The guarded storage interface allows to register a control block for
each thread that is activated with the guarded storage broadcast event.
To retrieve the complete state of a process from the kernel a register
set for the stored broadcast control block is required.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CAD instruction never worked quite as expected for the spinlock
code. It has been disabled by default with git commit 61b0b01686,
if the "cad" kernel parameter is specified it is enabled for both user
space and the spinlock code. Leave the option to enable the instruction
for user space but remove it from the spinlock code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There are three different code levels in regard to the identification
of guest samples. They differ in the way the LPP instruction is used.
1) Old kernels without the LPP instruction. The guest program parameter
is always zero.
2) Newer kernels load the process pid into the program parameter with LPP.
The guest program parameter is non-zero if the guest executes in a
process != idle.
3) The latest kernels load ((1UL << 31) | pid) with LPP to make the value
non-zero even for the idle task. The guest program parameter is non-zero
if the guest is running.
All kernels load the process pid to CR4 on context switch. The CPU sampling
code uses the value in CR4 to decide between guest and host samples in case
the guest program parameter is zero. The three cases:
1) CR4==pid, gpp==0
2) CR4==pid, gpp==pid
3) CR4==pid, gpp==((1UL << 31) | pid)
The load-control instruction to load the pid into CR4 is expensive and the
goal is to remove it. To distinguish the host CR4 from the guest pid for
the idle process the maximum value 0xffff for the PASN is used.
This adds a fourth case for a guest OS with an updated kernel:
4) CR4==0xffff, gpp=((1UL << 31) | pid)
The host kernel will have CR4==0xffff and will use (gpp!=0 || CR4!==0xffff)
to identify guest samples. This works nicely with all 4 cases, the only
possible issue would be a guest with an old kernel (gpp==0) and a process
pid of 0xffff. Well, don't do that..
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The 32-bit lctl instruction is quite a bit slower than the 64-bit
counter part lctlg. Use the faster instruction.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The return code of hw_perf_event_update() is not evaluated by
its callers. Hence, simplify the function by removing the
return code.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make clear that the event definitions relate to the counter
facility (cf) and not to the sampling facility (sf).
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add the event names for the IBM z13/z13s specific CPU-MF counters.
Also improve the merging of the generic and model specific events
so that their sysfs attribute definitions completely reside in
memory. Hence, flagging the generic event attribute definitions
as initdata too.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Complete the IBM z13 support and support counters from the
MT-diagnostic counter set. Note that this counter set is
available only if SMT is enabled.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The validate_event() function just checked for reserved counters
in particular CPU-MF counter sets. Because the number of counters
in counter sets vary among different hardware models, remove the
explicit check to tolerate new models.
Reserved counters are not accounted and, thus, will return zero.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the highest counter number that can be specified for the
ecctr (extract CPU counter) instruction for perf.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since linux v3.14 with commit 38dfac843c ("vmcore: prevent PT_NOTE
p_memsz overflow during header update") on s390 we get the following
message in the kdump kernel:
Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x6b6b6b6b,
n_descsz=0x6b6b6b6b
The reason for this is that we don't create a final zero note in
the ELF header which the proc/vmcore code uses to find out the end
of the notes section (see also kernel/kexec_core.c:final_note()).
It still worked on s390 by chance because we (most of the time?) have the
byte pattern 0x6b6b6b6b after the notes section which also makes the notes
parsing code stop in update_note_header_size_elf64() because 0x6b6b6b6b is
interpreded as note size:
if ((real_sz + sz) > max_sz) {
pr_warn("Warning: Exceeded p_memsz, dropping P ...);
break;
}
So fix this and add the missing final note to the ELF header.
We don't have to adjust the memory size for ELF header ("alloc_size")
because the new ELF note still fits into the 0x1000 base memory.
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is no need for the __ASSEMBLY__ ifdefery anymore since the
architecture level set code that deals with facility bits was
converted to C in the meantime.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Provide the remaining stsi information via debugfs files. This also
might be useful for debugging purposes.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Provide the raw stsi 15,1,x data contents via debugfs. This makes it
much easier to debug unexpected scheduling domains on machines that
provide cpu topology information.
Therefore this file adds a new 's390/stsi' debugfs directory with a
file for each possible topology nesting level that is allowed by the
architecture. The files will be created regardless if the machine
supports all, or any, level. If a level is not supported, or no data
is available, user space can recognize this with a -EINVAL error code
when trying to read such data.
In addition a 'topology' symlink is created that points to the file
that contains the data that is used to create the scheduling domains.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce a top-level 's390' directory which should be used when
adding new s390 specific debug feature files and/or directories.
