aboutsummaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/libstub
AgeCommit message (Collapse)AuthorFilesLines
2017-04-05efi/libstub: Unify command line param parsingArd Biesheuvel4-28/+21
Merge the parsing of the command line carried out in arm-stub.c with the handling in efi_parse_options(). Note that this also fixes the missing handling of CONFIG_CMDLINE_FORCE=y, in which case the builtin command line should supersede the one passed by the firmware. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-04-05efi/libstub: Fix harmless command line parsing bugArd Biesheuvel1-2/+2
When we parse the 'efi=' command line parameter in the stub, we fail to take spaces into account. Currently, the only way this could result in unexpected behavior is when the string 'nochunk' appears as a separate command line argument after 'efi=xxx,yyy,zzz ', so this is harmless in practice. But let's fix it nonetheless. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-04-05efi/arm32-stub: Allow boot-time allocations in the vmlinux regionArd Biesheuvel1-20/+128
The arm32 kernel decompresses itself to the base of DRAM unconditionally, and so it is the EFI stub's job to ensure that the region is available. Currently, we do this by creating an allocation there, and giving up if that fails. However, any boot services regions occupying this area are not an issue, given that the decompressor executes strictly after the stub calls ExitBootServices(). So let's try a bit harder to proceed if the initial allocation fails, and check whether any memory map entries occupying the region may be considered safe. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Leif Lindholm <[email protected]> Reviewed-by: Eugene Cohen <[email protected]> Reviewed-by: Roy Franz <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-04-05efi/arm-stub: Round up FDT allocation to mapping sizeArd Biesheuvel1-33/+24
The FDT is mapped via a fixmap entry that is at least 2 MB in size and 2 MB aligned on 4 KB page size kernels. On UEFI systems, the FDT allocation may share this 2 MB mapping with a reserved region (or another memory region that we should never map), unless we account for this in the size of the allocation (the alignment is already 2 MB) So instead of taking guesses at the needed space, simply allocate 2 MB immediately. The allocation will be recorded as EFI_LOADER_DATA, and the kernel only memblock_reserve()'s the actual size of the FDT, so the unused space will be released back to the kernel. Reviewed-By: Jeffrey Hugo <[email protected]> Tested-by: Richard Ruigrok <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-04-05efi/arm-stub: Correct FDT and initrd allocation rules for arm64Ard Biesheuvel1-3/+4
On arm64, we have made some changes over the past year to the way the kernel itself is allocated and to how it deals with the initrd and FDT. This patch brings the allocation logic in the EFI stub in line with that, which is necessary because the introduction of KASLR has created the possibility for the initrd to be allocated in a place where the kernel may not be able to map it. (This is mostly a theoretical scenario, since it only affects systems where the physical memory footprint exceeds the size of the linear mapping.) Since we know the kernel itself will be covered by the linear mapping, choose a suitably sized window (i.e., based on the size of the linear region) covering the kernel when allocating memory for the initrd. The FDT may be anywhere in memory on arm64 now that we map it via the fixmap, so we can lift the address restriction there completely. Tested-by: Richard Ruigrok <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Jeffrey Hugo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-04-05efi/libstub: Skip GOP with PIXEL_BLT_ONLY formatCohen, Eugene1-2/+4
The UEFI Specification permits Graphics Output Protocol (GOP) instances without direct framebuffer access. This is indicated in the Mode structure with a PixelFormat enumeration value of PIXEL_BLT_ONLY. Given that the kernel does not know how to drive a Blt() only framebuffer (which is only permitted before ExitBootServices() anyway), we should disregard such framebuffers when looking for a GOP instance that is suitable for use as the boot console. So modify the EFI GOP initialization to not use a PIXEL_BLT_ONLY instance, preventing attempts later in boot to use an invalid screen_info.lfb_base address. Signed-off-by: Eugene Cohen <[email protected]> [ Moved the Blt() only check into the loop and clarified that Blt() only GOPs are unusable by the kernel. ] Signed-off-by: Ard Biesheuvel <[email protected]> Cc: <[email protected]> # v4.7+ Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Fixes: 9822504c1fa5 ("efifb: Enable the efi-framebuffer platform driver ...") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-03-02efi/libstub: Treat missing SecureBoot variable as Secure Boot disabledArd Biesheuvel1-2/+2
