Commit Graph

705 Commits

Author SHA1 Message Date
Konstantin Belousov
0725fca53d Make rtld use libc_nossp_pic.a. Remove SSP shims.
Submitted by:	Luis Pires
Reviewed by:	brooks
Differential revision:	https://reviews.freebsd.org/D15341
2018-05-09 10:30:56 +00:00
Michal Meloun
fad101b3f2 Make rtld_bind_start() debugger friendly.
Save link register and annotate call frame structure so debugger can unwind
call frame created by rtld_bind_start().

MFC after:	2 weeks
2018-02-27 15:35:11 +00:00
Marius Strobl
41fc6f680b 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().
2018-02-03 23:14:11 +00:00
Pedro F. Giffuni
e6209940de 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.
2017-11-27 15:25:02 +00:00
Pedro F. Giffuni
8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00
Edward Tomasz Napierala
ef4968d9e7 Increase rtld initial memory pool size from 32kB to 128kB.
The old value was probably fine back in 1998, when that code was imported
(although the comments still mention VAX, which was quite obsolete by then);
now, however, it's too small to handle our libc, which results in some
additional calls to munmap/mmap later on.  Asking for more virtual address
space is virtually free, and syscalls are not, thus the change.

It was suggested by kib@ that this might be a symptom of a deeper problem.
It doesn't only affect libc, though - the change also improves rtld memory
management for eg KDE libraries.  I guess it's just a natural bloat.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D12834
2017-11-18 13:21:22 +00:00
John Baldwin
f2515b1cc1 Appease old GCC by disabling .cfi_sections for GCC 4.x. 2017-11-14 17:16:03 +00:00
John Baldwin
a264cb726b Some fixups to the CFI directives for PLT stub entry points.
The directives I added in r323466 and r323501 did not define a valid
CFA until several instructions into the associated functions.  This
triggers an assertion in GDB when generating a stack trace while
stopped at the first instruction of PLT stub entry point since there
is no valid CFA rule for the first instruction.

This is probably just wrong on my part as the non-simple .cfi_startproc
would have defined a valid CFA.  Instead, define a valid CFA as sp + 0
at the start of the functions and then use .cfa_def_offset to change the
offset when sp is adjusted later in the function.

Sponsored by:	DARPA / AFRL
2017-11-10 01:17:26 +00:00
John Baldwin
c3faeef12c Use NESTED() instead of LEAF() for rtld_start.
This is only cosmetic, but the entry point for rtld is not a leaf function,
and this avoids two .frame directives for rtld_start.

Sponsored by:	DARPA / AFRL
2017-11-10 01:13:45 +00:00
Bryan Drewery
ea825d0274 DIRDEPS_BUILD: Update dependencies.
Sponsored by:	Dell EMC Isilon
2017-10-31 00:07:04 +00:00
Edward Tomasz Napierala
be8f91d3d0 Use MAP_PRIVATE instead of obsolete MAP_COPY. No functional changes.
MFC after:	2 weeks
2017-10-30 08:56:04 +00:00
Edward Tomasz Napierala
152036a0f7 Plug memory leak on error case.
Reported by:	Coverity
CID:		1382112
MFC after:	2 weeks
2017-10-29 12:07:27 +00:00
Edward Tomasz Napierala
b4ed9a87f9 Remove unneeded calls to access(2) from rtld(1); just call open(2) instead.
The result looks like this:

--- przed       2017-10-21 23:19:21.445034000 +0100
+++ po  2017-10-21 23:18:50.031865000 +0100
@@ -11,7 +11,6 @@ mmap(0x0,102,PROT_READ,MAP_PRIVATE,3,0x0)      = 343665418
 close(3)                                        = 0 (0x0)
 open("/usr/local/etc/libmap.d",O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC,0165) ERR#2 'No such file or directory'
 munmap(0x80067d000,102)                                 = 0 (0x0)
-access("/usr/local/lib/libintl.so.8",F_OK)      = 0 (0x0)
 openat(AT_FDCWD,"/usr/local/lib/libintl.so.8",O_RDONLY|O_CLOEXEC|O_VERIFY,00) = 3 (0x3)
 fstat(3,{ mode=-rw-r--r-- ,inode=642560,size=55188,blksize=32768 }) = 0 (0x0)
 mmap(0x0,4096,PROT_READ,MAP_PRIVATE|MAP_PREFAULT_READ,3,0x0) = 34366541824 (0x80067d000)
@@ -20,14 +19,13 @@ mmap(0x800877000,40960,PROT_READ|PROT_EXEC,MAP_PRIVATE
 mmap(0x800a81000,4096,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_FIXED|MAP_PREFAULT_READ,3,0xa000) = 34370752512 (0x800a81000)
 munmap(0x80067d000,4096)                        = 0 (0x0)
 close(3)                                        = 0 (0x0)
-access("/usr/local/lib/libc.so.7",F_OK)                 ERR#2 'No such file or directory'
+openat(AT_FDCWD,"/usr/local/lib/libc.so.7",O_RDONLY|O_CLOEXEC|O_VERIFY,00) ERR#2 'No such file or directory'
 openat(AT_FDCWD,"/var/run/ld-elf.so.hints",O_RDONLY|O_CLOEXEC,00) = 3 (0x3)
 read(3,"Ehnt\^A\0\0\0\M^@\0\0\0\M-2\0\0"...,128) = 128 (0x80)
 fstat(3,{ mode=-r--r--r-- ,inode=970684,size=306,blksize=32768 }) = 0 (0x0)
 lseek(3,0x80,SEEK_SET)                          = 128 (0x80)
 read(3,"/lib:/usr/lib:/usr/lib/compat:/u"...,178) = 178 (0xb2)
 close(3)                                        = 0 (0x0)
-access("/lib/libc.so.7",F_OK)                   = 0 (0x0)
 openat(AT_FDCWD,"/lib/libc.so.7",O_RDONLY|O_CLOEXEC|O_VERIFY,00) = 3 (0x3)
 fstat(3,{ mode=-r--r--r-- ,inode=1605239,size=1910320,blksize=32768 }) = 0 (0x0)
 mmap(0x0,4096,PROT_READ,MAP_PRIVATE|MAP_PREFAULT_READ,3,0x0) = 34366541824 (0x80067d000)

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D12766
2017-10-24 12:56:08 +00:00
Edward Tomasz Napierala
2fe071d971 Replace lseek(2)/read(2) pair with pread(2), removing yet another syscall
from the binary startup code.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-10-24 12:04:07 +00:00
Edward Tomasz Napierala
1689a3c4ac Make find_library() conform to style(9). No functional changes.
Suggested by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-10-24 11:24:54 +00:00
Edward Tomasz Napierala
e65ad973b2 Reword the conditional; it was ugly, and adding another parameter,
which I'm going to do in a subsequent commit, would make it even uglier.
No functional changes.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-10-24 11:16:38 +00:00
Edward Tomasz Napierala
a8b31c14d2 Use xmalloc and read(2) instead of mmap(2) to read in libmap.conf(5).
This removes the need to call munmap(2) afterwards.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D12767
2017-10-24 10:48:26 +00:00
Edward Tomasz Napierala
6b61e3e47a Don't call realpath(3) from libmap rtld code. This gets rid of a few calls
to fstatat(2) at binary startup; the difference looks like this:

