Instead of aborting in locate_dependency(), propagate the error to
caller. The rtld startup function does the right thing with an error
from rtld_verify_versions(), depending on the mode of operation.
Reported by: maho
In collaboration with: kan
MFC after: 1 week
Place elements on DAG lists in breadth-first order. This allows us to
walk pre-built list in all cases where breadth-first dependency chain
enumeration is required.
Fix dlsym on special handle obtained by dlopen(NULL, ...) to do what
comment claims it does. Take advantage of recently added symlook_global
function to iterate over main objects and global DAGs lists properly in
search of a symbol. Since rtld itself provides part of the global
namespace, search rtld_obj too.
Remove recursion from init_dag and symlook_needed functions. Use
symlook_needed for ELF filtee processing only and change lookup order
used in the function to match the order used by Solaris runtime linker
under same circumstances. While there, fix weak symbol handling in the
loop so that we return the first weak symbol definition if no strong one
was found, instead of the last one.
Reviewed by: kib
MFC after: 1 month
one. Search global objects, together with main object and
dependencies, for the requested symbol.
Move the common code from symlook_default() into new helper
symlook_global(), and use it both in symlook_global() and
get_program_var_addr().
Supply lock state to get_program_var_addr().
Reviewed by: kan
Tested by: Mykola Dzham <i levsha me>
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
3DNow, MMX and floating point instructions in rtld-elf.
Otherwise, _rtld_bind() (and whatever it calls) could possibly clobber
function arguments that are passed in SSE/3DNow/MMX/FP registers,
usually floating point values. This can happen, for example, when clang
generates SSE code for memset() or memcpy() calls.
One symptom of this is sshd dying early on amd64 with "PRNG not seeded",
which is ultimately caused by libcrypto.so.6 calling RAND_add() with a
double parameter. That parameter is passed via %xmm0, which gets wiped
out by an SSE memset() in _rtld_bind().
Reviewed by: kib, kan
the caller. Currently, checkuser() does not differentiate between the
failure to open the file and the absence of a user in the file. Check
to see if there was an error opening the file. If there are any errors,
terminate the connection. Currently, the only exception to this rule
is ENOENT, since there is nothing that says the /etc/ftpuser
and /etc/ftpchroot has to exist.
MFC after: 3 weeks
C function, the caller's stack frame must have room to store all of the
arguments to that function. While here, fix stack frame alignment issues.
Without this change, the compiler will save r3 and r4 into the caller's
stack frame before calling setjmp() in _rtld_bind(). These would then
overwrite arguments to the newly-bound function, causing eventual failures.
filters are implemented.
Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.
Consolidate common arguments of the symbol lookup functions in the
SymLook structure. Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.
Reviewed by: kan
Tested by: Mykola Dzham <i levsha me>, nwhitehorn (powerpc)
dlclose() call may unload the object of the outer call prematurely
because objects are unreferenced before _fini() calls.
Fix this by unreferencing objects after calling objlist_call_fini() in
dlclose(). Therefore objlist_call_fini() now calls the fini function if
the reference count of an object is 1. In addition we must restart the
list_fini traversal after every _fini() call because another dlclose()
call might have modified the reference counts.
Add an XXX comment to objlist_call_fini() about possible race with
dlopen().
PR: 133246, 149464
Reviewed by: kan, kib
loaded as a dependency and marked -z nodlopen, object' DAG is already
initialized by load_needed_objects(). Due to this, the init_dag() call
from dlopen() does not increment refcount for the object [1].
Change init_dag() to not increment DAG refcount. Require explicit calls
to ref_dag() to increment, and assert that ref_dag() and unref_dag()
are called for root that has dag initialized. To fix the noted issue,
unconditionally call both init_dag() and ref_dag() in dlopen() for the
case when the object was already loaded, making it similar to the case
of newly loaded object.
Noted by: jh [1]
Reviewed by: jh, kan
MFC after: 6 days
dependency, then the dso never has its DAG initialized. Empty DAG
makes ref_dag() call in dlopen() a nop, and the dso refcount is off
by one.
Initialize the DAG on the first dlopen() call, using a boolean flag
to prevent double initialization.
From the PR (edited):
Assume we have a library liba.so, containing a function a(), and a
library libb.so, containing function b(). liba.so needs functionality
from libb.so, so liba.so links in libb.so.
An application doesn't know about the relation between these libraries,
but needs to call a() and b(). It dlopen()s liba.so and obtains a
pointer to a(), then it dlopen()s libb.so and obtains a pointer to b().
As soon as the application doesn't need a() anymore, it dlclose()s liba.so.
Expected result: the pointer to b() is still valid and can be called
Actual result: the pointer to b() has become invalid, even though the
application did not dlclose() the handle to libb.so. On calling b(), the
application crashes with a segmentation fault.
