linux/arch/x86
Thomas Gleixner ce28b9864b x86: fix vsyscall wreckage
based on a report from Arne Georg Gleditsch about user-space apps
misbehaving after toggling /proc/sys/kernel/vsyscall64, a review
of the code revealed that the "NOP patching" done there is
fundamentally unsafe for a number of reasons:

1) the patching code runs without synchronizing other CPUs

2) it inserts NOPs even if there is no clock source which provides vread

3) when the clock source changes to one without vread we run in
   exactly the same problem as in #2

4) if nobody toggles the proc entry from 1 to 0 and to 1 again, then
   the syscall is not patched out

as a result it is possible to break user-space via this patching.
The only safe thing for now is to remove the patching.

This code was broken since v2.6.21.

Reported-by: Arne Georg Gleditsch <arne.gleditsch@dolphinics.no>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-26 12:55:57 +01:00
..
boot x86: handle BIOSes which terminate e820 with CF=1 and no SMAP 2008-02-26 12:55:52 +01:00
configs x86, core: remove CONFIG_FORCED_INLINING 2008-02-09 23:24:09 +01:00
crypto [CRYPTO] twofish: Merge common glue code 2008-01-14 17:07:57 +11:00
ia32 Sanitize the type of struct user.u_ar0 2008-02-07 08:42:30 -08:00
kernel x86: fix vsyscall wreckage 2008-02-26 12:55:57 +01:00
kvm kvm: i386 fix 2008-02-05 09:44:06 -08:00
lguest x86/lguest: fix pgdir pmd index calculation 2008-02-26 12:55:49 +01:00
lib x86: clean up csum-wrappers_64.c some more 2008-02-19 16:18:32 +01:00
mach-default spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
mach-es7000 i386: es7000 minor cleanups 2007-10-17 20:16:15 +02:00
mach-generic spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
mach-rdc321x x86: add support for the RDC R-321x SoC 2008-01-30 13:33:36 +01:00
mach-visws x86: cleanup mpspec variants 2008-01-30 13:30:35 +01:00
mach-voyager calibrate_delay() must be __cpuinit 2008-02-06 10:41:08 -08:00
math-emu x86: arch/x86/math-emu/errors.c: fix printk warnings 2008-01-30 13:32:13 +01:00
mm x86: fix spontaneous reboot with allyesconfig bzImage 2008-02-26 12:55:56 +01:00
oprofile x86: rename stack_pointer to kernel_trap_sp 2008-01-30 13:33:16 +01:00
pci PCI: irq: patch for Intel ICH10 DeviceID's 2008-02-21 15:34:36 -08:00
power x86 cleanup: suspend_asm_64.S - use X86_CR4_PGE instead of numeric value 2008-02-19 16:18:33 +01:00
vdso x86: vdso_install fix 2008-02-11 20:50:09 -08:00
video i386: move video 2007-10-11 11:16:56 +02:00
xen xen: unpin initial Xen pagetable once we're finished with it 2008-02-13 16:20:35 +01:00
Kconfig Mark CC_STACKPROTECTOR as being BROKEN 2008-02-22 08:21:38 -08:00
Kconfig.cpu x86: don't use P6_NOPs if compiling with CONFIG_X86_GENERIC 2008-02-26 12:55:51 +01:00
Kconfig.debug x86: change IO delay back to 0x80 2008-02-19 16:18:34 +01:00
Makefile x86: fix vdso_install breaks user "make install" 2008-02-19 16:18:34 +01:00
Makefile_32.cpu x86: move i386 and x86_64 Makefiles to arch/x86 2007-10-25 22:27:34 +02:00