On Wed, Aug 26, 2020 at 11:53:24AM -0700, Hugh Dickins wrote:
On Mon, 24 Aug 2020, Hugh Dickins wrote:
On Sat, 22 Aug 2020, Hugh Dickins wrote:
On Sat, 22 Aug 2020, Sasha Levin wrote:
I've followed your instructions and backported the patches:
bbe98f9cadff ("khugepaged: khugepaged_test_exit() check mmget_still_valid()") - to all branches. f3f99d63a815 ("khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter()") - to all branches. 59ea6d06cfa9 ("coredump: fix race condition between collapse_huge_page() and core dumping") - for 4.4.
That's saved me time, thanks a lot for doing that work, Sasha.
I've checked the results (haha, read on) and they're all fine, but one minor flaw in bisectability: the added 4.4 backport of "coredump: fix race condition..." adds a line (deleted by the next commit) result = SCAN_ANY_PROCESS; but neither "result" nor "SCAN_ANY_PROCESS" is defined in that tree, so that intermediate step would generate an easily fixed build error.
FWIW - I don't know whether that's something to care about or not.
Ah, but I missed that this one that we originally held back from 5.8, did not in fact get re-added to 5.8: all the backport series have it, but today's 5.8.4-rc1 does not have it.
That's not a disaster - the series builds without it, and having its fix without the fixed commit is just odd, no more unsafe than before; but it should be re-added for a 5.8.4-rc2 or 5.8.5.
I see 5.8 is at 5.8.5-rc1 today, but the commit below still missing: please re-add it, then we can all forget about it at last - thanks!
Greg went for a fast release cycle and I didn't have time to queue it up, sorry. But don't worry - this patch isn't forgotten, I'll queue it for the next release on Friday/Saturday.