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commit 9bf3d3c4e4fd82c7174f4856df372ab2a71005b9 upstream.
Today's message is useless:
[ 42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0
This patch fixes it:
[ 66.905235] Kernel stack overflow in process sh[356], r1=c65560b0
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use task_pid_nr()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0bbea75c476b77fa7d7811d6be911cc7583e640f upstream.
Looks like book3s/32 doesn't set RI on machine check, so
checking RI before calling die() will always be fatal
allthought this is not an issue in most cases.
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit daf00ae71dad8aa05965713c62558aeebf2df48e ]
commit b96672dd840f ("powerpc: Machine check interrupt is a non-
maskable interrupt") added a call to nmi_enter() at the beginning of
machine check restart exception handler. Due to that, in_interrupt()
always returns true regardless of the state before entering the
exception, and die() panics even when the system was not already in
interrupt.
This patch calls nmi_exit() before calling die() in order to restore
the interrupt state we had before calling nmi_enter()
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit d40b6768e45bd9213139b2d91d30c7692b6007b1 ]
system_reset_exception does most of its own crash handling now,
invoking the debugger or crash dumps if they are registered. If not,
then it goes through to die() to print stack traces, and then is
supposed to panic (according to comments).
However after die() prints oopses, it does its own handling which
doesn't allow system_reset_exception to panic (e.g., it may just
kill the current process). This patch causes sreset exceptions to
return from die after it prints messages but before acting.
This also stops die from invoking the debugger on 0x100 crashes.
system_reset_exception similarly calls the debugger. It had been
thought this was harmless (because if the debugger was disabled,
neither call would fire, and if it was enabled the first call
would return). However in some cases like xmon 'X' command, the
debugger returns 0, which currently causes it to be entered
again (first in system_reset_exception, then in die), which is
confusing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 709b973c844c0b4d115ac3a227a2e5a68722c912 ]
The function get_user() can sleep while trying to fetch instruction
from user address space and causes the following warning from the
scheduler.
BUG: sleeping function called from invalid context
Though interrupts get enabled back but it happens bit later after
get_user() is called. This change moves enabling these interrupts
earlier covering the function get_user(). While at this, lets check
for kernel mode and crash as this interrupt should not have been
triggered from the kernel context.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 4552d128c26e0f0f27a5bd2fadc24092b8f6c1d7 ]
The die() oops path contains a serializing lock to prevent oops
messages from being interleaved. In the case of a system reset
initiated oops (e.g., qemu nmi command), __die was being called
which lacks that synchronisation and oops reports could be
interleaved across CPUs.
A recent patch 4388c9b3a6ee7 ("powerpc: Do not send system reset
request through the oops path") changed this to __die to avoid
the debugger() call, but there is no real harm to calling it twice
if the first time fell through. So go back to using die() here.
This was observed to fix the problem.
Fixes: 4388c9b3a6ee7 ("powerpc: Do not send system reset request through the oops path")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into fixes
Merge one commit from Scott which I missed while away.
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Use nmi_enter similarly to system reset interrupts. This uses NMI
printk NMI buffers and turns off various debugging facilities that
helps avoid tripping on ourselves or other CPUs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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There are quite a few machine check exceptions that can be caused by
kernel bugs. To make debugging easier, use the kernel crash path in
cases of synchronous machine checks that occur in kernel mode, if that
would not result in the machine going straight to panic or crash dump.
There is a downside here that die()ing the process in kernel mode can
still leave the system unstable. panic_on_oops will always force the
system to fail-stop, so systems where that behaviour is important will
still do the right thing.
As a test, when triggering an i-side 0111b error (ifetch from foreign
address) in kernel mode process context on POWER9, the kernel currently
dies quickly like this:
Severe Machine check interrupt [Not recovered]
NIP [ffff000000000000]: 0xffff000000000000
Initiator: CPU
Error type: Real address [Instruction fetch (foreign)]
[ 127.426651616,0] OPAL: Reboot requested due to Platform error.
Effective[ 127.426693712,3] OPAL: Reboot requested due to Platform error. address: ffff000000000000
opal: Reboot type 1 not supported
Kernel panic - not syncing: PowerNV Unrecovered Machine Check
CPU: 56 PID: 4425 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #35
Call Trace:
[ 128.017988928,4] IPMI: BUG: Dropping ESEL on the floor due to
buggy/mising code in OPAL for this BMC
Rebooting in 10 seconds..
Trying to free IRQ 496 from IRQ context!
