tracing process to obtain information about the LWP that caused the
traced process to stop. Debuggers can use this information to select
the thread currently running on the LWP as the current thread.
The request has been made compatible with NetBSD for as much as
possible. This implementation differs from NetBSD in the following
ways:
1. The data argument is allowed to be smaller than the size of the
ptrace_lwpinfo structure known to the kernel, but not 0. This
is opposite to what NetBSD allows. The reason for this is that
we can extend the structure without affecting older binaries.
2. On NetBSD the tracing process is to set the pl_lwpid field to
the Id of the LWP it wants information of. We don't do that.
Our ptrace interface allows passing the LWP Id instead of the
PID. The tracing process is to set the PID to the LWP Id it
wants information of.
3. When the PID is actually the PID of the tracing process, this
request returns the information about the LWP that caused the
process to stop. This was the whole purpose of the request in
the first place.
When the traced process has exited, this request will return the
LWP Id 0, indicating that the process state is not the result of
an event specific to a LWP.
more generic, but that didn't actually happen. Since the feature to
switch backends (and historically this means from DDB to GDB) is
important, make sure people can do just that until such the generic
mechanism actually sees the light of day.
Suggested by: rwatson@
changing the backend from outside the KDB frontend. For example from
within a backend. Rewrite kdb_sysctl_current to make use of this
function as well.
in soreceive() after removing an MT_SONAME mbuf from the head of the
socket buffer.
When processing MT_CONTROL mbufs in soreceive(), first remove all of
the MT_CONTROL mbufs from the head of the socket buffer to a local
mbuf chain, then feed them into dom_externalize() as a set, which
both avoids thrashing the socket buffer lock when handling multiple
control mbufs, and also avoids races with other threads acting on
the socket buffer when the socket buffer mutex is released to enter
the externalize code. Existing races that might occur if the protocol
externalize method blocked during processing have also been closed.
Now that we synchronize socket buffer and stack state following
modifications to the socket buffer, turn the manual synchronization
that previously followed control mbuf processing with a set of
assertions. This can eventually be removed.
The soreceive() code is now substantially more MPSAFE.
the head of the mbuf chains in a socket buffer, re-synchronizes the
cache pointers used to optimize socket buffer appends. This will be
used by soreceive() before dropping socket buffer mutexes to make sure
a consistent version of the socket buffer is visible to other threads.
While here, update copyright to account for substantial rewrite of much
socket code required for fine-grained locking.
locking on 'nextrecord' and concerns regarding potentially inconsistent
or stale use of socket buffer or stack fields if they aren't carefully
synchronized whenever the socket buffer mutex is released. Document
that the high-level sblock() prevents races against other readers on
the socket.
Also document the 'type' logic as to how soreceive() guarantees that
it will only return one of normal data or inline out-of-band data.
This also fixes the (runtime) breakage introduced in the previous
commit that was the result of a botched merge. This hasn't even
been compile-tested...
a problem that could also be fixed differently without reverting previous
attempts to fix DELAY while the debugger is active (rev 1.204). The bug
was that the i8254 implements a countdown timer, while for (k)db_active
a countup timer was implemented. This resulted in premature termination
and consequently the breakage of DELAY. The fix (relative to rev 1.211)
is to implement a countdown timer for the kdb_active case. As such the
ability to step clock initialization is preserved and DELAY does what is
expected of it.
Blushed: bde :-)
Submitted by: bde
name in the debug.kdb.current sysctl. All other dereferences are
properly guarded, but this one was overlooked.
Reported by: Morten Rodal (morten at rodal dot no)
o Sources that are shared between kernel and userland and that may
contain references to DDB or any of its functions may need to
know this.
o Userland tools may include <machine/gdb_machdep.h> from now on.
Think kernel debugger...
o The kernel core file now contains the TID of the kernel thread
that made the dump.
db_elf.c, db_kld.c: The new KDB backend supports both at the same time.
db_sysctl.c: The functionality has been moved to sys/kern/subr_kdb.c.
db_trap.c: The DDB entry point has been moved to sys/ddb/db_main.c.
o Rename WITNESS_DDB to WITNESS_KDB. In the new world order KDB is the
acronym to use for debugging related code. The DDB option is used
to enable the DDB debugger backend only.
o Likewise, rename DDB_TRACE to KDB_TRACE, rename DDB_UNATTENDED to
KDB_UNATTENDED and rename SC_HISTORY_DDBKEY to SC_HISTORY_KDBKEY.
o Remove DDB_NOKLDSYM. The new DDB backend supports pre-linker symbol
lookups as well as KLD symbol lookups at the same time.
o Remove GDB_REMOTE_CHAT. The GDB protocol hacks to allow this are
FreeBSD specific. At the same time, the GDB protocol has packets
for console output.
actually work.
Make the PCI and PCCARD attachments provide a bus_get_resource_list()
method so that resource listing for PCCARD works. PCCARD does not
have a bus_get_resource_list() method (yet), so I faked up the
resource list management in if_ndis_pccard.c, and added
bus_get_resource_list() methods to both if_ndis_pccard.c and if_ndis_pci.c.
The one in the PCI attechment just hands off to the PCI bus code.
The difference is transparent to the NDIS resource handler code.
Fixed ndis_open_file() so that opening files which live on NFS
filesystems work: pass an actual ucred structure to VOP_GETATTR()
(NFS explodes if the ucred structure is NOCRED).
Make NdisMMapIoSpace() handle mapping of PCMCIA attribute memory
resources correctly.
Turn subr_ndis.c:my_strcasecmp() into ndis_strcasecmp() and export
it so that if_ndis_pccard.c can use it, and junk the other copy
of my_strcasecmp() from if_ndis_pccard.c.
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
thread X switch to thread X (where X is the TID),
show threads list all threads.
The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.
With this change, ia64 has support for breakpoints.
o Make debugging code conditional upon KDB instead of DDB.
o Call kdb_enter() instead of Debugger().
o Remove implementation of Debugger().
o Check kdb_active instead of db_active.
o Call kdb_trap() according to the new world order.
o ksym_start and ksym_end changed type to vm_offset_t.
o Make debugging support conditional upon KDB instead of DDB.
o Call kdb_enter() instead of breakpoint().
o Remove implementation of Debugger().
o Call kdb_trap() according to the new world order.
unwinder:
o s/db_active/kdb_active/g
o Various s/ddb/kdb/g
o Add support for unwinding from the PCB as well as the trapframe.
Abuse a spare field in the special register set to flag whether
the PCB was actually constructed from a trapframe so that we can
make the necessary adjustments.
md_var.h:
o Add RSE convenience macros.
o Add ia64_bsp_adjust() to add or subtract from BSP while taking
NaT collections into account.
o Make debugging code conditional upon KDB instead of DDB.
o Declare ksym_start and ksym_end as extern and initialize them.
This was previously and bogusly handled by DDB itself.
o Call kdb_enter() instead of Debugger().
o Remove implementation of Debugger().
