Messages in this thread | | | Subject | Re: [PATCH 0/7] livepatch,module: Remove .klp.arch and module_disable_ro() | From | Joe Lawrence <> | Date | Tue, 14 Apr 2020 21:37:53 -0400 |
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On 4/14/20 9:31 PM, Josh Poimboeuf wrote: > On Tue, Apr 14, 2020 at 08:57:15PM -0400, Joe Lawrence wrote: >> On 4/14/20 12:28 PM, Josh Poimboeuf wrote: >>> Better late than never, these patches add simplifications and >>> improvements for some issues Peter found six months ago, as part of his >>> non-writable text code (W^X) cleanups. >>> >>> Highlights: >>> >>> - Remove the livepatch arch-specific .klp.arch sections, which were used >>> to do paravirt patching and alternatives patching for livepatch >>> replacement code. >>> >>> - Add support for jump labels in patched code. >> >> Re: jump labels and late-module patching support... >> >> Is there still an issue of a non-exported static key defined in a >> to-be-patched module referenced and resolved via klp-relocation when the >> livepatch module is loaded first? (Basically the same case I asked Petr >> about in his split livepatch module PoC. [1]) >> >> Or should we declare this an invalid klp-relocation use case and force the >> livepatch author to use static_key_enabled()? >> >> [1] https://lore.kernel.org/lkml/20200407205740.GA17061@redhat.com/ > > Right, if the static key lives in a module, then it's still not possible > for a jump label to use it. I added a check in kpatch-build to block > that case and suggest static_key_enabled() instead. >
Ok good. I didn't see a negative test case for this, so I wanted to make sure that kpatch-build wouldn't accidentally create unsupported klp-relocations for them. I'll try to review those changes over on github tomorrow.
-- Joe
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