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
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
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
it seems that glibc supports them, and such spelling is mentioned in the
ld.bfd manual. Idea seems to auto-correct some quoting/makefile sytnax
errors on linker command line.
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34247
- Include <machine/tls.h> in MD rtld_machdep.h headers.
- Remove local definitions of TLS_* constants from rtld_machdep.h
headers and libc using the values from <machine/tls.h> instead.
- Use _tcb_set() instead of inlined versions in MD
allocate_initial_tls() routines in rtld. The one exception is amd64
whose _tcb_set() invokes the amd64_set_fsbase ifunc. rtld cannot
use ifuncs, so amd64 inlines the logic to optionally write to fsbase
directly.
- Use _tcb_set() instead of _set_tp() in libc.
- Use '&_tcb_get()->tcb_dtv' instead of _get_tp() in both rtld and libc.
This permits removing _get_tp.c from rtld.
- Use TLS_TCB_SIZE and TLS_TCB_ALIGN with allocate_tls() in MD
allocate_initial_tls() routines in rtld.
Reviewed by: kib, jrtc27 (earlier version)
Differential Revision: https://reviews.freebsd.org/D33353
Consistently use `return ()'.
Fix some spacing issues with types formatting, and around binary ops.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
File descriptor we operate on might reference something that is not a
file, e.g. shmfd. In this case, we cannot check MNT_NOEXEC in
principle.
If fstatfs(2) caused some failure on normal filesystem, then typical
expectation is that read or mmap of this file would also fail. If not,
mmap(2) PROT_EXEC on MNT_NOEXEC filesystem returns EACCES.
Reported by: obiwac@gmail.com
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Default value for ld_dynamic_weak is true, non-default settings should
be activated for the false value.
Reported by: obiwac@gmail.com
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
but still for tightly coupled things like ldd(1)
Rename paths.h to rtld_paths.h.
Add guard for rtld-specific externs declarations.
Add _COMPAT32_BASENAME_RTLD and _COMPAT32_PATH_RTLD.
Reviewed by: arichardson, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32464
PIE and shared objects usually have many relative relocations. In
2017/2018, a compact relative relocation format RELR was proposed on
https://groups.google.com/g/generic-abi/c/bX460iggiKg/m/GxjM0L-PBAAJ
("Proposal for a new section type SHT_RELR") and is a pre-standard.
RELR usually takes 3% or smaller space than R_*_RELATIVE relocations.
The virtual memory size of a mostly statically linked PIE is typically
5~10% smaller.
ld.lld --pack-dyn-relocs=relr emits RELR relocations. DT_RELR has been
adopted by Android bionic, Linux kernel's arm64 port, Chrome OS (patched
glibc).
This patch adds DT_RELR support to FreeBSD rtld-elf.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D32524
to ignore lack of execute permission on the binary. The check is a
bad security theatre anyway.
Reviewed by: arichardson, imp
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32464
Scan through the set of environment variables during initialization and
store values in the corresponding ld_env_var_desc structure, in the
single pass at init time. This does not eliminate use of getenv(3) and
unsetenv(3) completely, but provides a foundation to do that as the next
step.
Also organize the scan in a way that makes it easier to support aliases
like LD_DEBUG vs. LD_64_DEBUG.
Suggested by: arichardson
Reviewed by: arichardson, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31545
Instead of specifying the main name part of the environment variable as the
string literal, create array of the var names and access them by symbolic
index. Convert main name parts into complete names by prefixing with
ABI-specific ld_env_vars.
This way the name is not repeated, and also it can carry additional
proporties explicitly. For instance, cleanup of the environment for
the setuid image does not require retyping all names.
Reviewed by: arichardson, markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31545
The current lookup prefers a strong definition to a STB_WEAK definition
(similar to glibc pre-2.2 behavior) which does not conform to the ELF
specification.
The non-compliant behavior provoked https://reviews.llvm.org/D4418
which was intended to fix -shared-libasan but introduced
new problems (and caused some sanitizer tests (e.g.
test/asan/TestCases/interception_failure_test.cpp) to fail): sanitizer
interceptors are STB_GLOBAL instead of STB_WEAK, so defining a second
STB_GLOBAL interceptor can lead to a multiple definition linker error.
For example, in a -fsanitize={address,memory,...} build, libc functions
like malloc/free/strtol/... cannot be provided by user object files.
See
https://docs.freebsd.org/cgi/getmsg.cgi?fetch=16483939+0+archive/2014/freebsd-current/20140716.freebsd-current
for discussions.
This patch implements the ELF-compliant behavior when LD_DYNAMIC_WEAK is
set. STB_WEAK wrestling in symbol lookups in `Search the dynamic linker
itself` are untouched.
Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26352
Variant I architectures use off and Variant II ones use size + off.
Define TLS_VARIANT_I/TLS_VARIANT_II symbols similarly to how libc
handles it.
Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31539
Differential revision: https://reviews.freebsd.org/D31541
lld rounds up p_memsz(PT_GNU_RELRO) to satisfy common-page-size. If the
page size is smaller than common-page-size, rounding up relro_size may
incorrectly make some RW pages read-only.
GNU ld, gold, and ld.lld ensures p_vaddr+p_memsz is a multiple of
common-page-size. While max-page-size >= system the page size,
common-page-size can be smaller than the system page size.
Submitted by: MaskRay
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31498
The mprotect() call was failing on CheriBSD when changing rtld's relro
page permissions due to missing CHERI capability permissions on the
mprotect() argument but did not report an error since the return value
was being ignored. It should never fail on any supported FreeBSD
architecture, but checking the return value seems like a good
sanity check to me.
Reviewed By: kib, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D30820
rtld preserves its current error message around calls to user init/fini
lists, to not override original error with potential secondary errors
caused by user code recursing into rtld. After 4d9128da54,
the preservation of the string itself is not enough, the 'seen'
indicator must be preserved as well. Otherwise, since new code does not
clear string (it cannot), call to _rtld_error() from errmsg_restore()
revived whatever message was consumed last.
Change errmsg_save() to return structure recording both 'seen' indicator
and the message, if any.
PR: 255698
Reported by: Eugene M. Kim <astralblue@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
This fixes a regression in d36d681615, where the call to
__tls_get_address() was performed under rtld_bind_lock write-locked.
Instead use tls_get_addr_slow() directly, with locked = true.
Reported by: jkim, many others
Tested by: jkim, bdragon (powerpc), mhorne (riscv)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623
