Windows error 0xDEADBEEF, -559038737

How do I manipulate bits in Python?

In C I could, for example, zero out bit #10 in a 32 bit unsigned value like so: unsigned long value = 0xdeadbeef; value &= ~(1<<10); How do I do that in Python ? read more

long double (GCC specific) and __float128

I'm looking for detailed information on long double and __float128 in GCC/x86 (more out of curiosity than because of an actual problem). Few people will probably ever need these (I've just, for the first time ever, truly needed a double), but I guess it is still worthwile (and interesting) to [...] read more

Getting information from an armored gpg public key file

When given a file with an armored public GnuPG key, i.e. a file (pubkey.gpg) that was created with: gpg -r 0xDEADBEEF --export --armored > pubkey.gpg What is the best way to get information such as the finger print in that file, without importing it into my keyring? The best way [...] read more

How can I access volume levels from the command line on Windows 7?

WHAT I NEED I'm looking for a tool or a script that allows me to access the Windows volume levels from the command line. Ideally it would allow me to get and set all volumes including application levels, but I'd settle for only getting, and only the master level. I [...] read more

Bluetooth device discovery in Android -- startDiscovery()

Goal: Build an Android app that discovers the names and addresses of BT devices within range and submits their values to a webservice. BT devices have not been previously bonded to the host device, I just want to poll everything as I walk about. What I've done: 1. Pored over [...] read more

How do you pronounce large hex numbers?

This question might be subjective, but I'm hoping there's some consensus that I just don't know about. Short hex numbers are relatively easy to spell out (e.g., 0xC4A might be "cee-four-ay"). Hex numbers ending with a multiple of three zeros are likewise pretty easy (e.g., 0xC000 might be "cee-thousand"). But [...] read more

Handling calls to (potentially) far away ahead-of-time compiled functions from JITed code

This question was put on hold as too broad, presumably because of the research I included in an effort to "show my work" instead of asking a low effort question. To remedy this, allow me to summarize the entire question in a single sentence (credit to @PeterCordes for this phrase): [...] read more

CORS and the OAuth 2 authorization code flow

I have a back end application that is protected with the OAuth 2 authorization code flow. The front end (javascript in browser) hits an authorization endpoint on the back end, the back end redirects the browser to an authorization code server, the user authenticates and then the authorization server redirects [...] read more

In C++ is it possible to specify which delete operator is used?

I am instrumenting some code and noticed that with the C++14 features there are two new delete operators (From http://en.cppreference.com/w/cpp/memory/new/operator_delete): > These are 5-6) Called instead of (1-2) if a user-defined replacement is provided except that it's implementation-defined whether (1-2) or (5-6) is called when deleting objects of incomplete type [...] read more

static linking not working for node module

I am developing a native node module for AWS lambda. This node module needed json-c As per AWS lambda guidelines the node module should not have dynamic dependencies. So tried linking the static version of json-c library. But I am getting compile time errors . As a node module is [...] read more

What happens when you seek past the end of a file opened for writing?

I have a binary data-set of known size that arrives in fixed-sized chunks. The chunks are out of order, but their position in the final result is known when I get them. Here is a simple example: from random import sample, seed import numpy as np chunk_size = 10 chunk_count [...] read more

Enabling AES-encrypted single sign-on to Apache in a Win2008 domain

All of the tutorials I could find on setting up single-sign on into an Apache-hosted website using Active Directory authentication do so by configuring Kerberos with insecure settings. It's been best practice for awhile now to disable RC4-HMAC encryption for Kerberos in Active Directory, but a lot of tutorials call [...] read more

defuse.ca online GAS assembler accepts AT&T syntax for movb and movw, but not movl?

I'm using https://defuse.ca/online-x86-assembler.htm#disassembly to assemble x86 instructions to machine code. (Editor's note: it uses GAS in .intel_syntax noprefix mode.) -------------------------------------------------------------------------------- The below code throws Error: no such instruction: `movl $0xdeadbeef,0x08048c5f' movl $0xdeadbeef,0x08048c5f But the following assembly code works fine movb $0xdeadbeef, 0x08048c5f movw $0xdeadbeef, 0x08048c5f read more

Efficient byte pattern search in matlab memory map

I have large binary files (2+ GB) that are arranged with a sync pattern (0xDEADBEEF) followed by a data block of a fixed size. Example: 0xDE AD BE EF ... 96 bytes of data 0xDE AD BE EF ... 96 bytes of data ... repeat ... I need to locate [...] read more

Javascript implementation of Jenkins Hash?

