We already have the RETURN_TO macro for this exact use case, and it's already
used in the non-static code path. Use it here too.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-9-bugaevc@gmail.com>
Instead of relying on the stack frame layout to figure out where the stack
pointer was prior to the _hurd_stack_setup () call, just pass the pointer
as an argument explicitly. This is less brittle and much more portable.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-8-bugaevc@gmail.com>
On x86_64, we have to pass function arguments in registers, not on the
stack. We also have to align the stack pointer in a specific way. Since
sharing the logic with i386 does not bring much benefit, split the file
back into i386- and x86_64-specific versions, and fix the x86_64 version
to set up the thread properly.
Bonus: i386 keeps doing the extra RPC inside __thread_set_pcsptp to
fetch the state of the thread before setting it; but x86_64 no lnoger
does that.
Checked on x86_64-gnu and i686-gnu.
Fixes be6d002ca2
"hurd: Set up the basic tree for x86_64-gnu"
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-9-bugaevc@gmail.com>
Unlike sigstate->thread, tcb->self did not hold a Mach port reference on
the thread port it names. This means that the port can be deallocated,
and the name reused for something else, without anyone noticing. Using
tcb->self will then lead to port use-after-free.
Fortunately nothing was accessing tcb->self, other than it being
intially set to then-valid thread port name upon TCB initialization. To
assert that this keeps being the case without altering TCB layout,
rename self -> self_do_not_use, and stop initializing it.
Also, do not (re-)allocate a whole separate and unused stack for the
main thread, and just exit __pthread_setup early in this case.
Found upon attempting to use tcb->self and getting unexpected crashes.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-7-bugaevc@gmail.com>
The real i386_thread_state Mach structure has an alignment of 8 on
x86_64. However, in struct sigcontext, the compiler was packing sc_gs
(which is the first member of sc_i386_thread_state) into the same 8-byte
slot as sc_error; this resulted in the rest of sc_i386_thread_state
members having wrong offsets relative to each other, and the overall
sc_i386_thread_state layout mismatching that of i386_thread_state.
Fix this by explicitly adding the required padding members, and
statically asserting that this results in the desired alignment.
The same goes for sc_i386_float_state.
Checked on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-4-bugaevc@gmail.com>
sizeof (*stackframe) appears to be divisible by 16, but we should not
rely on that. So make sure to leave enough space for the stackframe
first, and then align the final pointer at 16 bytes.
Checked on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-3-bugaevc@gmail.com>
Fixes 60f9bf9746
"hurd: Port trampoline.c to x86_64"
Checked on x86_64-gnu.
Reported-by: Bruno Haible <bruno@clisp.org>
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-2-bugaevc@gmail.com>
Properly differentiate between setting up the real TLS with
TLS_INIT_TP, and setting up the early TLS (__init1_tcbhead) in static
builds. In the latter case, don't yet migrate the reply port into the
TCB, and don't yet set __libc_tls_initialized to 1.
This also lets us move the __init1_desc assignment inside
_hurd_tls_init ().
Fixes cd019ddd89
"hurd: Don't leak __hurd_reply_port0"
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
When glibc is built as a shared library, TLS is always initialized by
the call of TLS_INIT_TP () macro made inside the dynamic loader, prior
to running the main program (see dl-call_tls_init_tp.h). We can take
advantage of this: we know for sure that __LIBC_NO_TLS () will evaluate
to 0 in all other cases, so let the compiler know that explicitly too.
Also, only define _hurd_tls_init () and TLS_INIT_TP () under the same
conditions (either !SHARED or inside rtld), to statically assert that
this is the case.
Other than a microoptimization, this also helps with avoiding awkward
sharing of the __libc_tls_initialized variable between ld.so and libc.so
that we would have to do otherwise -- we know for sure that no sharing
is required, simply because __libc_tls_initialized would always be set
to true inside libc.so.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-25-bugaevc@gmail.com>
This reverts commit b37899d34d.
Apparently we load libc.so (and thus start using its functions) before
calling TLS_INIT_TP, so libc.so functions should not actually assume
that TLS is always set up.
When glibc is built as a shared library, TLS is always initialized by
the call of TLS_INIT_TP () macro made inside the dynamic loader, prior
to running the main program (see dl-call_tls_init_tp.h). We can take
advantage of this: we know for sure that __LIBC_NO_TLS () will evaluate
to 0 in all other cases, so let the compiler know that explicitly too.
Also, only define _hurd_tls_init () and TLS_INIT_TP () under the same
conditions (either !SHARED or inside rtld), to statically assert that
this is the case.
Other than a microoptimization, this also helps with avoiding awkward
sharing of the __libc_tls_initialized variable between ld.so and libc.so
that we would have to do otherwise -- we know for sure that no sharing
is required, simply because __libc_tls_initialized would always be set
to true inside libc.so.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-25-bugaevc@gmail.com>
These do not need any changes to be used on x86_64.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-20-bugaevc@gmail.com>
Noone is or should be using __hurd_threadvar_stack_{offset,mask}, we
have proper TLS now. These two remaining variables are never set to
anything other than zero, so any code that would try to use them as
described would just dereference a zero pointer and crash. So remove
them entirely.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-6-bugaevc@gmail.com>
It is not Hurd-specific, but H.J. Lu wants it there.
Also, dc.a can be used to avoid hardcoding .long vs .quad and thus use
the same implementation for i386 and x86_64.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
