System firmware advertises the address of the 'Runtime
Configuration Interface table version 2 (RCI2)' via
an EFI Configuration Table entry. This code retrieves the RCI2
table from the address and exports it to sysfs as a binary
attribute 'rci2' under /sys/firmware/efi/tables directory.
The approach adopted is similar to the attribute 'DMI' under
/sys/firmware/dmi/tables.
RCI2 table contains BIOS HII in XML format and is used to populate
BIOS setup page in Dell EMC OpenManage Server Administrator tool.
The BIOS setup page contains BIOS tokens which can be configured.
Signed-off-by: Narendra K <Narendra.K@dell.com>
Reviewed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The SAL systab is an Itanium specific EFI configuration table, so
move its handling into arch/ia64 where it belongs.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The SGI UV UEFI machines are tightly coupled to the x86 architecture
so there is no need to keep any awareness of its existence in the
generic EFI layer, especially since we already have the infrastructure
to handle arch-specific configuration tables, and were even already
using it to some extent.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The function efi_is_table_address() and the associated array of table
pointers is specific to x86. Since we will be adding some more x86
specific tables, let's move this code out of the generic code first.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The old_memmap flow in efi_call_phys_prolog() performs numerous memory
allocations, and either does not check for failure at all, or it does
but fails to propagate it back to the caller, which may end up calling
into the firmware with an incomplete 1:1 mapping.
So let's fix this by returning NULL from efi_call_phys_prolog() on
memory allocation failures only, and by handling this condition in the
caller. Also, clean up any half baked sets of page tables that we may
have created before returning with a NULL return value.
Note that any failure at this level will trigger a panic() two levels
up, so none of this makes a huge difference, but it is a nice cleanup
nonetheless.
[ardb: update commit log, add efi_call_phys_epilog() call on error path]
Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Bradford <robert.bradford@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190525112559.7917-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following commit:
a893ea15d764 ("tpm: move tpm_chip definition to include/linux/tpm.h")
introduced a build error when both IMA and EFI are enabled:
In file included from ../security/integrity/ima/ima_fs.c:30:
../security/integrity/ima/ima.h:176:7: error: redeclaration of enumerator "NONE"
What happens is that both headers (ima.h and efi.h) defines the same
'NONE' constant, and it broke when they started getting included from
the same file:
Rework to prefix the EFI enum with 'EFI_*'.
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190215165551.12220-2-ard.biesheuvel@linaro.org
[ Cleaned up the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
d5052a7130a6 ("x86/efi: Unmap EFI boot services code/data regions from efi_pgd")
forgets to take two EFI modes into consideration, namely EFI_OLD_MEMMAP and
EFI_MIXED_MODE:
- EFI_OLD_MEMMAP is a legacy way of mapping EFI regions into swapper_pg_dir
using ioremap() and init_memory_mapping(). This feature can be enabled by
passing "efi=old_map" as kernel command line argument. But,
efi_unmap_pages() unmaps EFI boot services code/data regions *only* from
efi_pgd and hence cannot be used for unmapping EFI boot services code/data
regions from swapper_pg_dir.
Introduce a temporary fix to not unmap EFI boot services code/data regions
when EFI_OLD_MEMMAP is enabled while working on a real fix.
- EFI_MIXED_MODE is another feature where a 64-bit kernel runs on a
64-bit platform crippled by a 32-bit firmware. To support EFI_MIXED_MODE,
all RAM (i.e. namely EFI regions like EFI_CONVENTIONAL_MEMORY,
EFI_LOADER_<CODE/DATA>, EFI_BOOT_SERVICES_<CODE/DATA> and
EFI_RUNTIME_CODE/DATA regions) is mapped into efi_pgd all the time to
facilitate EFI runtime calls access it's arguments in 1:1 mode.
Hence, don't unmap EFI boot services code/data regions when booted in mixed mode.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181222022234.7573-1-sai.praneeth.prakhya@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull EFI updates for v4.20 from Ard Biesheuvel:
- Add support for enlisting the help of the EFI firmware to create memory
reservations that persist across kexec.
- Add page fault handling to the runtime services support code on x86 so
we can gracefully recover from buggy EFI firmware.
- Fix command line handling on x86 for the boot path that omits the stub's
PE/COFF entry point.
- Other assorted fixes.
EFI GOP uses 64-bit frame buffer address in some BIOS.
Add 64bit address support in efi earlyprintk.
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
efi_switch_mm() is a wrapper around switch_mm() which saves current's
->active_mm, sets the requests mm as ->active_mm and invokes
switch_mm().
