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path: root/drivers/firmware/efi/efi.c
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2020-12-15mm/gup: prevent gup_fast from racing with COW during forkJason Gunthorpe1-0/+1
Since commit 70e806e4e645 ("mm: Do early cow for pinned pages during fork() for ptes") pages under a FOLL_PIN will not be write protected during COW for fork. This means that pages returned from pin_user_pages(FOLL_WRITE) should not become write protected while the pin is active. However, there is a small race where get_user_pages_fast(FOLL_PIN) can establish a FOLL_PIN at the same time copy_present_page() is write protecting it: CPU 0 CPU 1 get_user_pages_fast() internal_get_user_pages_fast() copy_page_range() pte_alloc_map_lock() copy_present_page() atomic_read(has_pinned) == 0 page_maybe_dma_pinned() == false atomic_set(has_pinned, 1); gup_pgd_range() gup_pte_range() pte_t pte = gup_get_pte(ptep) pte_access_permitted(pte) try_grab_compound_head() pte = pte_wrprotect(pte) set_pte_at(); pte_unmap_unlock() // GUP now returns with a write protected page The first attempt to resolve this by using the write protect caused problems (and was missing a barrrier), see commit f3c64eda3e50 ("mm: avoid early COW write protect games during fork()") Instead wrap copy_p4d_range() with the write side of a seqcount and check the read side around gup_pgd_range(). If there is a collision then get_user_pages_fast() fails and falls back to slow GUP. Slow GUP is safe against this race because copy_page_range() is only called while holding the exclusive side of the mmap_lock on the src mm_struct. [akpm@linux-foundation.org: coding style fixes] Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com Fixes: f3c64eda3e50 ("mm: avoid early COW write protect games during fork()") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de> [seqcount_t parts] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kirill Shutemov <kirill@shutemov.name> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Leon Romanovsky <leonro@nvidia.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-25efi/efivars: Set generic ops before loading SSDTAmadeusz Sławiński1-1/+1
Efivars allows for overriding of SSDT tables, however starting with commit bf67fad19e493b ("efi: Use more granular check for availability for variable services") this use case is broken. When loading SSDT generic ops should be set first, however mentioned commit reversed order of operations. Fix this by restoring original order of operations. Fixes: bf67fad19e493b ("efi: Use more granular check for availability for variable services") Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Link: https://lore.kernel.org/r/20201123172817.124146-1-amadeuszx.slawinski@linux.intel.com Tested-by: Cezary Rojewski <cezary.rojewski@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-10-12Merge branch 'efi/urgent' into efi/core, to pick up fixesIngo Molnar1-23/+26
These fixes missed the v5.9 merge window, pick them up for early v5.10 merge. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-09-26efi: Add definition of EFI_MEMORY_CPU_CRYPTO and ability to report itArd Biesheuvel1-23/+24
Incorporate the definition of EFI_MEMORY_CPU_CRYPTO from the UEFI specification v2.8, and wire it into our memory map dumping routine as well. To make a bit of space in the output buffer, which is provided by the various callers, shorten the descriptive names of the memory types. Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16efi: Support for MOK variable config tableLenny Szubowicz1-0/+6
Because of system-specific EFI firmware limitations, EFI volatile variables may not be capable of holding the required contents of the Machine Owner Key (MOK) certificate store when the certificate list grows above some size. Therefore, an EFI boot loader may pass the MOK certs via a EFI configuration table created specifically for this purpose to avoid this firmware limitation. An EFI configuration table is a much more primitive mechanism compared to EFI variables and is well suited for one-way passage of static information from a pre-OS environment to the kernel. This patch adds initial kernel support to recognize, parse, and validate the EFI MOK configuration table, where named entries contain the same data that would otherwise be provided in similarly named EFI variables. Additionally, this patch creates a sysfs binary file for each EFI MOK configuration table entry found. These files are read-only to root and are provided for use by user space utilities such as mokutil. A subsequent patch will load MOK certs into the trusted platform key ring using this infrastructure. Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com> Link: https://lore.kernel.org/r/20200905013107.10457-2-lszubowi@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-08-20efi: add missed destroy_workqueue when efisubsys_init failsLi Heng1-0/+2
destroy_workqueue() should be called to destroy efi_rts_wq when efisubsys_init() init resources fails. Cc: <stable@vger.kernel.org> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Li Heng <liheng40@huawei.com> Link: https://lore.kernel.org/r/1595229738-10087-1-git-send-email-liheng40@huawei.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-07-09efi/efivars: Expose RT service availability via efivars abstractionArd Biesheuvel1-4/+8
