Messages in this thread | | | Subject | Re: [PATCH 1/1] cfi: Use rcu_read_{un}lock_sched_notrace | From | Elliot Berman <> | Date | Thu, 12 Aug 2021 20:33:27 -0700 |
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Hi Kees,
On 8/11/2021 1:10 PM, Kees Cook wrote: > On Wed, Aug 11, 2021 at 08:59:14AM -0700, Elliot Berman wrote: >> If rcu_read_lock_sched tracing is enabled, the tracing subsystem can >> perform a jump which needs to be checked by CFI. For example, stm_ftrace >> source is enabled as a module and hooks into enabled ftrace events. This >> can cause an recursive loop where find_shadow_check_fn -> >> rcu_read_lock_sched -> (call to stm_ftrace generates cfi slowpath) -> >> find_shadow_check_fn -> rcu_read_lock_sched -> ... >> >> To avoid the recursion, either the ftrace codes needs to be marked with >> __no_cfi or CFI should not trace. Use the "_notrace" in CFI to avoid >> tracing so that CFI can guard ftrace. >> >> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> > > Thanks for this patch! While applying it I noticed that the DKIM > signature failed. This is actually even visible in the lore archive: > https://lore.kernel.org/lkml/20210811155914.19550-1-quic_eberman@quicinc.com/raw > (DKIM_INVALID) > > $ b4 am -tls https://lore.kernel.org/lkml/20210811155914.19550-1-quic_eberman@quicinc.com/ > Grabbing thread from lore.kernel.org/lkml/20210811155914.19550-1-quic_eberman%40quicinc.com/t.mbox.gz > Analyzing 2 messages in the thread > Checking attestation on all messages, may take a moment... > --- > ✗ [PATCH 1/1] cfi: Use rcu_read_{un}lock_sched_notrace > + Reviewed-by: Sami Tolvanen <samitolvanen@google.com> (✓ DKIM/google.com) > + Signed-off-by: Kees Cook <keescook@chromium.org> > + Link: https://lore.kernel.org/r/20210811155914.19550-1-quic_eberman@quicinc.com > --- > ✗ BADSIG: DKIM/quicinc.com > > > > Do you know if qualcomm is mangling outbound emails? (i.e. was the > trailing body suffix added after calculating the DKIM signature?)
It's possible. I will check with our IT department. You may be aware that Qualcomm was previously using @codeaurora.org mails and this is my first time using new mail address.
I tried sending a patch to my personal Gmail address and it looked to be happy with the DKIM signature provided.
Please let me know if I should resend the patch a different way for you to be able to pull it in.
> > Thanks! > > -Kees >
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