rtld: introduce STATIC_TLS_EXTRA

The new STATIC_TLS_EXTRA variable provides a means for applications
to increases the size of the extra static TLS space allocated by
rtld beyond the default of '128'

rtld: introduce STATIC_TLS_EXTRA

The new STATIC_TLS_EXTRA variable provides a means for applications
to increases the size of the extra static TLS space allocated by
rtld beyond the default of '128'. This extra static TLS space is used
for objects loaded with dlopen.

The value specified in the variable must be no less than the default
value and no greater than the maximum allowed value for size_t type.

If an invalid value is specified, rtld will ignore it and just use
the default value.

The rtld(1) man page is updated to document this new option.

Obtained from: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D42025

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Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

rtld: rename tls_done to tls_static

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

rtld: rename tls_done to tls_static

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

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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

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

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sys/param.h: Add _WANT_P_OSREL

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.

R

sys/param.h: Add _WANT_P_OSREL

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

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TLS: Use <machine/tls.h> for libc and rtld.

- 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 va

TLS: Use <machine/tls.h> for libc and rtld.

- 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

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amd64: Allocate TCB with alignment of 16 rather than 8.

This matches the TLS_TCB_ALIGN definition in libc.

Reviewed by: kib, jrtc27
Sponsored by: The University of Cambridge, Google Inc.
Differenti

amd64: Allocate TCB with alignment of 16 rather than 8.

This matches the TLS_TCB_ALIGN definition in libc.

Reviewed by: kib, jrtc27
Sponsored by: The University of Cambridge, Google Inc.
Differential Revision: https://reviews.freebsd.org/D33349

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rtld: Remove calculate_tls_end

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

rtld: Remove calculate_tls_end

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

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rtld: Fix i386/amd64 TP offset when p_vaddr % p_align != 0

For a Variant II architecture, the TP offset of a TLS symbol is st_value -
tlsoffset + r_addend. tlsoffset is computed by either calculate_

rtld: Fix i386/amd64 TP offset when p_vaddr % p_align != 0

For a Variant II architecture, the TP offset of a TLS symbol is st_value -
tlsoffset + r_addend. tlsoffset is computed by either calculate_tls_offset
or calculate_first_tls_offset.

The return value of calculate_first_tls_offset is the smallest integer
satisfying res >= size and (-res) % p_align = p_vaddr % p_align
(= p_offset % p_align). (The formula is a bit contrived. The basic idea
is to subtract the minimum integer from size + align - 1 so that the result
ihas the expected remainder.)

Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31538
Differential revision: https://reviews.freebsd.org/D31541

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rtld: use _get_tp() in __tls_get_addr()

This eliminates some non-trivial amount of code duplication, where done.
Only x86 and mips are handled right now.

Tested by: bdragon (powerpc), mhorne (

rtld: use _get_tp() in __tls_get_addr()

This eliminates some non-trivial amount of code duplication, where done.
Only x86 and mips are handled right now.

Tested by: bdragon (powerpc), mhorne (riscv)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623

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rtld/x86/reloc.c: style

Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623

rtld-elf(1): remove obsolete pre_init() hook

It's no longer used since 600ee699ed2805894f5972c6ac2c3d17dca7f6ce
and r358358 respectively.

Align initial-exec TLS segments to the p_vaddr % align.

This is continuation of D21163/r359634, which handled the alignment
for global mode.

Non-x86 arches are not handled, maintainers are welcomed

Align initial-exec TLS segments to the p_vaddr % align.

This is continuation of D21163/r359634, which handled the alignment
for global mode.

Non-x86 arches are not handled, maintainers are welcomed.

Tested by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D24366

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Handle non-plt IRELATIVE relocations, at least for x86.

lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.

Reported, reviewed, and tested by: dim (amd64, previous version)

Handle non-plt IRELATIVE relocations, at least for x86.

lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.

Reported, reviewed, and tested by: dim (amd64, previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23652

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Improve R_AARCH64_TLSDESC relocation.
The original code did not support dynamically loaded libraries and used
suboptimal access to TLS variables.
New implementation removes lazy resolving of TLS relo

Improve R_AARCH64_TLSDESC relocation.
The original code did not support dynamically loaded libraries and used
suboptimal access to TLS variables.
New implementation removes lazy resolving of TLS relocation - due to flaw
in TLSDESC design is impossible to switch resolver function at runtime
without expensive locking.

Due to this, 3 specialized resolvers are implemented:
- load time resolver for TLS relocation from libraries loaded with main
executable (thus with known TLS offset).
- resolver for undefined thread weak symbols.
- slower lazy resolver for dynamically loaded libraries with fast path for
already resolved symbols.

PR: 228892, 232149, 233204, 232311
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D18417

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Silence gcc warnings.

