efi_mem_reserve() allows us to permanently mark EFI boot services
regions as reserved, which means we no longer need to copy the image
data out and into a separate buffer.
Leaving the data in the original boot services region has the added
benefit that BGRT images can now be passed across kexec reboot.
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Môshe van der Sterre <me@moshe.nl>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
The promise of pretty boot splashes from firmware via BGRT was at
best only that; a promise. The kernel diligently checks to make
sure the BGRT data firmware gives it is valid, and dutifully warns
the user when it isn't. However, it does so via the pr_err log
level which seems unnecessary. The user cannot do anything about
this and there really isn't an error on the part of Linux to
correct.
This lowers the log level by using pr_notice instead. Users will
no longer have their boot process uglified by the kernel reminding
us that firmware can and often is broken when the 'quiet' kernel
parameter is specified. Ironic, considering BGRT is supposed to
make boot pretty to begin with.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Môshe van der Sterre <me@moshe.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462303781-8686-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Unintuitively, the BGRT graphic is apparently meant to be usable
if the valid bit in not set. The valid bit only conveys
uncertainty about the validity in relation to the screen state.
Windows 10 actually uses the BGRT image for its boot screen even
if not 'valid', for example when the user triggered the boot
menu. Because it is unclear if all firmwares will provide a
usable graphic in this case, we now look at the BMP magic number
as an additional check.
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Môshe van der Sterre <me@moshe.nl>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: =?UTF-8?q?M=C3=B4she=20van=20der=20Sterre?= <me@moshe.nl>
Link: http://lkml.kernel.org/r/1454364428-494-10-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Môshe reported the following warning triggered on his machine since
commit 50a0cb5652 ("x86/efi-bgrt: Fix kernel panic when mapping BGRT
data"),
[ 0.026936] ------------[ cut here ]------------
[ 0.026941] WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:137 __early_ioremap+0x102/0x1bb()
[ 0.026941] Modules linked in:
[ 0.026944] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1 #2
[ 0.026945] Hardware name: Dell Inc. XPS 13 9343/09K8G1, BIOS A05 07/14/2015
[ 0.026946] 0000000000000000 900f03d5a116524d ffffffff81c03e60 ffffffff813a3fff
[ 0.026948] 0000000000000000 ffffffff81c03e98 ffffffff810a0852 00000000d7b76000
[ 0.026949] 0000000000000000 0000000000000001 0000000000000001 000000000000017c
[ 0.026951] Call Trace:
[ 0.026955] [<ffffffff813a3fff>] dump_stack+0x44/0x55
[ 0.026958] [<ffffffff810a0852>] warn_slowpath_common+0x82/0xc0
[ 0.026959] [<ffffffff810a099a>] warn_slowpath_null+0x1a/0x20
[ 0.026961] [<ffffffff81d8c395>] __early_ioremap+0x102/0x1bb
[ 0.026962] [<ffffffff81d8c602>] early_memremap+0x13/0x15
[ 0.026964] [<ffffffff81d78361>] efi_bgrt_init+0x162/0x1ad
[ 0.026966] [<ffffffff81d778ec>] efi_late_init+0x9/0xb
[ 0.026968] [<ffffffff81d58ff5>] start_kernel+0x46f/0x49f
[ 0.026970] [<ffffffff81d58120>] ? early_idt_handler_array+0x120/0x120
[ 0.026972] [<ffffffff81d58339>] x86_64_start_reservations+0x2a/0x2c
[ 0.026974] [<ffffffff81d58485>] x86_64_start_kernel+0x14a/0x16d
[ 0.026977] ---[ end trace f9b3812eb8e24c58 ]---
[ 0.026978] efi_bgrt: Ignoring BGRT: failed to map image memory
early_memremap() has an upper limit on the size of mapping it can
handle which is ~200KB. Clearly the BGRT image on Môshe's machine is
much larger than that.
There's actually no reason to restrict ourselves to using the early_*
version of memremap() - the ACPI BGRT driver is invoked late enough in
boot that we can use the standard version, with the benefit that the
late version allows mappings of arbitrary size.
Reported-by: Môshe van der Sterre <me@moshe.nl>
Tested-by: Môshe van der Sterre <me@moshe.nl>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1450707172-12561-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Starting with this commit 35eb8b81edd4 ("x86/efi: Build our own page
table structures") efi regions have a separate page directory called
"efi_pgd". In order to access any efi region we have to first shift %cr3
to this page table. In the bgrt code we are trying to copy bgrt_header
and image, but these regions fall under "EFI_BOOT_SERVICES_DATA"
and to access these regions we have to shift %cr3 to efi_pgd and not
doing so will cause page fault as shown below.
[ 0.251599] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4
[ 0.259126] Freeing SMP alternatives memory: 32K (ffffffff8230e000 - ffffffff82316000)
[ 0.271803] BUG: unable to handle kernel paging request at fffffffefce35002
[ 0.279740] IP: [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.286383] PGD 300f067 PUD 0
[ 0.289879] Oops: 0000 [#1] SMP
[ 0.293566] Modules linked in:
[ 0.297039] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1-eywa-eywa-built-in-47041+ #2
[ 0.306619] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B104.B01.1511110114 11/11/2015
[ 0.320925] task: ffffffff820134c0 ti: ffffffff82000000 task.ti: ffffffff82000000
[ 0.329420] RIP: 0010:[<ffffffff821bca49>] [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.338821] RSP: 0000:ffffffff82003f18 EFLAGS: 00010246
[ 0.344852] RAX: fffffffefce35000 RBX: fffffffefce35000 RCX: fffffffefce2b000
[ 0.352952] RDX: 000000008a82b000 RSI: ffffffff8235bb80 RDI: 000000008a835000
[ 0.361050] RBP: ffffffff82003f30 R08: 000000008a865000 R09: ffffffffff202850
[ 0.369149] R10: ffffffff811ad62f R11: 0000000000000000 R12: 0000000000000000
[ 0.377248] R13: ffff88016dbaea40 R14: ffffffff822622c0 R15: ffffffff82003fb0
[ 0.385348] FS: 0000000000000000(0000) GS:ffff88016d800000(0000) knlGS:0000000000000000
[ 0.394533] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.401054] CR2: fffffffefce35002 CR3: 000000000300c000 CR4: 00000000003406f0
[ 0.409153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 0.417252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 0.425350] Stack:
[ 0.427638] ffffffffffffffff ffffffff82256900 ffff88016dbaea40 ffffffff82003f40
[ 0.436086] ffffffff821bbce0 ffffffff82003f88 ffffffff8219c0c2 0000000000000000
[ 0.444533] ffffffff8219ba4a ffffffff822622c0 0000000000083000 00000000ffffffff
[ 0.452978] Call Trace:
[ 0.455763] [<ffffffff821bbce0>] efi_late_init+0x9/0xb
[ 0.461697] [<ffffffff8219c0c2>] start_kernel+0x463/0x47f
[ 0.467928] [<ffffffff8219ba4a>] ? set_init_arg+0x55/0x55
[ 0.474159] [<ffffffff8219b120>] ? early_idt_handler_array+0x120/0x120
[ 0.481669] [<ffffffff8219b5ee>] x86_64_start_reservations+0x2a/0x2c
[ 0.488982] [<ffffffff8219b72d>] x86_64_start_kernel+0x13d/0x14c
[ 0.495897] Code: 00 41 b4 01 48 8b 78 28 e8 09 36 01 00 48 85 c0 48 89 c3 75 13 48 c7 c7 f8 ac d3 81 31 c0 e8 d7 3b fb fe e9 b5 00 00 00 45 84 e4 <44> 8b 6b 02 74 0d be 06 00 00 00 48 89 df e8 ae 34 0$
[ 0.518151] RIP [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[ 0.524888] RSP <ffffffff82003f18>
[ 0.528851] CR2: fffffffefce35002
[ 0.532615] ---[ end trace 7b06521e6ebf2aea ]---
[ 0.537852] Kernel panic - not syncing: Attempted to kill the idle task!
As said above one way to fix this bug is to shift %cr3 to efi_pgd but we
are not doing that way because it leaks inner details of how we switch
to EFI page tables into a new call site and it also adds duplicate code.
Instead, we remove the call to efi_lookup_mapped_addr() and always
perform early_mem*() instead of early_io*() because we want to remap RAM
regions and not I/O regions. We also delete efi_lookup_mapped_addr()
because we are no longer using it.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reported-by: Wendy Wang <wendy.wang@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
The pr_*() calls in the x86 EFI code may or may not include a
subsystem tag, which makes it difficult to grep the kernel log for all
relevant EFI messages and leads users to miss important information.
Recently, a bug reporter provided all the EFI print messages from the
kernel log when trying to diagnose an issue but missed the following
statement because it wasn't prefixed with anything indicating it was
related to EFI,
pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
Cc: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
It's totally legitimate, per the ACPI spec, for the firmware to
set the BGRT 'status' field to zero to indicate that the BGRT
image isn't being displayed, and we shouldn't be printing an
error message in that case because it's just noise for users. So
swap pr_err() for pr_debug().
However, Josh points that out it still makes sense to test the
validity of the upper 7 bits of the 'status' field, since
they're marked as "reserved" in the spec and must be zero. If
firmware violates this it really *is* an error.
