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path: root/drivers/firmware/efi/arm-runtime.c
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2018-03-12efi: Use efi_mm in x86 as well as ARMSai Praneeth1-9/+0
Presently, only ARM uses mm_struct to manage EFI page tables and EFI runtime region mappings. As this is the preferred approach, let's make this data structure common across architectures. Specially, for x86, using this data structure improves code maintainability and readability. Tested-by: Bhupesh Sharma <bhsharma@redhat.com> [ardb: don't #include the world to get a declaration of struct mm_struct] Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180312084500.10764-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09efi/arm*: Stop printing addresses of virtual mappingsArd Biesheuvel1-4/+1
With the recent %p -> %px changes, we now get something like this in the kernel boot log on ARM/arm64 EFI systems: Remapping and enabling EFI services. EFI remap 0x00000087fb830000 => (ptrval) EFI remap 0x00000087fbdb0000 => (ptrval) EFI remap 0x00000087fffc0000 => (ptrval) The physical addresses of the UEFI runtime regions will also be printed when booting with the efi=debug command line option, and the virtual addresses can be inspected via /sys/kernel/debug/efi_page_tables (if enabled). So let's just remove the lines above. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> 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 Link: http://lkml.kernel.org/r/20180308080020.22828-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09efi/arm*: Only register page tables when they existMark Rutland1-0/+3
Currently the arm/arm64 runtime code registers the runtime servies pagetables with ptdump regardless of whether runtime services page tables have been created. As efi_mm.pgd is NULL in these cases, attempting to dump the efi page tables results in a NULL pointer dereference in the ptdump code: /sys/kernel/debug# cat efi_page_tables [ 479.522600] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 479.522715] Mem abort info: [ 479.522764] ESR = 0x96000006 [ 479.522850] Exception class = DABT (current EL), IL = 32 bits [ 479.522899] SET = 0, FnV = 0 [ 479.522937] EA = 0, S1PTW = 0 [ 479.528200] Data abort info: [ 479.528230] ISV = 0, ISS = 0x00000006 [ 479.528317] CM = 0, WnR = 0 [ 479.528317] user pgtable: 4k pages, 48-bit VAs, pgd = 0000000064ab0cb0 [ 479.528449] [0000000000000000] *pgd=00000000fbbe4003, *pud=00000000fb66e003, *pmd=0000000000000000 [ 479.528600] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 479.528664] Modules linked in: [ 479.528699] CPU: 0 PID: 2457 Comm: cat Not tainted 4.15.0-rc3-00065-g2ad2ee7ecb5c-dirty #7 [ 479.528799] Hardware name: FVP Base (DT) [ 479.528899] pstate: 00400009 (nzcv daif +PAN -UAO) [ 479.528941] pc : walk_pgd.isra.1+0x20/0x1d0 [ 479.529011] lr : ptdump_walk_pgd+0x30/0x50 [ 479.529105] sp : ffff00000bf4bc20 [ 479.529185] x29: ffff00000bf4bc20 x28: 0000ffff9d22e000 [ 479.529271] x27: 0000000000020000 x26: ffff80007b4c63c0 [ 479.529358] x25: 00000000014000c0 x24: ffff80007c098900 [ 479.529445] x23: ffff00000bf4beb8 x22: 0000000000000000 [ 479.529532] x21: ffff00000bf4bd70 x20: 0000000000000001 [ 479.529618] x19: ffff00000bf4bcb0 x18: 0000000000000000 [ 479.529760] x17: 000000000041a1c8 x16: ffff0000082139d8 [ 479.529800] x15: 0000ffff9d3c6030 x14: 0000ffff9d2527f4 [ 479.529924] x13: 00000000000003f3 x12: 0000000000000038 [ 479.530000] x11: 0000000000000003 x10: 0101010101010101 [ 479.530099] x9 : 0000000017e94050 x8 : 000000000000003f [ 479.530226] x7 : 0000000000000000 x6 : 0000000000000000 [ 479.530313] x5 : 0000000000000001 x4 : 0000000000000000 [ 479.530416] x3 : ffff000009069fd8 x2 : 0000000000000000 [ 479.530500] x1 : 0000000000000000 x0 : 0000000000000000 [ 479.530599] Process cat (pid: 2457, stack limit = 0x000000005d1b0e6f) [ 479.530660] Call trace: [ 479.530746] walk_pgd.isra.1+0x20/0x1d0 [ 479.530833] ptdump_walk_pgd+0x30/0x50 [ 479.530907] ptdump_show+0x10/0x20 [ 479.530920] seq_read+0xc8/0x470 [ 479.531023] full_proxy_read+0x60/0x90 [ 479.531100] __vfs_read+0x18/0x100 [ 479.531180] vfs_read+0x88/0x160 [ 479.531267] SyS_read+0x48/0xb0 [ 479.531299] el0_svc_naked+0x20/0x24 [ 479.531400] Code: 91400420 f90033a0 a90707a2 f9403fa0 (f9400000) [ 479.531499] ---[ end trace bfe8e28d8acb2b67 ]--- Segmentation fault Let's avoid this problem by only registering the tables after their successful creation, which is also less confusing when EFI runtime services are not in use. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.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 Link: http://lkml.kernel.org/r/20180308080020.22828-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-05efi/arm: Enable DMI/SMBIOSArd Biesheuvel1-0/+16
Wire up the existing arm64 support for SMBIOS tables (aka DMI) for ARM as well, by moving the arm64 init code to drivers/firmware/efi/arm-runtime.c (which is shared between ARM and arm64), and adding a asm/dmi.h header to ARM that defines the mapping routines for the firmware tables. This allows userspace to access these tables to discover system information exposed by the firmware. It also sets the hardware name used in crash dumps, e.g.: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ed3c0000 [00000000] *pgd=bf1f3835 Internal error: Oops: 817 [#1] SMP THUMB2 Modules linked in: CPU: 0 PID: 759 Comm: bash Not tainted 4.10.0-09601-g0e8f38792120-dirty #112 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 ^^^ NOTE: This does *NOT* enable or encourage the use of DMI quirks, i.e., the the practice of identifying the platform via DMI to decide whether certain workarounds for buggy hardware and/or firmware need to be enabled. This would require the DMI subsystem to be enabled much earlier than we do on ARM, which is non-trivial. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> 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 Link: http://lkml.kernel.org/r/20170602135207.21708-14-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02efi/arm: Fix boot crash with CONFIG_CPUMASK_OFFSTACK=yArd Biesheuvel1-0/+1
