Commit Graph

14 Commits

Author SHA1 Message Date
Pedro F. Giffuni
5e53a4f90f lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

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.
2017-11-26 02:00:33 +00:00
Will Andrews
8baaf913be libkvm: fix build failures 2017-11-12 01:36:48 +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
881b0edb8f libkvm: fix warning issues post-r291406
- Fix -Wunused warnings with *_native detection handlers by marking `kd`
  __unused, except with arm/mips, where a slightly more complicated scheme
  is required to handle the native case vs the non-native case.
- Fix -Wmissing-variable-declarations warnings by marking struct kvm_arch
  objects static.

Differential Revision:	D10071
MFC after:	1 week
Reviewed by:	vangyzen
Tested with:	WIP test code (D10024) // kgdb7121 (i386 crash/kernel on amd64)
Sponsored by:	Dell EMC Isilon
2017-03-22 02:42:00 +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
8fb15a24ce libkvm: Bounds check (more) PTE indices. 2016-07-18 01:03:39 +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
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
Ed Schouten
953e4134b5 Fix missing includes of <string.h>, to silence some compiler warnings.
Submitted by:	Pawel Worach
2009-06-14 12:42:06 +00:00
Xin LI
b7f8e2dab3 _kvm_malloc allocates memory through calloc() which
returns zeroed memory, so don't redo the initialization.
2008-10-17 20:09:00 +00:00
Xin LI
60555db2e2 Include strings.h for bzero() 2006-06-05 08:51:14 +00:00
Peter Wemm
e9ca6fe47e Teach libkvm how to read minidumps. It turns out that minidumps are
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.
2006-04-21 04:32:51 +00:00