Messages in this thread | | | From | Jue Wang <> | Date | Thu, 22 Jul 2021 06:54:37 -0700 | Subject | Re: [PATCH 2/3] x86/mce: Avoid infinite loop for copy from user recovery |
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This patch assumes the UC error consumed in kernel is always the same UC.
Yet it's possible two UCs on different pages are consumed in a row. The patch below will panic on the 2nd MCE. How can we make the code works on multiple UC errors?
> + int count = ++current->mce_count; > + > + /* First call, save all the details */ > + if (count == 1) { > + current->mce_addr = m->addr; > + current->mce_kflags = m->kflags; > + current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV); > + current->mce_whole_page = whole_page(m); > + current->mce_kill_me.func = func; > + } > ...... > + /* Second or later call, make sure page address matches the one from first call */ > + if (count > 1 && (current->mce_addr >> PAGE_SHIFT) != (m->addr >> PAGE_SHIFT)) > + mce_panic("Machine checks to different user pages", m, msg);
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