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authorPetr Mladek <pmladek@suse.com>2018-05-23 03:47:42 -0400
committerJiri Kosina <jkosina@suse.cz>2018-05-24 09:37:57 -0400
commita48c7709fe42712e86d2d68e1c9c4d2ce14c6a16 (patch)
treedee5ede0e4ef058f780a4f6429bee8a33b9b19b2
parent41e3bef52e42c03cb7234f2d8419352478c92926 (diff)
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>
-rw-r--r--Documentation/livepatch/livepatch.txt24
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.
429 429
430The current Livepatch implementation has several limitations: 430The current Livepatch implementation has several limitations:
431 431
432
433 + The patch must not change the semantic of the patched functions.
434
435 The current implementation guarantees only that either the old
436 or the new function is called. The functions are patched one
437 by one. It means that the patch must _not_ change the semantic
438 of the function.
439
440
441 + Data structures can not be patched.
442
443 There is no support to version data structures or anyhow migrate
444 one structure into another. Also the simple consistency model does
445 not allow to switch more functions atomically.
446
447 Once there is more complex consistency mode, it will be possible to
448 use some workarounds. For example, it will be possible to use a hole
449 for a new member because the data structure is aligned. Or it will
450 be possible to use an existing member for something else.
451
452 There are no plans to add more generic support for modified structures
453 at the moment.
454
455
456 + Only functions that can be traced could be patched. 432 + Only functions that can be traced could be patched.
457 433
458 Livepatch is based on the dynamic ftrace. In particular, functions 434 Livepatch is based on the dynamic ftrace. In particular, functions