The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ab8384442ee512fc0fc72deeb036110843d0e7ff Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" rostedt@goodmis.org Date: Sat, 20 Aug 2022 09:43:21 -0400 Subject: [PATCH] tracing/probes: Have kprobes and uprobes use $COMM too
Both $comm and $COMM can be used to get current->comm in eprobes and the filtering and histogram logic. Make kprobes and uprobes consistent in this regard and allow both $comm and $COMM as well. Currently kprobes and uprobes only handle $comm, which is inconsistent with the other utilities, and can be confusing to users.
Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.o...
Cc: stable@vger.kernel.org Cc: Ingo Molnar mingo@kernel.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Tzvetomir Stoyanov tz.stoyanov@gmail.com Cc: Tom Zanussi zanussi@kernel.org Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Suggested-by: Masami Hiramatsu (Google) mhiramat@kernel.org Acked-by: Masami Hiramatsu (Google) mhiramat@kernel.org Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 4daabbb8b772..36dff277de46 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -314,7 +314,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, } } else goto inval_var; - } else if (strcmp(arg, "comm") == 0) { + } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { code->op = FETCH_OP_COMM; #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API } else if (((flags & TPARG_FL_MASK) == @@ -625,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, * we can find those by strcmp. But ignore for eprobes. */ if (!(flags & TPARG_FL_TPOINT) && - (strcmp(arg, "$comm") == 0 || strncmp(arg, "\"", 2) == 0)) { + (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || + strncmp(arg, "\"", 2) == 0)) { /* The type of $comm must be "string", and not an array. */ if (parg->count || (t && strcmp(t, "string"))) goto out;