This makes hopefully sure that the contents of the s390 directory will
be a bit more structured. Right now we have a couple of top-level
files where it is not easy to tell to which subsystem they belong to.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If running within a level 3 hypervisor, the hypervisor provides a
SYSIB block which contains a control program indentifier string. Use
this string instead of the simple KVM and z/VM strings only. In case
of z/VM this provides addtional information: the z/VM version.
The new string looks similar to this:
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The arch description provided for the "Hardware name:" contains lots
of extra whitespace due to the way the SYSIB contents are defined
(strings aren't zero terminated).
This looks a bit odd and therefore remove the extra whitespace
characters. This also gives the opportunity to add more information,
if required, without hitting the magic 80 characters per line limit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow compiler warnings again for the sysinfo file. Compiler warnings
were disabled when the bogomips calculation with math-emu code was
introduced ("[S390] Calibrate delay and bogomips.").
Since that code is gone, we can enable warnings again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use MACHINE_FLAG_TOPOLOGY instead of MACHINE_HAS_TOPOLOGY when
clearing the bit that indicates if the machine provides topology
information (and if it should be used). Currently works anyway.
Fixes: 68cc795d19 ("s390/topology: make "topology=off" parameter work")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use a single long value instead of a single element array to represent
the core mask. The array is a leftover from 32/31 bit code so we were
able to use bitops helper functions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a new line to /proc/cpuinfo which shows all available facilities
as reported by the stfle instruction:
> cat /proc/cpuinfo
...
facilities : 0 1 2 3 4 6 7 ...
...
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit af51160ebd ("s390/smp: initialize cpu_present_mask in
setup_arch") initializes the cpu_present_mask much earlier than
before. However the cpu detection code relies on the fact that iff
logical cpu 0 is marked present then also the corresponding physical
cpu address within the pcpu_devices array slot is valid.
Since commit 44fd22992c ("[PATCH] Register the boot-cpu in the cpu
maps earlier") this assumption is not true anymore. The patch marks
logical cpu 0 as present in common code without that architecture code
had a chance to setup the logical to physical map.
With that change the cpu detection code assumes that the physical cpu
address of cpu 0 is also 0, which is not necessarily true.
Subsequently the physical cpu address of the ipl cpu will be mapped to
a different logical cpu. If that cpu is brought online later the ipl
cpu will send itself an initial cpu reset sigp signal. This in turn
completely resets the ipl cpu and the system stops working.
A dump of such a system looks like a "store status" has been
forgotten. But actually the kernel itself removed all traces which
would allow to easily tell what went wrong.
To fix this initialize the logical to physical cpu address already in
smp_setup_processor_id(). In addition remove the initialization of the
cpu_present_mask and cpu_online_mask for cpu 0, since that has already
been done. Also add a sanity check, just in case common code will be
changed again...
The problem can be easily reproduced within a z/VM guest:
> chcpu -d 0
> vmcp ipl
Fixes: af51160ebd ("s390/smp: initialize cpu_present_mask in setup_arch")
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This adds a new system call to enable the use of guarded storage for
user space processes. The system call takes two arguments, a command
and pointer to a guarded storage control block:
s390_guarded_storage(int command, struct gs_cb *gs_cb);
The second argument is relevant only for the GS_SET_BC_CB command.
The commands in detail:
0 - GS_ENABLE
Enable the guarded storage facility for the current task. The
initial content of the guarded storage control block will be
all zeros. After the enablement the user space code can use
load-guarded-storage-controls instruction (LGSC) to load an
arbitrary control block. While a task is enabled the kernel
will save and restore the current content of the guarded
storage registers on context switch.
1 - GS_DISABLE
Disables the use of the guarded storage facility for the current
task. The kernel will cease to save and restore the content of
the guarded storage registers, the task specific content of
these registers is lost.
2 - GS_SET_BC_CB
Set a broadcast guarded storage control block. This is called
per thread and stores a specific guarded storage control block
in the task struct of the current task. This control block will
be used for the broadcast event GS_BROADCAST.
3 - GS_CLEAR_BC_CB
Clears the broadcast guarded storage control block. The guarded-
storage control block is removed from the task struct that was
established by GS_SET_BC_CB.
4 - GS_BROADCAST
Sends a broadcast to all thread siblings of the current task.
Every sibling that has established a broadcast guarded storage
control block will load this control block and will be enabled
for guarded storage. The broadcast guarded storage control block
is used up, a second broadcast without a refresh of the stored
control block with GS_SET_BC_CB will not have any effect.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull s390 fixes from Martin Schwidefsky:
- four patches to get the new cputime code in shape for s390
- add the new statx system call
- a few bug fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: wire up statx system call
KVM: s390: Fix guest migration for huge guests resulting in panic
s390/ipl: always use load normal for CCW-type re-IPL
s390/timex: micro optimization for tod_to_ns
s390/cputime: provide archicture specific cputime_to_nsecs
s390/cputime: reset all accounting fields on fork
s390/cputime: remove last traces of cputime_t
s390: fix in-kernel program checks
s390/crypt: fix missing unlock in ctr_paes_crypt on error path
commit 14890678687c ("s390/ipl: use load normal for LPAR re-ipl")
missed to convert one code path to use load normal semantics for
re-IPL. Convert the missing code path as well.
