The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a recursive fault is
to have a low level "first opportunity handler" do_trap_or_bp() handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
Also added was a die notification for oops such that kdb can catch an
oops for analysis.
There appeared to be no obvious way to pass the struct pt_regs from
the original exception back to the stack back tracer, so a special
case was added to show_stack() for when kdb is active because you
generally desire to generally look at the back trace of the original
exception.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
"MIPS: Calculate proper ebase value for 64-bit kernels"
9af43ea080dd5d6c7b34f38261780e5dd43537bc (lmo) rsp.
f6be75d03c (kernel.org) broke some 64-bit
MIPS systems.
Before this we were using XKPHYS/cached as ebase and computed the uncached
xphsys/unchached address for that area. After that commit ebase became a
32-bit compat address and convert does not work anymore. We now should use
CKSEG1 for this. CKSEG1ADDR does just that in 32-bit and 64-bit.
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
To: Ralf Baechle <ralf@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1149/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The MIPS implementation of die() forgets to call notify_die() and thus notifiers
registered via register_die_notifier() are not called. This results in kgdb not
being activated on exceptions.
The only subtlety is that notify_die declares its regs argument w/o const, so
the const had to be removed from mips die() as well.
[Ralf: Fixed build error for SGI IP22 and IP28 platforms.]
Signed-off-by: Yury Polyanskiy <ypolyans@princeton.edu>
Cc: linux-mips@linux-mips.org
Patchworks: http://patchwork.linux-mips.org/patch/1142/
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
The ebase is relative to CKSEG0 not CAC_BASE. On a 32-bit kernel they
are the same thing, for a 64-bit kernel they are not.
It happens to kind of work on a 64-bit kernel as they both reference
the same physical memory. However since the CPU uses the CKSEG0 base,
determining if a J instruction will reach always gives the wrong result
unless we use the same number the CPU uses.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1093/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
AR7 has a larger physical offset than other MIPS based systems and therefore
needs to setup its handlers beyond the usual KSEG0 range. When running the
kernel in mapped mode this modification is also required. Remove function
comment which is now incorrect.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Eugene Konev <ejka@imfi.kspu.ru>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/889/
Patchwork: http://patchwork.linux-mips.org/patch/932/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
All call sites of set_except_vector are already annotated with __init, so
annotate that one too.
Signed-off-by: Regards, Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
To: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As reported by Maxime Bizon, the commit "MIPS: PowerTV: Fix support for
timer interrupts with > 64 external IRQs" have broken the r4k timer
since it didn't initialize the cp0_compare_irq_shift variable used in
c0_compare_int_pending() on the architectures whose cpu_has_mips_r2 is
false.
This patch fixes it via initializing the cp0_compare_irq_shift as the
cp0_compare_irq used in the old c0_compare_int_pending().
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: David VomLehn <dvomlehn@cisco.com>
Cc: mbizon@freebox.fr
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/922/
Tested-by: Shane McDonald <mcdonald.shane@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The MIPS processor is limited to 64 external interrupt sources. Using a
greater number without IRQ sharing requires reading platform-specific
registers. On such platforms, reading the IntCtl register to determine
which interrupt corresponds to a timer interrupt will not work.
On MIPSR2 systems there is a solution - the TI bit in the Cause register,
specifically indicates that a timer interrupt has occured. This patch uses
that bit to detect interrupts for MIPSR2 processors, which may be expected
to work regardless of how the timer interrupt may be routed in the hardware.
Signed-off-by: David VomLehn (dvomlehn@cisco.com)
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/804/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Away with the daemons of ifdef; get ready for future COP2 users.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/708/
We had an ugly #ifdef for Cavium Octeon hwrena bits in traps.c, remove
it to mach-cavium-octeon/cpu-feature-overrides.h
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some CPUs have implementation dependent rdhwr registers. Allow them
to be enabled on a per CPU basis.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 566f74f6b2 had a change that
incorrectly modified ebase. This backs out the lines that modified
ebase.
In addition, the ebase exception vector is now allocated with correct
alignment and the ebase register updated according to the architecture
specification.
Based on original patch by David VomLehn <dvomlehn@cisco.com>.
Signed-off-by: David VomLehn <dvomlehn@cisco.com>
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a context switch occurred between the watch exception and reading the
watch registers, it would be possible for the new process to corrupt their
state. Enabling interrupts only after the watch registers are read avoids
this race.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If on Cavium, be aware of cop2 and hwrena during do_cpu().
Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Arguably using the address error handler has always been ugly. But with
processors that handle unaligned loads and stores in hardware the
current mechanism ceases to work so switch it to a BREAK instruction and
allocate break code 514 to the FPU emulator.