Is there a javascript implemenation of the Jenkins Hash I could use - rather than implementing it on my own? I know there is a python implemenation I could use to write my own js. But I am no Javascript expert and therefor I would prefer someone elses implementation. -------------------------------------------------------------------------------- [...] read more

tcpdump default capture size differs on similar servers

Running /usr/sbin/tcpdump -n dst ${some_ip} and dst port 80 on two different but similar (distro, version) servers gives me different capture sizes (65535 bytes for one, 262144 bytes for another). What might cause this difference in tcpdump capture size? What discrepencies might it cause in resulting data output? EDIT: ldd [...] read more

gdb won't load shared libs symbols, not even libc.so (musl), when loading a core file

I'm trying to debug a program running remotely on a board with a MIPS cpu, using musl for its libc. If I start gdbserver on the board, set the sysroot via set sysroot /path/to/sysroot and connect live from gdb, I get a meaningful stack trace (which took hours of effort [...] read more

GNU LD filling unused space

I'm trying to understand the behaviour of the GNU linker and how sections are treated. I'm editing the stm32_flash.ld file in this stm32 project. When I modify the linker script to put the following as the first section: .my_test : { . = ALIGN(4); KEEP(*(.my_test)) LONG(0xdeadbeef); . = ALIGN(4); } [...] read more

Why does Visual C++ 2019 allow left operand (lvalue) casting of the assignment operator?

Working on a project that must run in Visual C++ and GCC Before understanding that lvalue casting of the assignment operator in C is not allowed, I was writing code like this in VC++: typedef uint64_t QWORD; QWORD A = 0xdeadbeef, T = 0; (char)A = T; Notice the (char)A [...] read more

Making std::to_string work with void pointers, like operator<<?

I have some code which std::to_string()'s a variable whose type is a template parameter. Suppose the code is: template <typename T> std::string foo(const T& t) { return std::string("I got ") + std::to_string(t); } Now, sometimes this parameter needs to be a void *; and I would like to get the [...] read more

what is the difference between "python -c 'print' " and "(python -c 'print'; cat)" in linux

I usually use "python -c" to pass arguments to C program. Like this: $ python -c 'print "a" * 12' | ./program but when I execute a BOF practice program pwnable.kr/bof, the python -c 'print' and ( python -c 'print'; cat ) work differently. 1. I wrote a exploit code [...] read more

ASM to C: how to dereference a pointer and add an offset?

I feel kind of dumb, but I'm struggling with dereferencing a pointer (+ adding an offset) in C. What I want to recreate in C is this behavior: movabs rax, 0xdeadbeef add rax, 0xa mov rax, QWORD PTR [rax] So at the end rax should be: *(0xdeadbeef+0xa)Especially the equivalent to [...] read more

Proper way for declaring binary rotation preprocessor macro

I would like to create macros for binary rotations. My goal was to make those macros universal for both uint32_t and uint64_t operand types. I came to this implementation: #define ROTL(X, N) (((X) << (N)) | ((X) >> (8 * sizeof(X) - (N)))) #define ROTR(X, N) (((X) >> (N)) | [...] read more

STM32L073RZ (rev Z) IAP jump to bootloader (system memory)

I use the STM32L073RZ (Nucleo 64 board). I would like to jump into the system memory in application programming (IAP). My code works on the revision B of the STM32L073 microcontroller but fails on the latest revision, rev Z. I read the errata sheet, no details are given, just a [...] read more

Is initializing a pointer with an arbitrary, literal, non-zero value defined?

