If a string is at or near the end of an input file and the amount of
remaining data in the file is smaller than the maximum string size,
the pread(2) system call would return a short read which is treated as
an error. Instead, add a new helper function for reading a string
which permits short reads so long as the data read from the file
contains a terminated string.
Reported by: jrtc27
Reviewed by: jrtc27
Sponsored by: University of Cambridge, Google, Inc.
Differential Revision: https://reviews.freebsd.org/D44419
(cherry picked from commit 785600d0fb)
Existing powerpc kernels include additional sections beyond .dynamic
in the PT_DYNAMIC segment. Relax the requirement for an exact size
match of the section and segment for PowerPC files as a workaround.
Reported by: jrtc27
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D43123
(cherry picked from commit 6631e2f9b4)
The glibc fts_open() callback type does not have the second const
qualifier and it appears that Clang 16 errors by default for mismatched
function pointer types. Add an ifdef to handle this case.
(cherry picked from commit 30887c7d48)
While parsing .dynamic, nsym is set when parsing the symbol table from
.dynsym. That parsing also sets ef->ef_symtab to a non-NULL value.
The value of nsym isn't validated until after a check for
ef->ef_symtab being NULL, so nsym always has a valid value when it is
read. However, that chain of events is a bit much for static analysis
to follow, so initialize nsym to 0 before parsing sections to quiet
the warning.
Reported by: Coverity Scan
CID: 1532339
Sponsored by: DARPA
(cherry picked from commit d281fece43)
Unlike the backend for ELF DSOs, the object file backend allocated an
aligned chunk of memory and read all of the in-memory sections from
the file into this memory even though most of the file contents were
never used. Instead, just track a set of virtual addresses (based at
0) that each loaded section would be loaded at and only read the
necessary bits from the backing file when needed.
Reviewed by: imp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D43126
(cherry picked from commit 0d557cdf6f)
Use pread as a valid offset is always passed now. Originally the DSO
code read the .hash section in two separate requests and relied on the
implicit offset for the second read, but now the hash table is fetched
in a single call.
Reviewed by: imp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D43125
(cherry picked from commit ed96fd7fc6)
Note that relbase is always 0 for DSOs so its omission for __KLD_SHARED
architectures was not a bug in practice.
Whilst here, also parenthesise the dest offset for where to avoid
transiently creating an out-of-bounds pointer, which is UB (though even
on CHERI architectures, where capability bounds compression can result
in that creating invalid capabilities that will trap on dereference,
optimisation will reassociate to the correct form in practice and thus
work just fine).
(cherry picked from commit 2a622f14e8)
Doing nothing seems to be sufficient but is strange, inconsistent with
other architectures, and not necessary when it's easy to support
properly.
(cherry picked from commit aaba1490ec)
R_PPC_RELATIVE lost its 32-bit handling in the libelf conversion.
Reported by: bapt
Fixes: 0299afdff1 ("kldxref: Make use of libelf to be a portable cross tool")
(cherry picked from commit d1ce87ae0d)
This is consistent with the other architecture-specific relocation
handlers.
Reported by: mjg
Sponsored by: DARPA
(cherry picked from commit 894f3f48c3)
This allows kldxref to operate on kernel objects from any
architecture, not just the native architecture. In particular, this
will permit generating linker.hints files as part of a cross-arch
release build.
- elf.c is a new file that includes various wrappers around libelf
including routines to read ELF data structures such as program and
section headers and ELF relocations into the "generic" forms
described in <gelf.h>. This file also provides routines for
converting a linker set into an array of addresses (GElf_Addr)
as well as reading architecture-specific mod_* structures and
converting them into "generic" Gmod_* forms where pointers are
replaced with addresses.
- The various architecture-specific reloc handlers now use GElf_*
types for most values (including GElf_Rel and GElf_Rela for
relocation structures) and use routines from <sys/endian.h> to read
and write target values. A new linker set matches reloc handlers
to specific ELF (class, encoding, machine) tuples.
- The bits of kldxref.c that write out linker.hints now use the
encoding (ELFDATA2[LM]SB) of the first file encountered in a
directory to set the endianness of the output file. Input files
with a different architecture in the same directory are skipped with
a warning. In addition, the initial version record for the file
must be deferred until the first record is finished since the
architecture of the output file is not known until then.
- Various places that used 'sizeof(void *)' throughout now use
'elf_pointer_size()' to determine the size of a pointer in the
target architecture.
Tested by: amd64 binary on both amd64 and i386 /boot/kernel
Reviewed by: imp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D42966
(cherry picked from commit 0299afdff1)
- Add a free_pnp_list to complement parse_pnp_list. Add freeing
of 'new_desc' which was previously leaked.
- Move body of loop that checked a single pnp list element against a
table entry into a parse_pnp_entry function to reduce indentation
and split parse_entry into a smaller function.