Commit bf67fad19e493b ("efi: Use more granular check for availability for variable services") introduced a check into the efivarfs, efi-pstore and other drivers that aborts loading of the module if not all three variable runtime services (GetVariable, SetVariable and GetNextVariable) are supported. However, this results in efivarfs being unavailable entirely if only SetVariable support is missing, which is only needed if you want to make any modifications. Also, efi-pstore and the sysfs EFI variable interface could be backed by another implementation of the 'efivars' abstraction, in which case it is completely irrelevant which services are supported by the EFI firmware. So make the generic 'efivars' abstraction dependent on the availibility of the GetVariable and GetNextVariable EFI runtime services, and add a helper 'efivar_supports_writes()' to find out whether the currently active efivars abstraction supports writes (and wire it up to the availability of SetVariable for the generic one). Then, use the efivar_supports_writes() helper to decide whether to permit efivarfs to be mounted read-write, and whether to enable efi-pstore or the sysfs EFI variable interface altogether. Fixes: bf67fad19e493b ("efi: Use more granular check for availability for variable services") Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-16efi: Make it possible to disable efivar_ssdt entirelyPeter Jones1-1/+1
In most cases, such as CONFIG_ACPI_CUSTOM_DSDT and CONFIG_ACPI_TABLE_UPGRADE, boot-time modifications to firmware tables are tied to specific Kconfig options. Currently this is not the case for modifying the ACPI SSDT via the efivar_ssdt kernel command line option and associated EFI variable. This patch adds CONFIG_EFI_CUSTOM_SSDT_OVERLAYS, which defaults disabled, in order to allow enabling or disabling that feature during the build. Cc: <stable@vger.kernel.org> Signed-off-by: Peter Jones <pjones@redhat.com> Link: https://lore.kernel.org/r/20200615202408.2242614-1-pjones@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-15efi: Replace zero-length array and use struct_size() helperGustavo A. R. Silva1-1/+2
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. Lastly, make use of the sizeof_field() helper instead of an open-coded version. This issue was found with the help of Coccinelle and audited _manually_. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200527171425.GA4053@embeddedor Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-09mmap locking API: add MMAP_LOCK_INITIALIZERMichel Lespinasse1-1/+1
Define a new initializer for the mmap locking api. Initially this just evaluates to __RWSEM_INITIALIZER as the API is defined as wrappers around rwsem. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-9-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-25Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixesIngo Molnar1-4/+1
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-05-17efi: Pull up arch-specific prototype efi_systab_show_arch()Benjamin Thiel1-4/+1
Pull up arch-specific prototype efi_systab_show_arch() in order to fix a -Wmissing-prototypes warning: arch/x86/platform/efi/efi.c:957:7: warning: no previous prototype for ‘efi_systab_show_arch’ [-Wmissing-prototypes] char *efi_systab_show_arch(char *str) Signed-off-by: Benjamin Thiel <b.thiel@posteo.de> Link: https://lore.kernel.org/r/20200516132647.14568-1-b.thiel@posteo.de Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi: Move arch_tables check to callerArd Biesheuvel1-10/+8
Instead of making match_config_table() test its table_types pointer for NULL-ness, omit the call entirely if no arch_tables pointer was provided to efi_config_parse_tables(). Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi: Clean up config table description arraysArd Biesheuvel1-14/+14
Increase legibility by adding whitespace to the efi_config_table_type_t arrays that describe which EFI config tables we look for when going over the firmware provided list. While at it, replace the 'name' char pointer with a char array, which is more space efficient on relocatable 64-bit kernels, as it avoids a 8 byte pointer and the associated relocation data (24 bytes when using RELA format) Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-03-08efi/x86: Ignore the memory attributes table on i386Ard Biesheuvel1-1/+1