PR: misc/151861
Based on patch by: jh
Reviewed by: kan
Tested by: Arjan van Leeuwen <freebsd-maintainer opera com>
MFC after: 1 week
I've noticed various terminal emulators that need to obtain a sane
default termios structure use very complex `hacks'. Even though POSIX
doesn't provide any functionality for this, extend our termios API with
cfmakesane(3), which is similar to the commonly supported cfmakeraw(3),
except that it fills the termios structure with sane defaults.
Change all code in our base system to use this function, instead of
depending on <sys/ttydefaults.h> to provide TTYDEF_*.
With r169630 I disabled symbol versioning because it broke rtld. With
r211706 rtld got broken for ia64 & powerpc64. It was fixed for powerpc64
with r212497. In between, r211749 removed the exports table because the
version script handled the exports. But wait, symbol versioning was
disabled on ia64.
With exports controlled by the version script and symbol versioning
disabled, all symbols are exported and too many symbols bind to the
definition in rtld. Let's just say that waird things happen.
So, enable symbol versioning on ia64 and apply a work-around for the
SIGSEGV that triggered r169630 to begin with: when rtld relocates
itself, it comes across r_debug_state and for some reason can't find the
definition. This causes a failure, relocation aborts and null pointers
galore. The work-around is to ignore the missing definition when rtld
is relocating itself and keep going.
Maybe with the next binutils this will all go away. Maybe not, in
which case I still need to figure out why r_debug_state cannot be found.
BTW: r_debug_state is in the symbol map -- I don't think any other rtld
symbols that rtld references are in the symbol map...
where long PLT calls in multi-threaded environments could end up with
incorrect jmptab values. The second is that, after the addition of extended
PLT support, I forgot to update the PLT icache synchronization code to cover
the extended PLT instead of just the basic PLT.
MFC after: 10 days
also was inappropriate as it triggered for every EACCESS and ENOTFOUND, not
just the case the -n option is intended to deal with and thus really spammed
us with ~20 messages in the default configuration when booting a diskless
FreeBSD client, introduced with r207608 again.
MFC after: 1 week
atexit and __cxa_atexit handlers that are either installed by unloaded
dso, or points to the functions provided by the dso.
Use _rtld_addr_phdr to locate segment information from the address of
private variable belonging to the dso, supplied by crtstuff.c. Provide
utility function __elf_phdr_match_addr to do the match of address against
dso executable segment.
Call back into libthr from __cxa_finalize using weak
__pthread_cxa_finalize symbol to remove any atfork handler which
function points into unloaded object.
The rtld needs private __pthread_cxa_finalize symbol to not require
resolution of the weak undefined symbol at initialization time. This
cannot work, since rtld is relocated before sym_zero is set up.
Idea by: kan
Reviewed by: kan (previous version)
MFC after: 3 weeks
Use local version of getpagesize(), rtld_getpagesize() in private allocator.
Override the __getosreldate() previously fetched from libc_pic.a with
local version that uses aux value if present. Note that __getosreldate()
is used by rtld indirectly, by mmap(2) libc wrapper.
To be able to utilize aux, split digest_dynamic() for use by init_rtld()
into two parts, where the first one does not call malloc(), and the
second part uses it. init_rtld() is able to initialize global variables
before digest_dynamic2() calls. In particular, pagesize and osreldate are
set up from the aux values.
Now, rtld avoids (two) sysctl calls in startup.
Tested by: marius (sparc64)
MFC after: 1 month
r211130 in favor of this more general fix.
This fixes a compilation error for mips 64-bit little endian build.
libexec/rtld-elf/mips/reloc.c:196: warning: right shift count >= width of type
Suggested by: stefanf, jchandra, bde
libexec/rtld-elf/mips/reloc.c:196: warning: right shift count >= width of type
When the expression '(r_info) >> 32' was passed to bswap32() it was promptly
changed to '(uint32_t)(r_info) >> 32' which is not what we intended.
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
fix for it.
The bug occurs when using the --as-needed flag to ld in the presence of
synthetic linker-generated symbols that reference symbols defined in
linked-to shared libraries with versioned symbols. When the only symbols
used from a library fall into this category, ld will drop the DT_NEEDED
entry for it, but retain the versioning information. This bug is best
fixed/hacked around in binutils, not in rtld.
Discussed with: kan
because calling mmap() etc. may use GOT which is not set up
yet. Use calloc() instead of mmap() in cases where this
was the case before (sparc64, powerpc, arm).
