Meelis Roos reported that kernels built with gcc-4.9 do not boot, we
eventually narrowed this down to only impacting machines using
UltraSPARC-III and derivitive cpus.
The crash happens right when the first user process is spawned:
[ 54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[ 54.451346]
[ 54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab #96
[ 54.666431] Call Trace:
[ 54.698453] [0000000000762f8c] panic+0xb0/0x224
[ 54.759071] [000000000045cf68] do_exit+0x948/0x960
[ 54.823123] [000000000042cbc0] fault_in_user_windows+0xe0/0x100
[ 54.902036] [0000000000404ad0] __handle_user_windows+0x0/0x10
[ 54.978662] Press Stop-A (L1-A) to return to the boot prom
[ 55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
Further investigation showed that compiling only per_cpu_patch() with
an older compiler fixes the boot.
Detailed analysis showed that the function is not being miscompiled by
gcc-4.9, but it is using a different register allocation ordering.
With the gcc-4.9 compiled function, something during the code patching
causes some of the %i* input registers to get corrupted. Perhaps
we have a TLB miss path into the firmware that is deep enough to
cause a register window spill and subsequent restore when we get
back from the TLB miss trap.
Let's plug this up by doing two things:
1) Stop using the firmware stack for client interface calls into
the firmware. Just use the kernel's stack.
2) As soon as we can, call into a new function "start_early_boot()"
to put a one-register-window buffer between the firmware's
deepest stack frame and the top-most initial kernel one.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Inconsistently, the raw_* IRQ routines do not interact with and update
the irqflags tracing and lockdep state, whereas the raw_* spinlock
interfaces do.
This causes problems in p1275_cmd_direct() because we disable hardirqs
by hand using raw_local_irq_restore() and then do a raw_spin_lock()
which triggers a lockdep trace because the CPU's hw IRQ state doesn't
match IRQ tracing's internal software copy of that state.
The CPU's irqs are disabled, yet current->hardirqs_enabled is true.
====================
reboot: Restarting system
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240()
DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
Modules linked in: openpromfs
CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G W 3.17.0-dirty #145
Call Trace:
[000000000045919c] warn_slowpath_common+0x5c/0xa0
[0000000000459210] warn_slowpath_fmt+0x30/0x40
[000000000048f41c] check_flags+0x7c/0x240
[0000000000493280] lock_acquire+0x20/0x1c0
[0000000000832b70] _raw_spin_lock+0x30/0x60
[000000000068f2fc] p1275_cmd_direct+0x1c/0x60
[000000000068ed28] prom_reboot+0x28/0x40
[000000000043610c] machine_restart+0x4c/0x80
[000000000047d2d4] kernel_restart+0x54/0x80
[000000000047d618] SyS_reboot+0x138/0x200
[00000000004060b4] linux_sparc_syscall32+0x34/0x60
---[ end trace 5c439fe81c05a100 ]---
possible reason: unannotated irqs-off.
irq event stamp: 2010267
hardirqs last enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580
hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580
softirqs last enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0
softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40
Resetting ...
====================
Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees
all of our changes.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the IRQ flag handling naming. In linux/irqflags.h under one configuration,
it maps:
local_irq_enable() -> raw_local_irq_enable()
local_irq_disable() -> raw_local_irq_disable()
local_irq_save() -> raw_local_irq_save()
...
and under the other configuration, it maps:
raw_local_irq_enable() -> local_irq_enable()
raw_local_irq_disable() -> local_irq_disable()
raw_local_irq_save() -> local_irq_save()
...
This is quite confusing. There should be one set of names expected of the
arch, and this should be wrapped to give another set of names that are expected
by users of this facility.
Change this to have the arch provide:
flags = arch_local_save_flags()
flags = arch_local_irq_save()
arch_local_irq_restore(flags)
arch_local_irq_disable()
arch_local_irq_enable()
arch_irqs_disabled_flags(flags)
arch_irqs_disabled()
arch_safe_halt()
Then linux/irqflags.h wraps these to provide:
raw_local_save_flags(flags)
raw_local_irq_save(flags)
raw_local_irq_restore(flags)
raw_local_irq_disable()
raw_local_irq_enable()
raw_irqs_disabled_flags(flags)
raw_irqs_disabled()
raw_safe_halt()
with type checking on the flags 'arguments', and then wraps those to provide:
local_save_flags(flags)
local_irq_save(flags)
local_irq_restore(flags)
local_irq_disable()
local_irq_enable()
irqs_disabled_flags(flags)
irqs_disabled()
safe_halt()
with tracing included if enabled.
The arch functions can now all be inline functions rather than some of them
having to be macros.
Signed-off-by: David Howells <dhowells@redhat.com> [X86, FRV, MN10300]
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [Tile]
Signed-off-by: Michal Simek <monstr@monstr.eu> [Microblaze]
Tested-by: Catalin Marinas <catalin.marinas@arm.com> [ARM]
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [AVR]
Acked-by: Tony Luck <tony.luck@intel.com> [IA-64]
Acked-by: Hirokazu Takata <takata@linux-m32r.org> [M32R]
Acked-by: Greg Ungerer <gerg@uclinux.org> [M68K/M68KNOMMU]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [MIPS]
Acked-by: Kyle McMartin <kyle@mcmartin.ca> [PA-RISC]
Acked-by: Paul Mackerras <paulus@samba.org> [PowerPC]
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [S390]
Acked-by: Chen Liqin <liqin.chen@sunplusct.com> [Score]
Acked-by: Matt Fleming <matt@console-pimps.org> [SH]
Acked-by: David S. Miller <davem@davemloft.net> [Sparc]
Acked-by: Chris Zankel <chris@zankel.net> [Xtensa]
Reviewed-by: Richard Henderson <rth@twiddle.net> [Alpha]
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp> [H8300]
Cc: starvik@axis.com [CRIS]
Cc: jesper.nilsson@axis.com [CRIS]
Cc: linux-cris-kernel@axis.com
This is based upon a report by Meelis Roos showing that it's possible
that we'll try to fetch a property that is 32K in size with some
devices. With the current fixed 3K buffer we use for moving data in
and out of the firmware during PROM calls, that simply won't work.
In fact, it will scramble random kernel data during bootup.
The reasoning behind the temporary buffer is entirely historical. It
used to be the case that we had problems referencing dynamic kernel
memory (including the stack) early in the boot process before we
explicitly told the firwmare to switch us over to the kernel trap
table.
So what we did was always give the firmware buffers that were locked
into the main kernel image.
But we no longer have problems like that, so get rid of all of this
indirect bounce buffering.
Besides fixing Meelis's bug, this also makes the kernel data about 3K
smaller.
It was also discovered during these conversions that the
implementation of prom_retain() was completely wrong, so that was
fixed here as well. Currently that interface is not in use.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we do something like try to print to the OF console from an NMI
while we're already in OpenFirmware, we'll deadlock on the spinlock.
Use a raw spinlock and disable NMIs when we take it.
Signed-off-by: David S. Miller <davem@davemloft.net>
- all files with identical names copied and renamed to *_64.c
- the remaning files copied as is
- added sparc64 specific files to sparc/prom/Makefile
- teach sparc64 Makefile to look into sparc/prom/
- delete unused Makefile from sparc64/prom/
linking order was not kept for sparc64 with this change.
It was not possible to keep linking order for both sparc and sparc64
and as sparc64 see more testing than sparc it was natural to
break linking order on sparc64. Should it have any effect it
would be detected sooner this way.
printf_32.c and printf_64.c are obvious candidates to be merged
but they are not 100% equal so that was left for later
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller