Commit Graph

61 Commits

Author SHA1 Message Date
Jung-uk Kim
483c6da3a2 libkvm: Refine the previous commit (645eaa2cca)
Resort free()'ing memory in kvm_close() to make it easier to MFC.

MFC after:	3 days
2021-03-03 18:50:45 -05:00
Jung-uk Kim
645eaa2cca libkvm: Plug couple of memory leaks and check possible calloc(3) failure
First, r204494 introduced dpcpu_off in struct __kvm and it was allocated
from _kvm_dpcpu_init() but it was not free(3)'ed from kvm_close(3).
Second, r291406 introduced kvm_nlist2(3) and converted kvm_nlist(3) to
use the new function but it did not free the temporary buffer.
Also, check possible calloc(3) failure while I am in the neighborhood.

MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D29019
2021-03-03 18:10:00 -05:00
Bjoern A. Zeeb
10108cb673 Partially revert VNET change and expand VNET structure.
Revert parts of r353274 replacing vnet_state with a shutdown flag.

Not having the state flag for the current SI_SUB_* makes it harder to debug
kernel or module panics related to VNET bringup or teardown.
Not having the state also does not allow us to check for other dependency
levels between components, e.g. for moving interfaces.

Expand the VNET structure with the new boolean flag indicating that we are
doing a shutdown of a given vnet and update the vnet magic cookie for the
change.

Update libkvm to compile with a bool in the kernel struct.

Bump __FreeBSD_version for (external) module builds to more easily detect
the change.

Reviewed by:	hselasky
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D23097
2020-02-17 11:08:50 +00:00
Leandro Lupori
38cf2a4334 Implement kvm_kerndisp
This change adds a new libkvm function, kvm_kerndisp(), that can be used to
retrieve the kernel displacement, that is the difference between the kernel's
base virtual address at run time and the kernel base virtual address specified
in the kernel image file.

This will be used by kgdb, to properly relocate kernel symbols, when needed.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D23285
2020-02-06 13:21:59 +00:00
John Baldwin
993d074be6 Use __SCCSID for SCCS IDs in libkvm sources.
Rather than using #ifdef's around a static char array, use the
existing helper macro from <sys/cdefs.h> for SCCS IDs.  To
preserve existing behavior, add -DNO__SCCSID to CFLAGS to not
include SCCS IDs in the built library by default.

Reviewed by:	brooks, dab (older version)
Reviewed by:	rgrimes
Differential Revision:	https://reviews.freebsd.org/D15459
2018-05-22 15:52:22 +00:00
Pedro F. Giffuni
8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00
Will Andrews
c9057838be libkvm: add kvm_walk_pages API.
This API allows callers to enumerate all known pages, including any
direct map & kernel map virtual addresses, physical addresses, size,
offset into the core, & protection configured.

For architectures that support direct map addresses, also generate pages
for any direct map only addresses that are not associated with kernel
map addresses.

Fix page size portability issue left behind from previous kvm page table
lookup interface.

Reviewed by:	jhb
Sponsored by:	Backtrace I/O
Differential Revision:	https://reviews.freebsd.org/D12279
2017-11-11 23:30:58 +00:00
Enji Cooper
0f5425a4fc kvm_write: fix -Wcast-qual warning in pointer arithmetic argument
Cast buf to `const char *` when doing arithmetic operation to match
`cp`'s type [1].

Differential Revision:	D10082
MFC after:	1 week
Reviewed by:	cem (earlier diff), vangyzen
Submitted by:	cem [1]
Sponsored by:	Dell EMC Isilon
2017-03-21 20:48:36 +00:00
Enji Cooper
7d0a282a12 kvm_geterr: handle kd == NULL in a deterministic/graceful manner
Return a NUL string instead of just working by accident with kvm_geterr(3)
when MALLOC_PRODUCTION is disabled (I didn't confirm the MALLOC_PRODUCTION
being enabled path).

Document the new explicit return behavior for kvm_geterr(3), as well
as the previous implicit behavior, i.e., the buffer attached to
returned via kvm_geterr(3) would be empty if a previous error hadn't been
stored in `kd`.

Differential Revision:	D10022
MFC after:	1 week
Reviewed by:	vangyzen
Sponsored by:	Dell EMC Isilon
2017-03-21 19:02:17 +00:00
Enji Cooper
54fc00f7f9 Handle kd == NULL gracefully with kvm_close(3)
Don't segfault in kvm_close(3) if provided a NULL pointer. Instead, return
-1 and set errno to EINVAL.

Document this new behavior explicitly.

MFC after:	1 week
Reviewed by:	vangyzen
Sponsored by:	Dell EMC Isilon
Differential Revision:	D10065
2017-03-20 18:28:22 +00:00
Enji Cooper
4937896a10 kvm_close(3): return error instead of blindly returning 0
`error` is the accumulated error from previous close(2) calls.

This bug has been present since the libcall's import from 4.4BSD
Lite (r1573).

MFC after:	1 week
Noticed by:	vangyzen (D10022)
Relnotes:	yes
Sponsored by:	Dell EMC Isilon
2017-03-20 02:47:28 +00:00
Enji Cooper
28047d83f0 Return NULL instead of 0 on failure in _kvm_open, kvm_open{,2,files}
This is being done for the following reasons:
- kvm_open(3), etc says they will return NULL.
- NULL by definition is (void*)0 per POSIX, but can be redefined,
  depending on the compiler, etc.

MFC after:	1 week
Sponsored by:	Dell EMC Isilon
2017-03-16 02:31:42 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Andriy Gapon
7502cc401b libkvm: support access to vmm guest memory, allow writes to fwmem and vmm
This change consists of two parts:
- allow libkvm to recognize /dev/vmm/* character devices as devices that
  provide access to the physical memory of a system (similarly to /dev/fwmem*)
- allow libkvm to recognize that /dev/vmm/* and /dev/fwmem* devices provide
  access to the physical memory of live remote systems and, thus, the memory
  is writable

As a result, it should be possible to run commands like
$ kgdb -w /path/to/kernel /dev/fwmem0.0
$ kgdb /path/to/kernel /dev/vmm/guest

Reviewed by:	kib, jhb
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	Panzura
Differential Revision: https://reviews.freebsd.org/D8679
2016-12-27 10:17:56 +00:00
Will Andrews
ffdeef3234 libkvm: Improve physical address lookup scaling.
Instead of using a hash table to convert physical page addresses to offsets
in the sparse page array, cache the number of bits set for each 4MB chunk of
physical pages.  Upon lookup, find the nearest cached population count, then
add/subtract the number of bits from that point to the page's PTE bit.
Then multiply by page size and add to the sparse page map's base offset.

This replaces O(n) worst-case lookup with O(1) (plus a small number of bits
to scan in the bitmap).  Also, for a 128GB system, a typical kernel core of
about 8GB will now only require ~4.5MB of RAM for this approach instead of
~48MB as with the hash table.

More concretely, /usr/sbin/crashinfo against the same core improves from a
max RSS of 188MB and wall time of 43.72s (33.25 user 2.94 sys) to 135MB and
9.43s (2.58 user 1.47 sys).  Running "thread apply all bt" in kgdb has a
similar RSS improvement, and wall time drops from 4.44s to 1.93s.

