rtld: add LD_NO_DL_ITERATE_PHDR_AFTER_FORK env var

PR: 280318

(cherry picked from commit 860c4d94ac46cee35a678cf3c9cdbd437dfed75e)

rtld(1): Spell value as VALUE, not NAME

(cherry picked from commit bc25bc6850e512c4c45effdff6178d20b5eca558)

rtld.1: clarify interaction between -u and -o

(cherry picked from commit 6a7819e43f938992304472054c83f4a6602a9e19)

rtld: add direct-exec option -o

(cherry picked from commit d1cd0cc32b53c09e72e33116b94a5b0b9781a183)

rtld(1): minor clarification for LD_STATIC_TLS_EXTRA

(cherry picked from commit 8d7473703520f315c1bcd3b3d12498eee10d563e)

rtld: introduce STATIC_TLS_EXTRA

(cherry picked from commit 95335dd3c19e0ade161bb4dc8462fc3d045ce4f8)

Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

rtld: add support for the $LIB token

similar to the same token in glibc.

Requested and reviewed by: bapt
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://review

rtld: add support for the $LIB token

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

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rtld.1: Fix misplaced text

PR: 262194
Fixes: f90218886fc8 ("rtld: introduce PRELOAD_FDS")
MFC after: 3 days

rtld: Implement LD_SHOW_AUXV

It dumps auxv as seen by interpreter, right before starting any user
code.

Copied from: glibc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

rtld direct exec: add -d option

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
M

rtld direct exec: add -d option

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

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rtld: Switch to the standard symbol lookup behavior if LD_DYNAMIC_WEAK is set

The current lookup prefers a strong definition to a STB_WEAK definition
(similar to glibc pre-2.2 behavior) which does n

rtld: Switch to the standard symbol lookup behavior if LD_DYNAMIC_WEAK is set

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

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rtld: Rename -t option to -u (ignore LD_ vars)

Requested by: arichardson
Sponsored by: The FreeBSD Foundation
MFC after: 3 days

rtld direct exec: add option to ignore LD_ variables

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

rtld dl_iterate_phdr(): dlpi_tls_data is wrong

dl_iterate_phdr() dlpi_tls_data should provide the TLS module segment
address, and not the TLS init segment address as it does now.

Reported by: emacs

rtld dl_iterate_phdr(): dlpi_tls_data is wrong

dl_iterate_phdr() dlpi_tls_data should provide the TLS module segment
address, and not the TLS init segment address as it does now.

Reported by: [email protected]
PR: 254774
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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rtld: fix the man page

In f90218886fc8 in man page I used LD_PRELOAD_PATH_FDS instead of
LD_PRELOAD_FDS.

Reported by: rpokala

rtld: introduce PRELOAD_FDS

The new PRELOAD_FDS variable accepts a list of file descriptors
that should be loaded into the process.

This may be used to optimize a loading process - in the case when

rtld: introduce PRELOAD_FDS

The new PRELOAD_FDS variable accepts a list of file descriptors
that should be loaded into the process.

This may be used to optimize a loading process - in the case when
we already have a file descriptor to the library; we don't have
to look into multiple PATH to find it.

It may also be used in capability mode to load a single additional
library without the need to open a directory that contains it.

The last use of this functionality t may be a race-free method
of loading libraries.

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D29334

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Fix a few mandoc issues

- whitespace at end of input line
- skipping paragraph macro: Pp at the end of Sh
- new sentence, new line
- consider using OS macro: Fx
- AUTHORS section without An macro
-

Fix a few mandoc issues

- whitespace at end of input line
- skipping paragraph macro: Pp at the end of Sh
- new sentence, new line
- consider using OS macro: Fx
- AUTHORS section without An macro
- skipping paragraph macro: Pp before Ss

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rtld: Add -b option to allow to specify image name different from arg0.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

rtld: Add -v switch to print some useful information about the rtld binary.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Add version indicators to rtld.

It is wrong to relate on __FreeBSD_version, either from
include/param.h, kernel, or libc, to check for rtld features.
Rtld might be from newer world than the running

Add version indicators to rtld.

It is wrong to relate on __FreeBSD_version, either from
include/param.h, kernel, or libc, to check for rtld features.
Rtld might be from newer world than the running userspace.

Add special private symbols exported by rtld itself, to indicate the
changes in runtime behavior, and features that cannot be otherwise
detected or deduced at runtime.

Note that the symbols are not exported from libc, so they intentionally
cannot be linked against, and exported from the private namespace from rtld.
Consumers are required to use dlsym(3). For instance, for
_rtld_version_laddr_offset, user should do
ptr = dlsym(RTLD_DEFAULT, "_rtld_version_laddr_offset")
or even
ptr = dlvsym(RTLD_DEFAULT, "_rtld_version_laddr_offset",
"FBSDprivate_1.0");
Non-null ptr means that the change is present.

Also add _rtld_version__FreeBSD_version indicator to report the
headers version used at time of the rtld build.

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24982

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Add serial comma.

Submitted by: wblock
MFC after: 3 days

Language improvements.

Submitted by: wblock
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D10826

Document direct execution mode for rtld.

Reviewed by: emaste, jonathan (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D1

Document direct execution mode for rtld.

Reviewed by: emaste, jonathan (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D10826

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Correct explanation of the dynamic tokens handling.

Reviewed by: emaste, jonathan
Sponsored by: The FreeBSD Foundation
X-Differential Revision: https://reviews.freebsd.org/D10826