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
(cherry picked from commit 1426fd6cff0603f0ee275b99f2ba35dc36f3d0c2)
net/frr[89] revealed an interesting edge-case on arm when dynamically
linking a shared library that declares more than one static TLS variable
with at least one using the "initial-exec" TLS model. In the case
of frr[89], this library was libfrr.so which essentially does the
following:
#include <stdio.h>
#include "lib.h"
static __thread int *a
__attribute__((tls_model("initial-exec")));
void lib_test()
{
static __thread int b = -1;
printf("&a = %p\n", &a);
printf(" a = %p\n", a);
printf("\n");
printf("&b = %p\n", &b);
printf(" b = %d\n", b);
}
Allocates a file scoped `static __thread` pointer with
tls_model("initial-exec") and later a block scoped TLS int. Notice in
the above minimal reproducer, `b == -1`. The relocation process does
the wrong thing and ends up pointing both `a` and `b` at the same place
in memory.
The output of the above in the broken state is:
&a = 0x4009c018
a = 0xffffffff
&b = 0x4009c018
b = -1
With the patch applied, the output becomes:
&a = 0x4009c01c
a = 0x0
&b = 0x4009c018
b = -1
Reviewed by: kib
Approved by: kp (mentor)
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D42415/
(cherry picked from commit 98fd69f0090da73d9d0451bd769d7752468284c6)
These were reported by `mandoc -T lint ...` as warnings.
Signed-off-by: Graham Percival <gperciva@tarsnap.com>
Reviewed by: mhorne
MFC after: 3 days
Sponsored by: Tarsnap Backup Inc.
Pull Request: https://github.com/freebsd/freebsd-src/pull/1475
(cherry picked from commit b74aaa1a2199261f9078247d29481a994b6b5e42)
These ones were unambiguous cases where the Foundation was the only
listed copyright holder.
Sponsored by: The FreeBSD Foundation
(cherry picked from commit 5c2bc3db201a4fe8d7911cf816bea104d5dc2138)
Add a macro the architectures can use to add per-arch fields to
Struct_Obj_Entry.
Reviewed by: kib
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D45116
(cherry picked from commit 06db20ffeca9898e5802d63f3b06caaa37c3a4ed)
Accept either little-endian or big-endian representation of the ELF
hints magic number in the header of a hints file and convert the
parameters to the native byte-order of the repsective system.
This is a pre-requisite for a planned change to always write the byte
order in little-endian format on all architectures. The only relvant
architecture that uses big-endian data is powerpc64, and it is not
likely that new architectures will choose that representation of data
in memory.
When all supported architectures use little-endian data in the hints
file, the byte swap logic can be enabled for big-endian CPUs at
compile time. Up to that point, there is a very small run-time penalty
that is paid on all systems to check the byte-order of the hints file
and to provide the option to byte-swap the parameters read from the
hints file header.
This commit contains the changes from review D44080 (which had been
split off from this patch for easier review),
Reviewed by: kib
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D44053
(cherry picked from commit 7b77d37a561b47db093a2528b8032dbfe5791698)
rtld-elf: add some debug print statements
The byte-order independent code has been reported to fail on powerpc64.
Add some more debug statements to help identify the parametrs used and
to verify the correct operation of the byte-swap macros used..
(cherry picked from commit 173953182af060dcab43990e179ee91e9f2d1e54)
rtld: fix check for endianess of elf hints file
Don't check if the elf hints file is in host byte order, but check
if it is in little endian by looking at the magic number.
This fixes rtld on big endian platforms.
Reviewed by: se, kib (prior version of the patch)
Fixes: 7b77d37a561b ("rtld-elf: support either byte-order of hints")
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D44472
(cherry picked from commit da2d6e2815d7694e3ccbd561508074c547b02dd6)
rtld: reduce debug messages after fix on big-endian hosts
Remove a debug message that had been added to support the debugging
of a mis-detection of the hint files endianness on powerpc64.
MFC after: 3 days
(cherry picked from commit c44bf7d2e9d2292867f2e23f291266af26762354)
dlopen_basic just tests that libthr.so can be dlopen()ed, which will
just serve as a sanity check that "libthr.so" is a thing that can be
dlopened in case we get a weird failure in dlopen_recursing.
dlopen_recursing tests a regression reported after the libsys split,
where some dlopen() may cause infinite recursion and a resulting crash.
This case is inspired by bdrewery's description of what seemed to be
causing his issue.
The corresponding fix landed in commit
968a18975ad ("rtld: ignore load_filtees() calls if we already [...]")
Reviewed by: kib
(cherry picked from commit c5796f1572c82b88e8b6a2810c92f30e5ac3e118)
Add the Branch Target Identification (BTI) note to libc assembly
sources. As all obect files need the note for rtld to have it we need
to insert it in all asm files.
Reviewed by: markj, emaste
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D42228
(cherry picked from commit 5270cc9757fb4e0c1303ec44c2602b75acf3806d)
In order to atomically upgrade the rtld bind lock, load_filtees() may
trigger a longjmp back to _rtld_bind() so that the binding can be done
with the write lock held. However, the write lock is only needed when
filtee objects haven't already been loaded, so move the
lock_restart_for_upgrade() call to avoid unnecessary lock upgrades when
a filtee is defined.
Reviewed by: kib
Tested by: brooks
MFC after: 1 week
Sponsored by: Innovate UK
(cherry picked from commit e7951d0b04e6464b37264b8166b1e9ce368a9f1d)
This was originally used (along with FREEBSD_AOUT) to prefer the use
of ELF in various tools instead of a.out as part of the a.out to ELF
transition in the 3.x days. The last use of it was removed from
<link.h> in commit 66422f5b7a back in
2002, but various files still #define it.
Reviewed by: kevans, imp, emaste
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D42964
(cherry picked from commit 4a3cf5f329d69076aa9d093d596eb0ee82d917f5)
This tests that with RTLD_DEEPBIND, symbols are looked up in all of the
object's needed objects before the global object.
PR: 275393
Reviewed by: kib
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
(cherry picked from commit d9c543b6b0cabea6e6679d70b4e701018e7eab80)
These do not use __FBSDID but instead use bare char arrays.
Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957
(cherry picked from commit eba230afba4932f02a1ca44efc797cf7499a5cb0)
Use regular free(), since it works now.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
It is modelled after aligned_alloc(3). Most importantly, to free the
allocation, __crt_free() can be used. Additionally, caller may specify
offset into the aligned allocation, so that we return offset-ed from
alignment pointer.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
Reorder it with magic, to keep alignment.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
for it to be useful to return unaligned pointer.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41150
The method might require resolving and binding symbols, which means
recursing on the bind lock. It is safe to unlock the bind lock,
since we operate on the private object list, and user attempting to
unload an object from the list of not yet fully loaded objects caused
self-inflicted race.
It is similar to how we treat user' init/fini methods.
Reported by: stevek
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