The newly refactored code that infers the firmware's Secure Boot state prints the following error when the EFI variable 'SecureBoot' does not exist: EFI stub: ERROR: Could not determine UEFI Secure Boot status. However, this variable is only guaranteed to be defined on a system that is Secure Boot capable to begin with, and so it is not an error if it is missing. So report Secure Boot as being disabled in this case, without printing any error messages. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-07efi/libstub: Make file I/O chunking x86-specificArd Biesheuvel1-1/+10
The ARM decompressor is finicky when it comes to uninitialized variables with local linkage, the reason being that it may relocate .text and .bss independently when executing from ROM. This is only possible if all references into .bss from .text are absolute, and this happens to be the case for references emitted under -fpic to symbols with external linkage, and so all .bss references must involve symbols with external linkage. When building the ARM stub using clang, the initialized local variable __chunk_size is optimized into a zero-initialized flag that indicates whether chunking is in effect or not. This flag is therefore emitted into .bss, which triggers the ARM decompressor's diagnostics, resulting in a failed build. Under UEFI, we never execute the decompressor from ROM, so the diagnostic makes little sense here. But we can easily work around the issue by making __chunk_size global instead. However, given that the file I/O chunking that is controlled by the __chunk_size variable is intended to work around known bugs on various x86 implementations of UEFI, we can simply make the chunking an x86 specific feature. This is an improvement by itself, and also removes the need to parse the efi= options in the stub entirely. Tested-by: Arnd Bergmann <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] [ Small readability edits. ] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-07efi: Disable secure boot if shim is in insecure modeJosh Boyer1-1/+24
A user can manually tell the shim boot loader to disable validation of images it loads. When a user does this, it creates a UEFI variable called MokSBState that does not have the runtime attribute set. Given that the user explicitly disabled validation, we can honor that and not enable secure boot mode if that variable is set. Signed-off-by: Josh Boyer <[email protected]> Signed-off-by: David Howells <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-07efi: Get and store the secure boot statusDavid Howells3-58/+68
Get the firmware's secure-boot status in the kernel boot wrapper and stash it somewhere that the main kernel image can find. The efi_get_secureboot() function is extracted from the ARM stub and (a) generalised so that it can be called from x86 and (b) made to use efi_call_runtime() so that it can be run in mixed-mode. For x86, it is stored in boot_params and can be overridden by the boot loader or kexec. This allows secure-boot mode to be passed on to a new kernel. Suggested-by: Lukas Wunner <[email protected]> Signed-off-by: David Howells <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] [ Small readability edits. ] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-07Merge tag 'v4.10-rc7' into efi/core, to pick up fixesIngo Molnar1-11/+3
Signed-off-by: Ingo Molnar <[email protected]>
2017-02-01efi/fdt: Avoid FDT manipulation after ExitBootServices()Ard Biesheuvel1-11/+3
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <[email protected]> Tested-by: Riku Voipio <[email protected]> Cc: <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-01efi/libstub: Preserve .debug sections after absolute relocation checkArd Biesheuvel1-8/+16
The build commands for the ARM and arm64 EFI stubs strip the .debug sections and other sections that may legally contain absolute relocations, in order to inspect the remaining sections for the presence of such relocations. This leaves us without debugging symbols in the stub for no good reason, considering that these sections are omitted from the kernel binary anyway, and that these relocations are thus only consumed by users of the ELF binary, such as debuggers. So move to 'strip' for performing the relocation check, and if it succeeds, invoke objcopy as before, but leaving the .debug sections in place. Note that these sections may refer to ksymtab/kcrctab contents, so leave those in place as well. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-02-01efi: Deduplicate efi_file_size() / _read() / _close()Lukas Wunner3-77/+63
There's one ARM, one x86_32 and one x86_64 version which can be folded into a single shared version by masking their differences with the shiny new efi_call_proto() macro. No functional change intended. Signed-off-by: Lukas Wunner <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-12-28efi/libstub/arm*: Pass latest memory map to the kernelArd Biesheuvel2-39/+56
