linux/arch/x86/kernel
Matthew Garrett 916f676f8d x86, efi: Retain boot service code until after switching to virtual mode
UEFI stands for "Unified Extensible Firmware Interface", where "Firmware"
is an ancient African word meaning "Why do something right when you can
do it so wrong that children will weep and brave adults will cower before
you", and "UEI" is Celtic for "We missed DOS so we burned it into your
ROMs". The UEFI specification provides for runtime services (ie, another
way for the operating system to be forced to depend on the firmware) and
we rely on these for certain trivial tasks such as setting up the
bootloader. But some hardware fails to work if we attempt to use these
runtime services from physical mode, and so we have to switch into virtual
mode. So far so dreadful.

The specification makes it clear that the operating system is free to do
whatever it wants with boot services code after ExitBootServices() has been
called. SetVirtualAddressMap() can't be called until ExitBootServices() has
been. So, obviously, a whole bunch of EFI implementations call into boot
services code when we do that. Since we've been charmingly naive and
trusted that the specification may be somehow relevant to the real world,
we've already stuffed a picture of a penguin or something in that address
space. And just to make things more entertaining, we've also marked it
non-executable.

This patch allocates the boot services regions during EFI init and makes
sure that they're executable. Then, after SetVirtualAddressMap(), it
discards them and everyone lives happily ever after. Except for the ones
who have to work on EFI, who live sad lives haunted by the knowledge that
someone's eventually going to write yet another firmware specification.

[ hpa: adding this to urgent with a stable tag since it fixes currently-broken
  hardware.  However, I do not know what the dependencies are and so I do
  not know which -stable versions this may be a candidate for. ]

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1306331593-28715-1-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@kernel.org>
2011-05-25 17:03:53 -07:00
..
acpi x86, ioapic: Consolidate mp_ioapics[] into 'struct ioapic' 2011-05-20 13:40:59 +02:00
apic x86, UV: Add support for SGI UV2 hub chip 2011-05-25 14:20:13 +02:00
cpu x86: Remove unnecessary check in detect_ht() 2011-05-25 23:01:08 +02:00
.gitignore
alternative.c Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 17:55:12 -07:00
amd_gart_64.c x86, gart: Rename pci-gart_64.c to amd_gart_64.c 2011-05-10 17:22:06 +02:00
amd_iommu_init.c x86/amd-iommu: Use threaded interupt handler 2011-05-10 11:07:58 +02:00
amd_iommu.c x86: Eliminate various 'set but not used' warnings 2011-05-21 19:10:33 +02:00
amd_nb.c x86, amd-nb: Rename CPU PCI id define for F4 2011-03-31 08:51:38 +02:00
apb_timer.c Merge branch 'consolidate-clksrc-i8253' of master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource 2011-05-14 12:06:36 +02:00
aperture_64.c x86, gart: Don't enforce GART aperture lower-bound by alignment 2011-04-18 10:31:38 -07:00
apm_32.c PM: Remove sysdev suspend, resume and shutdown operations 2011-05-11 21:37:15 +02:00
asm-offsets_32.c x86: Partly unify asm-offsets_{32,64}.c 2011-02-10 13:31:37 +01:00
asm-offsets_64.c x86: Partly unify asm-offsets_{32,64}.c 2011-02-10 13:31:37 +01:00
asm-offsets.c x86, asm: Cleanup unnecssary macros in asm-offsets.c 2011-02-25 16:37:32 -08:00
audit_64.c
bootflag.c
check.c x86: Don't check for BIOS corruption in first 64K when there's no need to 2011-03-09 16:36:41 +01:00
cpuid.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
crash_dump_32.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
