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path: root/drivers/firmware/efi/fake_mem.c (follow)
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2020-01-20efi: Fix handling of multiple efi_fake_mem= entriesDan Williams1-15/+16
Dave noticed that when specifying multiple efi_fake_mem= entries only the last entry was successfully being reflected in the efi memory map. This is due to the fact that the efi_memmap_insert() is being called multiple times, but on successive invocations the insertion should be applied to the last new memmap rather than the original map at efi_fake_memmap() entry. Rework efi_fake_memmap() to install the new memory map after each efi_fake_mem= entry is parsed. This also fixes an issue in efi_fake_memmap() that caused it to litter emtpy entries into the end of the efi memory map. An empty entry causes efi_memmap_insert() to attempt more memmap splits / copies than efi_memmap_split_count() accounted for when sizing the new map. When that happens efi_memmap_insert() may overrun its allocation, and if you are lucky will spill over to an unmapped page leading to crash signature like the following rather than silent corruption: BUG: unable to handle page fault for address: ffffffffff281000 [..] RIP: 0010:efi_memmap_insert+0x11d/0x191 [..] Call Trace: ? bgrt_init+0xbe/0xbe ? efi_arch_mem_reserve+0x1cb/0x228 ? acpi_parse_bgrt+0xa/0xd ? acpi_table_parse+0x86/0xb8 ? acpi_boot_init+0x494/0x4e3 ? acpi_parse_x2apic+0x87/0x87 ? setup_acpi_sci+0xa2/0xa2 ? setup_arch+0x8db/0x9e1 ? start_kernel+0x6a/0x547 ? secondary_startup_64+0xb6/0xc0 Commit af1648984828 "x86/efi: Update e820 with reserved EFI boot services data to fix kexec breakage" introduced more occurrences where efi_memmap_insert() is invoked after an efi_fake_mem= configuration has been parsed. Previously the side effects of vestigial empty entries were benign, but with commit af1648984828 that follow-on efi_memmap_insert() invocation triggers efi_memmap_insert() overruns. Reported-by: Dave Young <dyoung@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20191231014630.GA24942@dhcp-128-65.nay.redhat.com Link: https://lore.kernel.org/r/20200113172245.27925-14-ardb@kernel.org
2020-01-20efi: Add tracking for dynamically allocated memmapsDan Williams1-8/+6
In preparation for fixing efi_memmap_alloc() leaks, add support for recording whether the memmap was dynamically allocated from slab, memblock, or is the original physical memmap provided by the platform. Given this tracking is established in efi_memmap_alloc() and needs to be carried to efi_memmap_install(), use 'struct efi_memory_map_data' to convey the flags. Some small cleanups result from this reorganization, specifically the removal of local variables for 'phys' and 'size' that are already tracked in @data. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-12-ardb@kernel.org
2019-11-07x86/efi: Add efi_fake_mem support for EFI_MEMORY_SPDan Williams1-13/+11
Given that EFI_MEMORY_SP is platform BIOS policy decision for marking memory ranges as "reserved for a specific purpose" there will inevitably be scenarios where the BIOS omits the attribute in situations where it is desired. Unlike other attributes if the OS wants to reserve this memory from the kernel the reservation needs to happen early in init. So early, in fact, that it needs to happen before e820__memblock_setup() which is a pre-requisite for efi_fake_memmap() that wants to allocate memory for the updated table. Introduce an x86 specific efi_fake_memmap_early() that can search for attempts to set EFI_MEMORY_SP via efi_fake_mem and update the e820 table accordingly. The KASLR code that scans the command line looking for user-directed memory reservations also needs to be updated to consider "efi_fake_mem=nn@ss:0x40000" requests. Acked-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>
2019-11-07x86/efi: Push EFI_MEMMAP check into leaf routinesDan Williams1-1/+1
In preparation for adding another EFI_MEMMAP dependent call that needs to occur before e820__memblock_setup() fixup the existing efi calls to check for EFI_MEMMAP internally. This ends up being cleaner than the alternative of checking EFI_MEMMAP multiple times in setup_arch(). Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> 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>
2019-02-04efi: Replace GPL license boilerplate with SPDX headersArd Biesheuvel1-15/+1
Replace all GPL license blurbs with an equivalent SPDX header (most files are GPLv2, some are GPLv2+). While at it, drop some outdated header changelogs as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Alexander Graf <agraf@suse.de> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Lee Jones <lee.jones@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> 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: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190202094119.13230-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-07x86/efi: Don't allocate memmap through memblock after mm_init()Nicolai Stange1-2/+1