As reported by James Morse, the current libstub code involving the annotated memory map only works somewhat correctly by accident, due to the fact that a pool allocation happens to be reused immediately, retaining its former contents on most implementations of the UEFI boot services. Instead of juggling memory maps, which makes the code more complex than it needs to be, simply put placeholder values into the FDT for the memory map parameters, and only write the actual values after ExitBootServices() has been called. Reported-by: James Morse <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: <[email protected]> Cc: Jeffrey Hugo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Fixes: ed9cc156c42f ("efi/libstub: Use efi_exit_boot_services() in FDT") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-12-14Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: NTB: correct ntb_spad_count comment typo misc: ibmasm: fix typo in error message Remove references to dead make variable LINUX_INCLUDE Remove last traces of ikconfig.h treewide: Fix printk() message errors Documentation/device-mapper: s/getsize/getsz/
2016-12-14Remove references to dead make variable LINUX_INCLUDEPaul Bolle1-1/+1
Commit 4fd06960f120 ("Use the new x86 setup code for i386") introduced a reference to the make variable LINUX_INCLUDE. That reference got moved around a bit and copied twice and now there are three references to it. There has never been a definition of that variable. (Presumably that is because it started out as a mistyped reference to LINUXINCLUDE.) So this reference has always been an empty string. Let's remove it before it spreads any further. Signed-off-by: Paul Bolle <[email protected]> Signed-off-by: Jiri Kosina <[email protected]>
2016-11-25efi/libstub: Make efi_random_alloc() allocate below 4 GB on 32-bitArd Biesheuvel1-6/+7
The UEFI stub executes in the context of the firmware, which identity maps the available system RAM, which implies that only memory below 4 GB can be used for allocations on 32-bit architectures, even on [L]PAE capable hardware. So ignore any reported memory above 4 GB in efi_random_alloc(). This also fixes a reported build problem on ARM under -Os, where the 64-bit logical shift relies on a software routine that the ARM decompressor does not provide. A second [minor] issue is also fixed, where the '+ 1' is moved out of the shift, where it belongs: the reason for its presence is that a memory region where start == end should count as a single slot, given that 'end' takes the desired size and alignment of the allocation into account. To clarify the code in this regard, rename start/end to 'first_slot' and 'last_slot', respectively, and introduce 'region_end' to describe the last usable address of the current region. Reported-by: Arnd Bergmann <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-11-13efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG tableArd Biesheuvel3-0/+52
Invoke the EFI_RNG_PROTOCOL protocol in the context of the stub and install the Linux-specific RNG seed UEFI config table. This will be picked up by the EFI routines in the core kernel to seed the kernel entropy pool. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-11-13efi/libstub: Add random.c to ARM buildArd Biesheuvel4-14/+16
Make random.c build for ARM by moving the fallback definition of EFI_ALLOC_ALIGN to efistub.h, and replacing a division by a value we know to be a power of 2 with a right shift (this is required since ARM does not have any integer division helper routines in its decompressor) Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-11-13efi/libstub: Fix allocation size calculationsRoy Franz1-10/+14
Adjust the size used in calculations to match the actual size of allocation that will be performed based on EFI size/alignment constraints. efi_high_alloc() and efi_low_alloc() use the passed size in bytes directly to find space in the memory map for the allocation, rather than the actual allocation size that has been adjusted for size and alignment constraints. This results in failed allocations and retries in efi_high_alloc(). The same error is present in efi_low_alloc(), although failure will only happen if the lowest memory block is small. Also use EFI_PAGE_SIZE consistently and remove use of EFI_PAGE_SHIFT to calculate page size. Signed-off-by: Roy Franz <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-10-19efi/arm: Fix absolute relocation detection for older toolchainsArd Biesheuvel1-2/+3