Consider: struct T{}; int main() { T* p = (T*)0xDEADBEEF; } Using an invalid pointer is implementation-defined. Dereferencing it is undefined behavior. My question isn't about those. My question is whether the mere initialization of p, as is, is defined. If you think you already have all the information needed [...] read more

ethernet interface on Linux drops packets

I'm trying to capture some Ethernet frames with Linux. Some of these packets/frames are invalid and contain corrupted data. For example an Ethernet frame contains the type 0x0800 which is IPv4, but the following data contain just random bytes. Furthermore, the source and destination MAC are unknown and not predictable. [...] read more

OS X Mountain Lion Crashes When Installs Xcode

So I just recently upgraded to Mountain Lion and so I needed to upgrade Xcode to the newest version. Well everything was going fine during the download but then about 1 minute after it started installing my computer just instantly crashed and rebooted. When I got back into OS X, [...] read more

Setting Include Paths When Building Kernel Modules

I'm trying to compile a kernel module for Linux. I have the following files: testuio.c and Makefile. When I type make all I get the following errors: $ make all make -C /lib/modules/`uname -r`/build M=/srv/dev-disk-by-label-tboWolfRaid/home/alex/ma/source/kernel_modules/memory modules make[1]: Entering directory '/usr/src/linux-headers-5.4.0-0.bpo.2-amd64' CC [M] /srv/dev-disk-by-label-tboWolfRaid/home/alex/ma/source/kernel_modules/memory/testuio.o In file included from /usr/include/unistd.h:25, from /srv/dev-disk-by-label-tboWolfRaid/home/alex/ma/source/kernel_modules/memory/testuio.c:13: [...] read more

GDB: Initialize memory with fixed value

In my code I have somewhere an uninitialized pointer that seems to get freed. The project is quite large and I cannot find the value. The problem is: once I attach a debugger, memory seems to be initialized with zero causing the pointer to be NULL and free not causing [...] read more

FIO repeatable buffer fill

Is it possible to have a pseudo-random buffer fill pattern using FIO? ie, the fill pattern for a block would incorporate a seed + block number or offset into a pseudo-random fill generator. This way the entire fill data could be 100% repeatable and verifiable, but more varied than the [...] read more

Can two consecutive memory_order_release stores on the same thread be reordered with each other?

Can two consecutive memory_order_release stores on the same thread be reordered with each other? Either from the perspective of the same thread or a different thread loading them? The documentation on CPP reference says: > A store operation with this memory order performs the release operation: no reads or writes [...] read more

Stack frame preparation

In order to improve my binary exploitation skills, and deepen my understanding in low level environments I tried solving challenges in pwnable.kr, The third challenge- called bof has the following C code: #include <stdio.h> #include <string.h> #include <stdlib.h> void func(int key){ char overflowme[32]; printf("overflow me : "); gets(overflowme); // smash [...] read more

Why does operator () with type argument can be applied to type in the context of result_of?

As fas as I understand, result_of_t should be a type, that will be at the end of the evaluation of an expression. decltype(&foo) in the code below yields the type int (*)(int), but what does (int) outside of decltype? #include <type_traits> int foo(int) { return 0xdeadbeef; } int main() { [...] read more

MinGW64 bit field access across word-boundaries is wrong

I'm investigation how different compilers handle unaligned access of structure bitfields members as well as members that cross the primitive types' boundaries, and I think MinGW64 is bugged. My test program is: #include <stdint.h> #include <stdio.h> /* Structure for testing element access The crux is the ISO C99 6.7.2.1p10 item: [...] read more

Verification of a CRC checksum against zero

I had some contact with the CRC-16 checksum in the past and was accustomed to verifying it by recalculating the CRC-16 checksum over the file I want to verify, plus the 2 bytes of the CRC-16 itself. If the result was zero, then the file integrity was valid, otherwise not. [...] read more

why bits/libc-header-start.h folder is included in stdio.h header

I am unable to compile to c program for 32bit machine from 64bit linux machine using command gcc -m32 -Werror a.c -o aIt shows me the error In file included from a.c:1: /usr/include/stdio.h:27:10: fatal error: bits/libc-header-start.h: No such file or directory #include <bits/libc-header-start.h> ^~~~~~~~~~~~~~~~~~~~~~~~~~ compilation terminated. I check the stdio.h [...] read more

Using a float in Javascript in a hash function

I Have a hash function like this. class Hash { static rotate (x, b) { return (x << b) ^ (x >> (32-b)); } static pcg (a) { let b = a; for (let i = 0; i < 3; i++) { a = Hash.rotate((a^0xcafebabe) + (b^0xfaceb00c), 23); b = [...] read more

Initialize constexpr array with template functions

I am trying to create a constexpr std::array with precompiled handler functions for my emulator. The code below works just fine for smaller numbers like 0x250, but everything above causes a 'C1026 parser overflow, program too complex' when used with the recent version of MSVC. #include <array> #include <iostream> template<typename [...] read more

How do I cast to a templated type?