I don't think that task_lock() is required during that procedure. It
protects ->mm which isn't changed here.
It needs to be mentioned that during the whole procedure (switch to
EFI's mm and back) the preemption needs to be disabled. A context switch
at this point would reset the cr3 value based on current->mm. Also, this
function may not be invoked at the same time on a different CPU because
it would overwrite the efi_scratch.prev_mm information.
Remove task_lock() and also update the comment to reflect it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Memory accesses performed by UEFI runtime services should be limited to:
- reading/executing from EFI_RUNTIME_SERVICES_CODE memory regions
- reading/writing from/to EFI_RUNTIME_SERVICES_DATA memory regions
- reading/writing by-ref arguments
- reading/writing from/to the stack.
Accesses outside these regions may cause the kernel to hang because the
memory region requested by the firmware isn't mapped in efi_pgd, which
causes a page fault in ring 0 and the kernel fails to handle it, leading
to die(). To save kernel from hanging, add an EFI specific page fault
handler which recovers from such faults by
1. If the efi runtime service is efi_reset_system(), reboot the machine
through BIOS.
2. If the efi runtime service is _not_ efi_reset_system(), then freeze
efi_rts_wq and schedule a new process.
The EFI page fault handler offers us two advantages:
1. Avoid potential hangs caused by buggy firmware.
2. Shout loud that the firmware is buggy and hence is not a kernel bug.
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Suggested-by: Matt Fleming <matt@codeblueprint.co.uk>
Based-on-code-from: Ricardo Neri <ricardo.neri@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[ardb: clarify commit log]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Commit eeb89e2bb1 ("x86/efi: Load fixmap GDT in efi_call_phys_epilog()")
moved loading the fixmap in efi_call_phys_epilog() after load_cr3() since
it was assumed to be more logical.
Turns out this is incorrect: In efi_call_phys_prolog(), the gdt with its
physical address is loaded first, and when the %cr3 is reloaded in _epilog
from initial_page_table to swapper_pg_dir again the gdt is no longer
mapped. This results in a triple fault if an interrupt occurs after
load_cr3() and before load_fixmap_gdt(0). Calling load_fixmap_gdt(0) first
restores the execution order prior to commit eeb89e2bb1 and fixes the
problem.
Fixes: eeb89e2bb1 ("x86/efi: Load fixmap GDT in efi_call_phys_epilog()")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/1536689892-21538-1-git-send-email-linux@roeck-us.net
When PTI is enabled on x86-32 the kernel uses the GDT mapped in the fixmap
for the simple reason that this address is also mapped for user-space.
The efi_call_phys_prolog()/efi_call_phys_epilog() wrappers change the GDT
to call EFI runtime services and switch back to the kernel GDT when they
return. But the switch-back uses the writable GDT, not the fixmap GDT.
When that happened and and the CPU returns to user-space it switches to the
user %cr3 and tries to restore user segment registers. This fails because
the writable GDT is not mapped in the user page-table, and without a GDT
the fault handlers also can't be launched. The result is a triple fault and
reboot of the machine.
Fix that by restoring the GDT back to the fixmap GDT which is also mapped
in the user page-table.
Fixes: 7757d607c6 x86/pti: ('Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32')
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: hpa@zytor.com
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/1535702738-10971-1-git-send-email-joro@8bytes.org
Pull EFI updates from Thomas Gleixner:
"The EFI pile:
- Make mixed mode UEFI runtime service invocations mutually
exclusive, as mandated by the UEFI spec
- Perform UEFI runtime services calls from a work queue so the calls
into the firmware occur from a kernel thread
- Honor the UEFI memory map attributes for live memory regions
configured by UEFI as a framebuffer. This works around a coherency
problem with KVM guests running on ARM.