When building the ARM kernel with CONFIG_EFI=y, the following build error may occur when using a less recent version of binutils (2.23 or older): STUBCPY drivers/firmware/efi/libstub/lib-sort.stub.o 00000000 R_ARM_ABS32 sort 00000004 R_ARM_ABS32 __ksymtab_strings drivers/firmware/efi/libstub/lib-sort.stub.o: absolute symbol references not allowed in the EFI stub (and when building with debug symbols, the list above is much longer, and contains all the internal references between the .debug sections and the actual code) This issue is caused by the fact that objcopy v2.23 or earlier does not support wildcards in its -R and -j options, which means the following line from the Makefile: STUBCOPY_FLAGS-y := -R .debug* -R *ksymtab* -R *kcrctab* fails to take effect, leaving harmless absolute relocations in the binary that are indistinguishable from relocations that may cause crashes at runtime due to the fact that these relocations are resolved at link time using the virtual address of the kernel, which is always different from the address at which the EFI firmware loads and invokes the stub. So, as a workaround, disable debug symbols explicitly when building the stub for ARM, and strip the ksymtab and kcrctab symbols for the only exported symbol we currently reuse in the stub, which is 'sort'. Tested-by: Jon Hunter <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-09-05efi/libstub: Use efi_exit_boot_services() in FDTJeffrey Hugo1-10/+27
The FDT code directly calls ExitBootServices. This is inadvisable as the UEFI spec details a complex set of errors, race conditions, and API interactions that the caller of ExitBootServices must get correct. The FDT code does not handle EFI_INVALID_PARAMETER as required by the spec, which causes intermittent boot failures on the Qualcomm Technologies QDF2432. Call the efi_exit_boot_services() helper intead, which handles the EFI_INVALID_PARAMETER scenario properly. Signed-off-by: Jeffrey Hugo <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: <[email protected]> Signed-off-by: Matt Fleming <[email protected]>
2016-09-05efi/libstub: Introduce ExitBootServices helperJeffrey Hugo1-0/+73
The spec allows ExitBootServices to fail with EFI_INVALID_PARAMETER if a race condition has occurred where the EFI has updated the memory map after the stub grabbed a reference to the map. The spec defines a retry proceedure with specific requirements to handle this scenario. This scenario was previously observed on x86 - commit d3768d885c6c ("x86, efi: retry ExitBootServices() on failure") but the current fix is not spec compliant and the scenario is now observed on the Qualcomm Technologies QDF2432 via the FDT stub which does not handle the error and thus causes boot failures. The user will notice the boot failure as the kernel is not executed and the system may drop back to a UEFI shell, but will be unresponsive to input and the system will require a power cycle to recover. Add a helper to the stub library that correctly adheres to the spec in the case of EFI_INVALID_PARAMETER from ExitBootServices and can be universally used across all stub implementations. Signed-off-by: Jeffrey Hugo <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: <[email protected]> Signed-off-by: Matt Fleming <[email protected]>
2016-09-05efi/libstub: Allocate headspace in efi_get_memory_map()Jeffrey Hugo3-37/+88
efi_get_memory_map() allocates a buffer to store the memory map that it retrieves. This buffer may need to be reused by the client after ExitBootServices() is called, at which point allocations are not longer permitted. To support this usecase, provide the allocated buffer size back to the client, and allocate some additional headroom to account for any reasonable growth in the map that is likely to happen between the call to efi_get_memory_map() and the client reusing the buffer. Signed-off-by: Jeffrey Hugo <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: <[email protected]> Signed-off-by: Matt Fleming <[email protected]>
2016-05-16Merge tag 'arm64-upstream' of ↵Linus Torvalds2-26/+13
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - virt_to_page/page_address optimisations - support for NUMA systems described using device-tree - support for hibernate/suspend-to-disk - proper support for maxcpus= command line parameter - detection and graceful handling of AArch64-only CPUs - miscellaneous cleanups and non-critical fixes * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) arm64: do not enforce strict 16 byte alignment to stack pointer arm64: kernel: Fix incorrect brk randomization arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str arm64: secondary_start_kernel: Remove unnecessary barrier arm64: Ensure pmd_present() returns false after pmd_mknotpresent() arm64: Replace hard-coded values in the pmd/pud_bad() macros arm64: Implement pmdp_set_access_flags() for hardware AF/DBM arm64: Fix typo in the pmdp_huge_get_and_clear() definition arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL arm64: always use STRICT_MM_TYPECHECKS arm64: kvm: Fix kvm teardown for systems using the extended idmap arm64: kaslr: increase randomization granularity arm64: kconfig: drop CONFIG_RTC_LIB dependency arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION arm64: hibernate: Refuse to hibernate if the boot cpu is offline arm64: kernel: Add support for hibernate/suspend-to-disk PM / Hibernate: Call flush_icache_range() on pages restored in-place arm64: Add new asm macro copy_page arm64: Promote KERNEL_START/KERNEL_END definitions to a header file arm64: kernel: Include _AC definition in page.h ...
