Re: [PATCH] tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS

[Steven Rostedt]

On Fri,  6 Aug 2021 21:50:27 +0200
Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx> wrote:

> Commit 2860cd8a2353 ("livepatch: Use the default ftrace_ops instead of
> REGS when ARGS is available") intends to enable config LIVEPATCH when
> ftrace with ARGS is available. However, the chain of configs to enable
> LIVEPATCH is incomplete, as HAVE_DYNAMIC_FTRACE_WITH_ARGS is available,
> but the definition of DYNAMIC_FTRACE_WITH_ARGS, combining DYNAMIC_FTRACE
> and HAVE_DYNAMIC_FTRACE_WITH_ARGS, needed to enable LIVEPATCH, is missing
> in the commit.
> 
> Fortunately, ./scripts/checkkconfigsymbols.py detects this and warns:
> 
> DYNAMIC_FTRACE_WITH_ARGS
> Referencing files: kernel/livepatch/Kconfig
> 
> So, define the config DYNAMIC_FTRACE_WITH_ARGS analogously to the already
> existing similar configs, DYNAMIC_FTRACE_WITH_REGS and
> DYNAMIC_FTRACE_WITH_DIRECT_CALLS, in ./kernel/trace/Kconfig to connect the
> chain of configs.
> 
> Fixes: 2860cd8a2353 ("livepatch: Use the default ftrace_ops instead of REGS when ARGS is available")
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x

FYI, we don't add # 5.10.x anymore. The Fixes tag above is what
determines where it gets backported to.

> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
> ---
> 
> Steven, thanks for the quick response; please pick this quick config fix.

I placed it in my queue to go into the 5.14-rc cycle.

Since this affects live kernel patching, can I get a Tested-by from one
of the live kernel patching  folks?

Thanks!

-- Steve