On Sat, Oct 26, 2024 at 01:35:30PM +0900, Masami Hiramatsu (Google) wrote: > From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > > Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not > available, it passes a NULL instead. User callback function can access > some registers (including return address) via this ftrace_regs. > > Note that the ftrace_regs can be NULL when the arch does NOT define: > HAVE_DYNAMIC_FTRACE_WITH_ARGS or HAVE_DYNAMIC_FTRACE_WITH_REGS. > More specifically, if HAVE_DYNAMIC_FTRACE_WITH_REGS is defined but > not the HAVE_DYNAMIC_FTRACE_WITH_ARGS, and the ftrace ops used to > register the function callback does not set FTRACE_OPS_FL_SAVE_REGS. > In this case, ftrace_regs can be NULL in user callback. > > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Huacai Chen <chenhuacai@xxxxxxxxxx> > Cc: WANG Xuerui <kernel@xxxxxxxxxx> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Cc: Nicholas Piggin <npiggin@xxxxxxxxx> > Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> > Cc: Naveen N Rao <naveen@xxxxxxxxxx> > Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx> > Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> > Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> > > --- > Changes in v18: > - Remove unclear comment about `regs->fp` access on arm64. > Changes in v16: > - Add a note when the ftrace_regs can be NULL. > - Update against for the latest kernel. > Changes in v11: > - Update for the latest for-next branch. > Changes in v8: > - Just pass ftrace_regs to the handler instead of adding a new > entryregfunc. > - Update riscv ftrace_graph_func(). > Changes in v3: > - Update for new multiple fgraph. > --- > arch/arm64/kernel/ftrace.c | 15 ++++++++- For the arm64 bits: Acked-by: Will Deacon <will@xxxxxxxxxx> Will
