What is proc pid mem?
The /proc//mem file is an important mechanism that gives insight into contents of process memory. Because the process memory contains highly-sensitive information, data access to the file is determined by a complex set of poorly documented rules.
How can I see Proc in Linux?
If you list the directories, you will find that for each PID of a process there is dedicated directory. Now check the highlighted process with PID=7494, you can check that there is entry for this process in /proc file system….proc file system in Linux.
| directory | description |
|---|---|
| /proc/PID/status | Process status in human readable form. |
What is Proc pid CWD?
/proc/PID/cwd, a symlink to the current working directory of the process. /proc/PID/environ contains the names and values of the environment variables that affect the process. /proc/PID/fd, a directory containing a symbolic link for each open file descriptor.
How can I read from / proc /$ PID / Mem, then?
How can I read from /proc/$pid/mem, then? /proc/$pid/mem shows the contents of $pid’s memory mapped the same way as in the process, i.e., the byte at offset x in the pseudo-file is the same as the byte at address x in the process.
Is it possible to read from the MEM pseudo-file of another process?
If you try to read from the mem pseudo-file of another process, it doesn’t work: you get an ESRCH (No such process) error. The permissions on /proc/$pid/mem ( r——–) are more liberal than what should be the case. For example, you shouldn’t be able to read a setuid process’s memory.
How to read process memory without interruption in Linux?
Since the 3.2 version of the kernel. You can use the process_vm_readv system call to read process memory without interruption. These system calls transfer data between the address space of the calling process (“the local process”) and the process identified by pid (“the remote process”).
How does the remote process read process memory?
These system calls transfer data between the address space of the calling process (“the local process”) and the process identified by pid (“the remote process”). The data moves directly between the address spaces of the two processes, without passing through kernel space. You’ll have to use /proc/ pid /mem to read process memory.