Messages in this thread | | | Date | Tue, 1 Aug 2023 11:32:40 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v4 3/9] bpf/btf: Add a function to search a member of a struct/union |
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On Tue, 1 Aug 2023 11:20:36 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> The solution was to come up with ftrace_regs, which just means it has all > the registers to extract the arguments of a function and nothing more. Most
This isn't 100% true. The ftrace_regs may hold a fully filled pt_regs. As the FTRACE_WITH_REGS callbacks still get passed a ftrace_regs pointer. They will do:
void callback(..., struct ftrace_regs *fregs) { struct pt_regs *regs = ftrace_get_regs(fregs);
Where ftrace_get_regs() will return the pt_regs only if it is fully filled. If it is not, then it returns NULL. This was what the x86 maintainers agreed with.
-- Steve
> implementations just have a partially filled pt_regs within it, but an API > needs to be used to get to the argument values.
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