diff options
author | Jann Horn <jannh@google.com> | 2020-10-16 06:13:00 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 21:11:22 +0300 |
commit | 4d45e75a9955ade5c2f49bd96fc4173b2cec9a72 (patch) | |
tree | 71b16b0e22ee630e2956a3285990fb49df84685e /include/linux/sched | |
parent | 7f3bfab52cab96c510fd60dd757a32db7bc52d3c (diff) | |
download | linux-4d45e75a9955ade5c2f49bd96fc4173b2cec9a72.tar.xz |
mm: remove the now-unnecessary mmget_still_valid() hack
The preceding patches have ensured that core dumping properly takes the
mmap_lock. Thanks to that, we can now remove mmget_still_valid() and all
its users.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/20200827114932.3572699-8-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/sched')
-rw-r--r-- | include/linux/sched/mm.h | 25 |
1 files changed, 0 insertions, 25 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 15bfb06f2884..981e34cb1409 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -49,31 +49,6 @@ static inline void mmdrop(struct mm_struct *mm) __mmdrop(mm); } -/* - * This has to be called after a get_task_mm()/mmget_not_zero() - * followed by taking the mmap_lock for writing before modifying the - * vmas or anything the coredump pretends not to change from under it. - * - * It also has to be called when mmgrab() is used in the context of - * the process, but then the mm_count refcount is transferred outside - * the context of the process to run down_write() on that pinned mm. - * - * NOTE: find_extend_vma() called from GUP context is the only place - * that can modify the "mm" (notably the vm_start/end) under mmap_lock - * for reading and outside the context of the process, so it is also - * the only case that holds the mmap_lock for reading that must call - * this function. Generally if the mmap_lock is hold for reading - * there's no need of this check after get_task_mm()/mmget_not_zero(). - * - * This function can be obsoleted and the check can be removed, after - * the coredump code will hold the mmap_lock for writing before - * invoking the ->core_dump methods. - */ -static inline bool mmget_still_valid(struct mm_struct *mm) -{ - return likely(!mm->core_state); -} - /** * mmget() - Pin the address space associated with a &struct mm_struct. * @mm: The address space to pin. |