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author | Takashi Iwai <tiwai@suse.de> | 2022-12-22 11:11:48 +0300 |
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committer | Takashi Iwai <tiwai@suse.de> | 2022-12-22 11:11:48 +0300 |
commit | 2d78eb0342dd2c9c5cde9ae9ada1d33f189a858b (patch) | |
tree | f711bc9cab45f4963e4883ef15ff4c54a6cbc12e /mm/madvise.c | |
parent | b47068b4aa53a57552398e3f60d0ed1918700c2b (diff) | |
parent | ee0b089d660021792e4ab4dda191b097ce1e964f (diff) | |
download | linux-2d78eb0342dd2c9c5cde9ae9ada1d33f189a858b.tar.xz |
Merge branch 'for-next' into for-linus
Diffstat (limited to 'mm/madvise.c')
-rw-r--r-- | mm/madvise.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index 2baa93ca2310..c7105ec6d08c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -813,7 +813,14 @@ static bool madvise_dontneed_free_valid_vma(struct vm_area_struct *vma, if (start & ~huge_page_mask(hstate_vma(vma))) return false; - *end = ALIGN(*end, huge_page_size(hstate_vma(vma))); + /* + * Madvise callers expect the length to be rounded up to PAGE_SIZE + * boundaries, and may be unaware that this VMA uses huge pages. + * Avoid unexpected data loss by rounding down the number of + * huge pages freed. + */ + *end = ALIGN_DOWN(*end, huge_page_size(hstate_vma(vma))); + return true; } @@ -828,6 +835,9 @@ static long madvise_dontneed_free(struct vm_area_struct *vma, if (!madvise_dontneed_free_valid_vma(vma, start, &end, behavior)) return -EINVAL; + if (start == end) + return 0; + if (!userfaultfd_remove(vma, start, end)) { *prev = NULL; /* mmap_lock has been dropped, prev is stale */ |