Commit: 3a6b6c6fb23667fa ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures") moved the call to efi_memattr_init() from ARM specific to the generic EFI init code, in order to be able to apply the restricted permissions described in that table on x86 as well. We never enabled this feature fully on i386, and so mapping and reserving this table is pointless. However, due to the early call to memblock_reserve(), the memory bookkeeping gets confused to the point where it produces the splat below when we try to map the memory later on: ------------[ cut here ]------------ ioremap on RAM at 0x3f251000 - 0x3fa1afff WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:166 __ioremap_caller ... Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0 #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 EIP: __ioremap_caller.constprop.0+0x249/0x260 Code: 90 0f b7 05 4e 38 40 de 09 45 e0 e9 09 ff ff ff 90 8d 45 ec c6 05 ... EAX: 00000029 EBX: 00000000 ECX: de59c228 EDX: 00000001 ESI: 3f250fff EDI: 00000000 EBP: de3edf20 ESP: de3edee0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00200296 CR0: 80050033 CR2: ffd17000 CR3: 1e58c000 CR4: 00040690 Call Trace: ioremap_cache+0xd/0x10 ? old_map_region+0x72/0x9d old_map_region+0x72/0x9d efi_map_region+0x8/0xa efi_enter_virtual_mode+0x260/0x43b start_kernel+0x329/0x3aa i386_start_kernel+0xa7/0xab startup_32_smp+0x164/0x168 ---[ end trace e15ccf6b9f356833 ]--- Let's work around this by disregarding the memory attributes table altogether on i386, which does not result in a loss of functionality or protection, given that we never consumed the contents. Fixes: 3a6b6c6fb23667fa ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ") Tested-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org
2020-03-08Merge branch 'efi/urgent' into efi/core, to pick up fixesIngo Molnar1-2/+2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-08Merge tag 'efi-next' of ↵Ingo Molnar1-0/+57
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core More EFI updates for v5.7 - Incorporate a stable branch with the EFI pieces of Hans's work on loading device firmware from EFI boot service memory regions Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-03efi: Export boot-services code and data as debugfs-blobsHans de Goede1-0/+57
Sometimes it is useful to be able to dump the efi boot-services code and data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi, but only if efi=debug is passed on the kernel-commandline as this requires not freeing those memory-regions, which costs 20+ MB of RAM. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200115163554.101315-2-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-29efi: Mark all EFI runtime services as unsupported on non-EFI bootArd Biesheuvel1-3/+3
Recent changes to the way we deal with EFI runtime services that are marked as unsupported by the firmware resulted in a regression for non-EFI boot. The problem is that all EFI runtime services are marked as available by default, and any non-NULL checks on the EFI service function pointers (which will be non-NULL even for runtime services that are unsupported on an EFI boot) were replaced with checks against the mask stored in efi.runtime_supported_mask. When doing a non-EFI boot, this check against the mask will return a false positive, given the fact that all runtime services are marked as enabled by default. Since we dropped the non-NULL check of the runtime service function pointer in favor of the mask check, we will now unconditionally dereference the function pointer, even if it is NULL, and go boom. So let's ensure that the mask reflects reality on a non-EFI boot, which is that all EFI runtime services are unsupported. Reported-by: David Hildenbrand <david@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200228121408.9075-7-ardb@kernel.org
2020-02-29efi: Don't shadow 'i' in efi_config_parse_tables()Heinrich Schuchardt1-1/+0
Shadowing variables is generally frowned upon. Let's simply reuse the existing loop counter 'i' instead of shadowing it. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Hildenbrand <david@redhat.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200223221324.156086-1-xypron.glpk@gmx.de Link: https://lore.kernel.org/r/20200228121408.9075-4-ardb@kernel.org
2020-02-29efi/x86: Add RNG seed EFI table to unencrypted mapping checkTom Lendacky1-8/+10
When booting with SME active, EFI tables must be mapped unencrypted since they were built by UEFI in unencrypted memory. Update the list of tables to be checked during early_memremap() processing to account for the EFI RNG seed table. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Hildenbrand <david@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Link: https://lore.kernel.org/r/b64385fc13e5d7ad4b459216524f138e7879234f.1582662842.git.thomas.lendacky@amd.com Link: https://lore.kernel.org/r/20200228121408.9075-3-ardb@kernel.org
2020-02-26efi: READ_ONCE rng seed size before munmapJason A. Donenfeld1-2/+2
This function is consistent with using size instead of seed->size (except for one place that this patch fixes), but it reads seed->size without using READ_ONCE, which means the compiler might still do something unwanted. So, this commit simply adds the READ_ONCE wrapper. Fixes: 636259880a7e ("efi: Add support for seeding the RNG from a UEFI ...") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20200217123354.21140-1-Jason@zx2c4.com Link: https://lore.kernel.org/r/20200221084849.26878-5-ardb@kernel.org
2020-02-23efi: Register EFI rtc platform device only when availableArd Biesheuvel1-0/+3
Drop the separate driver that registers the EFI rtc on all EFI systems that have runtime services available, and instead, move the registration into the core EFI code, and make it conditional on whether the actual time related services are available. Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Use more granular check for availability for variable servicesArd Biesheuvel1-20/+8
