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pmladekJiri Kosina
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livepatch: Remove not longer valid limitations from the documentation
Semantic changes are possible since the commit d83a7cb ("livepatch: change to a per-task consistency model"). Also data structures can be patched since the commit 439e727 ("livepatch: introduce shadow variable API"). It is a high time we removed these limitations from the documentation. Signed-off-by: Petr Mladek <[email protected]> Acked-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Signed-off-by: Jiri Kosina <[email protected]>
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Documentation/livepatch/livepatch.txt

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@@ -429,30 +429,6 @@ See Documentation/ABI/testing/sysfs-kernel-livepatch for more details.
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The current Livepatch implementation has several limitations:
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+ The patch must not change the semantic of the patched functions.
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The current implementation guarantees only that either the old
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or the new function is called. The functions are patched one
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by one. It means that the patch must _not_ change the semantic
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of the function.
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+ Data structures can not be patched.
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There is no support to version data structures or anyhow migrate
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one structure into another. Also the simple consistency model does
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not allow to switch more functions atomically.
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Once there is more complex consistency mode, it will be possible to
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use some workarounds. For example, it will be possible to use a hole
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for a new member because the data structure is aligned. Or it will
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be possible to use an existing member for something else.
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There are no plans to add more generic support for modified structures
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at the moment.
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+ Only functions that can be traced could be patched.
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Livepatch is based on the dynamic ftrace. In particular, functions

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