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| author | Petr Mladek <pmladek@suse.com> | 2018-05-23 09:47:42 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2018-05-24 15:37:57 +0200 |
| commit | a48c7709fe42712e86d2d68e1c9c4d2ce14c6a16 (patch) | |
| tree | dee5ede0e4ef058f780a4f6429bee8a33b9b19b2 /Documentation/livepatch | |
| parent | 41e3bef52e42c03cb7234f2d8419352478c92926 (diff) | |
| download | lwn-a48c7709fe42712e86d2d68e1c9c4d2ce14c6a16.tar.gz lwn-a48c7709fe42712e86d2d68e1c9c4d2ce14c6a16.zip | |
livepatch: Remove not longer valid limitations from the documentation
Semantic changes are possible since the commit d83a7cb375eec21f04
("livepatch: change to a per-task consistency model").
Also data structures can be patched since the commit 439e7271dc2b63de37
("livepatch: introduce shadow variable API").
It is a high time we removed these limitations from the documentation.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'Documentation/livepatch')
| -rw-r--r-- | Documentation/livepatch/livepatch.txt | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/Documentation/livepatch/livepatch.txt b/Documentation/livepatch/livepatch.txt index 1ae2de758c08..2d7ed09dbd59 100644 --- a/Documentation/livepatch/livepatch.txt +++ b/Documentation/livepatch/livepatch.txt @@ -429,30 +429,6 @@ See Documentation/ABI/testing/sysfs-kernel-livepatch for more details. The current Livepatch implementation has several limitations: - - + The patch must not change the semantic of the patched functions. - - The current implementation guarantees only that either the old - or the new function is called. The functions are patched one - by one. It means that the patch must _not_ change the semantic - of the function. - - - + Data structures can not be patched. - - There is no support to version data structures or anyhow migrate - one structure into another. Also the simple consistency model does - not allow to switch more functions atomically. - - Once there is more complex consistency mode, it will be possible to - use some workarounds. For example, it will be possible to use a hole - for a new member because the data structure is aligned. Or it will - be possible to use an existing member for something else. - - There are no plans to add more generic support for modified structures - at the moment. - - + Only functions that can be traced could be patched. Livepatch is based on the dynamic ftrace. In particular, functions |