- Cleanups, improvements and fixes all over the place"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efivars: Call guid_parse() against guid_t type of variable
efi/cper: Use consistent types for UUIDs
efi/x86: Replace references to efi_early->is64 with efi_is_64bit()
efi: Deduplicate efi_open_volume()
efi/x86: Add missing NULL initialization in UGA draw protocol discovery
efi/x86: Merge 32-bit and 64-bit UGA draw protocol setup routines
efi/x86: Align efi_uga_draw_protocol typedef names to convention
efi/x86: Merge the setup_efi_pci32() and setup_efi_pci64() routines
efi/x86: Prevent reentrant firmware calls in mixed mode
efi/esrt: Only call efi_mem_reserve() for boot services memory
fbdev/efifb: Honour UEFI memory map attributes when mapping the FB
efi: Drop type and attribute checks in efi_mem_desc_lookup()
efi/libstub/arm: Add opt-in Kconfig option for the DTB loader
efi: Remove the declaration of efi_late_init() as the function is unused
efi/cper: Avoid using get_seconds()
efi: Use a work queue to invoke EFI Runtime Services
efi/x86: Use non-blocking SetVariable() for efi_delete_dummy_variable()
efi/x86: Clean up the eboot code
The current implementation of efi_mem_desc_lookup() includes the
following check on the memory descriptor it returns:
if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
md->type != EFI_BOOT_SERVICES_DATA &&
md->type != EFI_RUNTIME_SERVICES_DATA) {
continue;
}
This means that only EfiBootServicesData or EfiRuntimeServicesData
regions are considered, or any other region type provided that it
has the EFI_MEMORY_RUNTIME attribute set.
Given what the name of the function implies, and the fact that any
physical address can be described in the UEFI memory map only a single
time, it does not make sense to impose this condition in the body of the
loop, but instead, should be imposed by the caller depending on the value
that is returned to it.
Two such callers exist at the moment:
- The BGRT code when running on x86, via efi_mem_reserve() and
efi_arch_mem_reserve(). In this case, the region is already known to
be EfiBootServicesData, and so the check is redundant.
- The ESRT handling code which introduced this function, which calls it
both directly from efi_esrt_init() and again via efi_mem_reserve() and
efi_arch_mem_reserve() [on x86].
So let's move this check into the callers instead. This preserves the
current behavior both for BGRT and ESRT handling, and allows the lookup
routine to be reused by other [upcoming] users that don't have this
limitation.
In the ESRT case, keep the entire condition, so that platforms that
deviate from the UEFI spec and use something other than
EfiBootServicesData for the ESRT table will keep working as before.
For x86's efi_arch_mem_reserve() implementation, limit the type to
EfiBootServicesData, since it is the only type the reservation code
expects to operate on in the first place.
While we're at it, drop the __init annotation so that drivers can use it
as well.
Tested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180711094040.12506-8-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull EFI updates from Ingo Molnar:
"The main EFI changes in this cycle were:
- Fix the apple-properties code (Andy Shevchenko)
- Add WARN() on arm64 if UEFI Runtime Services corrupt the reserved
x18 register (Ard Biesheuvel)
- Use efi_switch_mm() on x86 instead of manipulating %cr3 directly
(Sai Praneeth)
- Fix early memremap leak in ESRT code (Ard Biesheuvel)
- Switch to L"xxx" notation for wide string literals (Ard Biesheuvel)
- ... plus misc other cleanups and bugfixes"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3
x86/efi: Replace efi_pgd with efi_mm.pgd
efi: Use string literals for efi_char16_t variable initializers
efi/esrt: Fix handling of early ESRT table mapping
efi: Use efi_mm in x86 as well as ARM
efi: Make const array 'apple' static
efi/apple-properties: Use memremap() instead of ioremap()
efi: Reorder pr_notice() with add_device_randomness() call
x86/efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store()
efi/arm64: Check whether x18 is preserved by runtime services calls
efi/arm*: Stop printing addresses of virtual mappings
efi/apple-properties: Remove redundant attribute initialization from unmarshal_key_value_pairs()
efi/arm*: Only register page tables when they exist
This commit in x86/mm changed EFI code:
116fef6408: x86/mm/dump_pagetables: Add the EFI pagetable to the debugfs 'page_tables' directory
So merge in that commit plus its dependencies, before continuing with
EFI work.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 pti updates from Thomas Gleixner:
"This contains:
- a PTI bugfix to avoid setting reserved CR3 bits when PCID is
disabled. This seems to cause issues on a virtual machine at least
and is incorrect according to the AMD manual.
- a PTI bugfix which disables the perf BTS facility if PTI is
enabled. The BTS AUX buffer is not globally visible and causes the
CPU to fault when the mapping disappears on switching CR3 to user
space. A full fix which restores BTS on PTI is non trivial and will
be worked on.
- PTI bugfixes for EFI and trusted boot which make sure that the user
space visible page table entries have the NX bit cleared
- removal of dead code in the PTI pagetable setup functions
- add PTI documentation
- add a selftest for vsyscall to verify that the kernel actually
implements what it advertises.
- a sysfs interface to expose vulnerability and mitigation
information so there is a coherent way for users to retrieve the
status.