Yoichi Yuasa provided a build fix for CONFIG_BUG=n.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
It just so happens to be zero on all currently supported systems so this
hasn't bitten yet ...
[Ralf: Original patch from Cavium; handling of set_uncached_handler() and
de-ifdef'ed trap_init() implementation by me.]
Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Here we hook up the watch exception handler so that it sends SIGTRAP when
the hardware watch registers are triggered.
Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If an interrupt happened between checking of NEED_RESCHED and WAIT
instruction, adjust EPC to restart from checking of NEED_RESCHED.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
trap_init issues flush_icache_range(), which uses ipi functions to
get icache flushing done on all cpus. But this is done before interrupts
are enabled and caused WARN_ON messages. This changeset introduces
a new local_flush_icache_range() and uses it before interrupts (and
additional CPUs) are enabled to avoid this problem.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With -ffunction-section the entries in __dbe_table aren't no longer
sorted, so the lookup of exception addresses in do_be() failed for
some addresses. To avoid this we now sort __dbe_table.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The new kgdb architecture specific handler registers and unregisters
dynamically for exceptions depending on when you configure a kgdb I/O
driver.
Aside from initializing the exceptions earlier in the boot process,
kgdb should have no impact on a device when it is compiled in so long
as an I/O module is not configured for use.
There have been quite a number of contributors during the existence of
this patch (see arch/mips/kernel/kgdb.c). Most recently Jason
re-wrote the mips kgdb logic to use the die notification handlers.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It is not used anywhere in tree.
Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The newly added check for valid stack pointer address breaks at least for
64bit kernels. Use __get_user() for accessing stack content to avoid crashes,
when doing the backtrace.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some of these are architecturally required for R2 processors so lets try
to be bit closer to the real thing. This also provides access to the
CPU cycle timer, even on multiprocessors. In that aspect its currently
bug compatible to what would happen on a R2-based SMP.
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Shadow register support would not possibly have worked on multicore
systems. The support code for it was also depending not on MIPS R2 but
VSMP or SMTC kernels even though it makes perfect sense with UP kernels.
SR sets are a scarce resource and the expected usage pattern is that
users actually hardcode the register set numbers in their code. So fix
the allocator by ditching it. Move the remaining CPU probe bits into
the generic CPU probe.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
One of the easiest things to isolate is the pid printed in kernel log.
There was a patch, that made this for arch-independent code, this one makes
so for arch/xxx files.
It took some time to cross-compile it, but hopefully these are all the
printks in arch code.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Userland, including the C library and the dynamic linker, is keen to use
the SYNC instruction, even for "generic" MIPS I binaries these days.
Which makes it less than useful on MIPS I processors.
This change adds the emulation, but as our do_ri() infrastructure was not
really prepared to take yet another instruction, I have rewritten it and
its callees slightly as follows.
Now there is only a single place a possible signal is thrown from. The
place is at the end of do_ri(). The instruction word is fetched in
do_ri() and passed down to handlers. The handlers are called in sequence
and return a result that lets the caller decide upon further processing.
If the result is positive, then the handler has picked the instruction,
but a signal should be thrown and the result is the signal number. If the
result is zero, then the handler has successfully simulated the
instruction. If the result is negative, then the handler did not handle
the instruction; to make it more obvious the calls do not follow the usual
0/-Exxx result convention they now return -1 instead of -EFAULT.
The calculation of the return EPC is now at the beginning. The reason is
it is easier to handle it there as emulation callees may modify a register
and an instruction may be located in delay slot of a branch whose result
depends on the register. It has to be undone if a signal is to be raised,
but it is not a problem as this is the slow-path case, and both actions
are done in single places now rather than the former being scattered
through emulation handlers.
The part of do_cpu() being covered follows the changes to do_ri().
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
CC arch/mips/sgi-ip22/ip22-berr.o
arch/mips/sgi-ip22/ip22-berr.c: In function 'ip22_be_interrupt':
arch/mips/sgi-ip22/ip22-berr.c💯 warning: passing argument 2 of 'die_if_kernel' discards qualifiers from pointer target type
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
So far /proc/cpuinfo has been the only user but human readable processor
name are more useful than that for proc.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It may not be perfect yet but the SB1 code is badly borken and has
horrible performance issues.
Downside: This seriously breaks support for pass 1 parts of the BCM1250
where indexed cacheops don't work quite reliable but I seem to be the
last one on the planet with a pass 1 part anyway.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The appended patch adds code to update siginfo_t's si_code field. It
fixes e.g. a floating point overflow regression in the SBCL testsuite.
Signed-off-By: Thiemo Seufer <ths@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Also removes the while(1); loop by propagating the ATTRIB_NORET of die()
to nmi_exception_handler.
Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If the kernel OOPSed or BUGed then it probably should be considered as
tainted. Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel. This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jason Wessel