Reviewed by:	jhb
Sponsored by:	Backtrace I/O
2016-07-18 01:55:25 +00:00
Will Andrews
197eca22ed libkvm: Put private kvm routines in kvm_private.c. 2016-07-18 01:02:52 +00:00
Pedro F. Giffuni
75f46cf6c8 lib: minor spelling fixes in comments.
No functional change.
2016-05-01 19:37:33 +00:00
Enji Cooper
fb0e1892d9 Fix up pointer issues with lib/libkvm
In particular,
- avoid dereferencing NULL pointers
- test pointers against NULL, not 0
- test for errout == NULL in the top-level functions (kvm_open, kvm_openfiles,
  kvm_open2, etc)
- Replace a realloc and free on failure with reallocf

Found with: devel/cocchinelle

Differential Revision: https://reviews.freebsd.org/D5954
MFC after: 1 week
Reviewed by: jhb
Sponsored by: EMC / Isilon Storage Division
2016-04-22 18:05:34 +00:00
John Baldwin
7f911abe54 Add support to libkvm for reading vmcores from other architectures.
- 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
2015-11-27 18:58:26 +00:00
John Baldwin
9789cd30e5 Remove trailing whitespace. 2015-11-26 19:42:10 +00:00
Marcel Moolenaar
3f6558c489 Allow building a cross libkvm by setting TARGET_ARCH. The library so
produced will be called libkvm-${ARCH} instead of libkvm. This allows
installing it alongside the native version.
For symbol lookups, use ps_pglobal_lookup() instead of __fdnlist()
when building a cross libkvm. It is assumed that the cross tool that
uses the cross libkvm also provides an implementation for this
proc_services function.

Note that this commit does not change any of the architecture-specific
code for cross-compilation.
2013-12-28 23:01:57 +00:00
Jilles Tjoelker
7b05a79942 libkvm: Make second /dev/null file descriptor close-on-exec as well.
MFC after:	1 week
2013-05-04 11:45:48 +00:00
Jilles Tjoelker
76dce67f0f libkvm: Use O_CLOEXEC instead of separate fcntl(F_SETFD) call.
MFC after:	1 week
2013-05-04 09:47:51 +00:00
Ulrich Spörlein
948db0b9e9 libkvm: fix logic inversion introduced with last commit
Reported by:	Brandon Gooch <jamesbrandongooch@gmail.com>
Pointy hat to:	uqs
2011-02-02 17:01:26 +00:00
Ulrich Spörlein
c10970dd7d libkvm code janitoring
- make WARNS=6 clean for archs w/o strict alignment requirments
- add const, ANSIfy, remove unused vars, cast types for comparison
- thanks to differing definitions of VM_MIN_ADDRESS across our archs, we
  need to trick the compiler to not complain about signedness. We could
  either fix VM_MIN_ADDRESS to always be a simple integer or make the
  check conditional on $ARCH.

Closes PRs:	kern/42386, kern/83364
Reviewed by:	bde
2011-01-23 11:08:28 +00:00
Dimitry Andric
5f67450d3a Similar to sys/net/vnet.h, define the linker set name for sys/sys/pcpu.h
as a macro, and use it instead of literal strings.
2010-11-14 20:14:25 +00:00
Robert Watson
ccd8bad0bb A first cut at teaching libkvm how to deal with dynamic per-CPU storage
(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.
2010-03-01 00:27:55 +00:00
Bjoern A. Zeeb
7cf8b4b933 Make libkvm work on live systems and crashdumps with and
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)
2009-07-23 21:12:21 +00:00
Xin LI
01c56ef230 Reduce code duplication: use calloc() intead of malloc()
and memset afterward.
2008-10-17 20:11:28 +00:00
Xin LI
8b8ffe64e9 Plug memory leaks that is observed when argbuf or argspc is used in the
context.

Submitted by:	Michal Vranek <michal.vranek seznam cz>
PR:		bin/118380
MFC after:	1 month
2008-01-12 00:54:47 +00:00
Hidetoshi Shimokawa
d7dc9f7649 Re-enable raw dump format support on i386 and amd64 for /dev/fwmem. 2007-06-15 11:35:11 +00:00
Warner Losh
67e405315d Remove the advertising clause. UCB did this some time ago, but these
files were never updated to reflect that.

