getting start and end user space address in c

avish78 · 01-05-2016, 06:35 AM

Hi,
I want to receive the start and end physical address of the user space in Linux. Is there a system function that I can use?
Also is there a system function that I can save a value to those address?

pan64 · 01-05-2016, 08:05 AM

do you mean the function getrlimit (see man page)?

avish78 · 01-05-2016, 09:19 AM

Hi,
Thanks for your reply.
No - I did not explain my problem correctly. As I understand there is system call mmap - which map a device to the memory of the program so I can read\write to this memory and it will be written to the device. My problem is that I can not find this device under /sys. Is there a way to get in the program a list of all the devices in the system?

NevemTeve · 01-05-2016, 09:50 AM

Try again, maybe the third time will be lucky: what do you actually want to achieve?
(A note: mmap works with 'files' (disk files, to be precise), not generally 'devices')

genss · 01-11-2016, 06:33 AM

Quote:

Originally Posted by avish78

Hi,
Thanks for your reply.
No - I did not explain my problem correctly. As I understand there is system call mmap - which map a device to the memory of the program so I can read\write to this memory and it will be written to the device. My problem is that I can not find this device under /sys. Is there a way to get in the program a list of all the devices in the system?

to get the definite list of all devices on your computer, you would go through /sys
this is clearly demonstrated by running
strace -e trace=file -f lsusb
or
strace -e trace=file -f lspci

other way, the one that gets all initialized devices, is to look at all the nodes in /dev