In gdb, if you have a pointer to something, you can cast it before printing it. For example, this works: print *(int*) 0xDEADBEEF However, how do I print a std::vector<T>? Specifically a std::vector<std::string>? If it's std::string, I can do it with std::__cxx11::string, which whatis std::string outputs, but I can't convince [...] read more

Boost Graph Library cannot store references to other vertices?

I'm using BGL to build a graph storing bundled vertices where one type of vertex stores a reference to the other vertex type. Both types are handled using std::variant: struct simple_node_t { size_t enabled; }; struct complex_node_t { bool foo1; size_t foo2; simple_node_t& control; }; using vertex_t = std::variant<simple_node_t, complex_node_t>; [...] read more

Determine which signal uncaught by terminated child process

I have a Mac OS X app (Cocoa), which spawns a C++ console helper app to do some work. The GUI spawns the helper via NSTask, and they communicate with each other via named pipes. This is all good. If the helper app dies, the GUI gets an NSTaskDidTerminateNotification, and [...] read more

After sending a pointer to an external function to make it null, it doesn't change to null

I have created a pointer of type "Vector" (see code). After creation I want to send a pointer of type Vector (meaning Vector*) to a function called "VectorDestroy(Vector* _vector), which frees the struct from memory and assigns it to null. However when I continue in the code and want to [...] read more

How can I use lwIP tcp/ip stack with microcontroller stm32f4 (client)

Core: Cortex-M4 Microcontroller: stm32f407 (stm32f4 discovery board) IP Stack: lwIP 1.4.1 I am using this microcontroller to control an automate and I want to send some information to a separate web server via a HTTP request in the form of: http://192.168.1.3/api/xdevices.json?SetR=01 lwIP has a http server for the microprocessor, but [...] read more

Make a constraint more difficult to solve for a constraint solver?

I am a newbie to SMT solving and I am writing to inquire some advice and pointers to understand what is a really difficult constraint for SMT solver to solve, for instance Z3. I tried to tweak the length of bit vectors, for instance in the following way: >>> a [...] read more

Iterate over list starting from a certain index

Here is an example: list_ = [5, 'cat', 0xDEADBEEF, 4.0] for offset in range(len(list_)): result = 0 for elem in list_[offset:]: result = func(result, elem) return result where func is non-commutative. In the code above, list_[offset:] will create a new list, but all I need is a view to list_. [...] read more

Using a template function in an anonymous namespace

I am trying to use Strong Types and to add stream operator for them. In my source file I put all of these helpers in an anonymous namespace. One of these helpers is using a template stream operator (utils::to_hex(T)) defined in another header. namespace { // Anonymous namespace // Example [...] read more

#define in inline assembly in GCC

I'm attempting to write inline assembly in GCC which writes a value in a #define to a register. #define SOME_VALUE 0xDEADBEEF void foo(void) { __asm__("lis r5, SOME_VALUE@ha"); __asm__("ori r5, r5, SOME_VALUE@l"); } However, I get an error when I compile: > undefined reference to `SOME_VALUE' Is there a way for [...] read more

Interleave 4 byte ints to 8 byte int

I'm currently working to create a function which accepts two 4 byte unsigned integers, and returns an 8 byte unsigned long. I've tried to base my work off of the methods depicted by this research but all my attempts have been unsuccessful. The specific inputs I am working with are: [...] read more

Reordering of access to multiple volatile variables in C

In this example: volatile uint32_t * pOne = 0xDEADBEEF; volatile uint32_t * pTwo = 0x0BADC0DE; void same(void) { uint32_t tmp; tmp = *pOne; // A *pOne = 0; // B *pOne = tmp; // C } void different(void) { uint32_t tmp; tmp = *pOne; *pOne = 0; // E *pTwo [...] read more

Does strict aliasing prevent you from writing to a char array through a different type?