MFC After: 2 days
2007-01-08 17:35:36 +00:00
Wojciech A. Koszek
6e6dfbf26e Don't forget to set internal error message in kvm_nlist().
Approved by:	cognet (mentor)
2006-09-20 12:09:21 +00:00
Christian S.J. Peron
65efc5ee23 Validate that the supplied file is not empty before trying mmap(2) it
and access the pages associated with it.

Submitted by:	Wojciech A. Koszek
PR:		bin/91411
MFC after:	1 week
2006-01-15 20:30:13 +00:00
Peter Wemm
e55a0cd805 Support crash dumps > 4GB in size on 32 bit platforms. _kvm_kvatop()
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
2005-06-29 22:39:41 +00:00
Stefan Farfeleder
1a5ff9285a Avoid assignments to cast expressions.
Reviewed by:	md5
Approved by:	das (mentor)
2004-06-08 13:08:19 +00:00
Hidetoshi Shimokawa
7928124aa5 Allow to specify a character special device as a core file.
This enable us to use /dev/fwmem* as a core file.
e.g.
	ps -M /dev/fwmem0.0 -N kernel.debug
	dmesg -M /dev/fwmem0.0 -N kernel.debug
	gdb -k -c /dev/fwmem0.0 kernel.debug
You need to set target EUI64 in hw.firewire.fwmem.eui64_hi/lo before
opening the device. On the target arch, (PCI) bus address must be
equivalent to physical address.
(We cannot use this for sparc64 because of IOMMU.)

No objection in: -audit
2003-10-29 14:02:16 +00:00
Poul-Henning Kamp
8d2fd95bc8 Remove unnecssary <vm/swap_pager.h> includes.
These were probably not cleaned up back in whatever murky past these
files were split into separate files.
2003-07-31 21:44:31 +00:00
Jacques Vidrine
f76b74d6d7 In kvm_openfiles/kvm_open, mark the file descriptors as close-on-exec.
Applications can not do this themselves, as the descriptors are hidden
behind the opaque `kvm_t' type.
2002-09-11 16:41:39 +00:00
Alfred Perlstein
a82bbc730e Assume __STDC__, remove non-__STDC__ code.
Submitted by: keramida
2002-05-28 17:03:12 +00:00
David E. O'Brien
69160b1eb7 Remove __P() usage. 2002-03-21 23:54:04 +00:00
David E. O'Brien
be04b6d190 Remove 'register' keyword. 2002-03-21 23:39:28 +00:00
Ruslan Ermilov
fe42e96eff Finish cleanup in kvm.c revisions 1.10 and 1.11 -- mark sf (swapfile)
argument to kvm_open() and kvm_openfiles() as unused.

BSD didn't read swap since kvm.c CSRG revision 5.21 (u-area is pageable
under new VM.  no need to read from swap.)

The old !NEWVM code was removed in CSRG revision 5.23 (~ten years ago).
2002-01-22 10:07:03 +00:00
Bruce Evans
6eabd84580 Compensate for "Compensate for header dethreading" by backing it out. 2001-10-10 17:48:44 +00:00
Matthew Dillon
e67f5b9fca Implement __FBSDID() 2001-09-16 21:35:07 +00:00
Mark Murray
82633431b3 Compensate for header dethreading. 2001-05-01 09:24:15 +00:00
Kris Kennaway
ba3c0383aa Limit the amount of data copied to the error buffer to _POSIX2_LINE_MAX.
This is the documented size which the user-provided buffer must be.
2000-08-04 09:23:07 +00:00
Jacques Vidrine
91a594d823 Change the return value of kvm_read/kvm_write to be -1 on error, to
match the documented interface.

Previously it returned 0 on error.

PR:		bin/10511
2000-03-31 15:04:25 +00:00
David E. O'Brien
b787589098 -Wall, which caught a real bug where buflen wasn't being set properly. 2000-03-27 00:33:45 +00:00
Peter Wemm
c4a7cdb3b6 Use kldsym(2) to lookup symbol values. This avoids the kvm_mkdb juggling
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.
1999-12-27 07:14:58 +00:00