Commit Graph

734 Commits

Author SHA1 Message Date
Konstantin Belousov
e8927aa6c6 rtld: parse FreeBSD Feature Control note on the object load.
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2018-11-23 22:37:35 +00:00
Conrad Meyer
c15faaac95 Revert r340843 - addressed independently in r340842! 2018-11-23 18:27:16 +00:00
Conrad Meyer
66a87f8cfd rtld: Silence a false positive GCC 6.4.0 warning
The function reloc_non_plt has complicated variable lifetimes that GCC 6.4.0
(the version currently used by amd64-xtoolchain-gcc) misunderstands and
produces an erroneous warning about.  Silence it to allow the -Werror build
to proceed.

Reviewed by:	emaste
2018-11-23 18:23:29 +00:00
Konstantin Belousov
bac111cc74 Silence gcc warnings.
Reported by:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
2018-11-23 18:15:23 +00:00
Konstantin Belousov
abfc3b2fef rtld: when immediate bind mode is requested, process irelocs in PLT
immediately after other PLT relocs.

Otherwise, if the object has relro page, we write to readonly page,
and we would need to use mprotect(2) two more times to fix it.  Note
that resolve_object_ifunc() does nothing when called second time, so
there is no need to avoid existing call.

Reported and tested by:	emaste
PR:	233333
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-11-20 14:52:43 +00:00
Alex Richardson
57fe7128b7 Handle the DT_MIPS_RLD_MAP_REL dynamic tag in RTLD
This dynamic tag contains the location of the .rld_map section relative to
the location of the dynamic tag. For PIE MIPS binaries DT_MIPS_RLD_MAP can
not be used since it contains an absolute address. Without this change
GDB can not find the function program counters in other libraries and once
I apply this change I can successfully run info sharedlibraries again.

Reviewed By:	kib
Differential Revision: https://reviews.freebsd.org/D17867
2018-11-07 15:04:41 +00:00
Ed Maste
eda66948fe rtld: move relro enforcement after ifunc processing
Previously the combination of relro (implicit), -z now and ifunc use
resulted in a segfault when applying ifuncs after relro (test binary
here just calls amd64_get_fsbase()):

| % env LD_DEBUG=1 libexec/rtld-elf/obj/ld-elf.so.1 a.out
| ...
| enforcing main obj relro
| ...
| resolving ifuncs
| reloc_jmpslot: *0x203198 = 0x189368ea4570
| zsh: bus error (core dumped)  LD_DEBUG=1 obj/ld-elf.so.1 ~/a.out

Reported by:	Shawn Webb
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
2018-11-04 19:21:12 +00:00
Konstantin Belousov
561991144e Remove Obj_Entry textsize member.
It is unused after r340102, and more important, I do not see how to
define textsize in both practically useful and correct way, for binaries
with more that one executable segments.

Sponsored by:	The FreeBSD Foundation
2018-11-04 00:32:28 +00:00
Konstantin Belousov
f846c80a9c Flush data cache for executable loadable segments explicitly.
Do not use textsize and do not flush everything between map base and
base + textsize, because unmapped areas cannot be flushed.

This makes Obj_Entry textsize only use go away, and I will remove it
later.

Reported by:	tuexen
Tested by:	Mark Millard <marklmi26-fbsd@yahoo.com>
Sponsored by:	The FreeBSD Foundation
2018-11-03 20:39:16 +00:00
Konstantin Belousov
ca2b9726c3 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
2018-10-29 23:59:26 +00:00
Konstantin Belousov
29ea8142f8 Initialize ifunc calling machinery earlier.
In particular, do it before the first call to allocate_initial_tls(),
which contains MD parts to set the initial thread' TLS pointer.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-10-29 23:56:39 +00:00
Alex Richardson
3ab5b6bd97 rtld-elf: fix more warnings to allow compiling with WARNS=6
Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17154
2018-10-29 21:08:28 +00:00
Alex Richardson
903e0ffd07 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
2018-10-29 21:08:19 +00:00
Alex Richardson
78b648465d rtld-elf: make it compile with WARNS=3
Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17150
2018-10-29 21:08:11 +00:00
Alex Richardson
ca7e27bbce rtld: set obj->textsize correctly
With lld-generated binaries the first PT_LOAD will usually be a read-only
segment unless you pass --no-rosegment. For those binaries the textsize is
determined by the next PT_LOAD. To allow both LLD and bfd 2.17 binaries to
be parsed correctly use the end of the last PT_LOAD that is marked as
executable instead.

I noticed that the value was wrong while adding some debug prints for some rtld
changes for CHERI binaries. `obj->textsize` only seems to be used by PPC so the
effect is untested. However, the value before was definitely wrong and the new
result matches the phdrs.

Reviewed By:	kib
Approved By:	brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17117
2018-10-29 21:08:02 +00:00
Andreas Tobler
953cba365f This commit reverts 338930. The approach was wrong.
Fix the issue with subtracting the TLS_TCB_SIZE too when we are trying to get
the 'where' in the R_PPC_TPREL32 case. At allocation time we added an offset
and the TLS_TCB_SIZE. This has to be subtracted as well.

Now all the issues reported are fixed. Tests were done on G4 and G5 PowerMac's.
Additionally I ran the tls tests from the gcc test suite and made sure the
results are as good as pre 338486.

Thanks to tuexen for reporting the malfunction and for patient testing.
Also testing thanks goes to jhibbits.

