On Tue, Aug 7, 2018 at 1:00 PM Krishna Chaitanya <[email protected]> wrote: > > On Mon, Aug 6, 2018 at 11:15 PM Y Song <[email protected]> wrote: > > > > On Mon, Aug 6, 2018 at 2:44 AM, Krishna Chaitanya > > <[email protected]> wrote: > > > On Mon, Aug 6, 2018 at 3:12 PM Krishna Chaitanya > > > <[email protected]> wrote: > > >> > > >> Hi, > > >> > > >> If we want to use BPF for memory leak for driver modules, we can only > > >> print outstanding allocations which could potentially be freed at a > > >> later time. > > >> > > >> Is there a simple way we could pre-load BPF (before driver insertion) > > >> and check for the outstanding entries after the driver removal, which > > >> are confirmed leaks? > > >> > > >> This is useful to debug memory allocations at insmod/rmmod. > > >> > > >> Currently, without insmod, BPF compilation fails as tracepoints are > > >> not installed. And also if tracing is active, rmmod fails with > > >> "resource in use". > > > > Which tracepoint you tried to attach? For kernel memory, a few kmem > > tracepoints are attached in memleak. If you want to attach a tracepoint > > only defined by the module, yes, you may have to wait until the module > > is inserted into the kernel. > > > I have defined a new tracepoint in my module and tried to attach to it. > I am using the memleak.py script as a reference and extended it to check > for leaks in my modules (using tracepoints defined by the module). > > Ideally, I would like to run BPF and do rmmod, and check is there are > still outstanding entries and print out the call stack of the leaked > allocation. Only solutions i can think of is
a) in insmod do the basic stuff, but block any memory allocs till BPF is loaded and in rmmod free the allocs, but dont exit yet, then stop the BPF and exit. b) move all memory alloc/free to interface down/up (my module is a wlan network driver). -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#1438): https://lists.iovisor.org/g/iovisor-dev/message/1438 Mute This Topic: https://lists.iovisor.org/mt/24207437/21656 Group Owner: [email protected] Unsubscribe: https://lists.iovisor.org/g/iovisor-dev/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
