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Avoid SIGBUS on armv6 #2633

Merged
merged 1 commit into from
May 11, 2021
Merged

Avoid SIGBUS on armv6 #2633

merged 1 commit into from
May 11, 2021

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bmwiedemann
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When running armv6 userspace on armv8 hardware with a 64 bit Linux kernel,
the mode 2 caused SIGBUS (unaligned memory access).
Running all our arm builds in the build farm
only on armv8 simplifies administration a lot.

Depending on compiler and environment, this change might slow down
memory accesses (did not benchmark it). The original analysis is 6 years old and compilers might have improved since then.

Fixes #2632

When running armv6 userspace on armv8 hardware with a 64 bit Linux kernel,
the mode 2 caused SIGBUS (unaligned memory access).
Running all our arm builds in the build farm
only on armv8 simplifies administration a lot.

Depending on compiler and environment, this change might slow down
memory accesses (did not benchmark it). The original analysis is 6 years old.

Fixes facebook#2632
@Cyan4973 Cyan4973 merged commit 162f540 into facebook:dev May 11, 2021
@Cyan4973
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Yes, that's a safer default behavior

@bmwiedemann bmwiedemann deleted the issue2632 branch May 11, 2021 18:22
Hello71 added a commit to Hello71/zstd that referenced this pull request Dec 6, 2021
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ARMv6 unaligned hack ends up in bus-error if running under a 64bit kernel
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