rtld: implement _dl_iterate_phdr_locked

Some sanitizers need to be able to use dl_iterate_phdr() after stopping
the rest of the process, but it's very hard to do so reliably as a
non-participant in

rtld: implement _dl_iterate_phdr_locked

Some sanitizers need to be able to use dl_iterate_phdr() after stopping
the rest of the process, but it's very hard to do so reliably as a
non-participant in the main logic of the program.

Introduce _dl_iterate_phdr_locked to bypass the locking that's normally
required for dl_iterate_phdr() and slap some scary warning on it. It
will remain undocumented and probably shouldn't be used for anything
else.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D47558

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rtld: add rtld_{get,set}_var

Reviewed by: brooks (previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D

rtld: add rtld_{get,set}_var

Reviewed by: brooks (previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D47351

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Remove $FreeBSD$: one-line .h pattern

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

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: emacsray@gmail.com
PR: 254774
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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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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Merge sync of head

MFhead @ r277403

Reintegrate head: r274132-r277384

Sponsored by: The FreeBSD Foundation

Reintegrate head revisions r273096-r277147

Sponsored by: The FreeBSD Foundation

Add rtld private interface for dso to detect dynamic loading
vs. static linking.

Tested by: pho, antoine (exp-run)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

MFC @ r266724

An SVM update will follow this.

IFC @266473

Merge from head

- Export the function added in r265456 rather than the non-existent
_rtld_debug_postinit(). [1]
- Use __compiler_membar() instead of inline asm in _r_debug_state() and
_r_debug_postinit(). [2]

P

- Export the function added in r265456 rather than the non-existent
_rtld_debug_postinit(). [1]
- Use __compiler_membar() instead of inline asm in _r_debug_state() and
_r_debug_postinit(). [2]

Pointy hat to: markj [1]
Reported by: attilio [2]
Discussed with: kib
X-MFC-With: r265456

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Add a postinit debugger hook to rtld. This will be used by dtrace(1) to halt
the victim process before its entry point is called, at which point probes
and DOF data are registered with the kernel. Th

Add a postinit debugger hook to rtld. This will be used by dtrace(1) to halt
the victim process before its entry point is called, at which point probes
and DOF data are registered with the kernel. The r_debug_state hook cannot
be used for this purpose, as it is called before the program's init routines
are invoked and in particular before DOF data is registered (via drti.o).

Reviewed by: kib
MFC after: 2 weeks

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IFC @ r234692

sys/amd64/include/cpufunc.h
sys/amd64/include/fpu.h
sys/amd64/amd64/fpu.c
sys/amd64/vmm/vmm.c

- Add API to allow vmm FPU state init/save/restore.

FP stuff discussed with: kib

IFC @230489 (pending review).

Implement fdlopen(3), an rtld interface to load shared object by file
descriptor.

Requested and tested by: des (previous version)
Reviewed by: des, kan (previous version)
MFC after: 2 weeks

Remove a hack made obsolete by the binutils 2.17 merge.

In rtld, read the initial stack access mode from AT_STACKPROT as set
by kernel, and parse PT_GNU_STACK phdr from linked and loaded dsos.

If the loaded dso requires executable stack, as specified by

In rtld, read the initial stack access mode from AT_STACKPROT as set
by kernel, and parse PT_GNU_STACK phdr from linked and loaded dsos.

If the loaded dso requires executable stack, as specified by PF_X bit
of p_flags of PT_GNU_STACK phdr, but current stack protection does not
permit execution, the __pthread_map_stacks_exec symbol is looked up
and called. It should be implemented in libc or threading library and
change the protection mode of all thread stacks to be executable.

Provide a private interface _rtld_get_stack_prot() to export the stack
access mode as calculated by rtld.

Reviewed by: kan

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Introduce implementation-private rtld interface _rtld_addr_phdr, which
fills struct dl_phdr_info for the shared object that contains the
specified address, if any.

Idea and reviewed by: kan
MFC afte

Introduce implementation-private rtld interface _rtld_addr_phdr, which
fills struct dl_phdr_info for the shared object that contains the
specified address, if any.

Idea and reviewed by: kan
MFC after: 3 weeks

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RTLD support for powerpc64. A few small modifications to the Makefile
and symbol map are required to support various consequences of the dot
symbol scheme:

- Symbols beginning with a dot are reserve

RTLD support for powerpc64. A few small modifications to the Makefile
and symbol map are required to support various consequences of the dot
symbol scheme:

- Symbols beginning with a dot are reserved, so start private symbols with
an underscore.
- In order to set RTLD breakpoints, gdb must be able to locate the text
entry point, not the data section function descriptor, so add
.r_debug_state to the symbol map on powerpc64.

Obtained from: projects/ppc64

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Merge from head

- Merge from HEAD

Allow the NULL, RTLD_SELF and RTLD_NEXT handles to work with dlfunc(3).
dlfunc() called dlsym() to do the work, and dlsym() determines the dso
that originating the call by the return address. Due to

Allow the NULL, RTLD_SELF and RTLD_NEXT handles to work with dlfunc(3).
dlfunc() called dlsym() to do the work, and dlsym() determines the dso
that originating the call by the return address. Due to this, dlfunc()
operated as if the caller is always the libc.

To fix this, move the dlfunc() to rtld, where it can call the internal
implementation of dlsym, and still correctly fetch return address.
Provide usual weak stub for the symbol from libc for static binaries.
dlfunc is put to FBSD_1.0 symver namespace in the ld.so export to
override dlfunc@FBSD_1.0 weak symbol, exported by libc.

Reported, analyzed and tested by: Tijl Coosemans <tijl ulyssis org>
PR: standards/133339
Reviewed by: kan

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