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MFC r340009:

Description

MFC r340009:

carpstats are the last virtualised variable in the file and end up at the
end of the vnet_set.  The generated code uses an absolute relocation at
one byte beyond the end of the carpstats array.  This means the relocation
for the vnet does not happen for carpstats initialisation and as a result
the kernel panics on module load.

This problem has only been observed with carp and only on i386.
We considered various possible solutions including using linker scripts
to add padding to all kernel modules for pcpu and vnet sections.

While the symbols (by chance) stay in the order of appearance in the file
adding an unused non-file-local variable at the end of the file will extend
the size of set_vnet and hence make the absolute relocation for carpstats
work (think of this as a single-module set_vnet padding).

This is a (tmporary) hack.  It is the least intrusive one as we need a
timely solution for the upcoming release.  We will revisit the problem in
HEAD.  For a lot more information and the possible alternate solutions
please see the PR and the references therein.

PR: 230857
Approved by: re (kib)

Details

Provenance
bzAuthored on
Parents
rS340108: Add aditional counter descriptions to AMD 0x17
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