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Mark Rutland
fbf6c73c5b
Architectures may need to perform special initialization of ftrace callsites, and today they do so by special-casing ftrace_make_nop() when the expected branch address is MCOUNT_ADDR. In some cases (e.g. for patchable-function-entry), we don't have an mcount-like symbol and don't want a synthetic MCOUNT_ADDR, but we may need to perform some initialization of callsites. To make it possible to separate initialization from runtime modification, and to handle cases without an mcount-like symbol, this patch adds an optional ftrace_init_nop() function that architectures can implement, which does not pass a branch address. Where an architecture does not provide ftrace_init_nop(), we will fall back to the existing behaviour of calling ftrace_make_nop() with MCOUNT_ADDR. At the same time, ftrace_code_disable() is renamed to ftrace_nop_initialize() to make it clearer that it is intended to intialize a callsite into a disabled state, and is not for disabling a callsite that has been runtime enabled. The kerneldoc description of rec arguments is updated to cover non-mcount callsites. Signed-off-by: Mark Rutland <[email protected]> Reviewed-by: Amit Daniel Kachhap <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Reviewed-by: Torsten Duwe <[email protected]> Tested-by: Amit Daniel Kachhap <[email protected]> Tested-by: Sven Schnelle <[email protected]> Tested-by: Torsten Duwe <[email protected]> Cc: Ingo Molnar <[email protected]>