Reported-by: Tom Yan <tom.ty89@gmail.com>
Tested-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438936621-5215-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Gracefully handle failures to allocate memory for the image, which might
be arbitrarily large.
efi_bgrt_init can fail in various ways as well, usually because the
BIOS-provided BGRT structure does not match expectations. Add
appropriate error messages rather than failing silently.
Reported-by: Srihari Vijayaraghavan <linux.bug.reporting@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81321
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Madper reported seeing the following crash,
BUG: unable to handle kernel paging request at ffffffffff340003
IP: [<ffffffff81d85ba4>] efi_bgrt_init+0x9d/0x133
Call Trace:
[<ffffffff81d8525d>] efi_late_init+0x9/0xb
[<ffffffff81d68f59>] start_kernel+0x436/0x450
[<ffffffff81d6892c>] ? repair_env_string+0x5c/0x5c
[<ffffffff81d68120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d685de>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d6871e>] x86_64_start_kernel+0x13e/0x14d
This is caused because the layout of the ACPI BGRT header on this system
doesn't match the definition from the ACPI spec, and so we get a bogus
physical address when dereferencing ->image_address in efi_bgrt_init().
Luckily the status field in the BGRT header clearly marks it as invalid,
so we can check that field and skip BGRT initialisation.
Reported-by: Madper Xie <cxie@redhat.com>
Suggested-by: Toshi Kani <toshi.kani@hp.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
CONFIG_X86_32 doesn't map the boot services regions into the EFI memory
map (see commit 700870119f ("x86, efi: Don't map Boot Services on
i386")), and so efi_lookup_mapped_addr() will fail to return a valid
address. Executing the ioremap() path in efi_bgrt_init() causes the
following warning on x86-32 because we're trying to ioremap() RAM,
WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x2ad/0x2c0()
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.13.0-0.rc5.git0.1.2.fc21.i686 #1
Hardware name: DellInc. Venue 8 Pro 5830/09RP78, BIOS A02 10/17/2013
00000000 00000000 c0c0df08 c09a5196 00000000 c0c0df38 c0448c1e c0b41310
00000000 00000000 c0b37bc1 00000066 c043bbfd c043bbfd 00e7dfe0 00073eff
00073eff c0c0df48 c0448ce2 00000009 00000000 c0c0df9c c043bbfd 00078d88
Call Trace:
[<c09a5196>] dump_stack+0x41/0x52
[<c0448c1e>] warn_slowpath_common+0x7e/0xa0
[<c043bbfd>] ? __ioremap_caller+0x2ad/0x2c0
[<c043bbfd>] ? __ioremap_caller+0x2ad/0x2c0
[<c0448ce2>] warn_slowpath_null+0x22/0x30
[<c043bbfd>] __ioremap_caller+0x2ad/0x2c0
[<c0718f92>] ? acpi_tb_verify_table+0x1c/0x43
[<c0719c78>] ? acpi_get_table_with_size+0x63/0xb5
[<c087cd5e>] ? efi_lookup_mapped_addr+0xe/0xf0
[<c043bc2b>] ioremap_nocache+0x1b/0x20
[<c0cb01c8>] ? efi_bgrt_init+0x83/0x10c
[<c0cb01c8>] efi_bgrt_init+0x83/0x10c
[<c0cafd82>] efi_late_init+0x8/0xa
[<c0c9bab2>] start_kernel+0x3ae/0x3c3
[<c0c9b53b>] ? repair_env_string+0x51/0x51
[<c0c9b378>] i386_start_kernel+0x12e/0x131
Switch to using early_memremap(), which won't trigger this warning, and
has the added benefit of more accurately conveying what we're trying to
do - map a chunk of memory.
This patch addresses the following bug report,
https://bugzilla.kernel.org/show_bug.cgi?id=67911
Reported-by: Adam Williamson <awilliam@redhat.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Header length should be validated for all ACPI tables before accessing
any non-header field.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/509A9E6002000078000A7079@nat28.tlf.novell.com
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The ACPI BGRT driver accesses the BIOS logo image when it initializes.
However, ACPI 5.0 (which introduces the BGRT) recommends putting the
logo image in EFI boot services memory, so that the OS can reclaim that
memory. Production systems follow this recommendation, breaking the
ACPI BGRT driver.
Move the bulk of the BGRT code to run during a new EFI late
initialization phase, which occurs after switching EFI to virtual mode,
and after initializing ACPI, but before freeing boot services memory.
Copy the BIOS logo image to kernel memory at that point, and make it
accessible to the BGRT driver. Rework the existing ACPI BGRT driver to
act as a simple wrapper exposing that image (and the properties from the
BGRT) via sysfs.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/93ce9f823f1c1f3bb88bdd662cce08eee7a17f5d.1348876882.git.josh@joshtriplett.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
