This patch fixes a problem within the SH implementation of resume_kernel code,
that implements in assembly the bulk of preempt_schedule_irq function without
taking care of the extra code needed to handle the BKL preemptible.
The patch basically consists of removing this asm code and calling the common
C implementation (see kernel/sched.c) as other archs do.
Another change is the missing 'cli' macro invocation at the beginning of
the resume_kernel.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This follows the changes in commits:
7d6d637dac4f72c4279e
on powerpc. Adding in TIF_NOTIFY_RESUME, and cleaning up the syscall
tracing to be more generic. This is an incremental step to turning
on tracehook, as well as unifying more of the ptrace and signal code
across the 32/64 split.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Without this patch, signals sent during architecture specific signal
handling (typically as a result of the user's stack being inaccessible)
are ignored.
This is the SH version of commit c3ff8ec31c
which was for the i386.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There are a few different types of debug trap exceptions, though now
that they are all going through a special jump table, the restorer needs
to be unified as well.
Presently this is falling through the ret_from_fork path, which more or
less does the right thing on SH-3/4 whilst being completely unsuitable on
MMU-less targets.
Ultimately what we want here is a branch through the platform's
restore_all directly, without worrying about the retval being clobbered.
We can accomplish that through a branch to __restore_all directly, so
switch it so we come back from the jump table and branch to the restorer.
This fixes up a recursion in the nommu WARN_ON() path, as well as some
other userspace nastiness where said recursion caused serious stack
corruption.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Entry to resume_userspace expects r8 to contain current_thread_info,
which happens in all paths except for syscall_badsys, where r8 was
being inadvertently trampled. Reload it before the branch.
Signed-off-by: Hideo Saito <saito@densan.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This conditionalizes gUSA support. gUSA is not supported on
SMP configurations, and it's not necessary there anyways due
to having other atomicity options (ie, movli.l/movco.l).
Anything implementing the LL/SC semantics (all SH-4A CPUs)
can switch to userspace atomicity implementations without
requiring gUSA. This is left default-enabled on all UP so
that glibc doesn't break.
Those that know what they are doing can disable this explicitly.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This takes care of tearing down the UBC so it's not inadvertently
left configured at the next context switch time. Failure to do
this results in spurious SIGTRAPs in certain debug sequences.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This rips out most of the needlessly complicated sh_bios and kgdb
trap handling, and forces it all through a common fast dispatch path.
As more debug traps are inserted, it's important to keep them in sync
for all of the parts, not just SH-3/4.
As the SH-2 parts are unable to do traps in the >= 0x40 range, we
restrict the debug traps to the 0x30-0x3f range on all parts, and
also bump the kgdb breakpoint trap down in to this range (from 0xff
to 0x3c) so it's possible to use for nommu.
Optionally, this table can be padded out to catch spurious traps for
SH-3/4, but we don't do that yet..
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This was inadvertently broken when the entry.S code split up,
restore the missing branch and get subsequent traps working
under debug again. This manifested itself as a lockup when
attempting to reload the VBR base.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The implementation of system call tracing in the kernel has a
couple of ordering problems:
- the validity of the system call number is checked before
calling out to system call tracing code, and should be
done after
- the system call number used when tracing is the one the
system call was invoked with, while the system call tracing
code can legitimatly change the call number (for example
strace permutes fork into clone)
This patch fixes both of these problems, and also reoders the
code slightly to make the direct path through the code the
common case.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This splits out common bits from the existing exception handler for
use between SH-2/SH-2A and SH-3/4, and adds support for the SH-2/2A
exceptions.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
