USDT support [1] requires architecture-specific handling for translating from argument strings describing each probe argument to appropriate values that can be made available to the BPF program. Determining value size, whether it refers to a dereference (and if there is an offset from the register value), a register value or a constant all has to be parsed slightly differently for different architectures. However a common representation is created for use within BPF programs (via usdt.bpf.h), and patch 1 abstracts out the initialization of struct usdt_arg_spec associated with the argument, rather than repeating those steps for each architecture. Patch 2 then adds aarch64-specific argument parsing. [1] https://lore.kernel.org/bpf/20220404234202.331384-1-andrii@xxxxxxxxxx/ Alan Maguire (2): libbpf: usdt: factor out common USDT arg handling libbpf: usdt aarch64 arg parsing support tools/lib/bpf/usdt.c | 134 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 87 insertions(+), 47 deletions(-) -- 1.8.3.1