With the following commit: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") ... efi_bgrt_init() calls into the memblock allocator through efi_mem_reserve() => efi_arch_mem_reserve() *after* mm_init() has been called. Indeed, KASAN reports a bad read access later on in efi_free_boot_services(): BUG: KASAN: use-after-free in efi_free_boot_services+0xae/0x24c at addr ffff88022de12740 Read of size 4 by task swapper/0/0 page:ffffea0008b78480 count:0 mapcount:-127 mapping: (null) index:0x1 flags: 0x5fff8000000000() [...] Call Trace: dump_stack+0x68/0x9f kasan_report_error+0x4c8/0x500 kasan_report+0x58/0x60 __asan_load4+0x61/0x80 efi_free_boot_services+0xae/0x24c start_kernel+0x527/0x562 x86_64_start_reservations+0x24/0x26 x86_64_start_kernel+0x157/0x17a start_cpu+0x5/0x14 The instruction at the given address is the first read from the memmap's memory, i.e. the read of md->type in efi_free_boot_services(). Note that the writes earlier in efi_arch_mem_reserve() don't splat because they're done through early_memremap()ed addresses. So, after memblock is gone, allocations should be done through the "normal" page allocator. Introduce a helper, efi_memmap_alloc() for this. Use it from efi_arch_mem_reserve(), efi_free_boot_services() and, for the sake of consistency, from efi_fake_memmap() as well. Note that for the latter, the memmap allocations cease to be page aligned. This isn't needed though. Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Nicolai Stange <nicstange@gmail.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> # v4.9 Cc: Dave Young <dyoung@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Link: http://lkml.kernel.org/r/20170105125130.2815-1-nicstange@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-09efi: Add efi_memmap_install() for installing new EFI memory mapsMatt Fleming1-7/+1
While efi_memmap_init_{early,late}() exist for architecture code to install memory maps from firmware data and for the virtual memory regions respectively, drivers don't care which stage of the boot we're at and just want to swap the existing memmap for a modified one. efi_memmap_install() abstracts the details of how the new memory map should be mapped and the existing one unmapped. 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: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi: Split out EFI memory map functions into new fileMatt Fleming1-137/+6
Also move the functions from the EFI fake mem driver since future patches will require access to the memmap insertion code even if CONFIG_EFI_FAKE_MEM isn't enabled. This will be useful when we need to build custom EFI memory maps to allow drivers to mark regions as reserved. 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: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi/fake_mem: Refactor main two code chunks into functionsMatt Fleming1-95/+134
There is a whole load of generic EFI memory map code inside of the fake_mem driver which is better suited to being grouped with the rest of the generic EFI code for manipulating EFI memory maps. In preparation for that, this patch refactors the core code, so that it's possible to move entire functions later. 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: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi: Refactor efi_memmap_init_early() into arch-neutral codeMatt Fleming1-6/+9
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>
2016-09-09x86/efi: Test for EFI_MEMMAP functionality when iterating EFI memmapMatt Fleming1-1/+1
Both efi_find_mirror() and efi_fake_memmap() really want to know whether the EFI memory map is available, not just whether the machine was booted using EFI. efi_fake_memmap() even has a check for EFI_MEMMAP at the start of the function. Since we've already got other code that has this dependency, merge everything under one if() conditional, and remove the now superfluous check from efi_fake_memmap(). 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: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-04-28efi: Remove global 'memmap' EFI memory mapMatt Fleming1-20/+20
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 Fleming1-2/+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>
2015-10-28efi: Fix warning of int-to-pointer-cast on x86 32-bit buildsTaku Izumi1-2/+2
Commit: 0f96a99dab36 ("efi: Add "efi_fake_mem" boot option") introduced the following warning message: drivers/firmware/efi/fake_mem.c:186:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] new_memmap_phy was defined as a u64 value and cast to void*, causing a int-to-pointer-cast warning on x86 32-bit builds. However, since the void* type is inappropriate for a physical address, the definition of struct efi_memory_map::phys_map has been changed to phys_addr_t in the previous patch, and so the cast can be dropped entirely. This patch also changes the type of the "new_memmap_phy" variable from "u64" to "phys_addr_t" to align with the types of memblock_alloc() and struct efi_memory_map::phys_map. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> [ Removed void* cast, updated commit log] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kamezawa.hiroyu@jp.fujitsu.com Cc: linux-efi@vger.kernel.org Cc: matt.fleming@intel.com Link: http://lkml.kernel.org/r/1445593697-1342-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-12efi: Add "efi_fake_mem" boot optionTaku Izumi1-0/+238
This patch introduces new boot option named "efi_fake_mem". By specifying this parameter, you can add arbitrary attribute to specific memory range. This is useful for debugging of Address Range Mirroring feature. For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000" is specified, the original (firmware provided) EFI memmap will be updated so that the specified memory regions have EFI_MEMORY_MORE_RELIABLE attribute (0x10000): <original> efi: mem36: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB) <updated> efi: mem36: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB) efi: mem37: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB) efi: mem38: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB) efi: mem39: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB) And you will find that the following message is output: efi: Memory: 4096M/131455M mirrored memory Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>