My understanding is that strict aliasing in C++ is defined in basic.lval 11: > (11) If a program attempts to access the stored value of an object through a glvalue of other than one of the following types the behavior is undefined: * (11.1) the dynamic type of the object, [...] read more

Command substitution within sed expression

I'm having little problem with bash/sed. I need to be able to use command substitution within sed expression. I have two big text files: * first is logfile.txt which sometimes* shows error messages by ID (0xdeadbeef is common example) in format ERRORID:0xdeadbeef * second errors.txt has error messages stored in [...] read more

Why can integer store a hex value but cannot store the same value in decimal?

I most recently successfully exploited a C executable by causing its char array to overflow in to another variable. I did this by piping in the output of exploit1.py in to the command line which was accepted as an argument by lab2C. Here is the command I used: ./lab2C.exe "$(python [...] read more

How to use a single malloc() call for a 2D array

I want to malloc a large block of memory then access it as a 2D array. The malloc call is pretty strait forward, something like this. const int rows = 1000; const int cols = 2048; uint32_t* mal_ptr = malloc(sizeof(uint32_t)*rows*cols); After that I don't know how to declare a pointer [...] read more

Random Number Generator in C++ for skipList

I wanted a random number generator for skiplist implementation and got the following logic. Can I get an explanation of how here random numbers are getting generated. I see use of bit wise operator but not able to understand the logic. #include <stdint.h> #include <iostream> using namespace std; typedef unsigned [...] read more

What does this code do? found &= pattern[j] == *(char*)(base + i + j)

I came across some confusing code, and I don't know what it signifies: found &= pattern[j] == *(char*)(base + i + j); I've tried rewriting it, and this is what I've made so far: if (pattern[j] == *(char*)(base + i + j)) { found = found & pattern[j]; } For [...] read more

MAPISendMail crashes UWP converted app. Alternatives to sending an email from a UWP app?

I have a Win32 application that is also distributed via the Windows Store (for that it's converted to UWP using the Desktop Bridge.) The application uses MAPISendMail function to automate creation of an email in a default email client with an arbitrary attachment, as such: BOOL SendEmail(HWND hParentWnd, LPCTSTR pStrEmailAddrTo, [...] read more

How to return or export result of function javascript from service file to use in another file

Function Of Service export const deviceInfoRequest = async (callback) => { var request = new DeviceInfoMessage(); var AuthToken = 'ciOiJIUzI1NiIsInR5cCI6IkpXVCJ9'; client.deviceInfo(request, {'x-authorization': AuthToken}, (err, response) => { var dataDevicename = response.getDevicename(); var dataDeviceid = response.getDeviceid(); console.log("DeviceName==>>>>",dataDevicename); console.log("DeviceId==>>>>",dataDeviceid); this.callback(dataDevicename,dataDeviceid); }); } =======> Result of "console.log"=="DeviceName== test" and "DeviceId==>>>> 0xdeadbeef". Function Of [...] read more

Can a field in react-final-form mark itself as invalid / prevent submission?

I have a custom file upload field that uploads files immediately once you select/drop them, and returns a UUID for later submission. So, basically what most webapps do nowadays (e.g. Facebook, Twitter, etc.) when you drop a file. This is all easy enough to handle with final-form - my field [...] read more

Stuck at hacking challenge in C (Stack buffer overflow)

I'm trying to overrun this buffer. I ran it like this: command here, but the value is not correct. I tried various inputs with which I actually overran the buffer but instead of my expected value of the check variable 0xdeadbeef the value is something like this: 0x73737373. What am [...] read more

In GDB, can you set memory as if it were a char array?

Say for instance I have a 32 element unsigned char array at address 0xdeadbeef. I would like to overwrite the contents of the array in memory. I am not compiled with -g, and so cannot just do a "set [variable name] = [my value]". Is it possible to set the [...] read more

Mock a sequence of calls to different methods

I want to unit test a class that reads data from a stream in a certain protocol. This will require different read() Methods on the stream in a certain order. Is there a way to mock the stream like this: MyClass readFrom(InputStream in) { byte b = in.readByte(); int c [...] read more

Why does this exploit require two separate payload injections rather than one?

