- New in Valgrind 3.10.1: 3.10.1 is a bug fix release. It fixes various bugs reported in 3.10.0 and backports fixes for all reported missing AArch64 ARMv8 instructions and syscalls from the trunk. If you package or deliver 3.10.0 for others to use, you might want to consider upgrading to 3.10.1 instead.
- Current release: valgrind-3.17.0. Valgrind is an instrumentation framework for building dynamic analysis tools. There are Valgrind tools that can automatically detect many memory management and threading bugs, and profile your programs in detail. You can also use Valgrind.
- Download valgrind 3.6.1 and untar the package. Download a version of the Code Sourcery toolchain. I used the Sourcery G Lite 2010q1-202 for ARM GNU/Linux.
When developing programs under Linux, especially server-side programs, it is always in a loop. If it is found that there is no problem when the program first runs, but after a period of time, the program stops. The high probability of this situation is a memory leak.
Download and build. Valgrind's Mac OS X support is now part of Valgrind's main development trunk. Follow their instructions to download and build the latest code.
Step 1：
We can use a simple command “free -m” to check whether it is really a memory leak. As shown below: If the memory usage is increasing and the free is decreasing as the program runs, it can be preliminarily identified as a memory leak.
Step 2:
In order to prevent memory leaks caused by other running programs in the system, we can use another tool to know more precisely whether our program has a memory leak.
We can use “pmap -x <pid>” command to see the result. The pid can be obtained through the “top” command. In this way, we can always look at the program we are running and this tool can also see the stack and heap allocation.
Suppose, we have a piece of code like this:
We use “pmap -x 20521” command to see the result. 20521 is the pid.
The RSS (Resident Set Size) in the result is closer to the size of the actual memory used by the computer. [anon] in mapping column indicates that it is allocated on the heap, which is also consistent with our code. As our program runs, we will find that more and more heaps are allocated, which means that our program has a memory leak.
This program was specially written by me, so it can be seen at a glance that the memory leak is because I have been malloc, but did not call free to release them. In many cases, it is easy to find the memory leak caused by without releasing malloc.
But sometimes, when we call other functions, such as the regcomp() function, there is a implicit memory allocatation process in this function.but because I did not call regfree to release, it caused a memory leak, which is more difficult to find.
Next, I will introduce how to download and install this tool.
Download and Install Valgrind
Method one:
- wget http://valgrind.org/downloads/valgrind-3.4.1.tar.bz2
- tar xvf [FileName].tar.bz2
- cd [Unzipped directory]
- ./configure
- make
- sudo make install
Method two:
- sudo apt-get install valgrind
Download Valgrind
It is said that this method is very slow. So I used method one.
But there is a problem with method one that is some dependencies, it does not follow the installation, so there will be an error when using it, the error message prompts you to say that xxx is missing. Then, at this time, just running “sudo apt-get install xxx” command is OK.
Then I can start to introduce this tool and how to use it.
Valgrind Usage
- Valgrind is a toolkit that helps us locate errors faster, make development faster, and make the application more correct. One of the most popular tools is MemCheck.It can detect many of the memory-related errors common in C/C++ that can cause a program to crash or have unpredictable results. This is the Memcheck tool that we’re going to use.
- In order for MemCheck to extract some debug information, we add -g when compiling the program. For example, if it is normally “gcc xxx.c“, then we are now “gcc -g xxx.c“.
- If we run a program normally is “./myprog arg1 arg2“. Now we are going to use “Valgrind –leak-check=yes./myprog arg1 arg2” command to run this program.
Let me give you an example, an example from the official webiste.
The result is:
Again, this tool is really powerful. And as you can see from the results, it’s very straightforward and precise, it finds the errors that are illegal, and it tells you in which function and in which line. It gets more and more precise from the bottom up, so let’s say we start with main, and then we start with f function. The following memory is not free is also directly pointed out. Such a handy tool is really worth spreading the word.
Have a good day! Any feedback is welcome.
Reference:
For more information, you can visit the website: http://valgrind.org/docs/manual/QuickStart.html
Dr. Memory is a memory monitoring tool capable of identifying memory-related programming errors such as accesses of uninitialized memory, accesses to unaddressable memory (including outside of allocated heap units and heap underflow and overflow), accesses to freed memory, double frees, memory leaks, and (on Windows) handle leaks, GDI API usage errors, and accesses to un-reserved thread local storage slots.
Dr. Memory operates on unmodified application binaries running on Windows, Mac, Linux, or Android on commodity IA-32, AMD64, and ARM hardware.
Dr. Memory is built on the DynamoRIO dynamic instrumentation tool platform.
Dr. Memory is released under an LGPL license. Windows, Linux, and Mac packages are available for download. The sources are also browsable.
Dr. Memory is faster than comparable tools, including Valgrind, as shown in our CGO 2011 paper Practical Memory Checking with Dr. Memory, where we compare the two tools on Linux on the SPECCPU 2006 benchmark suite:
(Valgrind is unable to run 434.zeusmp and 447.dealII).
Documentation is included in the release package as well as on this site: start with Installing Dr. Memory and Preparing Your Application.
The Dr. Memory release includes a System Call Tracer for Windows.
Dr. Memory includes Dr. Fuzz, a Fuzz Testing Mode, along with a configurable Dr. Fuzz: Dynamic Fuzz Testing Extension. Dr. Fuzz targets in-process function-level fuzzing, repeatedly running a target function while varying the inputs. It requires no access to source code, and supports code coverage-guided fuzzing, an input corpus, input dictionaries, and custom mutators.
Dr. Memory has its own discussion list.
Dr. Memory has its own Issue Tracker.
Download Valgrind On Linux
We welcome contributions to Dr. Memory. We use the same code review and workflow as for DynamoRIO.
How To Download Valgrind On Linux
- Dr. Memory version 2.3.18715 --- Sun Mar 28 2021 23:02:00