The Limitations section of the documentation describes the impossibility
to livepatch anything that is inlined to __schedule() function. This had
been true till 4.9 kernel came. Thanks to commit 0100301bfd
("sched/x86: Rewrite the switch_to() code") from Brian Gerst there is
__switch_to_asm function now (implemented in assembly) called properly
from context_switch(). RIP is thus saved on the stack and a task would
return to proper version of __schedule() et al. functions.
Of course __switch_to_asm() is not patchable for the reason described in
the section. But there is no __fentry__ call and I cannot imagine a
reason to do it anyway.
Therefore, remove the paragraphs from the section.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
gmame archive does not longer exist. Use the message id and
generic redirector instead.
Reported-by: John Donnelly <john.donnelly@canonical.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Document usage of arch-specific elf sections in livepatch as well
as implementation of arch-specific code.
[jkosina@suse.cz: fix wording as suggested by Petr Mladek]
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
livepatch framework deserves some documentation, definitely.
This is an attempt to provide some basic info. I hope that
it will be useful for both LivePatch producers and also
potential developers of the framework itself.
[jkosina@suse.cz:
- incorporated feedback (grammar fixes) from
Chris J Arges <chris.j.arges@canonical.com>
- s/LivePatch/livepatch in changelog as pointed out by
Josh Poimboeuf <jpoimboe@redhat.com>
- incorporated part of feedback (grammar fixes / reformulations) from
Balbir Singh <bsingharora@gmail.com>
]
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