2016-04-28arm64: kaslr: increase randomization granularityArd Biesheuvel1-3/+12
Currently, our KASLR implementation randomizes the placement of the core kernel at 2 MB granularity. This is based on the arm64 kernel boot protocol, which mandates that the kernel is loaded TEXT_OFFSET bytes above a 2 MB aligned base address. This requirement is a result of the fact that the block size used by the early mapping code may be 2 MB at the most (for a 4 KB granule kernel) But we can do better than that: since a KASLR kernel needs to be relocated in any case, we can tolerate a physical misalignment as long as the virtual misalignment relative to this 2 MB block size is equal in size, and code to deal with this is already in place. Since we align the kernel segments to 64 KB, let's randomize the physical offset at 64 KB granularity as well (unless CONFIG_DEBUG_ALIGN_RODATA is enabled). This way, the page table and TLB footprint is not affected. The higher granularity allows for 5 bits of additional entropy to be used. Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2016-04-28efi/arm*/libstub: Wire up GOP protocol to 'struct screen_info'Ard Biesheuvel1-0/+23
This adds the code to the ARM and arm64 versions of the UEFI stub to populate struct screen_info based on the information received from the firmware via the GOP protocol. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Herrmann <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Jones <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-28efi/arm/libstub: Make screen_info accessible to the UEFI stubArd Biesheuvel1-0/+37
In order to hand over the framebuffer described by the GOP protocol and discovered by the UEFI stub, make struct screen_info accessible by the stub. This involves allocating a loader data buffer and passing it to the kernel proper via a UEFI Configuration Table, since the UEFI stub executes in the context of the decompressor, and cannot access the kernel's copy of struct screen_info directly. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Herrmann <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Jones <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-28efi/libstub: Move Graphics Output Protocol handling to generic codeArd Biesheuvel2-1/+355
The Graphics Output Protocol code executes in the stub, so create a generic version based on the x86 version in libstub so that we can move other archs to it in subsequent patches. The new source file gop.c is added to the libstub build for all architectures, but only wired up for x86. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: David Herrmann <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Jones <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-28efi: Iterate over efi.memmap in for_each_efi_memory_desc()Matt Fleming1-2/+4
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 <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Mark Salter <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-28efi/arm64: Check SetupMode when determining Secure Boot statusLinn Crosetto1-7/+25
According to the UEFI specification (version 2.5 Errata A, page 87): The platform firmware is operating in secure boot mode if the value of the SetupMode variable is 0 and the SecureBoot variable is set to 1. A platform cannot operate in secure boot mode if the SetupMode variable is set to 1. Check the value of the SetupMode variable when determining the state of Secure Boot. Plus also do minor cleanup, change sizeof() use to match kernel style guidelines. Signed-off-by: Linn Crosetto <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Roy Franz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-28efi/arm64: Report unexpected errors when determining Secure Boot statusLinn Crosetto1-4/+18
Certain code in the boot path may require the ability to determine whether UEFI Secure Boot is definitely enabled, for example printing status to the console. Other code may need to know when UEFI Secure Boot is definitely disabled, for example restricting use of kernel parameters. If an unexpected error is returned from GetVariable() when querying the status of UEFI Secure Boot, return an error to the caller. This allows the caller to determine the definite state, and to take appropriate action if an expected error is returned. Signed-off-by: Linn Crosetto <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Roy Franz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-04-15efi: ARM/arm64: ignore DT memory nodes instead of removing themArd Biesheuvel1-23/+1
There are two problems with the UEFI stub DT memory node removal routine: - it deletes nodes as it traverses the tree, which happens to work but is not supported, as deletion invalidates the node iterator; - deleting memory nodes entirely may discard annotations in the form of additional properties on the nodes. Since the discovery of DT memory nodes occurs strictly before the UEFI init sequence, we can simply clear the memblock memory table before parsing the UEFI memory map. This way, it is no longer necessary to remove the nodes, so we can remove that logic from the stub as well. Reviewed-by: Matt Fleming <[email protected]> Acked-by: Steve Capper <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: David Daney <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2016-03-22kernel: add kcov code coverageDmitry Vyukov1-0/+3
kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [[email protected]: make task_struct.kcov_mode have type `enum kcov_mode'] [[email protected]: unbreak allmodconfig] [[email protected]: follow x86 Makefile layout standards] Signed-off-by: Dmitry Vyukov <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: syzkaller <[email protected]> Cc: Vegard Nossum <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Tavis Ormandy <[email protected]> Cc: Will Deacon <[email protected]> Cc: Quentin Casasnovas <[email protected]> Cc: Kostya Serebryany <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Kees Cook <[email protected]> Cc: Bjorn Helgaas <[email protected]> Cc: Sasha Levin <[email protected]> Cc: David Drysdale <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2016-03-20Merge branch 'efi-core-for-linus' of ↵Linus Torvalds4-7/+60