--- przed       2017-10-14 13:55:49.983528000 +0100
+++ po  2017-10-14 14:10:39.134343000 +0100
@@ -1,15 +1,10 @@
 mmap(0x0,32768,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANON,-1,0x0) = 34366173184 (0x800623000)
 issetugid()                                     = 0 (0x0)
-fstatat(AT_FDCWD,"/etc",{ mode=drwxr-xr-x ,inode=1364352,size=2560,blksize=32768 },AT_SYMLINK_NOFOLLOW) = 0 (0x0)
-fstatat(AT_FDCWD,"/etc/libmap.conf",{ mode=-rw-r--r-- ,inode=1373288,size=102,blksize=32768 },AT_SYMLINK_NOFOLLOW) = 0 (0x0)
 openat(AT_FDCWD,"/etc/libmap.conf",O_RDONLY|O_CLOEXEC,00) = 3 (0x3)
 fstat(3,{ mode=-rw-r--r-- ,inode=1373288,size=102,blksize=32768 }) = 0 (0x0)
 mmap(0x0,102,PROT_READ,MAP_PRIVATE,3,0x0)       = 34366205952 (0x80062b000)
 close(3)                                        = 0 (0x0)
-fstatat(AT_FDCWD,"/usr",{ mode=drwxr-xr-x ,inode=561792,size=512,blksize=32768 },AT_SYMLINK_NOFOLLOW) = 0 (0x0)
-fstatat(AT_FDCWD,"/usr/local",{ mode=drwxr-xr-x ,inode=561800,size=512,blksize=32768 },AT_SYMLINK_NOFOLLOW) = 0 (0x0)
-fstatat(AT_FDCWD,"/usr/local/etc",{ mode=drwxr-xr-x ,inode=653279,size=1536,blksize=32768 },AT_SYMLINK_NOFOLLOW) = 0 (0x0)
-fstatat(AT_FDCWD,"/usr/local/etc/libmap.d",0x7fffffffcf50,AT_SYMLINK_NOFOLLOW) ERR#2 'No such file or directory'
+open("/usr/local/etc/libmap.d",O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC,0165) ERR#2 'No such file or directory'
 munmap(0x80062b000,102)                                 = 0 (0x0)
 openat(AT_FDCWD,"/var/run/ld-elf.so.hints",O_RDONLY|O_CLOEXEC,00) = 3 (0x3)
 read(3,"Ehnt\^A\0\0\0\M^@\0\0\0\M-2\0\0"...,128) = 128 (0x80)

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D12741
2017-10-22 10:32:40 +00:00
John Baldwin
b4e9a36bf7 Handle relocations for newer non-PIC MIPS ABI.
Newer binutils supports extensions to the MIPS ABI for non-PIC code
that is used when compiling O32 binaries with clang 5 (but not used
for N64 oddly enough).  These extensions require support for
R_MIPS_COPY relocations as well as a second PLT GOT using
R_MIPS_JUMP_SLOT relocations.

For R_MIPS_COPY, use the same approach as on other architectures where
fixups are deferred to the MD do_copy_relocations.

The additional PLT GOT for jump slots is located in a .got.plt section
which is identified by a DT_MIPS_PLTGOT dynamic entry.  This GOT also
requires fixups for the first two GOT entries just as the normal GOT.
However, the entry point for this second GOT uses a different calling
convention. Rather than passing an offset into the GOT, it passes an
offset into the .rel.plt section.  This requires a second entry point
(_rtld_pltbind_start) which calls the normal _rtld_bind() rather than
_mips_rtld_bind().  This also means providing a real version of
reloc_jmpslot() which is used by _rtld_bind().

In addition, add real implementions of reloc_plt() and
reloc_jmpslots() which walk .rel.plt handling R_MIPS_JUMP_SLOT
relocations.

Reviewed by:	kib
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D12326
2017-09-12 17:46:30 +00:00
Warner Losh
08d1c5b152 End softfp->hardfp transition period for arm
On hard-float 32-bit arm platforms, always search for the soft float
binaries in the alternative locations.

Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D12274
MFC After: 1 week
2017-09-12 17:06:35 +00:00
John Baldwin
21a8b38698 Add CFI directives for _rtld_bind_start.
This allows debuggers to unwind back into the caller when stopped in the
runtime linker.

Sponsored by:	DARPA / AFRL
2017-09-11 22:18:01 +00:00
Konstantin Belousov
cf551abc8b Add serial comma.
Submitted by:	wblock
MFC after:	3 days
2017-09-01 16:56:37 +00:00
John Baldwin
f4711b38fd Compile reloc.o with -fno-jump-tables on MIPS.
In particular, the switch statement on the type of dynamic entries
in _rtld_relocate_nonplt_self() needs to not use a jump table since
jump tables on MIPS use local GOT entries which aren't initialized
until after this loop.

Suggested by:	arichardson
Reviewed by:	emaste
Sponsored by:	DARPA / AFRL
2017-08-30 20:00:15 +00:00
John Baldwin
83d33b2bb5 Read max_stack_flags from correct object.
'obj' is not initialized here.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	DARPA / AFRL
2017-08-30 18:22:52 +00:00
Enji Cooper
188e46ab03 Add supporting changes for Add limited sandbox capability to "make check"
Non-tests/... changes:
- Add HAS_TESTS= to Makefiles with libraries and programs to enable iteration
  and propagate the appropriate environment down to *.test.mk.

tests/... changes:
- Add appropriate support Makefile.inc's to set HAS_TESTS in a minimal manner,
  since tests/... is a special subdirectory tree compared to the others.

