From e6a750aab57e4dccefd6291dba4fee6b9b3bf9ee Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 14 Apr 2011 18:24:50 +0100 Subject: [PATCH] docs: Trace events must not expect pointer dereferencing Signed-off-by: Stefan Hajnoczi --- docs/tracing.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/docs/tracing.txt b/docs/tracing.txt index f15069c96b..905a0837db 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -69,6 +69,11 @@ Trace events should use types as follows: cannot include all user-defined struct declarations and it is therefore necessary to use void * for pointers to structs. + Pointers (including char *) cannot be dereferenced easily (or at all) in + some trace backends. If pointers are used, ensure they are meaningful by + themselves and do not assume the data they point to will be traced. Do + not pass in string arguments. + * For everything else, use primitive scalar types (char, int, long) with the appropriate signedness.