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A mirror of the official Linux kernel repository just in case
e6b8940e7e
patch_instruction() is designed for patching instructions in otherwise readonly memory. Other consumers also sometimes need to patch readonly memory, so have abused patch_instruction() for arbitrary data patches. This is a problem on ppc64 as patch_instruction() decides on the patch width using the 'instruction' opcode to see if it's a prefixed instruction. Data that triggers this can lead to larger writes, possibly crossing a page boundary and failing the write altogether. Introduce patch_uint(), and patch_ulong(), with aliases patch_u32(), and patch_u64() (on ppc64) designed for aligned data patches. The patch size is now determined by the called function, and is passed as an additional parameter to generic internals. While the instruction flushing is not required for data patches, it remains unconditional in this patch. A followup series is possible if benchmarking shows fewer flushes gives an improvement in some data-patching workload. ppc32 does not support prefixed instructions, so is unaffected by the original issue. Care is taken in not exposing the size parameter in the public (non-static) interface, so the compiler can const-propagate it away. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240515024445.236364-2-bgray@linux.ibm.com |
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| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
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| rust | ||
| samples | ||
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| usr | ||
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| .get_maintainer.ignore | ||
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| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
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| 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 reStructuredText markup notation.
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.