linux-stable/arch
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
..
alpha arch: Cleanup read_barrier_depends() and comments 2014-12-11 21:15:05 -05:00
arc Minor updates for ARC for 3.19 2014-12-18 16:26:41 -08:00
arm kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
arm64 kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
avr32 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
blackfin TTY/Serial driver patches for 3.19-rc1 2014-12-14 15:23:32 -08:00
c6x
cris CRISv32: Remove last remnants of ETRAX_SPI_MMC_BOARD 2014-12-20 00:06:13 +01:00
frv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
hexagon Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rkuo/linux-hexagon-kernel 2014-12-19 17:57:51 -08:00
ia64 __get_cpu_var removed from rest of tree, drop reference from comments in arch/ia64 2014-12-19 17:07:27 -08:00
m32r Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
m68k Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
metag arch: Add lightweight memory barriers dma_rmb() and dma_wmb() 2014-12-11 21:15:06 -05:00
microblaze Microblaze patches for 3.19-rc1 2014-12-17 09:54:05 -08:00
mips kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
mn10300 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
nios2 nios2/uaccess: fix sparse errors 2014-12-17 13:53:41 +08:00
openrisc
parisc parisc: percpu: update comments referring to __get_cpu_var 2014-12-13 12:42:53 -08:00
powerpc CONFIG_PM_RUNTIME elimination for 3.19-rc1 2014-12-20 13:37:44 -08:00
s390 kernel: Provide READ_ONCE and ASSIGN_ONCE 2014-12-20 16:48:59 -08:00
score
sh PM: Eliminate CONFIG_PM_RUNTIME 2014-12-19 22:55:06 +01:00
sparc sparc32: destroy_context() and switch_mm() needs to disable interrupts. 2014-12-18 12:47:54 -05:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2014-12-16 13:54:16 -08:00
um TTY/Serial driver patches for 3.19-rc1 2014-12-14 15:23:32 -08:00
unicore32 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
x86 x86, entry: Switch stacks on a paranoid entry from userspace 2015-01-02 10:22:45 -08:00
xtensa Xtensa fixes for 3.19: 2014-12-16 14:08:53 -08:00
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