Search results
Results from the WOW.Com Content Network
In most Unix-like systems, most of the machine code that makes up the dynamic linker is actually an external executable that the operating system kernel loads and executes first in a process address space newly constructed as a result of calling exec or posix_spawn functions. At link time, the path of the dynamic linker that should be used is ...
A linker script may be passed to GNU ld to exercise fine grain control of the linking process. [6] Two versions of ld are provided in binutils: the traditional GNU ld based on bfd, and a streamlined ELF-only version called gold. The LLVM project's linker, lld, is designed to be drop-in compatible, [7] and may be used directly with the GNU ...
This allows drivers and devices outside of the mainline kernel to continue working after a Linux kernel upgrade. [ 3 ] Another benefit of DKMS is that it allows the installation of a new driver on an existing system, running an arbitrary kernel version, without any need for manual compilation or precompiled packages provided by the vendor.
As the dynamic linker holds modules and resolves dependancies, it populates the IAT slots with actual addresses of the corresponding library functions. Although this adds an extra jump, incurring a performance penalty compared to intermodular calls, it minimizes the number of memory pages that that require copy-on-write changes, thus conserving ...
The number of system calls in Version 7 was only around 50, while later Unix and Unix-like systems continued to add many more: [5] Version 7 of the Research UNIX System provided about 50 system calls, 4.4BSD provided about 110, and SVR4 had around 120. The exact number of system calls varies depending on the operating system version.
Loadable kernel modules in Linux are loaded (and unloaded) by the modprobe command. They are located in /lib/modules or /usr/lib/modules and have had the extension .ko ("kernel object") since version 2.6 (previous versions used the .o extension). [5] The lsmod command lists the loaded kernel modules.
The dynamic linker on Linux, for example, reads through the DT_NEEDED section of an ELF object and loads needed libraries; but isn't told where required symbols are. For this, it must iterate through each unresolved symbol in the object, and for each of these, iterate through each loaded library, checking until it finds a matching symbol.
[9] Using weak symbols in static libraries has other semantics than in shared ones, i.e. with a static library the symbol lookup stops at the first symbol – even if it is just weak and an object file with a strong symbol is also included in the library archive. On Linux, the linker option --whole-archive changes that behavior. [10]