Date: Sat, 28 Feb 2015 14:57:57 +0000 (UTC) From: Garrett Cooper <ngie@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r279393 - head/sys/dev/ixgbe Message-ID: <201502281457.t1SEvv4Y009907@svn.freebsd.org>
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Author: ngie Date: Sat Feb 28 14:57:57 2015 New Revision: 279393 URL: https://svnweb.freebsd.org/changeset/base/279393 Log: Pad RX copy alignment calculation to avoid illegal memory accesses The optimization made in r239940 is valid for struct mbuf's current structure and size in FreeBSD, but hardcodes assumptions about sizes of struct mbuf, which are unfortunately broken if additional data is added to the beginning of struct mbuf X-MFC note (discussed with rwatson): This change requires the MPKTHSIZE definition, which is only available after head@r277203 and will not be MFCed as it breaks mbuf(9) KPI. A direct commit to stable/10 and merges to other branches to add the necessary definitions to work with the code as-is will be done to facilitate this MFC PR: 194314 MFC after: 2 weeks Approved/Reviewed by: erj, jfv Sponsored by: EMC / Isilon Storage Division Modified: head/sys/dev/ixgbe/ixgbe.h Modified: head/sys/dev/ixgbe/ixgbe.h ============================================================================== --- head/sys/dev/ixgbe/ixgbe.h Sat Feb 28 12:02:32 2015 (r279392) +++ head/sys/dev/ixgbe/ixgbe.h Sat Feb 28 14:57:57 2015 (r279393) @@ -162,8 +162,9 @@ * modern Intel CPUs, results in 40 bytes wasted and a significant drop * in observed efficiency of the optimization, 97.9% -> 81.8%. */ -#define IXGBE_RX_COPY_LEN 160 -#define IXGBE_RX_COPY_ALIGN (MHLEN - IXGBE_RX_COPY_LEN) +#define IXGBE_RX_COPY_HDR_PADDED ((((MPKTHSIZE - 1) / 32) + 1) * 32) +#define IXGBE_RX_COPY_LEN (MSIZE - IXGBE_RX_COPY_HDR_PADDED) +#define IXGBE_RX_COPY_ALIGN (IXGBE_RX_COPY_HDR_PADDED - MPKTHSIZE) /* Keep older OS drivers building... */ #if !defined(SYSCTL_ADD_UQUAD)
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