I am new to binary exploitation problems. This one comes from picoctf 2019, leap-frog. The particular solution I'm interested in uses a buffer overflow on the vuln() function to force execution to return to gets' PLT entry. This is done because gets allows us to write to an arbitrary place [...] read more

How to put mongodb sessions in creachadair/jrpc2 Handlers

I want to build a microservice that uses jrpc2 and mongodb to manage small IoT devices. These are the libraries in question: https://godoc.org/bitbucket.org/creachadair/jrpc2 https://godoc.org/github.com/globalsign/mgo The problem is, being rather new to Golang in general, I'm not sure how to combine these things together. Here's the code I have: func DeviceAdd(ctx [...] read more

Get around involuntary typing of columns in CSV file when using for unit test

I am using a CSV file to inject data into my test. [TestMethod] [DataSource( CsvData, CsvDir + "TC177023.csv", "TC177023#csv", SEQ )] The file looks somethings like this: (other strings removed) something,something,Value,something,something,something ,,0xDEADBEEF,, ,,-12,, ,,0,, ,,0,, ,,0,, I have one column that I have integers in and I wanted to extend [...] read more

Have some troubles to use lib installed with vcpkg in vscode and gcc

I'm a beginner in C and I want to use a lib called json-c. So I followed the git tutoriel and I installed vcpkg. After that I run the command: vcpkg install json-c vcpkg integrate install So now vscode can see the new lib, i see function descriptions, etc.. I [...] read more

Precise details of writing a byte into PCIe address space from CPU

I am extremely confused about the exact series of steps involved in having the CPU write a value into a PCIe card's memory. It's very difficult to understand the precise meaning of stuff you read on the internet, so I'm hoping someone can read my theory of what's happening and [...] read more

Integer within C binary: viewing it using readelf, objdump or similar

I have the following C source file, hello.c, compiled on linux via g++ -o hello hello.c: #include <stdio.h> const char* p = "Hello world"; const long nn = 0xDEADBEEF; int main() { printf("%s %ld", p, nn); return -1; } (Yes I know I am using g++ for C but that [...] read more

Creating a bitfield class that points to arbitrary data- is this safe?

Context I am creating a Bitfield class that is responsible for providing access to a contiguous set of bits in a UInt32. The source data is not managed by the Bitfield, but instead another object. In practice, the same object that owns the source data will also own any Bitfield [...] read more

Scripting a repetitive gdb job

I want to do the same repetitive job in gdb across a bunch of different files. Namely, bash$ gdb ./file1 ... gdb starts up ... gdb$ b *0xdeadbeef gdb$ r < file2 ... some output prints ... gdb$ x/3a $esp ... some addresses print ... Is there some way I [...] read more

having issues in understanding the buffer-overflow process

This is the problem from recent picoCTF buffer-overflow challenge. here i have some doubts. I am learning bufferoverlow, so my questions may be trivial. i am not able to understand the proper functionality of this program. This was the program given: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include [...] read more

why char* takes 4 bytes instead of 1 byte

I wrote a program to find endianness of a system. It doesnt work as the pointer value is 0xffffffef instead of 0xef. Why is the pointer value 0xffffffef? I declared it as a char* which should take only 1 byte. I can fix the problem by *ptr&0xff but I don't [...] read more

Is there a readable pattern for creating nested Protobuf messages in C++?

I'm new to Protobuf and would like to know if there is a good pattern for creating protobuf messages that results in readable code. You can do it like this: message.mutable_foo()->mutable_bar()->mutable_gazoo->set_gronk(4711); message.mutable_foo()->mutable_bar()->mutable_gazoo->set_grunk(0xdeadbeef); message.mutable_foo()->mutable_bar()->mutable_spunk->set_snafu("Boink!"); Or like this: auto foo = message.mutable_foo(); auto bar = foo->mutable_bar(); auto gazoo = bar->mutable_gazoo(); gazoo->set_gronk(4711); gazoo->set_grunk(0xdeadbeef); [...] read more

Why do my PCI-e I/O register reads appear to be cached?

