This is a note to let you know that I've just added the patch titled ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip records to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ftrace-add-more-checks-for-ftrace_fl_disabled-in-processing-ip-records.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 546fece4eae871f033925ccf0ff2b740725ae915 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> Date: Mon, 14 Nov 2016 16:31:49 -0500 Subject: ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip records From: Steven Rostedt (Red Hat) <rostedt@xxxxxxxxxxx> commit 546fece4eae871f033925ccf0ff2b740725ae915 upstream. When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov <ast@xxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/ftrace.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1856,6 +1856,10 @@ static int __ftrace_hash_update_ipmodify /* Update rec->flags */ do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + /* We need to update only differences of filter_hash */ in_old = !!ftrace_lookup_ip(old_hash, rec->ip); in_new = !!ftrace_lookup_ip(new_hash, rec->ip); @@ -1878,6 +1882,10 @@ rollback: /* Roll back what we did above */ do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + if (rec == end) goto err_out; @@ -2391,6 +2399,10 @@ void __weak ftrace_replace_code(int enab return; do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + failed = __ftrace_replace_code(rec, enable); if (failed) { ftrace_bug(failed, rec); @@ -3592,6 +3604,10 @@ match_records(struct ftrace_hash *hash, goto out_unlock; do_for_each_ftrace_rec(pg, rec) { + + if (rec->flags & FTRACE_FL_DISABLED) + continue; + if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { ret = enter_record(hash, rec, clear_filter); if (ret < 0) { @@ -3787,6 +3803,9 @@ register_ftrace_function_probe(char *glo do_for_each_ftrace_rec(pg, rec) { + if (rec->flags & FTRACE_FL_DISABLED) + continue; + if (!ftrace_match_record(rec, &func_g, NULL, 0)) continue; @@ -4679,6 +4698,9 @@ ftrace_set_func(unsigned long *array, in do_for_each_ftrace_rec(pg, rec) { + if (rec->flags & FTRACE_FL_DISABLED) + continue; + if (ftrace_match_record(rec, &func_g, NULL, 0)) { /* if it is in the array */ exists = false; Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are queue-4.8/disable-the-__builtin_return_address-warning-globally-after-all.patch queue-4.8/ftrace-add-more-checks-for-ftrace_fl_disabled-in-processing-ip-records.patch queue-4.8/ftrace-ignore-ftrace_fl_disabled-while-walking-dyn_ftrace-records.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html