The UEFI spec rev 2.8 permits firmware implementations to support only a subset of EFI runtime services at OS runtime (i.e., after the call to ExitBootServices()), so let's take this into account in the drivers that rely specifically on the availability of the EFI variable services. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Add support for EFI_RT_PROPERTIES tableArd Biesheuvel1-0/+12
Take the newly introduced EFI_RT_PROPERTIES_TABLE configuration table into account, which carries a mask of which EFI runtime services are still functional after ExitBootServices() has been called by the OS. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Store mask of supported runtime services in struct efiArd Biesheuvel1-10/+17
Revision 2.8 of the UEFI spec introduces provisions for firmware to advertise lack of support for certain runtime services at OS runtime. Let's store this mask in struct efi for easy access. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/arm: Move FDT param discovery code out of efi.cArd Biesheuvel1-135/+0
On ARM systems, we discover the UEFI system table address and memory map address from the /chosen node in the device tree, or in the Xen case, from a similar node under /hypervisor. Before making some functional changes to that code, move it into its own file that only gets built if CONFIG_EFI_PARAMS_FROM_FDT=y. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/x86: Make fw_vendor, config_table and runtime sysfs nodes x86 specificArd Biesheuvel1-34/+6
There is some code that exposes physical addresses of certain parts of the EFI firmware implementation via sysfs nodes. These nodes are only used on x86, and are of dubious value to begin with, so let's move their handling into the x86 arch code. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Clean up config_parse_tables()Ard Biesheuvel1-24/+23
config_parse_tables() is a jumble of pointer arithmetic, due to the fact that on x86, we may be dealing with firmware whose native word size differs from the kernel's. This is not a concern on other architectures, and doesn't quite justify the state of the code, so let's clean it up by adding a non-x86 code path, constifying statically allocated tables and replacing preprocessor conditionals with IS_ENABLED() checks. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Make efi_config_init() x86 onlyArd Biesheuvel1-31/+0
The efi_config_init() routine is no longer shared with ia64 so let's move it into the x86 arch code before making further x86 specific changes to it. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Merge EFI system table revision and vendor checksArd Biesheuvel1-0/+61
We have three different versions of the code that checks the EFI system table revision and copies the firmware vendor string, and they are mostly equivalent, with the exception of the use of early_memremap_ro vs. __va() and the lowest major revision to warn about. Let's move this into common code and factor out the commonalities. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Make memreserve table handling local to efi.cArd Biesheuvel1-6/+6
There is no need for struct efi to carry the address of the memreserve table and share it with the world. So move it out and make it __initdata as well. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Move mem_attr_table out of struct efiArd Biesheuvel1-2/+1
The memory attributes table is only used at init time by the core EFI code, so there is no need to carry its address in struct efi that is shared with the world. So move it out, and make it __ro_after_init as well, considering that the value is set during early boot. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Make rng_seed table handling local to efi.cArd Biesheuvel1-11/+10
Move the rng_seed table address from struct efi into a static global variable in efi.c, which is the only place we ever refer to it anyway. This reduces the footprint of struct efi, which is a r/w data structure that is shared with the world. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Move UGA and PROP table handling to x86 codeArd Biesheuvel1-24/+1
The UGA table is x86 specific (its handling was introduced when the EFI support code was modified to accommodate IA32), so there is no need to handle it in generic code. The EFI properties table is not strictly x86 specific, but it was deprecated almost immediately after having been introduced, due to implementation difficulties. Only x86 takes it into account today, and this is not going to change, so make this table x86 only as well. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/ia64: Move HCDP and MPS table handling into IA64 arch codeArd Biesheuvel1-8/+6
The HCDP and MPS tables are Itanium specific EFI config tables, so move their handling to ia64 arch code. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi: Drop handling of 'boot_info' configuration tableArd Biesheuvel1-3/+0