Reported by:	tuexen
Discussed with:	jhibbits, nwhitehorn
Approved by:	re (gjb)
Pointyhat to:	andreast
2018-10-01 18:46:35 +00:00
Andrew Turner
6e4fdb5c9d Add STT_GNU_IFUNC and R_AARCH64_IRELATIVE support on arm64.
This is based on the amd64 implementation. Support for both PLT and
non-PLT (e.g. a global variable initilised with a pointer to an ifunc)
cases are supported.

We don't pass anything to the resolver as it is expected they will read
the ID registers directly, with the number of registers with CPU info
likely to increase in the future.

Reviewed by:	kib
Approved by:	re (gjb)
Differential Revision:	https://reviews.freebsd.org/D17341
2018-10-01 14:02:29 +00:00
Konstantin Belousov
d2f2e4c02d Provide refobj context when doing libmap substitution inside
search_library_path().

This corrects the scope of libmap matches.

Reported and tested by:	Andreas Longwitz <longwitz@incore.de>
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
MFC after:	1 week
2018-09-26 21:28:14 +00:00
Konstantin Belousov
6c30676522 When doing lm_add(), check for duplicates.
This is useful when lm_find() moves the match to the global mapping,
since lm_find() could be called with a same path more than once.

Reported and tested by:	Andreas Longwitz <longwitz@incore.de>
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
MFC after:	1 week
2018-09-26 21:27:08 +00:00
Andreas Tobler
28337eb676 Bring the 32-bit powerpc (PowerMac) back to live. The commit 338486 reworked
some TLS bits. This broke operation on the PowerMac. Namely one could not login.
At login the screen/shell was giving back lots of backslashes and the login
shell dumped core.

The fix to this issue is to revert the powerpc commit from 338486 and to
increase the TLS_TCB_SIZE to 16.
Reverting only did not help, login was possible but userland applications
aborted with strange messages.

I tested this patch with world/kernel builds and with port upgrades.
Additionally a full gcc8 bootstrap was successfully completed.

Reviewed by: jhibbits@
Approved by: re (Glen)
2018-09-25 19:29:35 +00:00
Brad Davis
9a537769d6 Move libmap.conf to libexec/rtld-elf/
This leverages CONFS to handle the config file install.

Approved by:	re (gjb), will (mentor)
Differential Revision:	https://reviews.freebsd.org/D17161
2018-09-18 00:25:00 +00:00
Brooks Davis
17fb2856c3 Rework rtld's TLS Variant I implementation to match r326794
The above commit fixed handling overaligned TLS segments in libc's
TLS Variant I implementation, but rtld provides its own implementation
for dynamically-linked executables which lacks these fixes.  Thus,
port these changes to rtld.

This was previously commited as r337978 and reverted in r338149 due to
exposing a bug the ARM rtld.  This bug was fixed in r338317 by mmel.

Submitted by:	James Clarke
Approved by:	re (kib)
Reviewed by:	kbowling
Testing by:	kbowling (powerpc64), br (riscv), kevans (armv7)
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16510
2018-09-05 23:23:16 +00:00
Konstantin Belousov
c1a0a86ed4 Style cleanup. No functional changes.
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
Approved by:    re (rgrimes)
2018-09-02 15:42:37 +00:00
Michal Meloun
ee6281c3d3 Fix wrong offset calculation for R_ARM_TLS_TPOFF32 relocations.
TLS_TCB_SIZE is already accounted in defobj-> tlsoffset so all these symbols
were incorrectly relocated by +8.

Note:
The only consumer (for all binaries on my ARM board) of R_ARM_TLS_TPOFF32
relocation is _ThreadRuneLocale variable. And the incorrectly relocated
ThreadRuneLocale accidentally pointed to zeroed memory before memory layout
change from D16510 had changed status quo.

MFC after:	3 weeks
Reviewed by:	imp, jhb
Approved by:	re (marius)
2018-08-25 16:54:37 +00:00
Brooks Davis
a5207d3ef6 Revert r337978: Rework rtld's TLS Variant I implementation to match r326794
Michal Meloun reports that it breaks ctype (isspace()..) related
functions on armv7 so back out while we diagnose the issue.

Reported by:	Michal Meloun <melounmichal@gmail.com>
2018-08-21 18:22:12 +00:00
Brooks Davis
9b50d81646 Rework rtld's TLS Variant I implementation to match r326794
The above commit fixed handling overaligned TLS segments in libc's
TLS Variant I implementation, but rtld provides its own implementation
for dynamically-linked executables which lacks these fixes.  Thus,
port these changes to rtld.

Submitted by:	James Clarke
Reviewed by:	kbowling
Testing byL	kbowling (powerpc64), br (riscv), kevans (armv7)
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16510
2018-08-17 16:19:47 +00:00
Ruslan Bukin
f00ebc42b5 Save and restore floating-point arguments.
Sponsored by:	DARPA, AFRL
2018-08-02 12:21:39 +00:00
Edward Tomasz Napierala
50cf3bac62 Fix regression tests broken by r337067.
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2018-08-02 11:55:16 +00:00
Edward Tomasz Napierala
711a4538f8 Make sure the rtld(1) error messages go to stderr, not stdout.
While here fix capitalization of a few nearby strings, add the
rtld's file name prefix so it's obvious where the message come
from, and return zero when "-h" is used.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D16530
2018-08-02 07:43:28 +00:00
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