[PATCH 0/3] x86_64: Tidy up vsyscall emulation and make it optional

From: Andy Lutomirski
Date: Tue Oct 28 2014 - 13:22:40 EST


Now that arch/x86/kernel/vsyscall_64.c contains only vsyscall
emulation code, clean it up and make it optional.

Patch 1 makes vsyscall=none work be a bit more self-consistent: it
actually removes the fake vsyscall page instead of just segfaulting
anyone who tries to use it.

Patch 2 is pure cosmetic cleanup.

Patch 3 is the meat: it lets vsyscall emulation be configured out.
The config option to disable it is hidden under CONFIG_EXPERT, since
it will break legacy code.

Note that, last I checked, current userspace is unlikely to work if
the vDSO *and* vsyscalls are off. Take it up with the glibc
maintainers.

This applies on top of tip/x86/vdso.

Andy Lutomirski (3):
x86_64,vsyscall: Turn vsyscalls all the way off when vsyscall=none
x86_64,vsyscall: Rewrite comment and clean up headers in vsyscall code
x86_64,vsyscall: Make vsyscall emulation configurable

arch/x86/Kconfig | 18 ++++++++++++
arch/x86/include/asm/fixmap.h | 2 ++
arch/x86/include/asm/page_64.h | 4 ++-
arch/x86/include/asm/vsyscall.h | 8 +++++
arch/x86/kernel/Makefile | 3 +-
arch/x86/kernel/setup.c | 2 --
arch/x86/kernel/vsyscall_64.c | 65 +++++++++++++++++------------------------
arch/x86/xen/mmu.c | 6 ++--
8 files changed, 63 insertions(+), 45 deletions(-)

--
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/