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes are: - Use separate EFI page tables when executing EFI firmware code. This isolates the EFI context from the rest of the kernel, which has security and general robustness advantages. (Matt Fleming) - Run regular UEFI firmware with interrupts enabled. This is already the status quo under other OSs. (Ard Biesheuvel) - Various x86 EFI enhancements, such as the use of non-executable attributes for EFI memory mappings. (Sai Praneeth Prakhya) - Various arm64 UEFI enhancements. (Ard Biesheuvel) - ... various fixes and cleanups. The separate EFI page tables feature got delayed twice already, because it's an intrusive change and we didn't feel confident about it - third time's the charm we hope!" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/mm/pat: Fix boot crash when 1GB pages are not supported by the CPU x86/efi: Only map kernel text for EFI mixed mode x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() efi/arm*: Perform hardware compatibility check efi/arm64: Check for h/w support before booting a >4 KB granular kernel efi/arm: Check for LPAE support before booting a LPAE kernel efi/arm-init: Use read-only early mappings efi/efistub: Prevent __init annotations from being used arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections efi/arm64: Drop __init annotation from handle_kernel_image() x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled efi: Reformat GUID tables to follow the format in UEFI spec efi: Add Persistent Memory type name efi: Add NV memory attribute x86/efi: Show actual ending addresses in efi_print_memmap x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0 efivars: Use to_efivar_entry efi: Runtime-wrapper: Get rid of the rtc_lock spinlock ...
2016-03-20Merge branch 'core-objtool-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull 'objtool' stack frame validation from Ingo Molnar: "This tree adds a new kernel build-time object file validation feature (ONFIG_STACK_VALIDATION=y): kernel stack frame correctness validation. It was written by and is maintained by Josh Poimboeuf. The motivation: there's a category of hard to find kernel bugs, most of them in assembly code (but also occasionally in C code), that degrades the quality of kernel stack dumps/backtraces. These bugs are hard to detect at the source code level. Such bugs result in incorrect/incomplete backtraces most of time - but can also in some rare cases result in crashes or other undefined behavior. The build time correctness checking is done via the new 'objtool' user-space utility that was written for this purpose and which is hosted in the kernel repository in tools/objtool/. The tool's (very simple) UI and source code design is shaped after Git and perf and shares quite a bit of infrastructure with tools/perf (which tooling infrastructure sharing effort got merged via perf and is already upstream). Objtool follows the well-known kernel coding style. Objtool does not try to check .c or .S files, it instead analyzes the resulting .o generated machine code from first principles: it decodes the instruction stream and interprets it. (Right now objtool supports the x86-64 architecture.) From tools/objtool/Documentation/stack-validation.txt: "The kernel CONFIG_STACK_VALIDATION option enables a host tool named objtool which runs at compile time. It has a "check" subcommand which analyzes every .o file and ensures the validity of its stack metadata. It enforces a set of rules on asm code and C inline assembly code so that stack traces can be reliable. Currently it only checks frame pointer usage, but there are plans to add CFI validation for C files and CFI generation for asm files. For each function, it recursively follows all possible code paths and validates the correct frame pointer state at each instruction. It also follows code paths involving special sections, like .altinstructions, __jump_table, and __ex_table, which can add alternative execution paths to a given instruction (or set of instructions). Similarly, it knows how to follow switch statements, for which gcc sometimes uses jump tables." When this new kernel option is enabled (it's disabled by default), the tool, if it finds any suspicious assembly code pattern, outputs warnings in compiler warning format: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup warning: objtool:__schedule()+0x3c0: duplicate frame pointer save warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer ... so that scripts that pick up compiler warnings will notice them. All known warnings triggered by the tool are fixed by the tree, most of the commits in fact prepare the kernel to be warning-free. Most of them are bugfixes or cleanups that stand on their own, but there are also some annotations of 'special' stack frames for justified cases such entries to JIT-ed code (BPF) or really special boot time code. There are two other long-term motivations behind this tool as well: - To improve the quality and reliability of kernel stack frames, so that they can be used for optimized live patching. - To create independent infrastructure to check the correctness of CFI stack frames at build time. CFI debuginfo is notoriously unreliable and we cannot use it in the kernel as-is without extra checking done both on the kernel side and on the build side. The quality of kernel stack frames matters to debuggability as well, so IMO we can merge this without having to consider the live patching or CFI debuginfo angle" * 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) objtool: Only print one warning per function objtool: Add several performance improvements tools: Copy hashtable.h into tools directory objtool: Fix false positive warnings for functions with multiple switch statements objtool: Rename some variables and functions objtool: Remove superflous INIT_LIST_HEAD objtool: Add helper macros for traversing instructions objtool: Fix false positive warnings related to sibling calls objtool: Compile with debugging symbols objtool: Detect infinite recursion objtool: Prevent infinite recursion in noreturn detection objtool: Detect and warn if libelf is missing and don't break the build tools: Support relative directory path for 'O=' objtool: Support CROSS_COMPILE x86/asm/decoder: Use explicitly signed chars objtool: Enable stack metadata validation on 64-bit x86 objtool: Add CONFIG_STACK_VALIDATION option objtool: Add tool to perform compile-time stack metadata validation x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard sched: Always inline context_switch() ...
