Note that the pattern for matching is made slightly more specific, so as
to permit libcompats where one is a prefix of another (e.g. CheriBSD has
lib64 and lib64c).
Reviewed by: brooks, jhb, emaste, imp, kib
Differential Revision: https://reviews.freebsd.org/D41183
converting user allocation address into overhead pointer
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
The ovu_magic is not neccessary overlaps with low byte of the ov_next,
for the big endian machines.
There is no range checking in the allocator.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
With ifunc based SIMD dispatch, we cannot use the amd64 assembly
implementations of string functions. Modify rtld to instead use
the generic functions. To avoid an architecture-specific special
case, this change is applied to all architectures.
This change is a prerequisite to and formerly part of D40693.
Sponsored by: FreeBSD Foundation
Approved by: kib
See also: D40693
Differential Revision: https://reviews.freebsd.org/D41050
For instance, dso might be mapped as needed but not yet initialized from
the other subtree of needed objects, while current object' constructor
does dlopen() for the dso. Right now rtld does relocations and other
processing based on the arrival of new objects in the global list, which
is not happens there. Directly check for the initialization state of
the object, for which we would return the handle.
One practical use case of this support is e.g. dlopen("libthr.so",
RTLD_NOLOAD) by libraries that are threading-aware but happy to live
with libc pthread shims if the program is not multithreaded.
Reviewed by: tijl
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Add a stop indicator to rtld_start to satisfy unwinders:
The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Address register is defined in the virtual unwind table,
and its rule is undefined (for example, by DW_CFA_undefined), then
there is no return address and no call address, and the virtual
unwind of stack activations is complete.
That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40949
Initial stack pointer is preserved in calle-saved %esi,
use it bellow to pass initial stack pointer to _rtld().
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40950
These are no longer referenced, with the one user of each now using the
double-underscore version with "32" as an argument instead.
Reviewed by: kib, brooks, jhb
Differential Revision: https://reviews.freebsd.org/D40935
We still have a tiny amount of libcompat-specific code in rtld_paths.h,
but it's been deduplicated as much as possible, and in future we may
wish to just push these variables down to the few consumers of them and
make them use the double-underscore variants with a libcompat argument
rather than give them names here.
See commit 8fad2cda93 ("bsd.compat.mk: Provide new CPP and sub-make
variables") for the context behind this change.
Reviewed by: kib, brooks, jhb
Differential Revision: https://reviews.freebsd.org/D40925
1. Add a stop indicator to rtld_start to satisfy unwinders on aarch64:
The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Address register is defined in the virtual unwind table,
and its rule is undefined (for example, by DW_CFA_undefined), then
there is no return address and no call address, and the virtual
unwind of stack activations is complete.
2. Add a proper annotations for CFA.
That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D40844
Use the LDP (load pair registers) instruction to load entry point
arguments from the stack.
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D40843
The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Address register is defined in the virtual unwind table,
and its rule is undefined (for example, by DW_CFA_undefined), then
there is no return address and no call address, and the virtual
unwind of stack activations is complete.
That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40794
Some architectures (powerpc and RISC-V) always use 0 for the post TLS
size in which case tls_init_align isn't used by
calculate_tls_post_size. Use __unused to quiet the warning for these
platforms.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40673
If we are allocating static offset for an object with dynamic index,
return failure. In the opposite case, if dynamic index is requested for
statically allocated TLS area, directly use the offset instead of
setting the index.
Taken from NetBSD Joerg Sonnenberger change for src/libexec/ld.elf_so/tls.c
rev. 1.18.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The meaning of the flag is that static TLS allocation was done.
Taken from NetBSD Joerg Sonnenberger change for src/libexec/ld.elf_so/tls.c
rev. 1.18.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The SPDX folks have obsoleted the BSD-2-Clause-NetBSD 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
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
rtld's Makefile used to add -L${LIBDIR} to LDFLAGS when MK_TOOLCHAIN was
no. This was done as part of a change to fix building rtld with
MK_TOOLCHAIN == no (although I'm not sure this part was necessary).
In any case as of 5f2e84015d libc_pic.a is built independent of the
MK_TOOLCHAIN setting and the main part of the workaround has already
been removed. Remove the rest now.
This reverts commit c0f5aeb032.
Reviewed by: jrtc27
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39938
Do not terminate scanning group when 'd' is encountered.
The 'b' option must be last in the group, same as 'f'.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39544
Quoting from https://maskray.me/blog/2023-04-12-elf-hash-function:
The System V Application Binary Interface (generic ABI) specifies the
ELF object file format. When producing an output executable or shared
object needing a dynamic symbol table (.dynsym), a linker generates a
.hash section with type SHT_HASH to hold a symbol hash table. A DT_HASH
tag is produced to hold the address of .hash.
