Messages in this thread | | | Subject | Re: [PATCH] add param that allows bootline control of hardened usercopy | From | Paolo Abeni <> | Date | Tue, 26 Jun 2018 19:14:47 +0200 |
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[hopefully fixed the 'mm' recipient]
On Tue, 2018-06-26 at 09:54 -0700, Kees Cook wrote: > On Tue, Jun 26, 2018 at 2:48 AM, Paolo Abeni <pabeni@redhat.com> wrote: > > With CONFIG_HARDENED_USERCOPY=y, perf shows ~6% of CPU time spent > > cumulatively in __check_object_size (~4%) and __virt_addr_valid (~2%). > > Are you able to see which network functions are making the > __check_object_size() calls?
The call-chain is:
__GI___libc_recvfrom entry_SYSCALL_64_after_hwframe do_syscall_64 __x64_sys_recvfrom __sys_recvfrom inet_recvmsg udp_recvmsg __check_object_size
udp_recvmsg() actually calls copy_to_iter() (inlined) and the latters calls check_copy_size() (again, inlined).
Cheers,
Paolo
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