* when we have stop/sysrq/go, we get pt_regs of whatever executes
mc_work_proc(). Would be better to see what we had at the time of
interrupt that got us stop.
* stop/stop/stop..... will give stack overflow. Shouldn't allow stop
from mconsole_stop().
* stop/stop/go leaves us inside mconsole_stop() with
os_set_fd_block(req->originating_fd, 0);
reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
just done by nested mconsole_stop(). Ditto.
* once we'd seen stop, there's a period when INTR commands are executed
out of order (as they should; we might have the things stuck badly
enough to never reach mconsole_stop(), but still not badly enough to
block mconsole_interrupt(); in that situation we _want_ things like
"cad" to be executed immediately). Once we enter monsole_stop(), all
INTR commands will be executed in order, mixed with PROC ones. We'd
better let user see that such change of behaviour has happened.
(Suggested by lennert).
* stack footprint of monsole_interrupt() is an atrocity; AFAICS we can
safely make struct mc_request req; static in function there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is needed for the console output patch, since we have a possibly
non-NULL-terminated string there. So, the new interface takes a string and a
length, and the old interface calls strlen on its string and calls the new
interface with the length.
There's also a bit of whitespace cleanup.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements a stack trace for a thread, not unlike sysrq-t does.
The advantage to this is that a break point can be placed on showreqs, so that
upon showing the stack, you jump immediately into the debugger. While sysrq-t
does the same thing, sysrq-t shows *all* threads stacks. It also doesn't work
right now. In the future, I thought it might be acceptable to make this show
all pids stacks, but perhaps leaving well enough alone and just using sysrq-t
would be okay. For now, upon receiving the stack command, UML switches
context to that thread, dumps its registers, and then switches context back to
the original thread. Since UML compacts all threads into one of 4 host
threads, this sort of mechanism could be expanded in the future to include
other debugging helpers that sysrq does not cover.
Note by jdike - The main benefit to this is that it brings an arbitrary thread
back into context, where it can be examined by gdb. The fact that it dumps it
stack is secondary. This provides the capability to examine a sleeping
thread, which has existed in tt mode, but not in skas mode until now.
Also, the other threads, that sysrq doesn't cover, can be gdb-ed directly
anyway.
Signed-off-by: Allan Graves<allan.graves@gmail.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a bunch of compile fixes provoked by building UML with gcc 4. There
are a bunch of signedness mismatches, a couple of uninitialized references,
and a botched C99 structure initialization which had somehow gone unnoticed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Al Viro
Jeff Dike
Linus Torvalds