Patchwork [2/2] docs: Trace events must not expect pointer dereferencing

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Submitter Stefan Hajnoczi
Date April 15, 2011, 11:03 a.m.
Message ID <1302865433-5309-2-git-send-email-stefanha@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/91352/
State New
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Comments

Stefan Hajnoczi - April 15, 2011, 11:03 a.m.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 docs/tracing.txt |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

Patch

diff --git a/docs/tracing.txt b/docs/tracing.txt
index f15069c..905a083 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.