3 ms·
> For example, on modern systems the 'system call' to get the current time may not even enter the kernel (see vdso(7) on Linux). Is there a way to check from t
by jancsika 7y ago
> For example, on modern systems the 'system call' to get the current time may not even enter the kernel (see vdso(7) on Linux).
Is there a way to check from the running process whether that is the case or not?
- wyldfire 7y agoCheck whether it happened to do that for a given call or a portable way to predict whether it will? dump_vdso [1] will write the vdso to stdout, you can use binutils like objdump or nm to list the symbols present. [1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/luto/misc-tests/+/5655bd41ffedc002af69e3a8d1b0a168c22f2549/dump-vdso.c https://kernel.googlesource.com/pub/scm/linux/kernel/git/lut...
- monocasa 7y agoAnd if you wanted the same information at runtime, the base address of the VDSO is passed in as an auxv, and then passing that address into libelf would get you everything.