The result of the store-clock-fast (STCKF) instruction is a bit fuzzy.
It can happen that the value stored on one CPU is smaller than the value
stored on another CPU, although the order of the stores is the other
way around. This can cause deltas of get_tod_clock() values to become
negative when they should not be.
We need to be more careful with store-clock-fast, this patch partially
reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time:
always use stckf instead of stck if available". The get_tod_clock()
function now uses the store-clock-extended (STCKE) instruction.
get_tod_clock_fast() can be used if the fuzziness of store-clock-fast
is acceptable e.g. for wait loops local to a CPU.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The return value of copy_siginfo_(to|from)_user32() gets passed to
user space, however we do not convert a positive return value from
copy_(to|from)_user to -EFAULT.
Therefore these functions (and the calling system calls) my incorrectly
return a positive number (bytes not copied) instead of -EFAULT.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Git commit 616498813b "s390: system call path micro optimization"
introduced a regression in regard to system call restarting and inferior
function calls via the ptrace interface. The pointer to the system call
table needs to be loaded in sysc_sigpending if do_signal returns with
TIF_SYSCALl set after it restored a system call context.
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently copy_from_oldmem() is not able to copy to virtual memory.
When using kexec pre-allocated ELF header, copy_from_oldmem()
is used to copy the ELF notes information to vmalloc buffers.
So fix this and use the new function copy_from_realmem() that allows
copying also to vmalloc memory.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
"execute relative long" may have all sorts of side effects dependend on
the instructions it executes.
Therefore prohibit setting a kprobe on exrl just like we do for the
regular execute instruction.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With the general-instruction extension facility (z10) a couple of
instructions with a pc-relative long displacement were introduced. The
kprobes support for these instructions however was never implemented.
In result, if anybody ever put a probe on any of these instructions the
result would have been random behaviour after the instruction got executed
within the insn slot.
So lets add the missing handling for these instructions. Since all of the
new instructions have 32 bit signed displacement the easiest solution is
to allocate an insn slot that is within the same 2GB area like the
original instruction and patch the displacement field.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more s390 updates from Heiko Carstens:
"This includes one bpf/jit bug fix where the jit compiler could
sometimes write generated code out of bounds of the allocated memory
area.
The rest of the patches are only cleanups and minor improvements"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/irq: reduce size of external interrupt handler hash array
s390/compat,uid16: use current_cred()
s390/ap_bus: use and-mask instead of a cast
s390/ftrace: avoid pointer arithmetics with function pointers
s390: make various functions static, add declarations to header files
s390/compat signal: add couple of __force annotations
s390/mm: add __releases()/__acquires() annotations to gmap_alloc_table()
s390: keep Kconfig sorted
s390/irq: rework irq subclass handling
s390/irq: use hlists for external interrupt handler array
s390/dumpstack: convert print_symbol to %pSR
s390/perf: Remove print_hex_dump_bytes() debug output
s390: update defconfig
s390/bpf,jit: fix address randomization
Change the hash algorithm a bit so it produces only values in the
range of 0..31.
This allows to reduce the size of the external interrupt handler hash
array even further while making sure that each of the known interrupt
sources keeps its unique hash with the slightly modified algorithm:
0x1004 --> 12
0x1201 --> 10
0x1202 --> 11
0x1406 --> 16
0x1407 --> 17
0x2401 --> 19
0x2603 --> 22
0x4000 --> 0
This also means that the entire array now fits into exactly one cache
line; so add a proper align statement as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
86a264ab "CRED: Wrap current->cred and a few other accessors" converted
all uses of current->cred into current_cred() but left s390 alone.
So let's convert s390 finally as well, only five years later.
This way we also get rid of a sparse warning which complains about a
possible invalid rcu dereference which however is a false positive.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Pointer arithmetics with function pointers is not really defined, but
seems to do the right thing. Let's cast to a void pointer to have a
defined behaviour, at least when using gcc.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Make various functions static, add declarations to header files to
fix a couple of sparse findings.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Add __force annotations to get rid of a couple of sparse warnings:
arch/s390/kernel/compat_signal.c:335:35:
warning: cast removes address space of expression
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Pull timers/nohz changes from Ingo Molnar:
"It mostly contains fixes and full dynticks off-case optimizations, by
Frederic Weisbecker"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
nohz: Include local CPU in full dynticks global kick
nohz: Optimize full dynticks's sched hooks with static keys
nohz: Optimize full dynticks state checks with static keys
nohz: Rename a few state variables
vtime: Always debug check snapshot source _before_ updating it
vtime: Always scale generic vtime accounting results
vtime: Optimize full dynticks accounting off case with static keys
vtime: Describe overriden functions in dedicated arch headers
m68k: hardirq_count() only need preempt_mask.h
hardirq: Split preempt count mask definitions
context_tracking: Split low level state headers
vtime: Fix racy cputime delta update
vtime: Remove a few unneeded generic vtime state checks
context_tracking: User/kernel broundary cross trace events
context_tracking: Optimize context switch off case with static keys
context_tracking: Optimize guest APIs off case with static key
context_tracking: Optimize main APIs off case with static key
context_tracking: Ground setup for static key use
context_tracking: Remove full dynticks' hacky dependency on wide context tracking
nohz: Only enable context tracking on full dynticks CPUs
...
Let's not add a function for every external interrupt subclass for
which we need reference counting. Just have two register/unregister
functions which have a subclass parameter:
void irq_subclass_register(enum irq_subclass subclass);
void irq_subclass_unregister(enum irq_subclass subclass);
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Use hlists for the hashed array of external interrupt handlers.
Reduces the size of the array by 50% (2KB).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This is the same as what other architectures did.
The change has also the advantage that there won't be any interleaving
messages between printk() and print_symbol().
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Function handles may change while the system was in hibernation
use list pci functions and update the function handles.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Some functions that do arch specific resume actions are called
directly from swsusp_asm64.S . Before we add another function call
provide a generic s390_early_resume function which can be used
for this purpose.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A user space program using the transactional execution facility
should be allowed to do program interrupt filtering. Do not set the
transactional-execution program-interruption-filtering override (PIFO)
bit in CR0.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Modify the psw_idle waiting logic in entry[64].S to return with
interrupts disabled. This avoids potential issues with udelay
and interrupt loops as interrupts are not reenabled after
clock comparator interrupts.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The compare and branch instructions (not relative) all need special
handling when kprobed:
- if a branch was taken, the instruction pointer should be left alone
- if a branch was not taken, the instruction pointer must be adjusted
The compare and branch instructions family was introduced with the general
instruction extension facility (z10).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
