search for: funnel

...ance. We can regain some of those benefits if we know that the set of possible branch targets is fixed (this is sometimes known to be the case when using whole-program devirtualization or CFI -- see https://clang.llvm.org/docs/LTOVisibility.html). In that case, we can construct a so-called “branch funnel” that selects one of the possible targets by performing a binary search on an address associated with the indirect branch (for virtual calls, this is the address of the vtable, and for indirect calls via a function pointer, this is the function pointer itself), eventually directly branching to the...

We have these transforms from funnel shift to a simpler shift op: // fshl(X, 0, C) -> shl X, C // fshl(X, undef, C) -> shl X, C // fshl(0, X, C) -> lshr X, (BW-C) // fshl(undef, X, C) -> lshr X, (BW-C) These were part of: https://reviews.llvm.org/D54778 In all cases, one operand must be 0 or undef...

Don't we need to distinguish funnel shift from the more specific rotate? I'm not seeing how rotate (a single input op shifted by some amount) gets into trouble like funnel shift (two variables concatenated and shifted by some amount). Eg, if in pseudo IR we have: %funnel_shift = fshl %x, %y, %sh ; this is problematic because eith...

Wouldn't a branch funnel open the door to a type 1 attack? E.g. if the code looks like this, then a branch funnel basically turns into a standard type 1 pattern AFAICT: struct Base { virtual int f(long) = 0; }; struct A : Base { int f(long x) override { return 0; }; }; struct B : Base { int f(lo...

If I got poison propagation right, it's probably only by luck! Hopefully, the funnel shift bug is fixed here: https://reviews.llvm.org/rL354905 Nuno, IIUC this means that you do *not* need to change the funnel shift semantics in Alive. So I think that means we're still on track to go with John's suggestion that only select and phi can block poison? (I don't know of an...

Hi, Sean Silva via llvm-dev wrote: > Wouldn't a branch funnel open the door to a type 1 attack? Only if the code looks exactly as you wrote it. If I understand this correctly the problem with indirect branches is that the "gadget", the code leaking the data, could be *anywhere* in the binary, giving the attacker much more freedom. So restrictin...

There's a question about the behavior of funnel shift [1] + select and poison here that reminds me of previous discussions about select and poison [2]: https://github.com/AliveToolkit/alive2/pull/32#discussion_r257528880 Example: define i8 @fshl_zero_shift_guard(i8 %x, i8 %y, i8 %sh) { %c = icmp eq i8 %sh, 0 %f = fshl i8 %x, i8 %y, i8 %sh %s =...

...t from the bit-width of > the scalar type or vector element type. Or just negating, iff the shift amount is defined to be modulo and the machine is two's complement. I'm a bit worried that while modulo is the Obviously Right Thing for rotates, the situation is less clear for general funnel shifts. I looked over some of the ISAs I have docs at hand for: - x86 (32b/64b variants) has SHRD/SHLD, so both right and left variants. Count is modulo (mod 32 for 32b instruction variants, mod 64 for 64b instruction variants). As of BMI2, we also get RORX (non-flag-setting ROR) but no ROLX....

for the function funnelplot(), how do I include 95% confidence intervals for the effect estimate ( ie. / \ )? -- View this message in context: http://www.nabble.com/funnel-plots-tp24003106p24003106.html Sent from the R help mailing list archive at Nabble.com.

...le to perform PKCS11 certificate authentication, via pam_krb5.so (on Linux at least and likely something similar on other *NIX) which allows smartcard auth to a Kerberos (including AD) server, where a TGT can also be granted. How difficult would it be to add functionality to OpenSSH so that it can funnel PKCS11 certs from SSH client to server and on to PAM where it could be used by Kerberos/PKINIT? My thought is that this is at least part way there with the current PKCS11 support but I won't claim to be an expert regarding the internals of what would be needed. I would think that a number of...

