- Add a kvaddr_type to represent kernel virtual addresses instead of
unsigned long.
- Add a struct kvm_nlist which is a stripped down version of struct nlist
that uses kvaddr_t for n_value.
- Add a kvm_native() routine that returns true if an open kvm descriptor
is for a native kernel and memory image.
- Add a kvm_open2() function similar to kvm_openfiles(). It drops the
unused 'swapfile' argument and adds a new function pointer argument for
a symbol resolving function. Native kernels still use _fdnlist() from
libc to resolve symbols if a resolver function is not supplied, but cross
kernels require a resolver.
- Add a kvm_nlist2() function similar to kvm_nlist() except that it uses
struct kvm_nlist instead of struct nlist.
- Add a kvm_read2() function similar to kvm_read() except that it uses
kvaddr_t instead of unsigned long for the kernel virtual address.
- Add a new kvm_arch switch of routines needed by a vmcore backend.
Each backend is responsible for implementing kvm_read2() for a given
vmcore format.
- Use libelf to read headers from ELF kernels and cores (except for
powerpc cores).
- Add internal helper routines for the common page offset hash table used
by the minidump backends.
- Port all of the existing kvm backends to implement a kvm_arch switch and
to be cross-friendly by using private constants instead of ones that
vary by platform (e.g. PAGE_SIZE). Static assertions are present when
a given backend is compiled natively to ensure the private constants
match the real ones.
- Enable all of the existing vmcore backends on all platforms. This means
that libkvm on any platform should be able to perform KVA translation
and read data from a vmcore of any platform.
Tested on: amd64, i386, sparc64 (marius)
Differential Revision: https://reviews.freebsd.org/D3341
1. 50+% of NO_PIE use is fixed by adding -fPIC to INTERNALLIB and other
build-only utility libraries.
2. Another 40% is fixed by generating _pic.a variants of various libraries.
3. Some of the NO_PIE use is a bit absurd as it is disabling PIE (and ASLR)
where it never would work anyhow, such as csu or loader. This suggests
there may be better ways of adding support to the tree. Many of these
cases can be fixed such that -fPIE will work but there is really no
reason to have it in those cases.
4. Some of the uses are working around hacks done to some Makefiles that are
really building libraries but have been using bsd.prog.mk because the code
is cleaner. Had they been using bsd.lib.mk then NO_PIE would not have
been needed.
We likely do want to enable PIE by default (opt-out) for non-tree consumers
(such as ports). For in-tree though we probably want to only enable PIE
(opt-in) for common attack targets such as remote service daemons and setuid
utilities. This is also a great performance compromise since ASLR is expected
to reduce performance. As such it does not make sense to enable it in all
utilities such as ls(1) that have little benefit to having it enabled.
Reported by: kib
Make sure everything linking to a privatelib and/or an internallib does it directly
from the OBJDIR rather than DESTDIR.
Add src.libnames.mk so bsd.libnames.mk is not polluted by libraries not existsing
in final installation
Introduce the LD* variable which is what ld(1) is expecting (via LDADD) to link to
internal/privatelib
Directly link to the .so in case of private library to avoid having to complexify
LDFLAGS.
Phabric: https://phabric.freebsd.org/D553
Reviewed by: imp, emaste
variants. This allows usable file system images (i.e. those with both a
shell and an editor) to be created with only one copy of the curses library.
Exp-run: antoine
PR: 189842
Discussed with: bapt
Sponsored by: DARPA, AFRL
statically linked into consumers (GDB and variants) in the base
system, and the shared library is no longer installed.
That also allows ports to be able to use a modern version of readline
PR: 162948
Reviewed by: emaste
This is currently an opt-in build flag. Once ASLR support is ready and stable
it should changed to opt-out and be enabled by default along with ASLR.
Each application Makefile uses opt-out to ensure that ASLR will be enabled by
default in new directories when the system is compiled with PIE/ASLR. [2]
Mark known build failures as NO_PIE for now.
The only known runtime failure was rtld.
[1] http://www.bsdcan.org/2014/schedule/events/452.en.html
Submitted by: Shawn Webb <lattera@gmail.com>
Discussed between: des@ and Shawn Webb [2]
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.
it to recognise what ABI to use on amd64 (and possibly others) platform.
Display PID and process name as a part of the 'info threads' output, TIDs
alone are too confusing. Introduce new commmands 'tid <tid>' and 'proc <pid>'
to accompany gdb's default 'thread <thread num>' to make the task of switching
between different contexts easier.
is basicly a shell on top of libgdb that knows about kernel threads,
kernel modules and kvm(3). As the word "beginnings" implies, not
all of the features have been implemented yet. The tool is useful
and I'd like feedback on the taken route.
The simplest way to debug a kernel core file is:
kgdb -n 0
This opens /var/crash/vmcore.0 with the corresponding kernel in
the object directory (kernel.debug is used if it exists).
Typical things that need to be added are:
o Auto loading of kernel modules,
o Handling of trapframes so that backtraces can be taken across
them,
o Some fancy commands to extract useful information out of a core
file,
o Various (probably many) other things.
