b799a09f63
Patch series "kexec_file, x86, powerpc: refactoring for other architecutres", v2. This is a preparatory patchset for adding kexec_file support on arm64. It was originally included in a arm64 patch set[1], but Philipp is also working on their kexec_file support on s390[2] and some changes are now conflicting. So these common parts were extracted and put into a separate patch set for better integration. What's more, my original patch#4 was split into a few small chunks for easier review after Dave's comment. As such, the resulting code is basically identical with my original, and the only *visible* differences are: - renaming of _kexec_kernel_image_probe() and _kimage_file_post_load_cleanup() - change one of types of arguments at prepare_elf64_headers() Those, unfortunately, require a couple of trivial changes on the rest (#1, #6 to #13) of my arm64 kexec_file patch set[1]. Patch #1 allows making a use of purgatory optional, particularly useful for arm64. Patch #2 commonalizes arch_kexec_kernel_{image_probe, image_load, verify_sig}() and arch_kimage_file_post_load_cleanup() across architectures. Patches #3-#7 are also intended to generalize parse_elf64_headers(), along with exclude_mem_range(), to be made best re-use of. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2018-February/561182.html [2] http://lkml.iu.edu//hypermail/linux/kernel/1802.1/02596.html This patch (of 7): On arm64, crash dump kernel's usable memory is protected by *unmapping* it from kernel virtual space unlike other architectures where the region is just made read-only. It is highly unlikely that the region is accidentally corrupted and this observation rationalizes that digest check code can also be dropped from purgatory. The resulting code is so simple as it doesn't require a bit ugly re-linking/relocation stuff, i.e. arch_kexec_apply_relocations_add(). Please see: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-December/545428.html All that the purgatory does is to shuffle arguments and jump into a new kernel, while we still need to have some space for a hash value (purgatory_sha256_digest) which is never checked against. As such, it doesn't make sense to have trampline code between old kernel and new kernel on arm64. This patch introduces a new configuration, ARCH_HAS_KEXEC_PURGATORY, and allows related code to be compiled in only if necessary. [takahiro.akashi@linaro.org: fix trivial screwup] Link: http://lkml.kernel.org/r/20180309093346.GF25863@linaro.org Link: http://lkml.kernel.org/r/20180306102303.9063-2-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Dave Young <dyoung@redhat.com> Tested-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| fs | ||
| include | ||
| init | ||
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| kernel | ||
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| samples | ||
| scripts | ||
| security | ||
| sound | ||
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| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
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| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.