Re: DTrace, kernel loader, unknown probes, enable on load?

[Bjoern A. Zeeb]

On Fri, 11 Feb 2022, Mark Johnston wrote:

It appears to be sufficient to simply move the kld_load hook to before
module registration, patch below.  In the case of a subsequent error,
the unload hook is called so DTrace gets a chance to clean up.  I can't
see any reasons not to move it, though there's at least one non-dtrace
consumer that needs a look.

HWPMC?

It does work for my case with -Z which will ease work massively.
I can't wait for the "morning" and more time then to look at things :-)

Please put me on subscribers should you put up a review.

Thanks a lot Mark and a happy weekend!
Bjoern

diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c
index 2e4c95f16c8f..55661b9f9aa2 100644
--- a/sys/kern/kern_linker.c
+++ b/sys/kern/kern_linker.c
@@ -452,6 +452,7 @@ linker_load_file(const char *filename, linker_file_t 
*result)
                if (error != ENOENT)
                        foundfile = 1;
                if (lf) {
+                       EVENTHANDLER_INVOKE(kld_load, lf);
                        error = linker_file_register_modules(lf);
                        if (error == EEXIST) {
                                linker_file_unload(lf, LINKER_UNLOAD_FORCE);
@@ -472,7 +473,6 @@ linker_load_file(const char *filename, linker_file_t 
*result)
                                return (ENOEXEC);
                        }
                        linker_file_enable_sysctls(lf);
-                       EVENTHANDLER_INVOKE(kld_load, lf);
                        *result = lf;
                        return (0);
                }

--
Bjoern A. Zeeb                                                     r15:7