When looking up the absolute path for a kld, call find_kld_path() first.
This enables locating the module in a different directory than the one
stored in kernel memory.
With this change, kgdb can now be run on a kernel & vmcore whose associated
modules are located in the same directory as the kernel. This makes
independent triaging of problems much easier.
This change also does not break the normal kgdb use case where no arguments
are specified; in that case kgdb loads the running kernel and its modules.
Reviewed by: adrian
Approved by: ken (mentor)
Sponsored by: Spectra Logic
MFC after: 1 month
* document the kgdb -b flag
* better verify what's valid with -b
* add more comprehensive command line help
PR: kern/175743
Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
on a core, when the core was stopped, by calling kgdb_trgt_core_pcb().
This has 2 advantages:
1. We don't need to include a machine-specific header anymore and as
such kthr.c is truly machine independent. This allows the code to
be used in a cross-debugger.
2. We don't need to lookup stoppcbs in generic code when it's an
inherently target-spicific symbol. It does not exist for ia64.
Implement kgdb_trgt_core_pcb() for all architectures, except ia64, by
calling a common function called kgdb_trgt_stop_pcb(). This function
differs from kgdb_trgt_core_pcb() in that it gets the size of the PCB
structure as an argument and as such remains machine independent.
On ia64 the PCB for stopped cores is in the PCPU structure itself.
This for better scaling. The implementation of kgdb_trgt_core_pcb()
for ia64 uses the cpuid_to_pcpu[] array to to obtain the address of
the PCB structure.
This allows a remote session to be specified with '-r' as well as a
non-default baudrate setting using '-b'.
TODO: add to the kgdb manpage.
MFC after: 2 weeks
and processes in a kernel image. This allows examination of threads that
have exited or are in the late stages of exiting.
Tested by: avg
Approved by: re (kib)
MFC after: 1 week
cpuset_t objects.
That is going to offer the underlying support for a simple bump of
MAXCPU and then support for number of cpus > 32 (as it is today).
Right now, cpumask_t is an int, 32 bits on all our supported architecture.
cpumask_t on the other side is implemented as an array of longs, and
easilly extendible by definition.
The architectures touched by this commit are the following:
- amd64
- i386
- pc98
- arm
- ia64
- XEN
while the others are still missing.
Userland is believed to be fully converted with the changes contained
here.
Some technical notes:
- This commit may be considered an ABI nop for all the architectures
different from amd64 and ia64 (and sparc64 in the future)
- per-cpu members, which are now converted to cpuset_t, needs to be
accessed avoiding migration, because the size of cpuset_t should be
considered unknown
- size of cpuset_t objects is different from kernel and userland (this is
primirally done in order to leave some more space in userland to cope
with KBI extensions). If you need to access kernel cpuset_t from the
userland please refer to example in this patch on how to do that
correctly (kgdb may be a good source, for example).
- Support for other architectures is going to be added soon
- Only MAXCPU for amd64 is bumped now
The patch has been tested by sbruno and Nicholas Esborn on opteron
4 x 12 pack CPUs. More testing on big SMP is expected to came soon.
pluknet tested the patch with his 8-ways on both amd64 and i386.
Tested by: pluknet, sbruno, gianni, Nicholas Esborn
Reviewed by: jeff, jhb, sbruno
TARGET_BIG_ENDIAN is now completely dead, except where it was
originally supposed to be used (internally in the toolchain building).
TARGET_ARCH has changed in three cases:
(1) Little endian mips has changed to mipsel.
(2) Big endian mips has changed to mipseb.
(3) Big endian arm has changed to armeb.
Some additional changes are needed to make 'make universe' work on arm
and mips after this change, so those are commented out for now.
UPDATING information will be forthcoming. Any remaining rough edges
will be hammered out in -current.
Unlike for modules with dso type, in elf object modules all the sections
have virtual address of zero. So, it is insufficient to add module base
address to section virtual address (as recorded in section header) to
get section address in kernel memory.
Instead, we should apply the same calculations that are performed by
kernel loaders (in boot code and in kernel) when they lay out sections
in memory.
Discussed with: jhb, np
MFC after: 3 weeks
a variety of bugs in binutils related to handling of 64-bit PPC ELF,
provides a GCC configuration for 64-bit PowerPC on FreeBSD, and
associated build systems tweaks.
Obtained from: projects/ppc64
Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.
Reviewed by: ru
Approved by: philip, ed (mentors)
on mips. Its not fully done yet but its a start.
Obtained from: JC - c.jayachandran@gmail.com
M gnu/usr.bin/gdb/kgdb/trgt_mips.c
M gnu/usr.bin/gdb/arch/mips/init.c
M gnu/usr.bin/gdb/arch/mips/Makefile
M gnu/usr.bin/Makefile
M contrib/gdb/gdb/mips-tdep.h
kvm_nlist skips lookup for entries that have n_type != N_UNDF.
N_UNDF happens to be zero, so n_type typically has a correct
value by accident, but not always.
Note: jhb has a patch that replaces kvm_nlist use with direct
gdb parsing.
MFC after: 5 days
X-MFC-Note: unless jhb commits kvm_nlist => kgdb_parse change
- Use ptid_get_pid() rather than ptid_get_tid() (part of the changes to
let 'tid' work for remote kgdb).
- Add a stub kgdb_trgt_new_objfile() hook.
Silence from: obrien, mips@
now only use the TID and ignore the PID and use pid_to_ptid() to build a
ptid treating the TID as a PID. The benefit of this is that the vmcore
target now uses the same scheme as GDB's remote targets. As a result,
the 'tid' command now works for remote targets (however, it only accepts
TIDs and not addresses of 'struct thread' objects).
- Use gdb_thread_select() to do the actual thread switch for the 'tid' and
'proc' commands. This now gives the same UI feedback when switching
threads as the GDB 'thread' command rather than providing no visual
output at all.
MFC after: 1 week
so that kgdb can be used more like a normal gdb:
- Load the kernel via the standard 'exec' target and allow it to be changed
via the 'file' command.
- Instead of explicitly loading the kernel file as the mail symbol file
during startup, just pass it to gdb_main() as the executable file.
- Change the kld support (via shared libraries) to cache the address of
the linker_files and linker_kernel_file variables in addition to the
offsets of various members in 'struct linker_file'.
- When a new symbol file is loaded, recompute the addresses and offsets
used by the kld support code.
- When a new symbol file is loaded, recalculate the ofs_fix variable to
account for the different ways a trapframe can be passed to trap
frame handlers in i386. This is done by adding a MD
kgdb_trgt_new_objfile() hook that is empty on all but i386.
- Don't use the directory name of the kernel specified on the command
line to find kernel modules in the kld support code. Instead,
extract the filename of the current executable via exec_bfd. Now
the 'kernel' variable is private to main.c again.
- Make the 'add-kld' command explicitly fail if no executable is loaded.
- Make the support for vmcores a real core-dump target that opens the
kernel and vmcore on open and closes the kvm connection when closed, etc.
- The 'core' command can now be used to select a vmcore to use, either
a crash dump file or /dev/mem for live debugging.
- The 'detach' command can be used to detach from a vmcore w/o attaching
to a new one.
- kgdb no longer explicitly opens a core dump during startup and no longer
has to use an atexit() hook to close the kvm connection on shutdown.
- Symbols for kld's are automatically loaded anytime a core is opened.
Also, the unread portion of dmesg is dumped just as it was done on kgdb
startup previously.
- Don't require either a remote target or core dump if a kernel is specified.
You can now just run 'kgdb kernel' similar to running gdb on an executable
and later connect to a remote target or core dump.
- Use a more relaxed way to verify remote targets specified via -r.
Instead of explicitly allowing a few non-file target specifications,
just assume that if stat() on the arg and on "/dev/" + arg both fail
that is some non-file target and pass it to gdb.
- Don't use a custom interpreter. The existing kgdb_init() hook and the
target_new_objfile() hook give us sufficient hooks during startup to
setup kgdb-specific behavior now.
- Always add the 'proc', 'tid', and 'add-kld' commands on startup and not
just if we have a core dump. Currently the 'proc' and 'tid' commands do
not work for remote targets (I will fix at least 'tid' in the next round
of changes though). However, the 'add-kld' command works fine for
loading symbols for a kernel module on a remote target.
- Always setup the 'kld' shared library target operations instead of just
if we have a core dump. Although symbols for kernel modules are not
automatically loaded when connecting to a remote target, you can do
'info sharedlibrary' after connecting to the remote target and kgdb will
find all the modules. You can then use the 'sharedlibrary' command to
load symbols from the module files.
- Change kthr_init() to free the existing list of kthr objects before
generating a new one. This allows it to be invoked multiple times
w/o leaking memory.
MFC after: 1 week
evaluate_expression() so that any errors are caught and cause the function
to return to 0. Otherwise the errors posted an exception (via longjmp())
that aborted the current operation. This fixes the kld handling for
older kernels (6.x and 7.x) that don't have the full pathname stored in
the kernel linker.
MFC after: 3 days
a junk pointer and possibly causing a seg fault if we don't have any
non-kernel klds (or are unable to walk the list due to core / kernel
mismatch).
MFC after: 1 week
kgdb(8) now treats kld's as shared libraries relative to the kernel
"binary". Thus, you can use 'info sharedlibrary' to list the kld's
along with 'sharedlibrary' and 'nosharedlibrary' to manage symbol
loading and unloading. Note that there isn't an easy way to force GDB
to use a specific path for a shared library. However, you can use
'nosharedlibrary' to unload all the klds and then use 'sharedlibrary'
to load specific klds where it gets the kld correct and use
'add-kld' for the kld's where the default open behavior doesn't work.
klds opened via 'sharedlibrary' (and during startup) do have their
sections listed in 'info files'.
- Change the 'add-kld' command to use filename completion to complete its
argument.
and build a section table from the kernel file so that 'info files' output
for kgdb now matches the usage of gdb on a regular file with the exception
that we don't list sections for memory in the crash dump.
- Add a new 'kgdb_auto_load_klds()' routine which is invoked during
startup that walks the list of linker files and tries to find a matching
kld on disk for each non-kernel kld. If a kld file is found, then it
is added as if the 'add-kld' command is invoked. One change from
'add-kld' is that this method attempts to use the 'pathname' from the
linker_file structure first to try to load the file. If that fails
it then looks in the kernel directory followed by the directories in
the module path.
- Move the kld file suffix handling into a separate routine so that it
can be called standalone and to reduce duplicate code in find_kld_path().
- Cache the offsets of members of 'struct linker_file' during startup
instead of computing them for each 'add-kld'.
- Use GDB's target_read_string() instead of direct KVM access.
- Add all resident sections from a kld by using bfd_map_over_sections() to
build the section list rather than just adding symbols for ".text",
".data", ".bss", and ".rodata".
- Change the 'add-kld' command to do a y/n prompt before adding the
symbols when run interactively to match 'add-symbol-file'.
MFC after: 1 week
optional symbols that are missing (e.g. kgdb complains about _stoppcbs and
_stopped_cpus on UP kernels). Instead, callers that really want their
symbols to be present now do explicitly warnx() about the missing symbol.