On 2/25/2019 11:15 AM, John Regehr via llvm-dev wrote: > I'd just like to add that the general question here is "where does > poison stop propagating" and this question needs to be definitively > answered by this community. Does a call stop poison? Whatever the decision is may be contradicted after inlining, so what should such a call return? A superposition of poison

On 2/25/2019 12:28 PM, John Regehr via llvm-dev wrote: > Poison has to propagate through calls and loads/stores, or else > basically nothing works. Consider this: %v0 = call i32 @foo(poison) nounwind/readnone store i32 %v0, i32* %valid_address If we assume that poison propagates through calls, we could then optimize this to %v0 = poison store poison, i32* %valid_address If

On 2/25/2019 1:24 PM, John Regehr via llvm-dev wrote: > > This is a sound transformation only if foo() returns poison when it is > called with poison as an argument. Then how do you interpret "poison has to propagate through calls"? A typical analysis of a function will either see a call or the inlined body. If "call(poison)" cannot be assumed to be a poison, then

The R code below produces (after running for a few minutes on a decent computer) the plot shown at the following location: http://n2.nabble.com/Is-there-a-physical-and-quantitative-explanation-for-this-plot--td2542321.html I'm just taking the mean of a given set of random variables, where the set size is increased. There appears to be a quick convergence and then a pretty steady variance

...rnally) Functions metabin, metacont, metacor, metagen, metaprop: - new arguments: - hakn (Hartung-Knapp method) - method.tau (estimation method for tau-squared) - tau.preset (fixed value for tau) - TE.tau (prespecified treatment effect to estimate tau) - method.bias (test for funnel plot asymmetry used in metabias) - label.left (Label on left side of forest plot, new argument in functions metabin, metacont, and metagen) - label.right (Label on right side of forest plot, new argument in functions metabin, metacont, and metagen) -...

...rnally) Functions metabin, metacont, metacor, metagen, metaprop: - new arguments: - hakn (Hartung-Knapp method) - method.tau (estimation method for tau-squared) - tau.preset (fixed value for tau) - TE.tau (prespecified treatment effect to estimate tau) - method.bias (test for funnel plot asymmetry used in metabias) - label.left (Label on left side of forest plot, new argument in functions metabin, metacont, and metagen) - label.right (Label on right side of forest plot, new argument in functions metabin, metacont, and metagen) -...

> Transforms/InstCombine/select.ll > ================================ > define i1 @trueval_is_true(i1 %C, i1 %X) { >  %R = select i1 %C, i1 1, i1 %X >  ret i1 %R > } > => > define i1 @trueval_is_true(i1 %C, i1 %X) { >  %R = or i1 %C, %X >  ret i1 %R > } > ERROR: Target is more poisonous than source (when %C = #x1 & %X = poison) > > (there are

...do with BT102's (i.e. SIP handsets), but problem has since occurred with analogue phones as well.&nbsp; <br> <br> Appreciate any help with this, as source of problem not immediately apparent and customer patience wearing pretty thin.<br> <br> Cheers,<br> Damian Funnell.<br> </font></small> </body> </html>

...;> authentication, via pam_krb5.so (on Linux at least and likely something >> similar on other *NIX) which allows smartcard auth to a Kerberos >> (including AD) server, where a TGT can also be granted. How difficult >> would it be to add functionality to OpenSSH so that it can funnel PKCS11 >> certs from SSH client to server and on to PAM where it could be used by >> Kerberos/PKINIT? My thought is that this is at least part way there >> with the current PKCS11 support but I won't claim to be an expert >> regarding the internals of what would be need...

Chapter 9 might be of interest: https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/ And specifically, for funnel plots in R: https://wviechtb.github.io/metafor/reference/funnel.html Best, Rob On 7/25/2024 6:40 AM, Richard O'Keefe wrote: > I know you didn't want to stimulate discussion, but the problem is not > confined to publication. "Adverse reaction to medication" monitoring >...