-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Thanks David for your reply, next time (i.e. now) i will check the bug tracker first!
I noticed that passing a NULL (string) pointer to a tracepoint()'s argument is not handled properly (i.e not supposed to happen). It causes the program to SIGSEV because of strlen( NULL ) in ust-tracepoint-event.h:271 . I tried some trivial patching like - - __event_len += __dynamic_len[__dynamic_len_idx++] = strlen(_src) + 1; + __event_len += __dynamic_len[__dynamic_len_idx++] = (_src == NULL ? 1 : strlen(_src) + 1); but then lib_ring_buffer_do_copy causes a SIGSEV because of memcpy( .., NULL, .. ), so i assume a NULL pointer is not expected at all. Is there any particular reason to not handle a NULL pointer? That could save the developer a ternary statement on theorically every string argument given to tracepoint() and, most importantly, the application from crash because of LTTng. Thanks, Ettore On 10/5/2012 4:46 PM, David Goulet wrote: > Hey, > > We have right now an opened bug about this exact issue. We will soon fix this > and, as you said, > help considerably the user experience with subbuffer size :) > > Thanks for the report! > > Cheers David > > On 09/05/12 08:51 PM, Ettore Del Negro wrote: >> Hello, i have a simple question which may lead to a small user experience >> improvement: > >>> lttng create tsession >> Session tsession created. Traces will be written in >> .../lttng-traces/tsession-20120510-015819 >>> lttng enable-channel tchan -u -s tsession --subbuf-size=1024 >> UST channel tchan enabled for session tsession > >> a message stating that buffer size is set to a value different than default >> would be nice > >>> lttng enable-channel tchan -u -s tsession --subbuf-size=1022 >> UST channel tchan enabled for session tsession > >> What happens? Is it set to a value not power of 2? Is it set to the default >> value? (i guess >> the latter). The help says: --subbuf-size SIZE Subbuffer size in bytes >> (default: 4096, >> kernel default: 262144) Needs to be a power of 2 for kernel and ust tracers > >> Thanks, Ettore > >> _______________________________________________ lttng-dev mailing list >> [email protected] >> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJPrCZaAAoJEBroCbr/OjsadOkP/3D69W4daouFhhsWFWHUZdfz aWa1jWK1oTqSzI1aU8+wZA+XD0eV/qMiAVQWMguI9+/C9uI0qndWasaF6wZMH7h9 jFhoKzUssqMnSz6iIXQCYhdMm9v5z0NU+kKw3xnmlX4Wfxzn9wjzN1F62B/LwBiw slESKP72pRKMuigcUyUod1+C3Ddhl2odO/I091zHT3dYxA3qhLZL2sPKkR3I12YJ cP8+p4bii7rowAhUSt57dzU0V1k+yZUvvEvqvvuVFrjlf171kmy05f//Xm6npFxU Br4y/WFLg0Lf41uXRGMf0FFoXiWHPxgXpDc4vEYIjL3iHKn+JhYBxlZkw0YGPYbI G9kBw7TQogZrAxMkKL6djzuTTP/Ic/7GRqhiWP2kJrqdLI/zjobZLCy5YUOLYeZp 6iGUoZR2qMhCxpOAQuU226WuWaQmhwr3oFq5Eo602SQB58lBFqTFG+O8+rwZ+iQQ sc9MJb6Ov6WeQBzstbnQHnj1MVfbOcyz9bsztuyiMzbZ+JGk1OeDsl5sGlwzf5GP KLIukByYLvLH+7VIN2qIvIJyWQ5LobCkHjLVdMuCVgVGvemEYbt3bMaup+8acyjM +9FKw3HQER5RH7GazQylxGd9C7iV29bCWBAj2wFmh98YgWJ6V7uA73f3etpmAD0x 8ASlJci0JJVDPy8RN0hP =ds7n -----END PGP SIGNATURE----- _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
