arm64/ftrace,bpf: Fix partial regs after bpf_prog_run #6295
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hi, Mahe reported issue with bpf_override_return helper not working when executed from kprobe.multi bpf program on arm. The problem seems to be that on arm we use alternate storage for pt_regs object that is passed to bpf_prog_run and if any register is changed (which is the case of bpf_override_return) it's not propagated back to actual pt_regs object. The change below seems to fix the issue, but I have no idea if that's proper fix for arm, thoughts? I'm attaching selftest to actually test bpf_override_return helper functionality, because currently we only test that we are able to attach a program with it, but not the override itself. thanks, jirka
We do not actualy test the bpf_override_return helper functionality itself at the moment, only the bpf program being able to attach it. Adding test that override prctl syscall return value on top of kprobe and kprobe.multi. Signed-off-by: Jiri Olsa <[email protected]>
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Upstream branch: 4cb4897 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=1019877 expired. Closing PR. |
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Pull request for series with
subject: arm64/ftrace,bpf: Fix partial regs after bpf_prog_run
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=1019877