user/sven/linux.git/include/linux/kexec.h, branch v5.9.8

kexec_file: Allow archs to handle special regions while locating memory hole

2020-07-29T13:47:53Z

Some architectures may have special memory regions, within the given memory range, which can't be used for the buffer in a kexec segment. Implement weak arch_kexec_locate_mem_hole() definition which arch code may override, to take care of special regions, while trying to locate a memory hole. Also, add the missing declarations for arch overridable functions and and drop the __weak descriptors in the declarations to avoid non-weak definitions from becoming weak. Signed-off-by: Hari Bathini Tested-by: Pingfan Liu Reviewed-by: Thiago Jung Bauermann Acked-by: Dave Young Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini

kexec: Replace zero-length array with flexible-array

2020-06-16T04:08:31Z

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva

Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-09-28T15:14:15Z

Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...

kexec: restore arch_kexec_kernel_image_probe declaration

2019-09-26T00:51:40Z

arch_kexec_kernel_image_probe function declaration has been removed by commit 9ec4ecef0af7 ("kexec_file,x86,powerpc: factor out kexec_file_ops functions"). Still this function is overridden by couple of architectures and proper prototype declaration is therefore important, so bring it back. This fixes the following sparse warning on s390: arch/s390/kernel/machine_kexec_file.c:333:5: warning: symbol 'arch_kexec_kernel_image_probe' was not declared. Should it be static? Link: http://lkml.kernel.org/r/patch.git-ff1c9045ebdc.your-ad-here.call-01564402297-ext-5690@work.hours Signed-off-by: Vasily Gorbik Acked-by: Dave Young Reviewed-by: Bhupesh Sharma Cc: Eric Biederman Cc: AKASHI Takahiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec_elf: remove parsing of section headers

2019-09-06T21:58:43Z

We're not using them, so we can drop the parsing. Signed-off-by: Sven Schnelle Reviewed-by: Thiago Jung Bauermann Signed-off-by: Helge Deller

kexec: add KEXEC_ELF

2019-09-06T21:58:43Z

Right now powerpc provides an implementation to read elf files with the kexec_file_load() syscall. Make that available as a public kexec interface so it can be re-used on other architectures. Signed-off-by: Sven Schnelle Reviewed-by: Thiago Jung Bauermann Signed-off-by: Helge Deller

kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE

2019-08-20T04:54:15Z

This is a preparatory patch for kexec_file_load() lockdown. A locked down kernel needs to prevent unsigned kernel images from being loaded with kexec_file_load(). Currently, the only way to force the signature verification is compiling with KEXEC_VERIFY_SIG. This prevents loading usigned images even when the kernel is not locked down at runtime. This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE. Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG turns on the signature verification but allows unsigned images to be loaded. KEXEC_SIG_FORCE disallows images without a valid signature. Signed-off-by: Jiri Bohac Signed-off-by: David Howells Signed-off-by: Matthew Garrett cc: kexec@lists.infradead.org Signed-off-by: James Morris

Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-12-27T01:03:51Z

Pull x86 cleanups from Ingo Molnar: "Misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Remove trampoline_handler() prototype x86/kernel: Fix more -Wmissing-prototypes warnings x86: Fix various typos in comments x86/headers: Fix -Wmissing-prototypes warning x86/process: Avoid unnecessary NULL check in get_wchan() x86/traps: Complete prototype declarations x86/mce: Fix -Wmissing-prototypes warnings x86/gart: Rewrite early_gart_iommu_check() comment

powerpc, kexec_file: factor out memblock-based arch_kexec_walk_mem()

2018-12-06T14:38:50Z

Memblock list is another source for usable system memory layout. So move powerpc's arch_kexec_walk_mem() to common code so that other memblock-based architectures, particularly arm64, can also utilise it. A moved function is now renamed to kexec_walk_memblock() and integrated into kexec_locate_mem_hole(), which will now be usable for all architectures with no need for overriding arch_kexec_walk_mem(). With this change, arch_kexec_walk_mem() need no longer be a weak function, and was now renamed to kexec_walk_resources(). Since powerpc doesn't support kdump in its kexec_file_load(), the current kexec_walk_memblock() won't work for kdump either in this form, this will be fixed in the next patch. Signed-off-by: AKASHI Takahiro Cc: "Eric W. Biederman" Acked-by: Dave Young Cc: Vivek Goyal Cc: Baoquan He Acked-by: James Morse Signed-off-by: Will Deacon

s390, kexec_file: drop arch_kexec_mem_walk()

2018-12-06T14:38:49Z

Since s390 already knows where to locate buffers, calling arch_kexec_mem_walk() has no sense. So we can just drop it as kbuf->mem indicates this while all other architectures sets it to 0 initially. This change is a preparatory work for the next patch, where all the variant memory walks, either on system resource or memblock, will be put in one common place so that it will satisfy all the architectures' need. Signed-off-by: AKASHI Takahiro Reviewed-by: Philipp Rudo Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Dave Young Cc: Vivek Goyal Cc: Baoquan He Signed-off-by: Will Deacon