On ARM and arm64, we use a dedicated mm_struct to map the UEFI Runtime Services regions, which allows us to map those regions on demand, and in a way that is guaranteed to be compatible with incoming kernels across kexec. As it turns out, we don't fully initialize the mm_struct in the same way as process mm_structs are initialized on fork(), which results in the following crash on ARM if CONFIG_CPUMASK_OFFSTACK=y is enabled: ... EFI Variables Facility v0.08 2004-May-17 Unable to handle kernel NULL pointer dereference at virtual address 00000000 [...] Process swapper/0 (pid: 1) ... __memzero() check_and_switch_context() virt_efi_get_next_variable() efivar_init() efivars_sysfs_init() do_one_initcall() ... This is due to a missing call to mm_init_cpumask(), so add it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> # v4.5+ 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 Link: http://lkml.kernel.org/r/1488395154-29786-1-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-07arm64: dump: Make ptdump debugfs a separate optionLaura Abbott1-2/+2
ptdump_register currently initializes a set of page table information and registers debugfs. There are uses for the ptdump option without wanting the debugfs options. Split this out to make it a separate option. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-09-09efi/arm64: Add debugfs node to dump UEFI runtime page tablesArd Biesheuvel1-0/+20
Register the debugfs node 'efi_page_tables' to allow the UEFI runtime page tables to be inspected. Note that ARM does not have 'asm/ptdump.h' [yet] so for now, this is arm64 only. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi: Add efi_memmap_init_late() for permanent EFI memmapMatt Fleming1-3/+1
Drivers need a way to access the EFI memory map at runtime. ARM and arm64 currently provide this by remapping the EFI memory map into the vmalloc space before setting up the EFI virtual mappings. x86 does not provide this functionality which has resulted in the code in efi_mem_desc_lookup() where it will manually map individual EFI memmap entries if the memmap has already been torn down on x86, /* * If a driver calls this after efi_free_boot_services, * ->map will be NULL, and the target may also not be mapped. * So just always get our own virtual map on the CPU. * */ md = early_memremap(p, sizeof (*md)); There isn't a good reason for not providing a permanent EFI memory map for runtime queries, especially since the EFI regions are not mapped into the standard kernel page tables. 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> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi: Refactor efi_memmap_init_early() into arch-neutral codeMatt Fleming1-1/+1
Every EFI architecture apart from ia64 needs to setup the EFI memory map at efi.memmap, and the code for doing that is essentially the same across all implementations. Therefore, it makes sense to factor this out into the common code under drivers/firmware/efi/. The only slight variation is the data structure out of which we pull the initial memory map information, such as physical address, memory descriptor size and version, etc. We can address this by passing a generic data structure (struct efi_memory_map_data) as the argument to efi_memmap_init_early() which contains the minimum info required for initialising the memory map. In the process, this patch also fixes a few undesirable implementation differences: - ARM and arm64 were failing to clear the EFI_MEMMAP bit when unmapping the early EFI memory map. EFI_MEMMAP indicates whether the EFI memory map is mapped (not the regions contained within) and can be traversed. It's more correct to set the bit as soon as we memremap() the passed in EFI memmap. - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the regular naming scheme. This patch also uses a read-write mapping for the memory map instead of the read-only mapping currently used on ARM and arm64. x86 needs the ability to update the memory map in-place when assigning virtual addresses to regions (efi_map_region()) and tagging regions when reserving boot services (efi_reserve_boot_services()). There's no way for the generic fake_mem code to know which mapping to use without introducing some arch-specific constant/hook, so just use read-write since read-only is of dubious value for the EFI memory map. 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> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-07-06Xen: EFI: Parse DT parameters for Xen specific UEFIShannon Zhao1-0/+5
