Re: [PATCH 5.10.y] tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Nov 27, 2023 at 12:21:50PM +0100, Francis Laniel wrote:
> Hi!
> 
> 
> Le vendredi 24 novembre 2023, 17:16:43 CET Greg KH a écrit :
> > On Fri, Nov 24, 2023 at 02:09:35PM +0100, Francis Laniel wrote:
> > > When a kprobe is attached to a function that's name is not unique (is
> > > static and shares the name with other functions in the kernel), the
> > > kprobe is attached to the first function it finds. This is a bug as the
> > > function that it is attaching to is not necessarily the one that the
> > > user wants to attach to.
> > > 
> > > Instead of blindly picking a function to attach to what is ambiguous,
> > > error with EADDRNOTAVAIL to let the user know that this function is not
> > > unique, and that the user must use another unique function with an
> > > address offset to get to the function they want to attach to.
> > > 
> > > Link:
> > > https://lore.kernel.org/all/20231020104250.9537-2-flaniel@linux.microsoft
> > > .com/
> > > 
> > > Cc: stable@vger.kernel.org
> > > Fixes: 413d37d1eb69 ("tracing: Add kprobe-based event tracer")
> > > Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
> > > Signed-off-by: Francis Laniel <flaniel@linux.microsoft.com>
> > > Link:
> > > https://lore.kernel.org/lkml/20230819101105.b0c104ae4494a7d1f2eea742@kern
> > > el.org/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > > (cherry picked from commit b022f0c7e404887a7c5229788fc99eff9f9a80d5)
> > > ---
> > > 
> > >  kernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++
> > >  kernel/trace/trace_probe.h  |  1 +
> > >  2 files changed, 75 insertions(+)
> > 
> > We also need a version for 5.15.y before we can take this, you do not
> > want to upgrade and have a regression.
> 
> I sent the corresponding 5.15.y patch some times ago here:
> https://lore.kernel.org/stable/20231023122217.302483-2-flaniel@linux.microsoft.com/
> 
> If this is easier for you, I can resend it without problems.

Please resend, that doesn't seem to be in my queue anywhere :(