2016-02-29objtool: Mark non-standard object files and directoriesJosh Poimboeuf1-0/+1
Code which runs outside the kernel's normal mode of operation often does unusual things which can cause a static analysis tool like objtool to emit false positive warnings: - boot image - vdso image - relocation - realmode - efi - head - purgatory - modpost Set OBJECT_FILES_NON_STANDARD for their related files and directories, which will tell objtool to skip checking them. It's ok to skip them because they don't affect runtime stack traces. Also skip the following code which does the right thing with respect to frame pointers, but is too "special" to be validated by a tool: - entry - mcount Also skip the test_nx module because it modifies its exception handling table at runtime, which objtool can't understand. Fortunately it's just a test module so it doesn't matter much. Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it might eventually be useful for other tools. Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Bernd Petrovitsch <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Chris J Arges <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Marek <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Pedro Alves <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2016-02-24arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomnessArd Biesheuvel3-35/+97
Since arm64 does not use a decompressor that supplies an execution environment where it is feasible to some extent to provide a source of randomness, the arm64 KASLR kernel depends on the bootloader to supply some random bits in the /chosen/kaslr-seed DT property upon kernel entry. On UEFI systems, we can use the EFI_RNG_PROTOCOL, if supplied, to obtain some random bits. At the same time, use it to randomize the offset of the kernel Image in physical memory. Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2016-02-24efi: stub: use high allocation for converted command lineArd Biesheuvel1-1/+6
Before we can move the command line processing before the allocation of the kernel, which is required for detecting the 'nokaslr' option which controls that allocation, move the converted command line higher up in memory, to prevent it from interfering with the kernel itself. Since x86 needs the address to fit in 32 bits, use UINT_MAX as the upper bound there. Otherwise, use ULONG_MAX (i.e., no limit) Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2016-02-24efi: stub: add implementation of efi_random_alloc()Ard Biesheuvel2-0/+104
This implements efi_random_alloc(), which allocates a chunk of memory of a certain size at a certain alignment, and uses the random_seed argument it receives to randomize the address of the allocation. This is implemented by iterating over the UEFI memory map, counting the number of suitable slots (aligned offsets) within each region, and picking a random number between 0 and 'number of slots - 1' to select the slot, This should guarantee that each possible offset is chosen equally likely. Suggested-by: Kees Cook <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2016-02-24efi: stub: implement efi_get_random_bytes() based on EFI_RNG_PROTOCOLArd Biesheuvel3-1/+39
This exposes the firmware's implementation of EFI_RNG_PROTOCOL via a new function efi_get_random_bytes(). Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2016-02-22efi/arm*: Perform hardware compatibility checkArd Biesheuvel2-0/+6
Before proceeding with relocating the kernel and parsing the command line, insert a call to check_platform_features() to allow an arch specific check to be performed whether the current kernel can execute on the current hardware. Tested-by: Suzuki K Poulose <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-02-22efi/arm64: Check for h/w support before booting a >4 KB granular kernelArd Biesheuvel1-0/+20
A kernel built with support for a page size that is not supported by the hardware it runs on cannot boot to a state where it can inform the user about the failure. If we happen to be booting via UEFI, we can fail gracefully so check if the currently configured page size is supported by the hardware before entering the kernel proper. Note that UEFI mandates support for 4 KB pages, so in that case, no check is needed. Tested-by: Suzuki K Poulose <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-02-22efi/arm: Check for LPAE support before booting a LPAE kernelArd Biesheuvel1-0/+17
A kernel built with support for LPAE cannot boot to a state where it can inform the user about if it has to fail due to missing LPAE support in the hardware. If we happen to be booting via UEFI, we can fail gracefully so check for LPAE support in the hardware on CONFIG_ARM_LPAE builds before entering the kernel proper. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-02-22efi/efistub: Prevent __init annotations from being usedArd Biesheuvel1-0/+10
