similar to: [LLVMdev] Question about SimplifyXorInst

Hi all, I am master student in Edinburgh, UK. I am doing my MSc project with LLVM compiler and I have to modify LLVM to implement the StackGuard with a XOR random Canary. However, I am not familiar with LLVM. My problem is that I want to XOR the random canary word with the return address which are both 32 bits. I found a method called SimplifyXorInst(Value *, Value *, const TargetData

Hi all, I want to implement the Xor random canary, so I have to get the return address in the prologue and epilogue of the function. In the prologue of the function, before I insert into the canary on the stack, I can get the return address by: ConstantInt* ci = llvm::ConstantInt::get(Type::getInt32Ty(RI->getContext()), 0); Value* Args1[] = {ci}; CallInst* callInst =

Hi all, Here is my problem, overflow.c: int main() { return 0; } $ clang -c -fstack-protector-all overflow.c -emit-llvm overflow.bc $ llc -O0 overflow.bc The result seems like the Bug 9259 which had been fixed (r126812). But I find I still have the problem below: Both operands to a binary operator are not of the same type! %aaa = xor i8* %"Call Return Address", i32 1892499360

On 7/26/11 5:37 PM, Xueying ZHANG wrote: > Hi John, > > Thanks for your reply! I'm CC'ing this to the list in case anyone knows why you're seeing this behavior. > > Now, I know the different between llvm.returnaddress(0) and > llvm.returnaddress(1). I modify the StackPortector.cpp and I just want > to get value of the return address stored on the stack. >

Hello, I plan to implement "Stack Smashing Protection - Strong" support in LLVM. Below is a description of this feature and an overview of the implementation plan. I have divided up the implementation into stages that can be delivered incrementally. I'm looking for any feedback (suggestions, requests, etc) before I actually begin the work. Thank you! Josh

Dear LLVMers, I am trying to measure the performance overhead (if any) of the canaries that clang inserts in the code. I would like to do this automatically, using the LLVM test infra-structure. However, I am not sure if that is possible. Could someone tell me which flags in the TEST.nightly.Makefile script, (or any other script) I must change to have this done? Usually I insert canaries with

Hi all, How to XOR the return address on the stack with a canary word both are 32 bits? Is there a method to implement it? Thank you. Ying -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

If you compile this with optimizations, then the 'canary()' function should be totally inlined into the 'main()' function. In that case, the cost of the stack protectors will be very small compared to the loop. -bw On Mar 9, 2012, at 2:52 AM, Job Noorman <jobnoorman at gmail.com> wrote: > I have a question about the performance of the implementation of the stack >

I have a question about the performance of the implementation of the stack protector in LLVM. Consider the following C program: ===== void canary() { char buf[20]; buf[0]++; } int main() { int i; for (i = 0; i < 1000000000; ++i) canary(); return 0; } ===== This should definately run slower when stack protection is enabled, right? I have measured the runtime of

Hi everyone, As a front-end developer, I'd like to add a language-specific information at a fixed location of each stack frame. The reason is that I want to retrieve this information when dynamically walking the stack. For example, X86 has the following stack layout for a function with two arguments and two locals: 12(%ebp) - second function parameter 8(%ebp) - first function

Hi all, perhaps this is something of interest to all of us RedHat users ? Later Crispin added: | In response to many comments pointing out a glaring omission (grovel | grovel) the SOURCE CODE for StackGuard is now on line, both as a complete | tar ball and as a source patch to gcc 2.7.2.3, available here: | | http://www.cse.ogi.edu/DISC/projects/immunix/StackGuard/compiler.html Greetings,

Hello > In the prologue of the function, before I insert into the canary on > the stack, I can get the return address by: Note that there is no epilogue and prologue at IR level :) > But it does not work this time. I cannot get the return address. > What is problem? How can I get the return address? Thank you! What is the problem? It seems you're getting the return address via

All, I just noticed this in my logs, and am rather lost as to what module it pertains to. I would assume pseudo-realtime priority for the process, but I am looking for a little confirmation from the group: [Apr 28 12:28:36] WARNING[20773] asterisk.c: The canary is no more. He has ceased to be! He's expired and gone to meet his maker! He's a stiff! Bereft of life, he rests in

People, Anybody knows what mean this message in my CLI: [Apr 1 16:58:34] WARNING[3845]: asterisk.c:3050 canary_thread: The canary is no more. He has ceased to be! He's expired and gone to meet his maker! He's a stiff! Bereft of life, he rests in peace. His metabolic processes are now history! He's off the twig! He's kicked the bucket. He's shuffled off his mortal

Just compiled the SRPM for 3.3p1 on my Immunix 6.2 box (Redhat 6.2 + Stackguard compiler), fired up the server, and tried to connect to it. No joy. In the spec file I changed the following options: # Is this build for RHL 6.x? %define build6x 1 # Disable IPv6 (avoids DNS hangs on some glibc versions) %define noip6 1 This appears in the system log: Jun 24 16:11:51 johnh sshd[27774]: fatal:

I would be surprised if someone hasn''t encountered this already, but I haven''t found any discussion of the nature of this problem. I run RehHat 5.0. If a user makes a mistake in the login process such as the following: login: mistake password: xxx Login incorrect! login: username password xxxx bash$ a ps will show, among other things, 2333 /bin/login --mistake. Since

On Thu, Jun 30, 2016 at 8:29 AM, Martin J. O'Riordan via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I am trying to implement stack probes for our SHAVE target, and I see that > the compiler injects references to ‘__stack_chk_guard’ and > ‘__stack_chk_fail’. The code that gets generated is horribly wrong, but in > order to understand how to fix it I was wondering if

Hi all, I want to add some functionalities to Stack protection of llvm by modifying the file StackPrtoector.cpp under llvm/src/lib/CodeGen. However, I encounter some problems here. Here is my problem: I want to call the function Intrinsic::returnaddress with the same parameter twice in a function. However, llvm will optimize this process automatically by storing the result from the first call

John Criswell wrote: > If you're interested in SAFECode, the first step is to get SAFECode > working with a newer version of LLVM. A Master's student did some > work on this last summer with LLVM 3.7 but didn't finish. It would > now need to be updated to LLVM 3.8 (though I suppose a completed LLVM > 3.7 port would be fine with me). > > After that, there are

Hi, first sorry for cross-posting but I thought this patch might interest -CURRENT users as well as people concerned by security. I wrote a patch that integrates ProPolice/SSP into FreeBSD, one step further than it has been realized so far. It is available here : http://tataz.chchile.org/~tataz/FreeBSD/SSP/ Everything is explained on the web page, but I will repeat some informations here.