- 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
missing until it can be cleaned up.
Reviewed by: jhb
Approved by: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3319
(DPCPU):
A new API, kvm_dpcpu_setcpu(3), selects the active CPU for the purposes
of DPCPU. Calls to kvm_nlist(3) will automatically translate DPCPU
symbols and return a pointer to the current CPU's version of the data.
Consumers needing to read the same symbol on several CPUs will invoke a
series of setcpu/nlist calls, one per CPU of interest.
This addition makes it possible for tools like netstat(1) to query the
values of DPCPU variables during crashdump analysis, and is based on
similar code handling virtualized global variables.
MFC after: 1 week
Sponsored by: Juniper Networks, Inc.
without VIMAGE virtualization in the kernel.
If we cannot resolve a symbol try to see if we can find it with
prefix of the virtualized subsystem, currently only "vnet_entry"
by identifying either the vnet of the current process for a
live system or the vnet of proc0 (or of dumptid if compiled
in a non-default way).
The way this is done currently allows us to only touch libkvm
but no single application. Once we are going to virtualize more
subsystems we will have to review this decision for better scaling.
Submitted by: rwatson (initial version of kvm_vnet.c, lots of ideas)
Reviewed by: rwatson
Approved by: re (kib)
far more convenient for libkvm to work with because of the page table
block at the beginning. As a result, the MD code is smaller.
libkvm will automatically detect old vs mini dumps on i386 and amd64.
libkvm will handle i386 PAE and non-PAE modes. There is a PAE flag in
the i386 minidump header to signal the width of the entries in the
page table block.
Other convenient values are also present, such as kernbase and the direct
map addresses on amd64.
returned an lseek offset in a "u_long *" value, which can't express >4GB
offsets on 32 bit machines (eg: PAE). Change to "off_t *" for all.
Support ELF crashdumps on i386 and amd64.
Support PAE crashdumps on i386. This is done by auto-detecting the
presence of the IdlePDPT which means that PAE is active.
I used Marcel's _kvm_pa2off strategy and ELF header reader for ELF support
on amd64. Paul Saab ported the amd64 changes to i386 and we implemented
the PAE support from there.
Note that gdb6 in the src tree uses whatever libkvm supports. If you want
to debug an old crash dump, you might want to keep an old libkvm.so handy
and use LD_PRELOAD or the like. This does not detect the old raw dump
format.
Approved by: re
and is module aware. Yes, this means that kvm_nlist(3) will find symbols
in loaded modules. The emulation of the nlist struct is pretty crude but
seems to work well enough for all the users in the tree that I found.
for over 5 years since we switched to using procfs for kvm_uread().
This cleanup was motivated by recent breakage of the default swap file
(/dev/drum) when swapon() has not been called.
static executables that depend on this will need to be relinked (ie: do
this before 'ps'), but the dynamic linked stuff should be OK (ie: 'w')
Obtained from: NetBSD (not much point reinventing the wheel.. :-)