MFC after:	2 months
MFC with:	r322511
Reviewed by:	arch (silence), testing (silence)
Differential Revision:	D12014
2017-08-14 19:21:37 +00:00
Ruslan Bukin
af19cc59ca Support for v1.10 (latest) of RISC-V privilege specification.
New version is not compatible on supervisor mode with v1.9.1
(previous version).

Highlights:
    o BBL (Berkeley Boot Loader) provides no initial page tables
      anymore allowing us to choose VM, to build page tables manually
      and enable MMU in S-mode.
    o SBI interface changed.
    o GENERIC kernel.
      FDT is now chosen standard for RISC-V hardware description.
      DTB is now provided by Spike (golden model simulator). This
      allows us to introduce GENERIC kernel. However, description
      for console and timer devices is not provided in DTB, so move
      these devices temporary to nexus bus.
    o Supervisor can't access userspace by default. Solution is to
      set SUM (permit Supervisor User Memory access) bit in sstatus
      register.
    o Compressed extension is now turned on by default.
    o External GCC 7.1 compiler used.
    o _gp renamed to __global_pointer$
    o Compiler -march= string is now in use allowing us to choose
      required extensions (compressed, FPU, atomic, etc).

Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D11800
2017-08-10 14:18:09 +00:00
Ruslan Bukin
ca20f8ec29 o Replace __riscv__ with __riscv
o Replace __riscv64 with (__riscv && __riscv_xlen == 64)

This is required to support new GCC 7.1 compiler.
This is compatible with current GCC 6.1 compiler.

RISC-V is extensible ISA and the idea here is to have built-in define
per each extension, so together with __riscv we will have some subset
of these as well (depending on -march string passed to compiler):

__riscv_compressed
__riscv_atomic
__riscv_mul
__riscv_div
__riscv_muldiv
__riscv_fdiv
__riscv_fsqrt
__riscv_float_abi_soft
__riscv_float_abi_single
__riscv_float_abi_double
__riscv_cmodel_medlow
__riscv_cmodel_medany
__riscv_cmodel_pic
__riscv_xlen

Reviewed by:	ngie
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D11901
2017-08-07 14:09:57 +00:00
Enji Cooper
d511b20a69 Add HAS_TESTS to all Makefiles that are currently using the
`SUBDIR.${MK_TESTS}+= tests` idiom.

This is a follow up to r321912.
2017-08-02 08:50:42 +00:00
Enji Cooper
4b330699f8 Convert traditional ${MK_TESTS} conditional idiom for including test
directories to SUBDIR.${MK_TESTS} idiom

This is being done to pave the way for future work (and homogenity) in
^/projects/make-check-sandbox .

No functional change intended.

MFC after:	1 weeks
2017-08-02 08:35:51 +00:00
Konstantin Belousov
dd269a0bf4 Allow to specify targets by absolute paths in libmap.conf.
Submitted by:	Tatu Kilappa <tatu.kilappa@iki.fi>
PR:	221032
MFC after:	2 weeks
2017-07-27 08:33:31 +00:00
Konstantin Belousov
9152cb3868 Language improvements.
Submitted by:	wblock
MFC after:	3 days
Differential revision:	https://reviews.freebsd.org/D10826
2017-07-14 15:42:12 +00:00
Xin LI
2bbd226f5a In open_binary_fd: when using buffer size for strl* and snprintf,
always use >= instead of > to avoid truncation.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D11474
MFC after:	3 days
2017-07-05 06:12:21 +00:00
Konstantin Belousov
84de44d3f2 When reporting undefined symbol, note the version, if specified.
Use the standard syntax of name@version, I do not expect a confusion
due to unlikely possibility of the name containing the '@' character.

Requested by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-07-04 20:19:36 +00:00
Konstantin Belousov
a36deee3d3 Use address space guard to implement inter-segment gap.
Rtld checks and use old MAP_ANON/PROT_NONE method of creating gap if
running on old kernel.