- Similarly, split out a record_pnp_info function from parse_entry
which builds the pnp_list and walks a table.
Reviewed by: imp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D42965
(cherry picked from commit c40fa3dc98)
This was originally used (along with FREEBSD_AOUT) to prefer the use
of ELF in various tools instead of a.out as part of the a.out to ELF
transition in the 3.x days. The last use of it was removed from
<link.h> in commit 66422f5b7a back in
2002, but various files still #define it.
Reviewed by: kevans, imp, emaste
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D42964
(cherry picked from commit 4a3cf5f329)
This uses the statement from other files in kldxref when the tool was
first imported in commit 9c6f92408c.
Reviewed by: kevans
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D42963
(cherry picked from commit 087c4c90d1)
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
(cherry picked from commit 4d846d260e)
These are emitted in at least two kmods, and kldxref prints a warning.
While here, remove the unneeded local variable 'val'.
Reviewed by: jrtc27, imp, emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37038
(cherry picked from commit fc4c39c54f)
We convert a string like "W32:vendor/device" into "I:vendor;I:device",
where the output is longer than the input, but only allocate space equal
to the length of the input, leading to a buffer overflow.
Instead use open_memstream so we get a safe dynamically-grown buffer.
Found by: CHERI
Reviewed by: imp, jhb (mentor)
Approved by: imp, jhb (mentor)
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D26637
supposedly having too many segments, when lld 11 links it. Such kernels
should load just fine.
Note that we may still do some tweaking of our kernel linker scripts, to
lower the number of segments, although the exact benefit is not entirely
clear.
All of them are needed to be able to boot to single user and be able
to repair a existing FreeBSD installation so put them directly into
FreeBSD-runtime.
Reviewed by: bapt, gjb
Differential Revision: https://reviews.freebsd.org/D21503
MDT_MODULE info is required to be ordered before any other MDT metadata for
a given kld because it serves as an implicit record boundary between
distinct klds for linker.hints consumers. kldxref(8) has previously relied
on the assumption that MDT_MODULE was ordered relative to other module
metadata in kld objects by source code ordering.
However, C does not require implementations to emit file scope objects in
any particular order, and it seems that GCC 6.4.0 and/or binutils 2.32 ld
may reorder emitted objects with respect to source code ordering.
So: just take two passes over a given .ko's module metadata, scanning for
the MDT_MODULE on the first pass and the other metadata on subsequent
passes. It's not super expensive and not exactly a performance-critical
piece of code. This ensures MDT_MODULE is always ordered before
MDT_PNP_INFO and other MDTs, regardless of compiler/linker movement. As a
fringe benefit, it removes the requirement that care be taken to always
order MODULE_PNP_INFO after DRIVER_MODULE in source code.
Reviewed by: emaste, imp
Differential Revision: https://reviews.freebsd.org/D20405
Parse the R_MIPS_32 and R_MIPS_64 relocations. Both Elf_Rel and
Elf_Rela relocations are handled since O32 MIPS uses Elf_Rel while N64
uses Elf_Rela. Note that R_MIPS_32 is only handled for 32-bit mips
and R_MIPS_64 for 64-bit. N32 is untested.
Reviewed by: imp
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D19870
When using kldxref on kernel modules built with clang8 + lld8,
kldxref would be unable to find the modules metadata information,
because PowerPC64 was using the ef_nop.c implementation of
ef_reloc().
When GNU LD was used, it was also relocating the metadata section of
the .ko file. LLD does not do this, but only generate dynamic
relocations for it. With minor changes, ef_powerpc.c can now work
for PowerPC64 too.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D19370
The original spec for the strings describing the PNP info didn't allow
spaces. Several times now people have broken the install by including
them. Relax the syntax to allow them after the ; which is where
people's muscle memory tends to put them.
Approved by: re@ (gjb)
Normally, we can get away with just reading the 1k buffer for the
string, since the placement of the data is generally no where near the
end of the file. However, it's possible that the string is within the
last 1k of the file, in which case the read will fail, and we'll not
produce the proper records needed for devmatch to work. By reading
using EF_SEG_READ_STRING, we automatically work around these problems
while still retaining safety.
This fix a problem with devmatch where we wouldn't load certain
modules (like ums). This didn't always happen (my tree didn't exhibit
it, while nathan's did because his optimization options were more
agressive).
Reported by: nathanw@
Address style issues including some previously raised in D13923.
- Use designated initializers for structs
- Always use bracketed return style
- No initialization in declarations
- Align function prototype names
- Remove old commented code/unused includes
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D13943
Attempting to retrieve an md_cval string from a kernel module with
kldxref would throw a offset error for modules created using lld, since
this value would be placed at the end of all allocated sections.
Add an ef_read_seg_string method to the ef interface, to allow reading
strings of varying size without attempting to read beyond the segment's
bounds.
PR: 224875
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: cem, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D13923
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified 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.
No functional change intended.