I have a PCI-e hardware device that has a number of registers that I want to read from and write to. However, when I read a register, I will get a value from a previous read (the first read returns 0xFFFFFFFF). I'm using pci_iomap() to get the base address of [...] read more

How are stack pointers converted from virtual to physical memory

I've been working with a lot of assembly, and reviewing virtual memory I've run into some new confusion. Briefly, I don't understand how an address in assembly, the code that interfaces with the processor directly, could be converted from a virtual address to a physical address. I was always told [...] read more

STM32 uC after exit DFU mode does not return to normal but has breakpoints

I'm entering the DFU mode of the STM32 without using the Boot0 physical pin. I do this by sending a command via the UART and switch the uC to DFU mode. I'm using the STM32F042G6U6. But it doesn't restart when I use the ST tools to exit from DFU mode. [...] read more

How to perform a specific buffer overflow bypassing a length check

I'm trying to perform a bufferoverflow so that a variable (type) has a specific value in it. I struggle with the strlen & check for my input. I tried using something like: 'AAAAA\x00AAA...A\x00\xbc\xd4\xb9' for tricking the strlen check that my input is just 5 A's long. But something strips my [...] read more

Unexpected typecasting between values in C

I have a snippet of C code unsigned int x = 0xDEADBEEF; unsigned short y = 0xFFFF; signed int z = -1; if (x > (signed short) y) printf("Hello"); if (x > z) printf("World"); I wanted to know if the comparison in the first statement evaluates to DEADBEEF > FFFFFFFF [...] read more

Vivado/XSDK: How to access address from Zynq M_AXI_GP0 Bus?

Let's say I built a vivado Zynq FPGA project, and I want to write and read the Zynq's "M_AXI_GP0" port from a c-program running on the zynq as follows. Further, let's suppose the address I want to read and write on the "M_AXI_GP0" port of the Zynq is address "0x000A1000". [...] read more

What does '.() at 0xdeadbeef' mean in a (core file) stacktrace generated by dbx on AIX?

I'm running some tests on AIX, and I'm getting a bunch of crashes similar to the following: build 25-May-2019 18:40:46 Segmentation fault in ThreadSafeSharedObject_cpp::ChangeRefCount(unsigned int&,int) at line 21 in file "" ($t8) build 25-May-2019 18:40:46 Thread $t1 build 25-May-2019 18:40:46 glinkl.pthread_mutex_unlock() at 0xd5d4baac build 25-May-2019 18:40:46 BlockingResponseQueue.Simba::Support::CriticalSection::Leave() const(0x2055a320), line 54 [...] read more

Process_vm_readv Returning Random Values

I am trying to use the process_vm_readv systemcall to read a value from another Linux process. When attempting to read a magic number at a known location, I receive a random value. I have tried writing two simple programs to see if I can get it working but I have [...] read more

How to copy the value at a certain address in memory to a register in gcc AT&T style

I want to copy the value at a certain address in memory to a register using AT&T style assembly. I know this shouldn't be hard, and I think in Intel style it's something like: mov rdi, [0xdeadbeef] But I don't know much about the AT&T style (or assembly in general). [...] read more

Allow modification of list during loop

In most cases, the user is modifying the array directly within the original loop. In my case, the array is being modified by a method being called inside of the loop, outside of the loop's control. I need a way for an outsider to be able to add a value [...] read more

Why traditional GetProcAddress to std::function is not working straightforward

As in the title I'd like to convert GetProcAddress into std::function. Yes, there are multiple solutions in stack overflow, but none actually explains why those workarounds are needed. I can't really understand the exact error message and why it happens. The sample source is simple: #include <functional> #include <Windows.h> using [...] read more

C++ assigning integer (containing address) to pointer

I am new to C++, I have a function which returns address of a memory location and I want to assign that address to a pointer, just like: unsigned int address = 0xdeadbeef; unsigned int* memory_ptr = (unsigned int*) address; But above code is through warning: cast to pointer from [...] read more

Address operator and variable token joining macro

I have had a problem with running a program that (when simplified) looks something like this. #include <stdio.h> #define ADDR_TOKEN_MACRO(x) & ## x int main() { int *i; int **y; int b = 0xDEADBEEF; *y = ADDR_TOKEN_MACRO(b); return 0; } I'm trying to set the integer pointer i's address to [...] read more

Problem with Stack based Euler-Tree-traversal

I want a function that traverses a binary tree with the Euler traversal (this is how it works). Of course this is easily achievable with recursion - I know how that works. But now I want to implement an iterative version of this algorithm using a stack instead of recursion. [...] read more

Using a public PRNG and uniform distribution (C++17)