Reported by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 3 days

Remove rtld use of libc amd64_set_fsbase().

One less non-trivial dependency of rtld on libc. Also,
amd64_set_fsbase() is to be converted to ifunc, which I do not want to
support inside rtld.

Spons

Remove rtld use of libc amd64_set_fsbase().

One less non-trivial dependency of rtld on libc. Also,
amd64_set_fsbase() is to be converted to ifunc, which I do not want to
support inside rtld.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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rtld-elf: compile with WANRS=4 warnings other than -Wcast-align

Reviewed By: kib
Approved By: brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17153

o Let rtld(1) set up psABI user trap handlers prior to executing the
objects' init functions instead of doing the setup via a constructor
in libc as the init functions may already depend on these

o Let rtld(1) set up psABI user trap handlers prior to executing the
objects' init functions instead of doing the setup via a constructor
in libc as the init functions may already depend on these handlers
to be in place. This gets us rid of:
- the undefined order in which libc constructors as __guard_setup()
and jemalloc_constructor() are executed WRT __sparc_utrap_setup(),
- the requirement to link libc last so __sparc_utrap_setup() gets
called prior to constructors in other libraries (see r122883).
For static binaries, crt1.o still sets up the user trap handlers.
o Move misplaced prototypes for MD functions in to the MD prototype
section of rtld.h.
o Sprinkle nitems().

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libexec: adoption of SPDX licensing ID tags.

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 -

libexec: adoption of SPDX licensing ID tags.

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.

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Implement LD_BIND_NOT knob for rtld.

From the manpage:
When set to a nonempty string, prevents modifications of the PLT slots
when doing bindings. As result, each call of the PLT-resolved
function

Implement LD_BIND_NOT knob for rtld.

From the manpage:
When set to a nonempty string, prevents modifications of the PLT slots
when doing bindings. As result, each call of the PLT-resolved
function is resolved. In combination with debug output, this provides
complete account of all bind actions at runtime.

Same feature exists on Linux and Solaris.

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

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Adjust r308689 to make rtld compilable with either in-tree or
(hopefully) stock gcc 4.2.1 on i386 and other arches.

In particular:
- Do not use %ebx in the asm constraints on i386, since rtld is
c

Adjust r308689 to make rtld compilable with either in-tree or
(hopefully) stock gcc 4.2.1 on i386 and other arches.

In particular:
- Do not use %ebx in the asm constraints on i386, since rtld is
compiled with -fPIC and gcc cannot handle GOT-base register reload
(clang and newer gcc can).
- Avoid direct use of [static N] construct in the function
declaration/definion. In-tree gcc was patched to support this, but
stock 4.2.1 cannot handle the feature.

Requested by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Pass CPUID[1] %edx (cpu_feature), %ecx (cpu_feature2) and
CPUID[7].%ebx (cpu_stdext_feature), %ecx (cpu_stdext_feature2) to the
ifunc resolvers on x86.

It is much more clean to use CPUID instruction

Pass CPUID[1] %edx (cpu_feature), %ecx (cpu_feature2) and
CPUID[7].%ebx (cpu_stdext_feature), %ecx (cpu_stdext_feature2) to the
ifunc resolvers on x86.

It is much more clean to use CPUID instruction in usermode to retrieve
this information than to pass AT_HWCAP aux vector from kernel, on
x86. Still, the change does allow for use of AT_HWCAP on arches where it is
needed, by passing aux array to ifunc_init() initializer which should
prepare arguments for ifunc resolvers.

Current signature for resolvers on x86 is
func_t iresolve(uint32_t cpu_feature, uint32_t cpu_feature2,
uint32_t cpu_stdext_feature, uint32_t cpu_stdext_feature2);
where arguments have identical meaning as the kernel variables of the
same name. The ABIs allow to use resolvers with the void or shortened
list of arguments.

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D8448

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Do not call callbacks for dl_iterate_phdr(3) with the rtld bind and
phdr locks locked. This allows to call rtld services from the
callback, which is only reasonable for dlopen(path, RTLD_NOLOAD) to

Do not call callbacks for dl_iterate_phdr(3) with the rtld bind and
phdr locks locked. This allows to call rtld services from the
callback, which is only reasonable for dlopen(path, RTLD_NOLOAD) to
test existence of the library in the image, and for dlsym(). The
later might still be not quite safe, due to the lazy resolution of
filters.

To allow dropping the locks around iteration in dl_iterate_phdr(3), we
insert markers to track current position between relocks. The global
objects list is converted to tailq and all iterators skip markers,
globallist_next() and globallist_curr() helpers are added.

Reported and tested by: davide
Reviewed by: kan
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks

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rtld: wrap a comment to 80 columns