Reviewed by:	alc, markj
Tested by:	pho, Qualys
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-06-24 17:04:27 +00:00
Konstantin Belousov
109f3b8c69 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
2017-05-29 13:38:26 +00:00
Konstantin Belousov
18934eb6b8 Correct explanation of the dynamic tokens handling.
Reviewed by:	emaste, jonathan
Sponsored by:	The FreeBSD Foundation
X-Differential Revision:	https://reviews.freebsd.org/D10826
2017-05-29 13:36:32 +00:00
Eric van Gyzen
7fb37371e8 rtld: fix warnings about redundant declarations
Fix warnings about redundant declarations in rtld
when libthr in increased to WARNS=6.

Reviewed by:	kib
MFC after:	3 days
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D10934
2017-05-26 15:55:03 +00:00
Konstantin Belousov
9e5e0e8850 For ld.so direct execution mode, implement -p option: search for the
binary in $PATH.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D10790
2017-05-23 10:00:52 +00:00
Konstantin Belousov
ce9600b12e Update my copyright, note The FreeBSD Foundation involvement.
While tweaking copyright block, switch to use __FBSDID for tag.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-05-18 09:34:26 +00:00
Konstantin Belousov
591986a8da Fix style [1], add static keyword before static function definition.
Noted by:	bapt [1]
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-05-18 09:31:30 +00:00
Jonathan Anderson
dc902dbd60 Fix some nroff syntax in rtld.1.
When I originally documented the LD_LIBRARY_PATH_FDS environment variable,
I used `.Ev` rather than `.It Ev` to introduce it; this led to the
documentation being embedded in the previous paragraph (LD_LIBRARY_PATH).
2017-05-18 00:32:05 +00:00
Jonathan Anderson
d5a5e50d3b Allow rtld direct-exec to take a file descriptor.
When executing rtld directly, allow a file descriptor to be explicitly
specified rather than opened from the given path. This, together with the
LD_LIBRARY_PATH_FDS environment variable, allows dynamically-linked
applications to be executed from within capability mode.

Also add some rudimentary argument parsing (without pulling in getopt or
the like) to accept this file descriptor, a help (-h) option and a basic
usage string.

Reviewed by:	kib
Sponsored by:	NSERC, RDC
Differential Revision:	https://reviews.freebsd.org/D10751
2017-05-17 22:51:28 +00:00
Konstantin Belousov
da403aea11 Pretend that there is some security when executing in direct mode.
Do not allow direct exec if we the process is suid. Try to follow Unix
permission checks for DACs, ignore ACLs.

Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D10750
2017-05-16 19:53:38 +00:00
Jonathan Anderson
7a36bd9ffd Rename rtld's parse_libdir to parse_integer.
This is a more accurate name, as the integer doesn't have to be a library
directory descriptor. It is also a prerequisite for more argument parsing
coming in the near future (e.g., parsing explicit binary descriptors).

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	NSERC
2017-05-16 13:27:44 +00:00
Konstantin Belousov
0fc65b0ab8 Make ld-elf.so.1 directly executable.
Check if passed phdr is actually phdr of the interpreter itself, and
decide that this is the case of direct execution.  In this case, the
binary to activate is specified in the argv[1].  After opening it,
shift down on-stack structure with argv, env and aux vectors to
emulate execution of the binary and not of the interpreter.

Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D10701
2017-05-15 18:48:58 +00:00
Konstantin Belousov
9104191924 Fix the AT_EXECFD functionality.
If the mapped object is linked at specific address, we must obey it.
If AT_EXECFD is not used, only in-kernel ELF image activator needed to
keep the mapping address, since only binaries are linked at the fixed
address, and binaries are mapped by kernel in this case.

Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
X-Differential revision:	https://reviews.freebsd.org/D10701
2017-05-15 18:47:25 +00:00
Konstantin Belousov
c4f7cccbe7 In _rtld(), reorder local declarations to compact the block and
partially sort them by style(9).  Move locals declarations from nested
blocks into the block at function start.

Discussed with:	emaste
MFC after:	1 week
2017-05-13 18:59:27 +00:00
Jilles Tjoelker
2d6acb22fe rtld(1): Document that LD_BIND_NOT is unset for setugid processes.
MFC after:	2 weeks
2017-03-16 22:15:43 +00:00
Konstantin Belousov
018865f8e8 Disable LD_BIND_NOT for setugid processes.
Requested by:	jilles
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-03-15 23:47:19 +00:00
Konstantin Belousov
e35ddbe448 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
2017-03-15 21:11:57 +00:00