Hi…
I have an embedded system here (rtp6.2), and in /proc/ I see a number
of files, inside each one of them, there is a file called ‘as’. What is
this? These files increase in both number and size, what is this, and
why do we have this behavior?
(Note: a search in the news groups is useless since so many entries come
up with ‘as’…)
Thanks for any help on this…
Regards…
Miguel.
go it.
as = address space, and the folder names are pid numbers.
M.
Miguel Simon wrote:
Hi…
I have an embedded system here (rtp6.2), and in /proc/ I see a number
of files, inside each one of them, there is a file called ‘as’. What is
this? These files increase in both number and size, what is this, and
why do we have this behavior?(Note: a search in the news groups is useless since so many entries come
up with ‘as’…)Thanks for any help on this…
Regards…
Miguel.
Miguel Simon <simon@ou.edu> wrote:
go it.
as = address space, and the folder names are pid numbers.
And, if you open /proc/pid/as, and seek to a location, and then
issue a read(), you will get the memory contents of that process
from that address.
Pretty nifty, hunh?
QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.
Hi David…
David Gibbs wrote:
Miguel Simon <> simon@ou.edu> > wrote:
go it.
as = address space, and the folder names are pid numbers.
And, if you open /proc/pid/as, and seek to a location, and then
issue a read(), you will get the memory contents of that process
from that address.
When you say ‘seek to a location’, how do I know which location
corresponds to which process? Do you have a sample code somewhere?
Pretty nifty, hunh?
Yup. I have been looking for something like this, I think. I have
another question: since I have the .elf file from a compiled source, I
wonder if you have some comments on how I could utilize this information
to retrieve memory content from /proc/pid/as?
Thanks…
Miguel.
-David
Miguel Simon <simon@ou.edu> wrote:
Hi David…
David Gibbs wrote:
Miguel Simon <> simon@ou.edu> > wrote:go it.
as = address space, and the folder names are pid numbers.
And, if you open /proc/pid/as, and seek to a location, and then
issue a read(), you will get the memory contents of that process
from that address.When you say ‘seek to a location’, how do I know which location
corresponds to which process? Do you have a sample code somewhere?
Look on the www.parse.com/books/book_v2 “cookbook” site – the sample
chapter does just that – digs into the “as” address space file to
get a thread fingerprint… There’s a complete commented code walkthrough.
Robert Krten, PARSE Software Devices +1 613 599 8316.
Realtime Systems Architecture, Books, Video-based and Instructor-led
Training and Consulting at www.parse.com.
Email my initials at parse dot com.
Miguel Simon <simon@ou.edu> wrote:
Hi David…
David Gibbs wrote:
Miguel Simon <> simon@ou.edu> > wrote:go it.
as = address space, and the folder names are pid numbers.
And, if you open /proc/pid/as, and seek to a location, and then
issue a read(), you will get the memory contents of that process
from that address.When you say ‘seek to a location’, how do I know which location
corresponds to which process? Do you have a sample code somewhere?
/proc/pid → that tells you which process.
When I say seek, I mean do an lseek() to a value. This corresponds
to a virtual address in the process pid.
read() then returns the contents of the virtual memory address that
you seeked to in process pid.
Pretty nifty, hunh?
Yup. I have been looking for something like this, I think. I have
another question: since I have the .elf file from a compiled source, I
wonder if you have some comments on how I could utilize this information
to retrieve memory content from /proc/pid/as?
Not off-hand. You might actually need to use the debug information.
(I don’t know much about ELF, or how things get loaded.)
QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.