powerpc/bpf: Handle large branch ranges with BPF_EXIT

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In some scenarios, it is possible that the program epilogue is outside
the branch range for a BPF_EXIT instruction. Instead of rejecting such
programs, emit epilogue as an alternate exit point from the program.
Track the location of the same so that subsequent exits can take either
of the two paths.

Reported-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/33aa2e92645a92712be23b18035a2c6dcb92ff8d.1644834730.git.naveen.n.rao@linux.vnet.ibm.com

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Naveen N. Rao 2022-02-14 16:11:37 +05:30 • committed by Michael Ellerman

parent bafb5898de

commit 0ffdbce6f4

4 changed files with 33 additions and 5 deletions

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2

arch/powerpc/net/bpf_jit.h

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arch/powerpc/net/bpf_jit_comp.c

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arch/powerpc/net/bpf_jit_comp32.c

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arch/powerpc/net/bpf_jit_comp64.c

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