The function is supposed to return a value no larger than 0x0fffffff.
Unfortunately, there is a bug. When unsigned long consists of more than
32 bits, the return value may be larger than UINT32_MAX. For instance,
elf_hash((const unsigned char *)"\xff\x0f\x0f\x0f\x0f\x0f\x12") returns
0x100000002, which is clearly unintended, as the function should behave
the same way regardless of whether long represents a 32-bit integer or
a 64-bit integer.
Reviewed by: kib, Fangrui Song
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39517
These libraries are linked to directly by applications rather than
opened at runtime via dlopen().
Discussed with: oshogbo
Reviewed by: markj, emaste
Differential Revision: https://reviews.freebsd.org/D39245
Use it instead of defining IN_RTLD by base sources that want P_OSREL_
defines in userspace, but are not rtld.
This allows to remove abuse of IN_RTLD from userspace.
Reviewed by: dchagin, markj, imp
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38585
After the removal of ia64 and sparc64, all current architectures
support executable stacks at an architectural level.
This reverts commit 1290d38ac5.
Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D37904
similar to the same token in glibc.
Requested and reviewed by: bapt
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D37329
for the default output. For '-a' (per-object needed printout) the
[preloaded] banner is kept.
Instead, use special format2 for printing the preloaded objects (and
vdso), which does not include DT_NEEDED, since there is no object
needing the printed one.
In this way, the output is more compatible with glibc.
Example:
LD_PRELOAD=/lib/libthr.so.3 LD_TRACE_LOADED_OBJECTS=1 /libexec/ld-elf.so.1 /bin/ls
libutil.so.9 => /lib/libutil.so.9 (0x801099000)
libncursesw.so.9 => /lib/libncursesw.so.9 (0x8010b0000)
libc.so.7 => /lib/libc.so.7 (0x801123000)
[vdso] (0x7ffffffff000)
/lib/libthr.so.3 (0x80106c000)
Note the absense of the part before and including '=>' for preloaded
libthr.so.3, and for vdso.
PR: 265750
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D36616
Rtld locks from libthr defer signals delivery, which means that binding
is not possible while a signal handler is executed.
Binding might upgrade read-locked rtld_bind_lock to write-lock, if
symbol resolution requires loading filters. If a signal would be delivered
while rtld is in read-locked section, and signal handler needs binding
which upgrades the lock, for non-threaded image that uses default rtld
locks, we get the rtld data structures modified under the top-level
active rtld frame.
To correct the problem, mask signals for read-locking of default locks
in addition to the write-locking. It is very cheap now with
sigfastblock(2).
Note that the global state is used to track pre-locked state of either
sigfastblock(2) or signal mask (if sigfastblock(2) is administratively
disabled). It is fine for non-threaded images since there are no other
threads. But I believe that it is fine for threaded images using libc_r
as well, since masking signals disables preemption (I did not tested
it).
NetBSD PR: https://gnats.netbsd.org/56979
Reported by: tmunro
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D36396
Commit 24d0c9c1f5 introduced the following regression:
% ldd /bin/ls
/bin/ls:
libutil.so.9 => /lib/libutil.so.9 (0x1021000)
libncursesw.so.9 => /lib/libncursesw.so.9 (0x1021000)
libc.so.7 => /lib/libc.so.7 (0x1021000)
Note that the base address is the same for all displayed libraries.
Fix it by passing correct object to trace_print_obj().
Fixes: 24d0c9c1f5
Reviewed by: jrtc27
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D36198
55abf23dd3 inverted the value passed to origin_subst_one when rolling
up the existing code into a loop. If the first token is found ($ORIGIN),
this results in a wild free of part of strtab. Processing the second
token works fine and will act how the first should have regardless of
whether found, allocating memory for the string without freeing.
Processing subsequent tokens however will then leak, regardless of
whether found, as they will also believe they need to allocate memory
and can't free the string.
Found by: CHERI
Reviewed by: kib, markj
Fixes: 55abf23dd3 ("rtld: make token substitution table-driven")
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D35792
To allow for a dynamic page size on arm64 have the runtime linker
query the kernel for the currentl page size.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34765
Before, preloaded objects, if not listed as needed for any normally
linked objects, were silently ignored.
Preloaded objects are printed with the `[preloaded]` herald. The list
includes the objects not listed explicitly as recursive dependencies of
the main object, effectively dsos loaded by LD_PRELOAD mechanism.
vdso is listed as well, since it is not needed by anything.
Since there is no DT_NEEDED entry for LD_PRELOADed objects, they are
usually printed using LD_TRACE_LOADED_OBJECTS_FTM2 format due to the
failure of the heuristic based on the presence of the 'lib' prefix.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34716