crash_dump_64.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
crash.c
devicetree.c x86, ioapic: Consolidate gsi routing info into 'struct ioapic' 2011-05-20 13:41:01 +02:00
doublefault_32.c
dumpstack_32.c x86, dumpstack: Correct stack dump info when frame pointer is available 2011-03-18 10:51:42 +01:00
dumpstack_64.c x86, dumpstack: Correct stack dump info when frame pointer is available 2011-03-18 10:51:42 +01:00
dumpstack.c Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 2011-05-19 18:24:11 -07:00
e820.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
early_printk.c x86, earlyprintk: Move mrst early console to platform/ and fix a typo 2010-12-06 20:52:04 +01:00
early-quirks.c x86, quirk: Fix SB600 revision check 2011-03-16 14:03:32 +01:00
entry_32.S Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-16 10:10:02 -07:00
entry_64.S x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
ftrace.c x86, cpu: Clean up and unify the NOP selection infrastructure 2011-04-18 16:40:21 -07:00
head32.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 18:08:06 -07:00
head64.c x86: Cleanup highmap after brk is concluded 2011-03-19 11:58:19 -07:00
head_32.S Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 20:01:36 -07:00
head_64.S x86, trampoline: Common infrastructure for low memory trampolines 2011-02-17 21:02:43 -08:00
head.c
hpet.c x86: hpet: Cleanup the clockevents init and register code 2011-05-19 14:24:16 +02:00
hw_breakpoint.c x86: Use this_cpu_ops to optimize code 2010-12-30 12:20:28 +01:00
i386_ksyms_32.c
i387.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
i8237.c x86: Use syscore_ops instead of sysdev classes and sysdevs 2011-03-23 22:15:54 +01:00
i8253.c x86: Convert PIT to clockevents_config_and_register() 2011-05-19 14:24:16 +02:00
i8259.c x86: Use syscore_ops instead of sysdev classes and sysdevs 2011-03-23 22:15:54 +01:00
init_task.c
io_delay.c
ioport.c x86: Use bitmap library functions 2011-02-17 14:59:22 +01:00
irq_32.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
irq_64.c
irq_work.c irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
irq.c x86: Don't unmask disabled irqs when migrating them 2011-05-19 14:51:08 +02:00
irqinit.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-15 20:01:36 -07:00
jump_label.c x86, cpu: Clean up and unify the NOP selection infrastructure 2011-04-18 16:40:21 -07:00
kdebugfs.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
kgdb.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb 2011-03-25 21:04:56 -07:00
kprobes.c kprobes, x86: Disable irqs during optimized callback 2011-05-11 13:21:23 +02:00
kvm.c KVM guest: Fix section mismatch derived from kvm_guest_cpu_online() 2011-03-17 13:08:25 -03:00
kvmclock.c x86: Convert remaining x86 clocksources to clocksource_register_hz/khz 2011-02-21 13:33:33 -08:00
ldt.c
machine_kexec_32.c
machine_kexec_64.c x86, cleanups: Use clear_page/copy_page rather than memset/memcpy 2010-09-22 15:36:49 -07:00
Makefile Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 18:08:06 -07:00
mca_32.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
microcode_amd.c x86, microcode, AMD: Fix signedness bug in generic_load_microcode() 2011-02-20 14:01:32 +01:00
microcode_core.c x86, microcode: Unregister syscore_ops after microcode unloaded 2011-03-29 11:12:04 +02:00
microcode_intel.c x86/microcode: Fix double vfree() and remove redundant pointer checks before vfree() 2010-12-27 14:33:30 +01:00
mmconf-fam10h_64.c x86-64: Fix and clean up AMD Fam10 MMCONF enabling 2010-11-18 13:41:35 +01:00
module.c jump label: Introduce static_branch() interface 2011-04-04 12:48:08 -04:00
