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mte: note why 0 tag is excluded

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Dmitry Muhomor 2023-10-30 12:31:12 +02:00
parent 75190a3eec
commit 2136e8bfff
1 changed files with 2 additions and 1 deletions
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h_malloc.c
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@ -577,7 +577,8 @@ static void *tag_and_clear_slab_slot(struct slab_metadata *metadata, void *slot_
// is constructed.
u8 *slot_tags = metadata->arm_mte_tags;
// Tag exclusion mask
// Tag exclusion mask. 0 tag is always excluded to detect accesses to slab memory via untagged
// pointers. Moreover, 0 tag is excluded in bionic via PR_MTE_TAG_MASK prctl
u64 tem = (1 << 0) | (1 << RESERVED_TAG);
// current or previous tag of left neighbor or 0 if there's no left neighbor or if it was never used