Some plumbing exists to handle a UEFI configuration table of type BOOT_INFO but since we never match it to a GUID anywhere, we never actually register such a table, or access it, for that matter. So simply drop all mentions of it. Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-01-20efi: Fix comment for efi_mem_type() wrt absent physical addressesAnshuman Khandual1-1/+1
A previous commit f99afd08a45f ("efi: Update efi_mem_type() to return an error rather than 0") changed the return value from EFI_RESERVED_TYPE to -EINVAL when the searched physical address is not present in any memory descriptor. But the comment preceding the function never changed. Let's change the comment now to reflect the new return value -EINVAL. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-10-ardb@kernel.org
2019-12-17Merge branch 'efi-urgent-for-linus' of ↵Linus Torvalds1-2/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI fixes from Ingo Molnar: "Protect presistent EFI memory reservations from kexec, fix EFIFB early console, EFI stub graphics output fixes and other misc fixes." * 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Don't attempt to map RCI2 config table if it doesn't exist efi/earlycon: Remap entire framebuffer after page initialization efi: Fix efi_loaded_image_t::unload type efi/gop: Fix memory leak in __gop_query32/64() efi/gop: Return EFI_SUCCESS if a usable GOP was found efi/gop: Return EFI_NOT_FOUND if there are no usable GOPs efi/memreserve: Register reservations as 'reserved' in /proc/iomem
2019-12-09treewide: Use sizeof_field() macroPankaj Bharadiya1-1/+1
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
2019-12-08efi/memreserve: Register reservations as 'reserved' in /proc/iomemArd Biesheuvel1-2/+26
Memory regions that are reserved using efi_mem_reserve_persistent() are recorded in a special EFI config table which survives kexec, allowing the incoming kernel to honour them as well. However, such reservations are not visible in /proc/iomem, and so the kexec tools that load the incoming kernel and its initrd into memory may overwrite these reserved regions before the incoming kernel has a chance to reserve them from further use. Address this problem by adding these reservations to /proc/iomem as they are created. Note that reservations that are inherited from a previous kernel are memblock_reserve()'d early on, so they are already visible in /proc/iomem. Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Tested-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Cc: <stable@vger.kernel.org> # v5.4+ Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191206165542.31469-2-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-26Merge branch 'acpi-mm'Rafael J. Wysocki1-2/+11
* acpi-mm: ACPI: HMAT: use %u instead of %d to print u32 values ACPI: NUMA: HMAT: fix a section mismatch ACPI: HMAT: don't mix pxm and nid when setting memory target processor_pxm ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device ACPI: NUMA: HMAT: Register HMAT at device_initcall level device-dax: Add a driver for "hmem" devices dax: Fix alloc_dax_region() compile warning lib: Uplevel the pmem "region" ida to a global allocator x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP arm/efi: EFI soft reservation to memblock x86/efi: EFI soft reservation to E820 enumeration efi: Common enable/disable infrastructure for EFI soft reservation x86/efi: Push EFI_MEMMAP check into leaf routines efi: Enumerate EFI_MEMORY_SP ACPI: NUMA: Establish a new drivers/acpi/numa/ directory
2019-11-26Merge branch 'acpica'Rafael J. Wysocki1-1/+1
* acpica: ACPICA: Update version to 20191018 ACPICA: debugger: remove leading whitespaces when converting a string to a buffer ACPICA: acpiexec: initialize all simple types and field units from user input ACPICA: debugger: add field unit support for acpi_db_get_next_token ACPICA: debugger: surround field unit output with braces '{' ACPICA: debugger: add command to dump all fields of particular subtype ACPICA: utilities: add flag to only display data when dumping buffers ACPICA: make acpi_load_table() return table index ACPICA: Add new external interface, acpi_unload_table() ACPICA: More Clang changes ACPICA: Win OSL: Replace get_tick_count with get_tick_count64 ACPICA: Results from Clang
2019-11-07efi: Common enable/disable infrastructure for EFI soft reservationDan Williams1-0/+8
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The proposed Linux behavior for specific purpose memory is that it is reserved for direct-access (device-dax) by default and not available for any kernel usage, not even as an OOM fallback. Later, through udev scripts or another init mechanism, these device-dax claimed ranges can be reconfigured and hot-added to the available System-RAM with a unique node identifier. This device-dax management scheme implements "soft" in the "soft reserved" designation by allowing some or all of the reservation to be recovered as typical memory. This policy can be disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with efi=nosoftreserve. As for this patch, define the common helpers to determine if the EFI_MEMORY_SP attribute should be honored. The determination needs to be made early to prevent the kernel from being loaded into soft-reserved memory, or otherwise allowing early allocations to land there. Follow-on changes are needed per architecture to leverage these helpers in their respective mem-init paths. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-07efi: Enumerate EFI_MEMORY_SPDan Williams1-2/+3
