On Thu, 12 Dec 2019 19:07:46 +0200 John Koepi <john.koepi@xxxxxxxxx> wrote: > > $ cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_submit/format > > name: sys_enter_io_submit > > ID: 897 > > format: > > field:unsigned short common_type; offset:0; size:2; signed:0; > > ... > > field:struct iocb __attribute__((user)) * __attribute__((user)) * iocbpp; offset:32; size:8; signed:0; > > ... > > Having __attribute__ leaked into syscalls format, it makes its > impossible for the traceevent lib from the kernel/tools/lib to > parse such fields, like in the example above. > > This in its turn makes it impossible to use tracing for those syscalls: > > > $ sudo perf record -e syscalls:sys_enter_io_submit -aR > > libtraceevent: No such file or directory > > Error: expected type 4 but read 5 > > Thus, tracing does not work for some syscalls in Arch Linux kernels. > And I suppose for all kernels that built with structleak plugin support. > > Reproduce: https://github.com/sitano/traceevent_attribute > > My question: > > Is it a bug that the traceevent lib does not support parsing __attribute__ > in syscalls formats? > > or it is a bug of the SYSCALL_DEFINEx macroses / build system that > they do allow C attributes to leak? > > maybe this is already fixed in the latest kernel? or maybe I am missing > something? Thanks for the report. This looks like something we can have libtraceveent handle, no need to change the kernel. Could you file a bug report? https://bugzilla.kernel.org/buglist.cgi?component=Trace-cmd%2FKernelshark&product=Tools&resolution=--- -- Steve
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