When tracing a function with IPMODIFY ftrace_ops (livepatch), the bpf trampoline must follow the instruction pointer saved on stack. This needs extra handling for bpf trampolines with BPF_TRAMP_F_CALL_ORIG flag. Implement bpf_tramp_ftrace_ops_func and use it for the ftrace_ops used by BPF trampoline. This enables tracing functions with livepatch. This also requires moving bpf trampoline to *_ftrace_direct_mult APIs. Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/ Link: https://lore.kernel.org/bpf/20220720002126.803253-5-song@kernel.org
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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