__init annotations should not be used in the EFI stub, since the code is either included in the decompressor (x86, ARM) where they have no effect, or the whole stub is __init annotated at the section level (arm64), by renaming the sections. In the second case the __init annotations will be redundant, and will result in section names like .init.init.text, and our linker script does not expect that. So un-#define __init so that its inadvertent use will force a build error. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-02-22efi/arm64: Drop __init annotation from handle_kernel_image()Ard Biesheuvel1-7/+7
After moving arm64-stub.c to libstub/, all of its sections are emitted as .init.xxx sections automatically, and the __init annotation of handle_kernel_image() causes it to end up in .init.init.text, which is not recognized as an __init section by the linker scripts. So drop the annotation. Tested-by: Mark Rutland <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Acked-by: Will Deacon <[email protected]> Acked-by: Mark Rutland <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-01-20UBSAN: run-time undefined behavior sanity checkerAndrey Ryabinin1-0/+1
UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<[email protected]> * undefined rol32(0) - http://lkml.kernel.org/r/<[email protected]> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<[email protected]> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<[email protected]> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com> WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<[email protected]> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<[email protected]> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com> * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com> [[email protected]: fix unused local warning] [[email protected]: fix __int128 build woes] Signed-off-by: Andrey Ryabinin <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sasha Levin <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Michal Marek <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Yury Gribov <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Konstantin Khlebnikov <[email protected]> Cc: Kostya Serebryany <[email protected]> Cc: Johannes Berg <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2016-01-14Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: floppy: make local variable non-static exynos: fixes an incorrect header guard dt-bindings: fixes some incorrect header guards cpufreq-dt: correct dead link in documentation cpufreq: ARM big LITTLE: correct dead link in documentation treewide: Fix typos in printk Documentation: filesystem: Fix typo in fs/eventfd.c fs/super.c: use && instead of & for warn_on condition Documentation: fix sysfs-ptp lib: scatterlist: fix Kconfig description
2016-01-12Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds3-1/+97
Pull ARM updates from Russell King: - UEFI boot and runtime services support for ARM from Ard Biesheuvel and Roy Franz. - DT compatibility with old atags booting protocol for Nokia N900 devices from Ivaylo Dimitrov. - PSCI firmware interface using new arm-smc calling convention from Jens Wiklander. - Runtime patching for udiv/sdiv instructions for ARMv7 CPUs that support these instructions from Nicolas Pitre. - L2x0 cache updates from Dirk B and Linus Walleij. - Randconfig fixes from Arnd Bergmann. - ARMv7M (nommu) updates from Ezequiel Garcia * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (34 commits) ARM: 8481/2: drivers: psci: replace psci firmware calls ARM: 8480/2: arm64: add implementation for arm-smccc ARM: 8479/2: add implementation for arm-smccc ARM: 8478/2: arm/arm64: add arm-smccc ARM: 8494/1: mm: Enable PXN when running non-LPAE kernel on LPAE processor ARM: 8496/1: OMAP: RX51: save ATAGS data in the early boot stage ARM: 8495/1: ATAGS: move save_atags() to arch/arm/include/asm/setup.h ARM: 8452/3: PJ4: make coprocessor access sequences buildable in Thumb2 mode ARM: 8482/1: l2x0: make it possible to disable outer sync from DT ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI ARM: 8487/1: Remove IPI_CALL_FUNC_SINGLE ARM: 8485/1: cpuidle: remove cpu parameter from the cpuidle_ops suspend hook ARM: 8484/1: Documentation: l2c2x0: Mention separate controllers explicitly ARM: 8483/1: Documentation: l2c: Rename l2cc to l2c2x0 ARM: 8477/1: runtime patch udiv/sdiv instructions into __aeabi_{u}idiv() ARM: 8476/1: VDSO: use PTR_ERR_OR_ZERO for vma check ARM: 8453/2: proc-v7.S: don't locate temporary stack space in .text section ARM: add UEFI stub support ARM: wire up UEFI init and runtime support ARM: only consider memblocks with NOMAP cleared for linear mapping ...