3e8d1bae5f
From Jake: iflib_encap calls bus_dmamap_load_mbuf_sg. Upon it returning EFBIG, an m_collapse and an m_defrag are attempted to shrink the mbuf cluster to fit within the DMA segment limitations. However, if we call m_defrag, and then bus_dmamap_load_mbuf_sg returns EFBIG on the now defragmented mbuf, we will continuously re-call bus_dmamap_load_mbuf_sg over and over. This happens because m_head isn't NULL, and remap is >1, so we don't try to m_collapse or m_defrag again. The only way we exit the loop is if m_head is NULL. However, m_head can't be modified by the call to bus_dmamap_load_mbuf_sg, because we don't pass it as a double pointer. I believe this will be an incredibly rare occurrence, because it is unlikely that bus_dmamap_load_mbuf_sg will actually fail on the second defragment with an EFBIG error. However, it still seems like a possibility that we should account for. Fix the exit check to ensure that if remap is >1, we will also exit, even if m_head is not NULL. Submitted by: Jacob Keller <jacob.e.keller@intel.com> Reviewed by: shurd@, gallatin@ MFC after: 1 week Sponsored by: Intel Corporation Differential Revision: https://reviews.freebsd.org/D19468 |
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| etc | ||
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| include | ||
| kerberos5 | ||
| lib | ||
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| release | ||
| rescue | ||
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| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
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| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
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| README | ||
| README.md | ||
| UPDATING | ||
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