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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-11 09:09:02 +0100 |
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| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-11 09:09:02 +0100 |
| commit | 9481caf39bf55a862067007ffc53621b4305a387 (patch) | |
| tree | ed7d011557a7edd33839d4e0e2eeb57e901afcbe /Documentation/bpf/bpf_design_QA.rst | |
| parent | 344c0152d878922365464b7140c74c2a5e073d99 (diff) | |
| parent | d13937116f1e82bf508a6325111b322c30c85eb9 (diff) | |
| download | linux-9481caf39bf55a862067007ffc53621b4305a387.tar.gz | |
Merge 5.0-rc6 into driver-core-next
We need the debugfs fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/bpf/bpf_design_QA.rst')
| -rw-r--r-- | Documentation/bpf/bpf_design_QA.rst | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst index 6780a6d81745..7cc9e368c1e9 100644 --- a/Documentation/bpf/bpf_design_QA.rst +++ b/Documentation/bpf/bpf_design_QA.rst @@ -157,12 +157,11 @@ Q: Does BPF have a stable ABI? ------------------------------ A: YES. BPF instructions, arguments to BPF programs, set of helper functions and their arguments, recognized return codes are all part -of ABI. However when tracing programs are using bpf_probe_read() helper -to walk kernel internal datastructures and compile with kernel -internal headers these accesses can and will break with newer -kernels. The union bpf_attr -> kern_version is checked at load time -to prevent accidentally loading kprobe-based bpf programs written -for a different kernel. Networking programs don't do kern_version check. +of ABI. However there is one specific exception to tracing programs +which are using helpers like bpf_probe_read() to walk kernel internal +data structures and compile with kernel internal headers. Both of these +kernel internals are subject to change and can break with newer kernels +such that the program needs to be adapted accordingly. Q: How much stack space a BPF program uses? ------------------------------------------- |