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The intent of this bit is to allow the OS to identify precious or scarce memory resources and optionally manage it separately from EfiConventionalMemory. As defined older OSes that do not know about this attribute are permitted to ignore it and the memory will be handled according to the OS default policy for the given memory type. In other words, this "specific purpose" hint is deliberately weaker than EfiReservedMemoryType in that the system continues to operate if the OS takes no action on the attribute. The risk of taking no action is potentially unwanted / unmovable kernel allocations from the designated resource that prevent the full realization of the "specific purpose". For example, consider a system with a high-bandwidth memory pool. Older kernels are permitted to boot and consume that memory as conventional "System-RAM" newer kernels may arrange for that memory to be set aside (soft reserved) by the system administrator for a dedicated high-bandwidth memory aware application to consume. Specifically, this mechanism allows for the elimination of scenarios where platform firmware tries to game OS policy by lying about ACPI SLIT values, i.e. claiming that a precious memory resource has a high distance to trigger the OS to avoid it by default. This reservation hint allows platform-firmware to instead tell the truth about performance characteristics by indicate to OS memory management to put immovable allocations elsewhere. Implement simple detection of the bit for EFI memory table dumps and save the kernel policy for a follow-on change. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-31efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomnessDominik Brodowski1-1/+1
Commit 428826f5358c ("fdt: add support for rng-seed") introduced add_bootloader_randomness(), permitting randomness provided by the bootloader or firmware to be credited as entropy. However, the fact that the UEFI support code was already wired into the RNG subsystem via a call to add_device_randomness() was overlooked, and so it was not converted at the same time. Note that this UEFI (v2.4 or newer) feature is currently only implemented for EFI stub booting on ARM, and further note that CONFIG_RANDOM_TRUST_BOOTLOADER must be enabled, and this should be done only if there indeed is sufficient trust in the bootloader _and_ its source of randomness. [ ardb: update commit log ] Tested-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> 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: https://lkml.kernel.org/r/20191029173755.27149-4-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-29ACPICA: make acpi_load_table() return table indexNikolaus Voss1-1/+1
ACPICA commit d1716a829d19be23277d9157c575a03b9abb7457 For unloading an ACPI table, it is necessary to provide the index of the table. The method intended for dynamically loading or hotplug addition of tables, acpi_load_table(), should provide this information via an optional pointer to the loaded table index. This patch fixes the table unload function of acpi_configfs. Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Fixes: d06c47e3dd07f ("ACPI: configfs: Resolve objects on host-directed table loads") Link: https://github.com/acpica/acpica/commit/d1716a82 Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> Signed-off-by: Erik Schmauss <erik.schmauss@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-07efivar/ssdt: Don't iterate over EFI vars if no SSDT override was specifiedArd Biesheuvel1-0/+3
The kernel command line option efivar_ssdt= allows the name to be specified of an EFI variable containing an ACPI SSDT table that should be loaded into memory by the OS, and treated as if it was provided by the firmware. Currently, that code will always iterate over the EFI variables and compare each name with the provided name, even if the command line option wasn't set to begin with. So bail early when no variable name was provided. This works around a boot regression on the 2012 Mac Pro, as reported by Scott. Tested-by: Scott Talbert <swt@techie.net> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> # v4.9+ Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Dave Young <dyoung@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Lyude Paul <lyude@redhat.com> Cc: Matthew Garrett <mjg59@google.com> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables") Link: https://lkml.kernel.org/r/20191002165904.8819-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-08-20efi: Restrict efivar_ssdt_load when the kernel is locked downMatthew Garrett1-0/+6
efivar_ssdt_load allows the kernel to import arbitrary ACPI code from an EFI variable, which gives arbitrary code execution in ring 0. Prevent that when the kernel is locked down. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: linux-efi@vger.kernel.org Signed-off-by: James Morris <jmorris@namei.org>