I have been looking through the documentation for /proc and the "stack" object being a new'ish object in proc, I have also looked through the kernel commit to create it -- however the documentation does not detail exactly what is in the /proc/self/stack file -- and since I intuitively expected it to be the actual stack of the process -- however the old
pstack tool gives a different (and more believable) output.
So as an example of the stack for bash
$ cat /proc/self/stack [<ffffffff8106f955>] do_wait+0x1c5/0x250 [<ffffffff8106fa83>] sys_wait4+0xa3/0x100 [<ffffffff81013172>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff
and, using pstack
$ pstack $$ #0 0x00000038cfaa664e in waitpid () from /lib64/libc.so.6 #1 0x000000000043ed42 in ?? () #2 0x000000000043ffbf in wait_for () #3 0x0000000000430bc9 in execute_command_internal () #4 0x0000000000430dbe in execute_command () #5 0x000000000041d526 in reader_loop () #6 0x000000000041ccde in main ()
The addresses are different, and obviously the symbols are not at all the same....
Does anybody have an explanation for the difference and/or a document which describes what is actually shown in /proc-stack?