The patch titled Subject: fork: silence a false postive warning in __mmdrop has been added to the -mm tree. Its filename is fork-silence-a-false-postive-warning-in-__mmdrop.patch

This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fork-silence-a-false-postive-warnin... and later at http://ozlabs.org/~akpm/mmotm/broken-out/fork-silence-a-false-postive-warnin...

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------------------------------------------------------ From: Qian Cai cai@lca.pw Subject: fork: silence a false postive warning in __mmdrop

commit bf2c59fce407 ("sched/core: Fix illegal RCU from offline CPUs") delayed,

idle->active_mm = &init_mm;

into finish_cpu() instead of idle_task_exit() which results in a false positive warning that was originally designed in the commit 3eda69c92d47 ("kernel/fork.c: detect early free of a live mm").

WARNING: CPU: 127 PID: 72976 at kernel/fork.c:697 __mmdrop+0x230/0x2c0 do_exit+0x424/0xfa0 Call Trace: do_exit+0x424/0xfa0 do_group_exit+0x64/0xd0 sys_exit_group+0x24/0x30 system_call_exception+0x108/0x1d0 system_call_common+0xf0/0x278

Link: http://lkml.kernel.org/r/20200604150344.1796-1-cai@lca.pw Fixes: bf2c59fce407 ("sched/core: Fix illegal RCU from offline CPUs") Signed-off-by: Qian Cai cai@lca.pw Cc: Peter Zijlstra (Intel) peterz@infradead.org Cc: Michael Ellerman mpe@ellerman.id.au (powerpc) Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

kernel/fork.c | 1 - 1 file changed, 1 deletion(-)

--- a/kernel/fork.c~fork-silence-a-false-postive-warning-in-__mmdrop +++ a/kernel/fork.c @@ -694,7 +694,6 @@ void __mmdrop(struct mm_struct *mm) { BUG_ON(mm == &init_mm); WARN_ON_ONCE(mm == current->mm); - WARN_ON_ONCE(mm == current->active_mm); mm_free_pgd(mm); destroy_context(mm); mmu_notifier_subscriptions_destroy(mm); _

Patches currently in -mm which might be from cai@lca.pw are

fork-silence-a-false-postive-warning-in-__mmdrop.patch mm-page_alloc-silence-a-kasan-false-positive.patch mm-kmemleak-silence-kcsan-splats-in-checksum.patch mm-frontswap-mark-various-intentional-data-races.patch mm-page_io-mark-various-intentional-data-races.patch mm-page_io-mark-various-intentional-data-races-v2.patch mm-swap_state-mark-various-intentional-data-races.patch mm-swapfile-fix-and-annotate-various-data-races.patch mm-swapfile-fix-and-annotate-various-data-races-v2.patch mm-page_counter-fix-various-data-races-at-memsw.patch mm-memcontrol-fix-a-data-race-in-scan-count.patch mm-list_lru-fix-a-data-race-in-list_lru_count_one.patch mm-mempool-fix-a-data-race-in-mempool_free.patch mm-rmap-annotate-a-data-race-at-tlb_flush_batched.patch mm-swap-annotate-data-races-for-lru_rotate_pvecs.patch mm-annotate-a-data-race-in-page_zonenum.patch