linux/arch/x86
Andy Lutomirski 48e08d0fb2 x86, entry: Switch stacks on a paranoid entry from userspace
This causes all non-NMI, non-double-fault kernel entries from
userspace to run on the normal kernel stack.  Double-fault is
exempt to minimize confusion if we double-fault directly from
userspace due to a bad kernel stack.

This is, suprisingly, simpler and shorter than the current code.  It
removes the IMO rather frightening paranoid_userspace path, and it
make sync_regs much simpler.

There is no risk of stack overflow due to this change -- the kernel
stack that we switch to is empty.

This will also enable us to create non-atomic sections within
machine checks from userspace, which will simplify memory failure
handling.  It will also allow the upcoming fsgsbase code to be
simplified, because it doesn't need to worry about usergs when
scheduling in paranoid_exit, as that code no longer exists.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
2015-01-02 10:22:45 -08:00
..
boot Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-10 12:42:16 -08:00
configs x86/kconfig/defconfig: Enable CONFIG_FHANDLE=y 2014-12-08 12:04:17 +01:00
crypto crypto: sha - replace memset by memzero_explicit 2014-12-02 22:55:49 +08:00
ia32 x86: hook up execveat system call 2014-12-13 12:42:51 -08:00
include kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
kernel x86, entry: Switch stacks on a paranoid entry from userspace 2015-01-02 10:22:45 -08:00
kvm 3.19 changes for KVM: 2014-12-18 16:05:28 -08:00
lguest x86: Avoid building unused IRQ entry stubs 2014-12-16 14:08:14 +01:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
math-emu
mm kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-12-10 15:48:20 -05:00
oprofile percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t 2014-08-28 08:58:57 -04:00
pci Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
platform Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
power nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
purgatory Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-10 12:35:46 -08:00
realmode
syscalls x86: hook up execveat system call 2014-12-13 12:42:51 -08:00
tools Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-10 12:10:24 -08:00
um Merge branch 'akpm' (second patch-bomb from Andrew) 2014-12-13 13:00:36 -08:00
vdso x86,vdso: Use LSL unconditionally for vgetcpu 2014-11-03 13:41:53 +01:00
video
xen xen: additional features for 3.19-rc0 2014-12-16 13:23:03 -08:00
.gitignore x86/build: Add arch/x86/purgatory/ make generated files to gitignore 2014-10-09 09:29:46 +02:00
Kbuild kexec: create a new config option CONFIG_KEXEC_FILE for new syscall 2014-08-29 16:28:16 -07:00
Kconfig Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-19 14:02:02 -08:00
Kconfig.cpu
Kconfig.debug
Makefile Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 18:17:33 +02:00
Makefile_32.cpu
Makefile.um