----- On May 31, 2019, at 5:04 PM, Gabriel-Andrew Pollo-Guilbert gabriel.pollo-guilb...@efficios.com wrote:
> In case of a per-UID buffer, events following a change of user ID should be > forwarded to buffers of the new UID. In order to do so, we add a wrapper > around > setuid(3), setreuid(3) and setresuid(2) that unregister and re-register the > application from the session daemon. > > While there exist some other functions such as seteuid(3) or setfsuid(2), we > don't need to add a wrapper for them since they do not edit the real user ID, > the actual ID returned by getuid(3) and used for creating the buffers. [...] > > diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt > index 5c9c9f5d..b252c11d 100644 > --- a/doc/man/lttng-ust.3.txt > +++ b/doc/man/lttng-ust.3.txt > @@ -744,6 +744,17 @@ library before you start the application. Typical use > cases > include > daemons closing all file descriptors after man:fork(2), and buggy > applications doing ``double-closes''. > > +Using LTTng-UST with applications that change user > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > +If your application is traced using per-UID buffers and changes user ID using > +man:setuid(2), the library `liblttng-ust-setuid.so` needs to be preloaded > +before starting the application with the `LD_PRELOAD` environment variable > (see > +man:ld.so(8)). This way, events generated after the UID change will be > fowarded fowarded -> forwarded The rest looks good, please add this tag to your next round for this patch: Acked-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> I'll wait until feedback is provided on the testing side (lttng-tools) and the work on that front is finalized before merging this patch into lttng-ust. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev