happens, the context of the interrupted thread is exported to
userland. Unlike most contexts, it will be an async context and
we cannot easily use our existing functions to set such a
context.
To avoid a lot of complexity that may possibly interfere with
the common case, we simply let the kernel deal with it. However,
we don't use the EPC based syscall path to invoke setcontext(2).
No, we use the break-based syscall path. That way the trapframe
will be compatible with the context we're trying to restore and
we save the kernel a lot of trouble. The kind of trouble we did
not want to go though ourselves...
However, we also need to set the threads mailbox and there's no
syscall to help us out. To avoid creating a new syscall, we use
the context itself to pass the information to the kernel so that
the kernel can update the mailbox. This involves setting a flag
(_MC_FLAGS_KSE_SET_MBOX) and setting ifa (the address) and isr
(the value).
wctob() in terms of wcrtomb() instead of sputrune(). There should be
no functional differences, but there may be a small performance hit
because we make an extra function call.
The aim here is to have as few functions as possible calling
s{get,put}rune() to make it easier to remove them in the future.
TCB. We know that the thread pointer points to &tcb->tcb_tp, so all
we have to do is subtract offsetof(struct tcb, tcb_tp) from the
thread pointer to get to the TCB. Any reasonably smart compiler will
translate accesses to fields in the TCB as negative offsets from TP.
In _tcb_set() make sure the fake TCB gets a pointer to the current
KCB, just like any other TCB. This fixes a NULL-pointer dereference
in _thr_ref_add() when it tried to get the current KSE.
makecontext(). We only supply 3, not 4. This is mostly harmless,
except that on ia64 the garbage can include NaT bits, resulting
in NaT consumption faults.
that the TLS is 16-byte aligned, as well as guarantee that the thread
pointer is 16-byte aligned as it points to struct ia64_tp. Likewise,
struct tcb and struct ksd are also guaranteed to be 16-byte aligned
(if they weren't already).
archs that can (or are required to) have per-thread registers.
Tested on i386, amd64; marcel is testing on ia64 and will
have some follow-up commits.
Reviewed by: davidxu
context functions. We don't need to enter the kernel anymore. The
contexts are compatible (ie a context created by getcontext() can
be restored by _ia64_restore_context()).
While here, make the use of THR_ALIGNBYTES and THR_ALIGN a no-op.
They are going to be removed anyway.
We write 1 for r8 in the context so that _ia64_restore_context()
will return with a non-zero value. _ia64_save_context() always
return 0.
o In _ia64_restore_context(), don't restore the thread pointer. It
is not normally part of the context. Also, restore the return
registers. We get called for contexts created by getcontext(),
which means we have to restore all the syscall return values.
Also change "Auto mode" to use a "special" value
instead of 0, and define and document it.
I had thought libpthread had already been switched to use auto mode but
it appears that patch hasn't been committed yet.
Discussed with: Davidxu
First of all, it should be written as: tr 'a-z' 'A-Z'
ranges not encolosed in [] according to POSIX, so [] just included
in the replacement.
Second, it should be written: tr '[:lower:]' '[:upper:]'
since a-z and A-Z may have different length in some locales.
that we can flush the register stack prior to entering the kernel.
This avoids having dirty registers and saves us from having to
manually write them to the backing store from within the kernel.
In that respect, flushing the RSE is both functionally required as
well as performance optimal.
On average we had 18 dirty registers when getcontext(2) was called
from libthr. Since libthr does not switch back to a context created
by getcontext(2), not having dealt with the dirty registers was
harmless.
on the corresponding .proc directive, or the .endp must not have a
name at all.
While here, remove an artificial dependency in Ovfork.S by performing
manual register renaming.
the userland version of [gs]etcontext to switch between a thread
and the UTS scheduler (and back again). This also fixes a bug
in i386 _thr_setcontext() which wasn't properly restoring the
context.
Reviewed by: davidxu
almost identical.
* Merge strchr(3) and strrchr(3) to strchr(3) since the two functions
are almost identical.
* Make the wording of index(3) and strchr(3) more similar.
* mdoc(7) cleanup.
Submitted by: SUZUKI Koichi <metal@gc5.so-net.ne.jp>, keramida, myself
PR: docs/32054
Reviewed by: ru
Approved by: ceri (mentor)
