ARM MTE: properly check the memory tag of small allocations for h_free/h_free_sized/h_free_aligned_sized during deallocation

[rdevshp]

Properly check the memory tag of small allocations for h_free/h_free_sized/h_free_aligned_sized during deallocation.

[rdevshp]

ping

[thestinger]

It should be possible to do this with regular tag checks instead of our array of tags. Not sure which would be more efficient.

[rdevshp]

It should be possible to do this with regular tag checks instead of our array of tags. Not sure which would be more efficient.

I did some local benchmarks, and it looks like using __arm_mte_get_tag is either better or equal to reading from the metadata array of tags in terms of performance. I have switched the patch to using __arm_mte_get_tag.

[rdevshp]

There is an unrelated flaky CI issue caused by passing the combination of -Werror and -march=native flags to clang-19 (the build error was gone after I retriggered the CI). actions/runner-images#14296

Run CC=clang CXX=clang++ make test
mkdir -p out
clang  -std=c23 -pipe -O3 -flto -fPIC -fvisibility=hidden -fno-plt -fstack-clash-protection -fcf-protection -fstack-protector-strong -Wall -Wextra -Wcast-align -Wcast-qual -Wwrite-strings -Wundef -Werror -march=native -Wmissing-prototypes -Wstrict-prototypes  -D_GNU_SOURCE -I include -DCONFIG_SEAL_METADATA=false -DZERO_ON_FREE=true -DWRITE_AFTER_FREE_CHECK=true -DSLOT_RANDOMIZE=true -DSLAB_CANARY=true -DSLAB_QUARANTINE_RANDOM_LENGTH=1 -DSLAB_QUARANTINE_QUEUE_LENGTH=1 -DCONFIG_EXTENDED_SIZE_CLASSES=true -DCONFIG_LARGE_SIZE_CLASSES=true -DGUARD_SLABS_INTERVAL=1 -DGUARD_SIZE_DIVISOR=2 -DREGION_QUARANTINE_RANDOM_LENGTH=256 -DREGION_QUARANTINE_QUEUE_LENGTH=1024 -DREGION_QUARANTINE_SKIP_THRESHOLD=33554432  -DFREE_SLABS_QUARANTINE_RANDOM_LENGTH=32 -DCONFIG_CLASS_REGION_SIZE=34359738368  -DN_ARENA=4 -DCONFIG_STATS=false -DCONFIG_SELF_INIT=true -DCONFIG_LABEL_MEMORY=false  -c -o out/chacha.o chacha.c
error: invalid feature combination:  +avx10.1-256; will be promoted to avx10.1-512 [-Werror,-Winvalid-feature-combination]
1 error generated.
make: *** [Makefile:127: out/chacha.o] Error 1
Error: Process completed with exit code 2.