I am trying to implement a PRNG I found online yet I am having compile time issues (seen below): 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.15.26726\include\xutility(4010): error C2061: syntax error: identifier 'result_type' 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.15.26726\include\xutility(4012): error C2065: '_Ty1': undeclared identifier 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.15.26726\include\xutility(4012): error C2065: '_Ty1': undeclared identifier [...] read more

Visual Studio natvis displaying pointer-to-interface

I'm trying to create debug visualizers for our company custom smart pointers. I would like to use ExpandItem to get the contents just one level down, which works for concrete types like ref_ptr<Vector2d>, but not for virtual types like ref_ptr<IStreamManager>. When using the virtual types, I get two entries, one [...] read more

how to create an assembly-only project in Code Composer Studio (CCS) for TI MSP432 series

I can copy some existing assembly project, however there are a lot files associated with it that I wonder if they are necessary. Another way of re-phrasing this question would be, is I wanted to set up either CCS or Eclipse to build/install/debug an MSP432 Launchpad development board, what would [...] read more

Can I dereference CRC32 checksum?

Is it possible to create CRC32 checksum as I want? Like, crc32(???) = 0xdeadbeef. In this case, 0xdeadbeef is what I want as a CRC32 checksum result. read more

Needing advice for implementing malloc and free in C

For school, I need to write a program that uses my own implementation of malloc and free. I need to be able to report on all the chunks of memory in my 'heap', whether it's allocated or not. I feel like I've written good code to do so, but evidently [...] read more

Assembly basics - multiple arguments

Suppose I have the following snippet: push ebp (1) mov ebp,esp (2) mov eax,0xaf (3) xor al,al (4) mov ah,BYTE PTR [ebp+0x9] (5) And I call this with the following arguments: 0xdeadbeef, 0xdeefbeab, 0xf00b1den. I'm basically unsure of BYTE PTR is. My assumption: at (3) the eax stack looks as [...] read more

Julia: Using the Underscore as a Digit Separator in BigFloat and BigInt

According to the Julia 1.0.0 docs: > The underscore _ can be used as digit separator: julia> 10_000, 0.000_000_005, 0xdead_beef, 0b1011_0010 (10000, 5.0e-9, 0xdeadbeef, 0xb2) However, in the Julia 1.0.0 REPL I get this: julia> VERSION v"1.0.0" # Underscore does not work work on right side of decimal in BigFloat. [...] read more

Passing a pointer to a function but the pointer remains unchanged

I have created the following two files to illustrate what my problem is. main.c #include <gtk/gtk.h> #include "app_struct.h" static void activation(GtkApplication *app, gpointer user_data); static void check_file(GFile *file); int main(int argc, char **argv) { int status; GtkApplication *test = gtk_application_new("idk.for.now.test", G_APPLICATION_FLAGS_NONE); g_signal_connect(test, "activate", G_CALLBACK(activation), NULL); status = g_application_run(G_APPLICATION(test), argc, argv); [...] read more

How to compile C function at specific address Visual C++

I'm using Visual Studio 2017. I have a compiled dll which sets some variables and uses some functions at some addresses when loaded like this: #define func_address 0xdeadbeef; typedef int func(int a, int b); BOOL APIENTRY DllMain( HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved ) { switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: [...] read more

Pointer parameter NULL when entering in function scope but not at function call

I'm working on stm32f469 doing some bare metal code to try to use the libtomcrypt / libtomfastmath libraries. The code I'm trying to debug has been checked by valgrind and is working on many platforms like macos, raspberrypi, ios, android. To keep things simple, I am doing the following which [...] read more

Direct Call x86 Assembly

I'm trying to essentially patch in a dll a far call to my own address instead of the one compiled already. Here is the bytes I am trying to patch : { 0xFF, 0x15, 0x30, 0x20, 0x00, 0x10 } Which should translate to : call DWORD PTR ds:0x10002030 Which I [...] read more

GDB disassembly filled with zeros

When I run objdump -D on my file, I get the assembly code I expect. kernel.elf: file format elf32-i386 Disassembly of section .text: 00100000 <__code>: 100000: 02 b0 ad 1b 03 00 add 0x31bad(%eax),%dh 100006: 00 00 add %al,(%eax) 100008: fb sti 100009: 4f dec %edi 10000a: 52 push %edx [...] read more