On 03/07/2018 03:20 AM, Petr Mladek wrote: > The atomic replace allows to create cumulative patches. They > are useful when you maintain many livepatches and want to remove > one that is lower on the stack. In addition it is very useful when > more patches touch the same function and there are dependencies > between them. > > > Changes against v9: > > + Fixed check of valid NOPs for already loaded objects, > regression introduced in v9 [Joe, Mirek] > + Allow to replace even disabled patches [Evgenii] > > Changes against v8: > > + Fixed handling of statically defined struct klp_object > with empty array of functions [Joe, Mirek] > + Removed redundant func->new_func assignment for NOPs [Mirek] > + Improved some wording [Mirek] > > [ ... snip ... ] Hi Petr, I tried updating the test cases I was adding in "[PATCH v0 0/3] additional cumulative livepatch doc/samples" and although one of the cases is better than before, I'm running into a new issue: an expected pre-unpatch callback is not executed (its obj->patched is false). Here's the updated test case: Test 11 ------- - load livepatch - load second livepatch (atomic replace) <- callbacks ok - disable second livepatch <- pre-unpatch skipped - unload livepatch - unload second livepatch % insmod samples/livepatch/livepatch-callbacks-demo.ko [ 2306.806046] livepatch: enabling patch 'livepatch_callbacks_demo' [ 2306.806048] livepatch: 'livepatch_callbacks_demo': initializing patching transition [ 2306.806083] livepatch_callbacks_demo: pre_patch_callback: vmlinux [ 2306.806083] livepatch: 'livepatch_callbacks_demo': starting patching transition [ 2307.743170] livepatch: 'livepatch_callbacks_demo': completing patching transition [ 2307.743317] livepatch_callbacks_demo: post_patch_callback: vmlinux [ 2307.743319] livepatch: 'livepatch_callbacks_demo': patching complet % insmod samples/livepatch/livepatch-callbacks-demo2.ko replace=1 [ 2316.161804] livepatch: enabling patch 'livepatch_callbacks_demo2' [ 2316.161807] livepatch: 'livepatch_callbacks_demo2': initializing patching transition [ 2316.161842] livepatch_callbacks_demo2: pre_patch_callback: vmlinux [ 2316.161843] livepatch: 'livepatch_callbacks_demo2': starting patching transition [ 2317.727141] livepatch: 'livepatch_callbacks_demo2': completing patching transition [ 2317.727254] livepatch_callbacks_demo2: post_patch_callback: vmlinux [ 2317.727255] livepatch: 'livepatch_callbacks_demo2': patching complete % echo 0 > /sys/kernel/livepatch/livepatch_callbacks_demo2/enabled [ 2328.995854] livepatch: 'livepatch_callbacks_demo2': initializing unpatching transition [ 2328.995898] livepatch: 'livepatch_callbacks_demo2': starting unpatching transition [ 2330.719234] livepatch: 'livepatch_callbacks_demo2': completing unpatching transition [ 2330.719597] livepatch_callbacks_demo2: post_unpatch_callback: vmlinux [ 2330.719599] livepatch: 'livepatch_callbacks_demo2': unpatching complete % rmmod samples/livepatch/livepatch-callbacks-demo2.ko % rmmod samples/livepatch/livepatch-callbacks-demo.ko Running against v10, callbacks seem to be good up until I disable an atomic replace patch. My understanding is that the original patch's unpatch callbacks should be skipped (as they were). I was surprised to see that atomic replacement patch only ran it's post-unpatch callback. Unfortunately I'm running out of time to further debug today, but thought I would share these results. I can dig in more tomorrow. Regards, -- Joe -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
