linux/arch/x86
Josh Boyer 700870119f x86, efi: Don't map Boot Services on i386
Add patch to fix 32bit EFI service mapping (rhbz 726701)

Multiple people are reporting hitting the following WARNING on i386,

  WARNING: at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x3d3/0x440()
  Modules linked in:
  Pid: 0, comm: swapper Not tainted 3.9.0-rc7+ #95
  Call Trace:
   [<c102b6af>] warn_slowpath_common+0x5f/0x80
   [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440
   [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440
   [<c102b6ed>] warn_slowpath_null+0x1d/0x20
   [<c1023fb3>] __ioremap_caller+0x3d3/0x440
   [<c106007b>] ? get_usage_chars+0xfb/0x110
   [<c102d937>] ? vprintk_emit+0x147/0x480
   [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de
   [<c102406a>] ioremap_cache+0x1a/0x20
   [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de
   [<c1418593>] efi_enter_virtual_mode+0x1e4/0x3de
   [<c1407984>] start_kernel+0x286/0x2f4
   [<c1407535>] ? repair_env_string+0x51/0x51
   [<c1407362>] i386_start_kernel+0x12c/0x12f

Due to the workaround described in commit 916f676f8 ("x86, efi: Retain
boot service code until after switching to virtual mode") EFI Boot
Service regions are mapped for a period during boot. Unfortunately, with
the limited size of the i386 direct kernel map it's possible that some
of the Boot Service regions will not be directly accessible, which
causes them to be ioremap()'d, triggering the above warning as the
regions are marked as E820_RAM in the e820 memmap.

There are currently only two situations where we need to map EFI Boot
Service regions,

  1. To workaround the firmware bug described in 916f676f8
  2. To access the ACPI BGRT image

but since we haven't seen an i386 implementation that requires either,
this simple fix should suffice for now.

[ Added to changelog - Matt ]

Reported-by: Bryan O'Donoghue <bryan.odonoghue.lkml@nexus-software.ie>
Acked-by: Tom Zanussi <tom.zanussi@intel.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-09-18 14:42:33 +01:00
..
boot Merge branch 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-04 09:38:10 -07:00
configs x86, platform, kvm, kconfig: Turn existing .config's into KVM-capable configs 2013-05-28 12:11:32 +02:00
crypto Reinstate "crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework" 2013-09-07 12:56:26 +10:00
ia32 Merge branch 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-04 11:08:32 -07:00
include mm: make sure _PAGE_SWP_SOFT_DIRTY bit is not set on present pte 2013-09-11 15:58:06 -07:00
kernel Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-12 10:44:54 -07:00
kvm shrinker: convert remaining shrinkers to count/scan API 2013-09-10 18:56:32 -04:00
lguest lguest: fix GPF in guest when using gdb. 2013-09-06 08:09:28 +09:30
lib Merge branch 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-04 11:08:32 -07:00
math-emu
mm x86: finish user fault error path with fatal signal 2013-09-12 15:38:01 -07:00
net x86: bpf_jit_comp: secure bpf jit against spraying attacks 2013-05-19 23:55:41 -07:00
oprofile oprofilefs_create_...() do not need superblock argument 2013-09-03 22:52:48 -04:00
pci PCI changes for the v3.12 merge window: 2013-09-03 16:24:35 -07:00
platform x86, efi: Don't map Boot Services on i386 2013-09-18 14:42:33 +01:00
power x86, asmlinkage, power: Make various symbols used by the suspend asm code visible 2013-08-06 14:21:03 -07:00
realmode x86, relocs: Refactor the relocs tool to merge 32- and 64-bit ELF 2013-04-16 16:02:58 -07:00
syscalls unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
tools Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-04 08:39:38 -07:00
um um: prctl: Do not include linux/ptrace.h 2013-09-07 10:57:11 +02:00
vdso remove sched notifier for cross-cpu migrations 2013-07-18 12:29:30 +02:00
video
xen Bug-fixes: 2013-09-10 20:07:04 -07:00
.gitignore
Kbuild
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Kconfig.cpu x86, 386 removal: Document Nx586 as a 386 and thus unsupported 2012-11-29 13:28:39 -08:00
Kconfig.debug Merge branch 'kconfig-diet' from Dave Hansen 2013-07-04 11:25:51 -07:00
Makefile x86, relocs: Move ELF relocation handling to C 2013-08-07 21:00:04 -07:00
Makefile_32.cpu x86, 386 removal: Remove CONFIG_M386 from Kconfig 2012-11-29 13:23:01 -08:00
Makefile.um