- the initial spectre_v2 mitigations, aka retpoline:
+ The necessary ASM thunk and compiler support
+ The ASM variants of retpoline and the conversion of affected ASM
code
+ Make LFENCE serializing on AMD so it can be used as speculation
trap
+ The RSB fill after vmexit
- initial objtool support for retpoline
As I said in the status mail this is the most of the set of patches
which should go into 4.15 except two straight forward patches still on
hold:
- the retpoline add on of LFENCE which waits for ACKs
- the RSB fill after context switch
Both should be ready to go early next week and with that we'll have
covered the major holes of spectre_v2 and go back to normality"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
x86,perf: Disable intel_bts when PTI
security/Kconfig: Correct the Documentation reference for PTI
x86/pti: Fix !PCID and sanitize defines
selftests/x86: Add test_vsyscall
x86/retpoline: Fill return stack buffer on vmexit
x86/retpoline/irq32: Convert assembler indirect jumps
x86/retpoline/checksum32: Convert assembler indirect jumps
x86/retpoline/xen: Convert Xen hypercall indirect jumps
x86/retpoline/hyperv: Convert assembler indirect jumps
x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
x86/retpoline/entry: Convert entry assembler indirect jumps
x86/retpoline/crypto: Convert crypto assembler indirect jumps
x86/spectre: Add boot time option to select Spectre v2 mitigation
x86/retpoline: Add initial retpoline support
objtool: Allow alternatives to be ignored
objtool: Detect jumps to retpoline thunks
x86/pti: Make unpoison of pgd for trusted boot work for real
x86/alternatives: Fix optimize_nops() checking
sysfs/cpu: Fix typos in vulnerability documentation
x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
...
Commit:
82c3768b8d ("efi/capsule-loader: Use a cached copy of the capsule header")
... refactored the capsule loading code that maps the capsule header,
to avoid having to map it several times.
However, as it turns out, the vmap() call we ended up removing did not
just map the header, but the entire capsule image, and dropping this
virtual mapping breaks capsules that are processed by the firmware
immediately (i.e., without a reboot).
Unfortunately, that change was part of a larger refactor that allowed
a quirk to be implemented for Quark, which has a non-standard memory
layout for capsules, and we have slightly painted ourselves into a
corner by allowing quirk code to mangle the capsule header and memory
layout.
So we need to fix this without breaking Quark. Fortunately, Quark does
not appear to care about the virtual mapping, and so we can simply
do a partial revert of commit:
2a457fb31d ("efi/capsule-loader: Use page addresses rather than struct page pointers")
... and create a vmap() mapping of the entire capsule (including header)
based on the reinstated struct page array, unless running on Quark, in
which case we pass the capsule header copy as before.
Reported-by: Ge Song <ge.song@hxt-semitech.com>
Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Tested-by: Ge Song <ge.song@hxt-semitech.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 82c3768b8d ("efi/capsule-loader: Use a cached copy of the capsule header")
Link: http://lkml.kernel.org/r/20180102172110.17018-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 page table isolation updates from Thomas Gleixner:
"This is the final set of enabling page table isolation on x86:
- Infrastructure patches for handling the extra page tables.
- Patches which map the various bits and pieces which are required to
get in and out of user space into the user space visible page
tables.
- The required changes to have CR3 switching in the entry/exit code.
- Optimizations for the CR3 switching along with documentation how
the ASID/PCID mechanism works.
- Updates to dump pagetables to cover the user space page tables for
W+X scans and extra debugfs files to analyze both the kernel and
the user space visible page tables
The whole functionality is compile time controlled via a config switch
and can be turned on/off on the command line as well"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
x86/ldt: Make the LDT mapping RO
x86/mm/dump_pagetables: Allow dumping current pagetables
x86/mm/dump_pagetables: Check user space page table for WX pages
x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy
x86/mm/pti: Add Kconfig
x86/dumpstack: Indicate in Oops whether PTI is configured and enabled
x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming
x86/mm: Use INVPCID for __native_flush_tlb_single()
x86/mm: Optimize RESTORE_CR3
x86/mm: Use/Fix PCID to optimize user/kernel switches
x86/mm: Abstract switching CR3
x86/mm: Allow flushing for future ASID switches
x86/pti: Map the vsyscall page if needed
x86/pti: Put the LDT in its own PGD if PTI is on
x86/mm/64: Make a full PGD-entry size hole in the memory map
x86/events/intel/ds: Map debug buffers in cpu_entry_area
x86/cpu_entry_area: Add debugstore entries to cpu_entry_area
x86/mm/pti: Map ESPFIX into user space
x86/mm/pti: Share entry text PMD
x86/entry: Align entry text section to PMD boundary
...