After this patch, the process is killed and the kernel continues with
this message, which gives enough information to identify the offending
branch (i.e., with CFAR):
Severe Machine check interrupt [Not recovered]
NIP [ffff000000000000]: 0xffff000000000000
Initiator: CPU
Error type: Real address [Instruction fetch (foreign)]
Effective address: ffff000000000000
Oops: Machine check, sig: 7 [#1]
SMP NR_CPUS=2048
NUMA
PowerNV
Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 ...
CPU: 22 PID: 4436 Comm: syscall Tainted: G M 4.12.0-rc1-13857-ga4700a261072-dirty #36
task: c000000932300000 task.stack: c000000932380000
NIP: ffff000000000000 LR: 00000000217706a4 CTR: ffff000000000000
REGS: c00000000fc8fd80 TRAP: 0200 Tainted: G M (4.12.0-rc1-13857-ga4700a261072-dirty)
MSR: 90000000001c1003 <SF,HV,ME,RI,LE>
CR: 24000484 XER: 20000000
CFAR: c000000000004c80 DAR: 0000000021770a90 DSISR: 0a000000 SOFTE: 1
GPR00: 0000000000001ebe 00007fffce4818b0 0000000021797f00 0000000000000000
GPR04: 00007fff8007ac24 0000000044000484 0000000000004000 00007fff801405e8
GPR08: 900000000280f033 0000000024000484 0000000000000000 0000000000000030
GPR12: 9000000000001003 00007fff801bc370 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR28: 00007fff801b0000 0000000000000000 00000000217707a0 00007fffce481918
NIP [ffff000000000000] 0xffff000000000000
LR [00000000217706a4] 0x217706a4
Call Trace:
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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A system reset is a request to crash / debug the system rather than
necessarily caused by encountering a BUG. So there is no need to
serialize all CPUs behind the die lock, adding taints to all
subsequent traces beyond the first, breaking console locks, etc.
The system reset is NMI context which has its own printk buffers to
prevent output being interleaved. Then it's better to have all
secondaries print out their debug as quickly as possible and the
primary will flush out all printk buffers during panic().
So remove the 0x100 path from die, and move it into system_reset. Name
the crash/dump reasons "System Reset".
This gives "not tained" traces when crashing an untainted kernel. It
also gives the panic reason as "System Reset" as opposed to "Fatal
exception in interrupt" (or "die oops" for fadump).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This patch updates the machine check handler of Linux kernel to
handle the e6500 architecture case. In e6500 core, L1 Data Cache Write
Shadow Mode (DCWS) register is not implemented but L1 data cache always
runs in write shadow mode. So, on L1 data cache parity errors, hardware
will automatically invalidate the data cache but will still log a
machine check interrupt.
Signed-off-by: Ronak Desai <ronak.desai@rockwellcollins.com>
Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Scott Wood <oss@buserror.net>
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Just because it looks less gross.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Although the MSR tells you what endian you're in it's possible that
isn't the same endian the kernel was built for, and if that happens
you're usually having a very bad day. So print a marker to make
it 100% clear which endian the kernel was built for.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When we oops we print a few markers for significant config options
such as PREEMPT, SMP etc. Currently these appear on separate lines
because we're not using pr_cont() properly. Fix it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Since commit aa42c69c67f82 ("[POWERPC] Add support for FP emulation
for the e300c2 core"), program_check_exception() can be called for
math emulation. In that case, 'reason' is 0.
On the 8xx, there is a Software Emulation interrupt which is
called for all unimplemented and illegal instructions. This
interrupt calls SoftwareEmulation() which does almost the
same as program_check_exception() called with reason = 0.
The Software Emulation interrupt sets all reason bits to 0,
it is therefore possible to call program_check_exception()
directly from the interrupt handler.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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In the same spirit as what was done for 4xx and 44x, move
the 8xx machine check into platforms/8xx
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Currently we open code the reason codes for program checks. Instead use
the existing SRR1 defines.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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We already have mce.c which is built for 64bit and contains other parts
of the machine check code, so move these bits in there too.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Make it clear that the fallback version of machine_check_generic() is
only used on 32-bit configs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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get_mc_reason() no longer provides (if it ever really did) any
meaningful abstraction, so remove it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Now that we have 4xx platform directory we can move the 4xx machine
check handler in there. Again we drop get_mc_reason() and replace it
with regs->dsisr directly (which is actually SPRN_ESR).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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We have several 44x machine check handlers defined in traps.c. It would
be preferable if they were split out with the platforms that use them.
Do that.
In the process, drop get_mc_reason() and instead just open code the
lookup of reason from regs->dsisr. This avoids a pointless layer of
abstraction.
