This modification is required to fix debugging function for m32r targets
with !CONFIG_ISA_DSP_LEVEL2, by unifying 'struct pt_regs' and 'struct
sigcontext' size for all M32R ISA.
Some m32r processor core with !CONFIG_ISA_DSP_LEVEL2 configuration has only
single accumulator a0 (ex. VDEC2 core, M32102 core, etc.), the others with
CONFIG_ISA_DSP_LEVEL2 has two accumulators, a0 and a1.
This means there are two variations of thread context. So far, we reduced
and changed stackframe size at a syscall for their context size. However,
this causes a problem that a GDB for processors with CONFIG_ISA_DSP_LEVEL2
cannot be used for processors with !CONFIG_ISA_DSP_LEVEL2.
From the viewpoint of GDB support, we should reduce such variation of
stackframe size for simplicity.
In this patch, dummy members are added to 'struct pt_regs' and 'struct
sigcontext' to adjust their size for !CONFIG_ISA_DSP_LEVEL2.
This modification is also a one step for a GDB update in future.
Currently, on the m32r, GDB can access process's context by using ptrace
functions in a simple way of register by register access. By unifying
stackframe size, we have a possibility to make use of ptrace functions of
not only a single register access but also block register access,
PTRACE_{GETREGS,PUTREGS}.
However, for this purpose, we might have to modify stackframe structure
some more; for example, PSW (processor status word) register should be
pre-processed before pushing to stack at a syscall, and so on. In this
case, we must update carefully both kernel and GDB at a time...
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: Kei Sakamoto <ksakamot@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While cleaning up parisc_ksyms.c earlier, I noticed that strpbrk wasn't
being exported from lib/string.c. Investigating further, I noticed a
changeset that removed its export and added it to _ksyms.c on a few more
architectures. The justification was that "other arches do it."
I think this is wrong, since no architecture currently defines
__HAVE_ARCH_STRPBRK, there's no reason for any of them to be exporting it
themselves. Therefore, consolidate the export to lib/string.c.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update {get,put}_user macros for m32r kernel.
- Modify get_user to use __get_user_asm macro, instead of __get_user_x macro.
- Remove arch/m32r/lib/{get,put}user.S.
- Some cosmetic updates.
I would like to thank NIIBE Yutaka for his reporting about the m32r kernel's
security problem in {get,put}_user macros.
There were no address checking for user space access in {get,put}_user macros.
;-)
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: NIIBE Yutaka <gniibe@fsij.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes a boot problem of the m32r SMP kernel 2.6.16-rc1-mm3 or
later.
In this patch, cpu_possible_map is statically initialized, and cpu_present_map
is also copied from cpu_possible_map in smp_prepare_cpus(), because the m32r
architecture has not supported CPU hotplug yet.
Signed-off-by: Hayato Fujiwara <fujiwara.hayato@renesas.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Just about every architecture defines some macros to do operations on pfns.
They're all virtually identical. This patch consolidates all of them.
One minor glitch is that at least i386 uses them in a very skeletal header
file. To keep away from #include dependency hell, I stuck the new
definitions in a new, isolated header.
Of all of the implementations, sh64 is the only one that varied by a bit.
It used some masks to ensure that any sign-extension got ripped away before
the arithmetic is done. This has been posted to that sh64 maintainers and
the development list.
Compiles on x86, x86_64, ia64 and ppc64.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix and update for gcc-4.0.
- arch/m32r/kernel/signal.c:
Change type of the 8th parameter of sys_rt_sigsuspend() from
'struct pt_regs' to 'struct pt_regs *'.
This functions make use of the 'regs' parameter to return status value,
but gcc-4.0 optimizes and removes it as a dead code.
Functions, sys_sigaltstack() and sys_rt_sigreturn(), have also modified.
- arch/m32r/lib/usercopy.c, include/asm-m32r/uaccess.h:
Add early-clobber constraints('&') to output values of asm statements;
these constraints seems to be required for gcc-4.0 register assignment.
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch updates and fixes sys_tas() routine for m32r.
In the previous implementation, a lockup rarely caused at sys_tas()
routine in SMP environment.
> > The problem is that touching *addr will generate an oops if that page isn't
> > paged in. If we convert it to use get_user() then that's an improvement,
> > but we must not run get_user() under spinlock or local_irq_disable().
I rewrote sys_tas() routine by using "lock -> unlock" instructions, and
utilizing the m32r's interrupt handling characteristics; the m32r processor
can accept interrupts only at the 32-bit instruction boundary. So, the
"unlock" instruction can be executed continuously after the "lock"
instruction execution without any interruptions.
In addition, to solve such a page_fault problem, I use a fixup code like
get_user().
And, as for the kernel lockup problem, we found that a calling
do_page_fault() routine with disabling interrupts might cause a lockup at
flush_tlb_others(), because we checked a completion of IPI handler's
operations in a spin-locked critical section.
Therefore, by using "lock -> unlock" code, we can implement the sys_tas()
rouitine without disabling interrupts explicitly, then no lockups would
happen at flush_tlb_others(), I hope.
Compile check and some working test in SMP environment have done.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
)
From: Adrian Bunk <bunk@stusta.de>
- create one common dump_thread() prototype in kernel.h
- dump_thread() is only used in fs/binfmt_aout.c and can therefore be
removed on all architectures where CONFIG_BINFMT_AOUT is not
available
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem. It is expected that /sbin/halt -p works exactly like
/sbin/halt, when the kernel does not implement power off functionality.
The kernel can do a lot of work in the reboot notifiers and in
device_shutdown before we even get to machine_power_off. Some of that
shutdown is not safe if you are leaving the power on, and it definitely
gets in the way of using sysrq or pressing ctrl-alt-del. Since the
shutdown happens in generic code there is no way to fix this in
architecture specific code :(
Some machines are kernel oopsing today because of this.
The simple solution is to turn LINUX_REBOOT_CMD_POWER_OFF into
LINUX_REBOOT_CMD_HALT if power_off functionality is not implemented.
This has the unfortunate side effect of disabling the power off
functionality on architectures that leave pm_power_off to null and still
implement something in machine_power_off. And it will break the build on
some architectures that don't have a pm_power_off variable at all.
On both counts I say tough.
For architectures like alpha that don't implement the pm_power_off variable
pm_power_off is declared in linux/pm.h and it is a generic part of our
power management code, and all architectures should implement it.
For architectures like parisc that have a default power off method in
machine_power_off if pm_power_off is not implemented or fails. It is easy
enough to set the pm_power_off variable. And nothing bad happens there,
the machines just stop powering off.
The current semantics are impossible without a flag at the top level so we
can avoid the problem code if a power off is not implemented. pm_power_off
is as good a flag as any with the bonus that it works without modification
on at least x86, x86_64, powerpc, and ppc today.
Andrew can you pick this up and put this in the mm tree. Kernels that
don't compile or don't power off seem saner than kernels that oops or
panic. Until we get the arch specific patches for the problem
architectures this probably isn't smart to push into the stable kernel.
Unfortunately I don't have the time at the moment to walk through every
architecture and make them work. And even if I did I couldn't test it :(
From: Hirokazu Takata <takata@linux-m32r.org>
Add pm_power_off() for build fix of arch/m32r/kernel/process.c.
From: Miklos Szeredi <miklos@szeredi.hu>
UML build fix
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.
Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface. We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns. It's a bit more code in the callers, but we have two sane routines
that do one thing well now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modify _port2addr*() routines in arch/m32r/kernel/io_*.c to use
NONCACHE_OFFSET instead of hard-coding of a constant address.
This modification is also required to support an M3A-ZA36 FPGA eva board in
case an MMU-less synthesizable m32r core is used.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes a deadlock problem of the m32r SMP kernel.
In the m32r kernel, sys_tas() system call is provided as a test-and-set
function for userspace, for backward compatibility.
In some multi-threading application program, deadlocks were rarely caused
at sys_tas() funcion. Such a deadlock was caused due to a collision of
__pthread_lock() and __pthread_unlock() operations.
The "tas" syscall is repeatedly called by pthread_mutex_lock() to get a
lock, while a lock variable's value is not 0. On the other hand,
pthead_mutex_unlock() sets the lock variable to 0 for unlocking.
In the previous implementation of sys_tas() routine, there was a
possibility that a unlock operation was ignored in the following case:
- Assume a lock variable (*addr) was equal to 1 before sys_tas() execution.
- __pthread_unlock() operation is executed by the other processor
and the lock variable (*addr) is set to 0, between a read operation
("oldval = *addr;") and the following write operation ("*addr = 1;")
during a execution of sys_tas().
In this case, the following write operation ("*addr = 1;") overwrites the
__pthread_unlock() result, and sys_tas() fails to get a lock in the next
turn and after that.
According to the attatched patch, sys_tas() returns 0 value in the next
turn and deadlocks never happen.
Signed-off-by: Hitoshi Yamamoto <Yamamoto.Hitoshi@ap.MitsubishiElectric.co.jp>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Define jiffies_64 in kernel/timer.c rather than having 24 duplicated
defines in each architecture.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
