tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
authorFrancis Laniel <flaniel@linux.microsoft.com>
Fri, 20 Oct 2023 10:42:49 +0000 (13:42 +0300)
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>
Fri, 20 Oct 2023 13:10:41 +0000 (22:10 +0900)
commitb022f0c7e404887a7c5229788fc99eff9f9a80d5
tree95530445f13532a18f8e7b9d5d95fb4ee05ccaca
parent700b2b439766e8aab8a7174991198497345bd411
tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols

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@kernel.org/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
kernel/trace/trace_kprobe.c
kernel/trace/trace_probe.h