We know to use regs->dsisr because 44x enables BOOKE which enables
PPC_ADV_DEBUG_REGS, and FSL_BOOKE is not enabled on 44x builds.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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On 64-bit Book3s, when we're in HV mode, we have already counted the
machine check exception in machine_check_early().
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use IS_ENABLED() rather than an #ifdef]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Blacklist all functions involved while handling a trap. We:
- convert some of the symbols into private symbols, and
- blacklist most functions involved while handling a trap.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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machine_check_early() gets called in real mode. The very first time when
add_taint() is called, it prints a warning which ends up calling opal
call (that uses OPAL_CALL wrapper) for writing it to console. If we get a
very first machine check while we are in opal we are doomed. OPAL_CALL
overwrites the PACASAVEDMSR in r13 and in this case when we are done with
MCE handling the original opal call will use this new MSR on it's way
back to opal_return. This usually leads to unexpected behaviour or the
kernel to panic. Instead move the add_taint() call later in the virtual
mode where it is safe to call.
This is broken with current FW level. We got lucky so far for not getting
very first MCE hit while in OPAL. But easily reproducible on Mambo.
Fixes: 27ea2c420cad ("powerpc: Set the correct kernel taint on machine check errors.")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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System reset is a non-maskable interrupt from Linux's point of view
(occurs under local_irq_disable()), so it should use nmi_enter/exit.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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In preparation for using a dedicated stack for system reset interrupts,
prevent a nested system reset from recovering, in order to simplify
code that is called in crash/debug path. This allows a system reset
interrupt to just use the base stack pointer.
Keep an in_nmi nesting counter similarly to the in_mce counter. Consider
the interrrupt non-recoverable if it is taken inside another system
reset.
Interrupt nesting could be allowed similarly to MCE, but system reset
is a special case that's not for normal operation, so simplicity wins
until there is requirement for nested system reset interrupts.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Add the bit definition and use it in facility_unavailable_exception() so we can
intelligently report the cause if we take a fault for SCV. This doesn't actually
enable SCV.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop whitespace changes to the existing entries, flush out change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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powerpc_debugfs_root is the dentry representing the root of the
"powerpc" directory tree in debugfs.
Currently it sits in asm/debug.h, a long with some other things that
have "debug" in the name, but are otherwise unrelated.
Pull it out into a separate header, which also includes linux/debugfs.h,
and convert all the users to include debugfs.h instead of debug.h.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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<linux/sched/debug.h>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The current facility_strings[] are correct when the trap address is
0xf80 (hypervisor facility unavailable). When the trap address is
0xf60 (facility unavailable) IC (Interruption Cause) a.k.a status in the
code is undefined for values 0 and 1.
Add a check to prevent printing the (misleading) facility name for IC 0
and 1 when we came in via 0xf60. In all cases, print the actual IC
value, to avoid any confusion.
This hasn't been seen on real hardware, on only qemu which was
misreporting an exception.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Fix indentation, combine printks(), massage change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Commit 2965faa5e03d ("kexec: split kexec_load syscall from kexec core
code") introduced CONFIG_KEXEC_CORE so that CONFIG_KEXEC means whether
the kexec_load system call should be compiled-in and CONFIG_KEXEC_FILE
means whether the kexec_file_load system call should be compiled-in.
These options can be set independently from each other.
Since until now powerpc only supported kexec_load, CONFIG_KEXEC and
CONFIG_KEXEC_CORE were synonyms. That is not the case anymore, so we
need to make a distinction. Almost all places where CONFIG_KEXEC was
being used should be using CONFIG_KEXEC_CORE instead, since
kexec_file_load also needs that code compiled in.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Invoke the kprobe handlers directly rather than through notify_die(), to
reduce path taken for handling kprobes. Similar to commit 6f6343f53d13
("kprobes/x86: Call exception handlers directly from do_int3/do_debug").
While at it, rename post_kprobe_handler() to kprobe_post_handler() for
more uniform naming.
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When ending an oops, don't clear die_owner unless the nest count
went to zero. This prevents a second nested oops from hanging forever
on the die_lock.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When exiting xmon with 'x' (exit and recover), oops_begin bails
out immediately, but die then calls __die() and oops_end(), which
cause a lot of bad things to happen.
If the debugger was attached then went to graceful recovery, exit
from die() immediately.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Load monitored is no longer supported on POWER9 so let's remove the
code.
This reverts commit bd3ea317fddf ("powerpc: Load Monitor Register
Support").
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This halves the exception table size on 64-bit builds, and it allows
build-time sorting of exception tables to work on relocated kernels.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Minor asm fixups and bits to keep the selftests working]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next
Freescale updates from Scott:
"Highlights include qbman support (a prerequisite for datapath drivers
such as ethernet), a PCI DMA fix+improvement, reset handler changes, more
8xx optimizations, and some cleanups and fixes."