Submitted by: Dimitry Andric (dimitry andric com)
Reviewed by: kan
Approved by: ed (mentor)
lot better than what's in the tree now. Edwin tested it at a prior
employer, but can't test it today. I've found that it works a lot
better with the various uboot versions that I've used in my embedded
work. Here's the pkg-descr from the port that describes the changes:
It all started when we got some new routers, which told me the
following when trying to upload configuration or download images
from it: The TFTP server doesn't support the blocksize option.
My curiousity was triggered, it took me some reading of RFCs and
other documentation to find out what was possible and what could
be done. Was plain TFTP very simple in its handshake, TFTP with
options was kind of messy because of its backwards capability: The
first packet returned could either be an acknowledgement of options,
or the first data packet.
Going through the source code of src/libexec/tftpd and going through
the code of src/usr.bin/tftp showed that there was a lot of duplicate
code, and the addition of options would only increase the amount
of duplicate code. After all, both the client and the server can
act as a sender and receiver.
At the end, it ended up with a nearly complete rewrite of the tftp
client and server. It has been tested against the following TFTP
clients and servers:
- Itself (yay!)
- The standard FreeBSD tftp client and server
- The Fedora Core 6 tftp client and server
- Cisco router tftp client
- Extreme Networks tftp client
It supports the following RFCs:
RFC1350 - THE TFTP PROTOCOL (REVISION 2)
RFC2347 - TFTP Option Extension
RFC2348 - TFTP Blocksize Option
RFC2349 - TFTP Timeout Interval and Transfer Size Options
RFC3617 - Uniform Resource Identifier (URI) Scheme and Applicability
Statement for the Trivial File Transfer Protocol (TFTP)
It supports the following unofficial TFTP Options as described at
http://www.compuphase.com/tftp.htm:
blksize2 - Block size restricted to powers of 2, excluding protocol headers
rollover - Block counter roll-over (roll back to zero or to one)
From the tftp program point of view the following things are changed:
- New commands: "blocksize", "blocksize2", "rollover" and "options"
- Development features: "debug" and "packetdrop"
If you try this tftp/tftpd implementation, please let me know if
it works (or doesn't work) and against which implementaion so I can
get a list of confirmed working systems.
Author: Edwin Groothuis <edwin@FreeBSD.org>
64-bit quota sizes by scaling down the sizes by the minimum amount
necessary to fit in a 32-bit field and then upscale the filesystem
block size to compensate. For example, if the hard block limit is
0x300000008 then we set the hard block limit to 0xA0000002 and claim
that the blocksize is 4 * DEV_BSIZE. This will lose the minimal
amount of information thus delivering nearly correct answers.
o Use obj->tlsinitsize to determine whether there's initialized data.
o If obj->tlssize > obj->tlsinitsize, then bzero uninitialized data.
o Don't exclude variant I from the work-around in free_tls_offset().
This makes it a little easier to figure out which application was
responsible for this log entry. Ideally we should add an ut_process or
something similar.
Suggested by: Vincent Poy <vincepoy gmail com>
Also perform a small cleanup to ftpd_logwtmp(). Just use a NULL
parameter for the username to indicate a logout, instead of an empty
string.
Reported by: Alexey Shuvaev <shuvaev physik uni-wuerzburg de>
The ttyslot() function was originally part for SUSv1, marked LEGACY in
SUSv2 and removed later on. This function only makes sense when using
utmp(5), because it was used to determine the offset of the record for
the controlling TTY. It makes little sense to keep it here, because the
new utmpx file format doesn't index based on TTY slots.
Unfortunately I have to partially wreck its functionality, though. ftpd
used to keep a file descriptor to the wtmp, which allowed it to work
from within a chroot. The current utmpx implementation doesn't offer a
way to do this. Maybe we can address this in the future, if it turns out
to be a real issue.
It seems comsat stats the utmpx database each 15 seconds to see whether
it has been changed. I am changing this behaviour to look at the utmpx
database upon processing. I don't want to allow direct interference with
the database files. I also wonder whether this optimization has any
measurable performance benefit nowadays.
- It shouldn't call logwtmp(). Applications like login(1) already make
sure both login and logout entries are written to the storage.
- There's no need to restore permissions on the pseudo-terminal, since
it should be garbage collected by the kernel.
Just like bin/ and sbin/, I think setting WARNS to the highest value
possible will make it more attractive for people to fix warnings.
- The WARNS variable is set in the Makefile in the directory of the
application itself, making it more likely that it will be removed out
of curiosity to see what happens.
- New applications will most likely build with WARNS=6 out of the box,
because the author would more likely fix the warnings during
development than lower WARNS.
Unfortunately almost all apps in libexec require a lowered value of
WARNS.
Because strings are now null-terminated, I've decided to just use an
array of utmpx structures, instead of the separated strings. This means
we just copy the entire utmpx structure and point to the strings within
the structures directly.
