped above 47-bits. > > Let's fix this. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Fixes: c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes") > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Nicholas Piggin <npiggin@xxxxxxxxx> FWIW Acked-by: Michal Hocko <mhocko@xxxxxxxx> > --- > arch/x86/include/asm/elf.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h > index c1a125e47ff3..3a091cea36c5 100644 > --- a/arch/x86/include/asm/elf.h > +++ b/arch/x86/include/asm/elf.h > @@ -253,7 +253,7 @@ extern int force_personality32; > * space open for things that want to use the area for 32-bit pointers. > */ > #define ELF_ET_DYN_BASE (mmap_is_ia32() ? 0x000400000UL : \ > - (TASK_SIZE / 3 * 2)) > + (DEFAULT_MAP_WINDOW / 3 * 2)) > > /* This yields a mask that user programs can use to figure out what > instruction set this CPU supports. This could be done in user space, > -- > 2.14.2 -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>