mpparse.c x86, ioapic: Consolidate mp_ioapics[] into 'struct ioapic' 2011-05-20 13:40:59 +02:00
msr.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c thp: add pmd paravirt ops 2011-01-13 17:32:39 -08:00
pci-calgary_64.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
pci-dma.c x86/PCI: Remove dma32_reserve_bootmem 2011-05-10 15:43:32 -07:00
pci-iommu_table.c arch/x86/kernel/pci-iommu_table.c: Convert sprintf_symbol to %pS 2011-05-10 10:21:35 +02:00
pci-nommu.c
pci-swiotlb.c
pcspeaker.c
probe_roms.c x86: Introduce pci_map_biosrom() 2011-03-15 15:34:15 -07:00
process_32.c cpuidle/x86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layer 2011-01-12 18:05:16 -05:00
process_64.c x86: mark associated mm when running a task in 32 bit compatibility mode 2011-03-23 16:36:53 -04:00
process.c x86: A fast way to check capabilities of the current cpu 2011-03-29 10:18:30 +02:00
ptrace.c x86: Get rid of asmregparm 2011-05-24 14:33:35 +02:00
pvclock.c x86/pvclock: Zero last_value on resume 2010-11-28 09:33:20 +01:00
quirks.c x86: HPET force enable for CX700 / VIA Epia LT 2010-09-15 16:27:04 +02:00
reboot_32.S x86, reboot: Fix relocations in reboot_32.S 2011-05-02 14:44:46 -07:00
reboot_fixups_32.c x86: Ce4100: Add reboot_fixup() for CE4100 2010-11-12 00:45:41 +01:00
reboot.c x86: Reorder reboot method preferences 2011-04-06 10:36:50 +02:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c x86: avoid high BIOS area when allocating address space 2010-12-17 10:01:30 -08:00
rtc.c rtc: cmos: Add OF bindings 2011-02-23 22:27:55 +01:00
setup_percpu.c x86: Unify CPU -> NUMA node mapping between 32 and 64bit 2011-01-28 14:54:09 +01:00
setup.c x86, efi: Retain boot service code until after switching to virtual mode 2011-05-25 17:03:53 -07:00
signal.c x86: signal: sys_rt_sigreturn() should use set_current_blocked() 2011-04-28 13:01:38 +02:00
smp.c sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() 2011-04-14 08:52:32 +02:00
smpboot.c Revert "x86, NUMA: Fix fakenuma boot failure" 2011-04-21 11:30:59 +02:00
stacktrace.c x86: Remove warning and warning_symbol from struct stacktrace_ops 2011-05-12 15:31:28 +02:00
step.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
sys_i386_32.c i386: Make kernel_execve() suitable for stack unwinding 2010-09-03 08:16:02 +02:00
sys_x86_64.c
syscall_64.c
syscall_table_32.S net: Add sendmmsg socket system call 2011-05-05 11:10:14 -07:00
tboot.c thp: pte alloc trans splitting 2011-01-13 17:32:40 -08:00
tce_64.c
test_nx.c x86: Eliminate various 'set but not used' warnings 2011-05-21 19:10:33 +02:00
test_rodata.c
time.c x86, nmi_watchdog: Remove all stub function calls from old nmi_watchdog 2010-11-18 09:08:23 +01:00
tls.c
tls.h
topology.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
trampoline_32.S x86, trampoline: Common infrastructure for low memory trampolines 2011-02-17 21:02:43 -08:00
trampoline_64.S x86-64, trampoline: Remove unused variable 2011-02-18 15:50:36 -08:00
trampoline.c x86, trampoline: Common infrastructure for low memory trampolines 2011-02-17 21:02:43 -08:00
traps.c x86, NMI: Clean-up default_do_nmi() 2011-01-07 15:08:53 +01:00
tsc_sync.c
tsc.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
verify_cpu.S x86: Fix common misspellings 2011-03-18 10:39:30 +01:00
vm86_32.c thp: split_huge_page_mm/vma 2011-01-13 17:32:41 -08:00
vmlinux.lds.S Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-05-24 11:53:42 -07:00
vsmp_64.c
vsyscall_64.c
x86_init.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 18:08:06 -07:00
x8664_ksyms_64.c x86-64, mem: Convert memmove() to assembly file and fix return value bug 2011-01-25 16:58:39 -08:00
xsave.c x86: Fix common misspellings 2011-03-18 10:39:30 +01:00