Since commit d19ad0775dcd ("ftrace: Have the callbacks receive a struct
ftrace_regs instead of pt_regs") the callback function receives a
ftrace_regs argument, and not a pt_regs anymore. Change the
documentation to reflect the reality.Signed-off-by: Marcos Paulo de Souza <[email protected]> --- Documentation/trace/ftrace-uses.rst | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/Documentation/trace/ftrace-uses.rst b/Documentation/trace/ftrace-uses.rst index e198854ace79..05620714d99f 100644 --- a/Documentation/trace/ftrace-uses.rst +++ b/Documentation/trace/ftrace-uses.rst @@ -87,7 +87,7 @@ The prototype of the callback function is as follows (as of v4.14): .. code-block:: c void callback_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs); + struct ftrace_ops *op, struct ftrace_regs *regs); @ip This is the instruction pointer of the function that is being traced. @@ -104,7 +104,7 @@ The prototype of the callback function is as follows (as of v4.14): @regs If the FTRACE_OPS_FL_SAVE_REGS or FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED flags are set in the ftrace_ops structure, then this will be pointing - to the pt_regs structure like it would be if an breakpoint was placed + to the ftrace_regs structure like it would be if an breakpoint was placed at the start of the function where ftrace was tracing. Otherwise it either contains garbage, or NULL. @@ -169,10 +169,10 @@ Some of the flags are used for internal infrastructure of ftrace, but the ones that users should be aware of are the following: FTRACE_OPS_FL_SAVE_REGS - If the callback requires reading or modifying the pt_regs + If the callback requires reading or modifying the ftrace_regs passed to the callback, then it must set this flag. Registering a ftrace_ops with this flag set on an architecture that does not - support passing of pt_regs to the callback will fail. + support passing of ftrace_regs to the callback will fail. FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED Similar to SAVE_REGS but the registering of a @@ -199,7 +199,7 @@ FTRACE_OPS_FL_IPMODIFY Requires FTRACE_OPS_FL_SAVE_REGS set. If the callback is to "hijack" the traced function (have another function called instead of the traced function), it requires setting this flag. This is what live - kernel patches uses. Without this flag the pt_regs->ip can not be + kernel patches uses. Without this flag the ftrace_regs->ip can not be modified. Note, only one ftrace_ops with FTRACE_OPS_FL_IPMODIFY set may be --- base-commit: 256abd8e550ce977b728be79a74e1729438b4948 change-id: 20240727-ftrace-docs-cb-args-963ef5676a81 Best regards, -- Marcos Paulo de Souza <[email protected]>