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Currently the MSR TM bit is always set if the hardware is TM capable.
This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and
TFAIR) must be swapped for each process regardless of if they use TM.
For processes that don't use TM the TM MSR bit can be turned off
allowing the kernel to avoid the expensive swap of the TM registers.
A TM unavailable exception will occur if a thread does use TM and the
kernel will enable MSR_TM and leave it so for some time afterwards.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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If the kernel disables transactional memory (TM) and userspace still
tries TM related actions (TM instructions or TM SPR accesses) TM aware
hardware will cause the kernel to take a facility unavailable
exception.
Add checks for the exception being caused by illegal TM access in
userspace.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Rewrite comment entirely, bugs in it are mine]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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There is currently an inconsistency as to how the entire CPU register
state is saved and restored when a thread uses transactional memory
(TM).
Using transactional memory results in the CPU having duplicated
(almost) all of its register state. This duplication results in a set
of registers which can be considered 'live', those being currently
modified by the instructions being executed and another set that is
frozen at a point in time.
On context switch, both sets of state have to be saved and (later)
restored. These two states are often called a variety of different
things. Common terms for the state which only exists after the CPU has
entered a transaction (performed a TBEGIN instruction) in hardware are
'transactional' or 'speculative'.
Between a TBEGIN and a TEND or TABORT (or an event that causes the
hardware to abort), regardless of the use of TSUSPEND the
transactional state can be referred to as the live state.
The second state is often to referred to as the 'checkpointed' state
and is a duplication of the live state when the TBEGIN instruction is
executed. This state is kept in the hardware and will be rolled back
to on transaction failure.
Currently all the registers stored in pt_regs are ALWAYS the live
registers, that is, when a thread has transactional registers their
values are stored in pt_regs and the checkpointed state is in
ckpt_regs. A strange opposite is true for fp_state/vr_state. When a
thread is non transactional fp_state/vr_state holds the live
registers. When a thread has initiated a transaction fp_state/vr_state
holds the checkpointed state and transact_fp/transact_vr become the
structure which holds the live state (at this point it is a
transactional state).
This method creates confusion as to where the live state is, in some
circumstances it requires extra work to determine where to put the
live state and prevents the use of common functions designed (probably
before TM) to save the live state.
With this patch pt_regs, fp_state and vr_state all represent the
same thing and the other structures [pending rename] are for
checkpointed state.
Acked-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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During a machine check, the 8xx provides indication of
whether the check is due to data or instruction access, so
let's display it.
Lets also move 8xx specific handling into the new handler.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
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When the watchdog is in NMI mode, the system reset interrupt is
generated when the watchdog counter expires.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
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Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
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Currently we mark the C implementations of some exception handlers as
__kprobes. This has the effect of putting them in the ".kprobes.text"
section, which separates them from the rest of the text.
Instead we can use the blacklist macros to add the symbols to a
blacklist which kprobes will check. This allows the linker to move
exception handler functions close to callers and avoids trampolines in
larger kernels.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Reword change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Currently, if userspace or the kernel accesses a completely bogus address,
for example with any of bits 46-59 set, we first take an SLB miss interrupt,
install a corresponding SLB entry with VSID 0, retry the instruction, then
take a DSI/ISI interrupt because there is no HPT entry mapping the address.
However, by the time of the second interrupt, the Come-From Address Register
(CFAR) has been overwritten by the rfid instruction at the end of the SLB
miss interrupt handler. Since bogus accesses can often be caused by a
function return after the stack has been overwritten, the CFAR value would
be very useful as it could indicate which function it was whose return had
led to the bogus address.
This patch adds code to create a full exception frame in the SLB miss handler
in the case of a bogus address, rather than inserting an SLB entry with a
zero VSID field. Then we call a new slb_miss_bad_addr() function in C code,
which delivers a signal for a user access or creates an oops for a kernel
access. In the latter case the oops message will show the CFAR value at the
time of the access.
In the case of the radix MMU, a segment miss interrupt indicates an access
outside the ranges mapped by the page tables. Previously this was handled
by the code for an unrecoverable SLB miss (one with MSR[RI] = 0), which is
not really correct. With this patch, we now handle these interrupts with
slb_miss_bad_addr(), which is much more consistent.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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These files were only including module.h for exception table
related functions. We've now separated that content out into its
own file "extable.h" so now move over to that and avoid all the
extra header content in module.h that we don't really need to compile
these files.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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