Tighten GCC 2-region _sbrk #11572
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Tighten GCC 2-region _sbrk #11572
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When moving to the second heap region due to overflowing the first region, the `_sbrk` implementation assumed the allocation would fit in the second region, and didn't check for that overflowing too. Problem revealed in `stats_heap` test with GCC 8 on K64F - the allocation attempt for 1GiB crashed, as `_sbrk` indicated 1GiB was available at the start of the second region. second region. Presumably older versions of newlib fault that allocation attempt before passing to `_sbrk`. While there, adjust the code to not use a separate static `bool`, saving RAM. We can track with just one pointer, as order of the two regions is fixed, and already relied on by newlib.
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@kjbracey-arm, thank you for your changes. |
OPpuolitaival
approved these changes
Sep 27, 2019
evedon
approved these changes
Sep 27, 2019
0xc0170
approved these changes
Sep 30, 2019
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CI started |
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Built has not finished, I aborted and restarted it |
Test run: FAILEDSummary: 1 of 11 test jobs failed Failed test jobs:
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bulislaw
approved these changes
Oct 2, 2019
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Description
When moving to the second heap region due to overflowing the first region, the
_sbrkimplementation assumed the allocation would fit in the second region, and didn't check for that overflowing too.Problem revealed in
stats_heaptest with GCC 8 on K64F - the allocation attempt for 1GiB crashed, as_sbrkindicated 1GiB was available at the start of the second region.Presumably older versions of newlib fault that allocation attempt before passing to
_sbrk.While there, adjust the code to not use a separate static
bool, saving RAM. We can track with just one pointer, as order of the two regions is fixed, and already relied on by newlib.Pull request type
Reviewers
@OPpuolitaival, @evedon