On 13/07/2016 1:14 AM, Mark Johnston wrote: > On Thu, Jul 07, 2016 at 12:51:52PM +0800, Julian Elischer wrote: >> I'm specifically interested in the case of kernel modules that >> instantiate new syscalls. >> >> How much support do we have for that? In the one example in our >> sources of a kld with a syscall (kgssapi.ko) dtrace seems to find >> regular function entrypoints but not the syscall. >> >> >> root_at_porridge:/usr/src # dtrace -n ":kgssapi::entry {}" >> dtrace: description ':kgssapi::entry ' matched 138 probes >> ^C >> >> root_at_porridge:/usr/src # dtrace -n "syscall:kgssapi::entry {}" >> dtrace: invalid probe specifier syscall:kgssapi::entry {}: probe >> description syscall:kgssapi::entry does not match any probes >> root_at_porridge:/usr/src # >> >> >> Do we have plans to support dynamic syscall support? > I don't know of any plans to add support. It would be fairly > straightforward to dynamically create syscall probes using a hook or > eventhandler in syscall_register(), but getting argument type info would > be more difficult. Right now, argument types are specified by code > generated by makesyscalls.sh using the types in syscalls.master. I'm not > sure how one might obtain these types for dynamically-registered > syscalls. > yes that is the tricky part for sure. for now function calls is probably enough because every syscall ends up calling a function somewhere :-)Received on Tue Jul 12 2016 - 22:24:55 UTC
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