From: Eva Kurchatova Date: Wed, 3 Jun 2026 15:31:42 +0000 (+0300) Subject: tracing: Fix CFI violation in probestub being called by tprobes X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=0652a3daa78723f955b1ebeb621665ce72bec53e;p=thirdparty%2Fkernel%2Flinux.git tracing: Fix CFI violation in probestub being called by tprobes The probestub is a function to allow tprobes to hook to a tracepoint to gain access to its parameters. The function itself is only referenced by the tracepoint structure which lives in the __tracepoint section. objtool explicitly ignores that section and when processing functions in the kernel, if it detects one that has no references it will seal it to have its ENDBR stripped on boot up. This means when a tprobe is attached to the sched_wakeup tracepoint, when it is triggered it will call __probestub_sched_wakeup and due to the missing ENDBR on a CFI-enabled machine it will take a #CP exception. Fix this by adding CFI_NOSEAL annotation to probestub declaration. Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Link: https://patch.msgid.link/20260603153147.573589-1-eva.kurchatova@virtuozzo.com Fixes: d5173f753750 ("objtool: Exclude __tracepoints data from ENDBR checks") Signed-off-by: Eva Kurchatova [ Updated change log ] Signed-off-by: Steven Rostedt --- diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 763eea4d80d8..2d2b9f8cdda4 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -20,6 +20,7 @@ #include #include #include +#include struct module; struct tracepoint; @@ -389,6 +390,13 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) void __probestub_##_name(void *__data, proto) \ { \ } \ + /* \ + * Annotate the probestub 'CFI_NOSEAL' to stop objtool from \ + * requesting the kernel remove the ENDBR, because the only \ + * references to the function are in the __tracepoint section, \ + * that objtool doesn't scan. \ + */ \ + CFI_NOSEAL(__probestub_##_name); \ DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \ DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))