The EFI DT parameters for bare metal are located under /chosen node, while for Xen Dom0 they are located under /hyperviosr/uefi node. These parameters under /chosen and /hyperviosr/uefi are not expected to appear at the same time. Parse these EFI parameters and initialize EFI like the way for bare metal except the runtime services because the runtime services for Xen Dom0 are available through hypercalls and they are always enabled. So it sets the EFI_RUNTIME_SERVICES flag if it finds /hyperviosr/uefi node and bails out in arm_enable_runtime_services() when EFI_RUNTIME_SERVICES flag is set already. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-04-28efi/arm*: Take the Memory Attributes table into accountArd Biesheuvel1-2/+8
Call into the generic memory attributes table support code at the appropriate times during the init sequence so that the UEFI Runtime Services region are mapped according to the strict permissions it specifies. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-15-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi/arm*: Use memremap() to create the persistent memmap mappingArd Biesheuvel1-2/+1
Instead of using ioremap_cache(), which is slightly inappropriate for mapping firmware tables, and is not even allowed on ARM for mapping regions that are covered by a struct page, use memremap(), which was invented for this purpose, and will also reuse the existing kernel direct mapping if the requested region is covered by it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-10-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi: Remove global 'memmap' EFI memory mapMatt Fleming1-6/+6
Abolish the poorly named EFI memory map, 'memmap'. It is shadowed by a bunch of local definitions in various files and having two ways to access the EFI memory map ('efi.memmap' vs. 'memmap') is rather confusing. Furthermore, IA64 doesn't even provide this global object, which has caused issues when trying to write generic EFI memmap code. Replace all occurrences with efi.memmap, and convert the remaining iterator code to use for_each_efi_mem_desc(). Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Luck, Tony <tony.luck@intel.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/1461614832-17633-8-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi: Iterate over efi.memmap in for_each_efi_memory_desc()Matt Fleming1-1/+1
Most of the users of for_each_efi_memory_desc() are equally happy iterating over the EFI memory map in efi.memmap instead of 'memmap', since the former is usually a pointer to the latter. For those users that want to specify an EFI memory map other than efi.memmap, that can be done using for_each_efi_memory_desc_in_map(). One such example is in the libstub code where the firmware is queried directly for the memory map, it gets iterated over, and then freed. This change goes part of the way toward deleting the global 'memmap' variable, which is not universally available on all architectures (notably IA64) and is rather poorly named. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Salter <msalter@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/1461614832-17633-7-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi/arm*: Drop writable mapping of the UEFI System tableArd Biesheuvel1-11/+16
Commit: 2eec5dedf770 ("efi/arm-init: Use read-only early mappings") updated the early ARM UEFI init code to create the temporary, early mapping of the UEFI System table using read-only attributes, as a hardening measure against inadvertent modification. However, this still leaves the permanent, writable mapping of the UEFI System table, which is only ever referenced during invocations of UEFI Runtime Services, at which time the UEFI virtual mapping is available, which also covers the system table. (This is guaranteed by the fact that SetVirtualAddressMap(), which is a runtime service itself, converts various entries in the table to their virtual equivalents, which implies that the table must be covered by a RuntimeServicesData region that has the EFI_MEMORY_RUNTIME attribute.) So instead of creating this permanent mapping, record the virtual address of the system table inside the UEFI virtual mapping, and dereference that when accessing the table. This protects the contents of the system table from inadvertent (or deliberate) modification when no UEFI Runtime Services calls are in progress. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Rutland <mark.rutland@arm.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/1461614832-17633-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28efi: Get rid of the EFI_SYSTEM_TABLES status bitArd Biesheuvel1-1/+0
The EFI_SYSTEM_TABLES status bit is set by all EFI supporting architectures upon discovery of the EFI system table, but the bit is never tested in any code we have in the tree. So remove it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Luck, Tony <tony.luck@intel.com> Cc: Mark Rutland <mark.rutland@arm.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/1461614832-17633-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-09arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-32/+16
This refactors the EFI init and runtime code that will be shared between arm64 and ARM so that it can be built for both archs. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: split off EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-0/+151
This splits off the early EFI init and runtime code that - discovers the EFI params and the memory map from the FDT, and installs the memblocks and config tables. - prepares and installs the EFI page tables so that UEFI Runtime Services can be invoked at the virtual address installed by the stub. This will allow it to be reused for 32-bit ARM. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>