On 01/07/2015 07:07 AM, Pratyush Anand wrote: > Hi Will, > > > On Monday 05 January 2015 09:36 PM, William Cohen wrote: >> Hi All, >> >> Pratyush has been implementing uprobes support for aarch64 and has >> posted a set of patches >> (http://comments.gmane.org/gmane.linux.ports.arm.kernel/382237) for >> review. The really new Linux kernels requires a patch to the >> systemtap runtime because the f_dentry macro has been removed. With >> the patched systemtap I was able to run the systemtap testsuite and >> get some test results exercising the uprobes support: >> >> https://web.elastic.org/~dejazilla/viewsummary.php?summary=%3D%27%3C54A9E21C.2080504%40redhat.com%3E%27 >> >> There looked to be a localized fixes for plt support to eliminate the >> unsupported systemtap.base/list.exp plt-* tests. >> >> A number of the tests appear to fail because of userspace arguments >> cannot be found for sdt probes. >> >> The uprobe patches still need some refinement. On a number of >> systemtap "make installcheck" runs the kernel would get stuck spewing >> out: >> >> Unexpected kernel single-step exception at EL1 > > There are at least two functions of arm64/uprobe implementation uprobe_breakpoint_handler and uprobe_single_step_handler, where a kprobe insertion might be causing above issue. Currently I have qualified these functions with __kprobe, so that one can not insert a kprobe there. With this you should not be able to see the above message. > > However, I am still investigating if a kprobe insertion be allowed to these functions or any other function which is called directly from debug exception handler (do_debug_exception) > Hi Pratyush, Are there any other places that need to be protected from kprobe probing in the arm64 code? > Update code is here: > > https://github.com/pratyushanand/linux.git : ml_arm64_uprobe_devel_v2 > > ~Pratyush I will give the new kernel a try. -Will > >> >> However, things are looking better for user-space probing on arm64. >> >> -Will >> _______________________________________________ arm mailing list arm@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/arm