Fixes: 14890678687c ("s390/ipl: use load normal for LPAR re-ipl")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
But first introduce a trivial header and update usage sites.
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>
Introduce a trivial, mostly empty <linux/sched/cputime.h> header
to prepare for the moving of cputime functionality out of sched.h.
Update all code that relies on these facilities.
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>
Update code that relied on sched.h including various MM types for them.
This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>.
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>
We are going to split <linux/sched/task_stack.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/task_stack.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>
We are going to split <linux/sched/task.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/task.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>
We are going to split <linux/sched/hotplug.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/hotplug.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>
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>
We are going to split <linux/sched/signal.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/signal.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>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.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>
We are going to split <linux/sched/topology.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/topology.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>
copy_thread has to reset all cputime related field in the task struct,
not only user_timer and system_timer.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The cputime_t type is a thing of the past, replace the last occurences
of the type in the s390 code with a simple u64.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A program check inside the kernel takes a slightly different path in
entry.S compare to a normal user fault. A recent change moved the store
of the breaking event address into the path taken for in-kernel program
checks as well, but %r14 has not been setup to point to the correct
location. A wild store is the consequence.
Move the store of the breaking event address to the code path for
user space faults.
Fixes: 34525e1f7e ("s390: store breaking event address only for program checks")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull more s390 updates from Martin Schwidefsky:
"Next to the usual bug fixes (including the TASK_SIZE fix), there is
one larger crypto item. It allows to use protected keys with the
in-kernel crypto API
The protected key support has two parts, the pkey user space API to
convert key formats and the paes crypto module that uses a protected
key instead of a standard AES key"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: TASK_SIZE for kernel threads
s390/crypt: Add protected key AES module
s390/dasd: fix spelling mistake: "supportet" -> "supported"
s390/pkey: Introduce pkey kernel module
s390/zcrypt: export additional symbols
s390/zcrypt: Rework CONFIG_ZCRYPT Kconfig text.
s390/zcrypt: Cleanup leftover module code.
s390/nmi: purge tlbs after control register validation
s390/nmi: fix order of register validation
s390/crypto: Add PCKMO inline function
s390/zcrypt: Enable request count reset for cards and queues.
s390/mm: use _SEGMENT_ENTRY_EMPTY in the code
s390/chsc: Add exception handler for CHSC instruction
s390: opt into HAVE_COPY_THREAD_TLS
s390: restore address space when returning to user space
s390: rename CIF_ASCE to CIF_ASCE_PRIMARY
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/'
git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/'
This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.
(Michal Hocko provided most of the kerneldoc comment.)
Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typos and add the following to the scripts/spelling.txt:
an one||a one
I dropped the "an" before "one or more" in
drivers/net/ethernet/sfc/mcdi_pcol.h.
Link: http://lkml.kernel.org/r/1481573103-11329-6-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide the name of each memblock type with struct memblock_type. This
allows to get rid of the function memblock_type_name() and duplicating
the type names in __memblock_dump_all().
The only memblock_type usage out of mm/memblock.c seems to be
arch/s390/kernel/crash_dump.c. While at it, give it a name.
Link: http://lkml.kernel.org/r/20170120123456.46508-4-heiko.carstens@de.ibm.com
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Play safe and purge all tlbs after the control registers that contain
the primary, secondary and home space asces have been validated.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When validating register contents first validate control registers
since these control the availability of features later being
validated.
For example the control register 0 should be validated first, before
the additional floating point (AFP) registers are validated, since
control register 0 contains the AFP-register control bit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This the s390 version of commit c1bd55f922 ("x86: opt into
HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit").
Simply use the tls system call argument instead of extracting the tls
argument by magic from the pt_regs structure.
See commit 3033f14ab7 ("clone: support passing tls argument via C
rather than pt_regs magic") for more background.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Unbalanced set_fs usages (e.g. early exit from a function and a
forgotten set_fs(USER_DS) call) may lead to a situation where the
secondary asce is the kernel space asce when returning to user
space. This would allow user space to modify kernel space at will.
This would only be possible with the above mentioned kernel bug,
however we can detect this and fix the secondary asce before returning
to user space.
Therefore a new TIF_ASCE_SECONDARY which is used within set_fs. When
returning to user space check if TIF_ASCE_SECONDARY is set, which
would indicate a bug. If it is set print a message to the console,
fixup the secondary asce, and then return to user space.
This is similar to what is being discussed for x86 and arm:
"[RFC] syscalls: Restore address limit after a syscall".
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
