Use snprintf() here as well so we won't have to deal with this again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch fixed bugzilla #12965:
https://bugzilla.kernel.org/show_bug.cgi?id=12965
The original code contains some inproper use of sprintf
function where a buffer is used both as input string
as well as output string. It should remember the written
bytes in the previous and use that as the offset for
later writing. Also replace sprintf with snprintf.
Signed-off-by: Chen Liu <chenliu@asset.uwaterloo.ca>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support
percpu: Generic support for this_cpu_cmpxchg_double()
alpha: use L1_CACHE_BYTES for cacheline size in the linker script
percpu: align percpu readmostly subsection to cacheline
Fix up trivial conflict in arch/x86/kernel/vmlinux.lds.S due to the
percpu alignment having changed ("x86: Reduce back the alignment of the
per-CPU data section")
Disable ftrace during kexec. Same as on x86/powerpc.
ac4414e "powerpc/kdump: Disable ftrace during kexec".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
task_show_regs used to be a debugging aid in the early bringup days
of Linux on s390. /proc/<pid>/status is a world readable file, it
is not a good idea to show the registers of a process. The only
correct fix is to remove task_show_regs.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.
This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.
This is based on Shaohua's x86 only patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
Randomize ELF_ET_DYN_BASE, which is used when loading position
independent executables.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Randomize heap address like other architectures do already.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Randomize the lower bits of the stack address like x86 and powerpc.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The vdso object is currently always mapped with mm->mmap_base used as
requested address. In case of flexible mmap layout this means it gets
mapped above mmap_base and therefore potentially stealing a bit of
address space that is reserved for the stack.
In case of flexible mmap layout the object should be mapped below
mmap base. For legacy mmap layout above.
To fix this just don't request any specific address and let the mmap
code figure out an address that fits.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When the seqfile /proc/cpuinfo gets accesses for each possible cpu
loops_per_jiffy gets recalculated. However its value is only needed
on first access.
In addition loops_per_jiffy should be recalculated when the machine
reports a capability change.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use get_online_cpus() instead of preempt_disable() to make sure cpus
don't go offline while accessing their per cpu data.
The preempt_disable() stuff is old code which was used before
get_online_cpus() was available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Get rid of messages that indicate if a cpu went online or offline.
There is nothing special about this anymore and these messages might
flood the kernel log buffer which makes debugging harder since more
important messages might be overwritten.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Call init_idle() which (re-)initializes the idle task structure before
it gets used on a new cpu.
That way we can also get rid of the odd preempt_enable_no_resched()
call we have in the cpu offline path within cpu_idle(). That call
prevented preempt count imbalances between cpu hotplug operations.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Delay idle task creation until a cpu gets set online instead of
creating them for all possible cpus at system startup.
For one cpu system this should safe more than 1 MB.
On my debug system with lots of debug stuff enabled this saves 2 MB.
Same as on x86.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Until now machine checks for the swapper process of the IPL cpu are just
implicitly (and more or less accidently) enabled when the first time the
idle process goes into idle state and loads an enabled wait psw.
Before that machine checks are disabled.
So let's enable them explicitly in trap_init() so we have a well defined
time when machine checks are enabled.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make the code in the 31 bit entry.S code as similar as possible to the
64 bit version in entry64.S. That makes it easier to add new code to
the first level interrupt handler that affects both 31 and 64 bit kernels.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Get rid of register/unregister_early_external_interrupt() and clean up
the code while at it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use an early init call to initialize pfault. That way it is possible to
use the register_external_interrupt() instead of the early variant.
No need to enable pfault any earlier since it has only effect if user
space processes are running.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for AP Bus I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for CTC I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for CLAW I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for LCS I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for VMUR I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for ccw based tape I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for 3270 I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for 3215 I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for DASD I/O interrupt statistics in /proc/interrupts.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Count traditional qdio interrupts and adapter interrupts for qdio
in the interrupt statistics.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Up to now /proc/interrupts only has statistics for external and i/o
interrupts but doesn't split up them any further.
This patch adds a line for every single interrupt source so that it
is possible to easier tell what the machine is/was doing.
Part of the output now looks like this;
CPU0 CPU2 CPU4
EXT: 3898 4232 2305
I/O: 782 315 245
CLK: 1029 1964 727 [EXT] Clock Comparator
IPI: 2868 2267 1577 [EXT] Signal Processor
TMR: 0 0 0 [EXT] CPU Timer
TAL: 0 0 0 [EXT] Timing Alert
PFL: 0 0 0 [EXT] Pseudo Page Fault
[...]
NMI: 0 1 1 [NMI] Machine Checks
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add kprobes annotations to get the massive 'probe kernel.function("*") {}'
stress test working.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Restructure the kprobe breakpoint handler function. Add comments to
make it more comprehensible and add a sanity check for re-entering
kprobes.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Register %r14 and %r15 are already stored in jprobe_saved_regs, no need
to store them a second time in jprobe_saved_r14 / jprobe_saved_r15.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The s390 architecture can execute code on kmalloc/vmalloc memory.
No need for the __ARCH_WANT_KPROBES_INSN_SLOT detour.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace set_current_kprobe/reset_current_kprobe/save_previous_kprobe/
restore_previous_kprobe with a simpler scheme push_kprobe/pop_kprobe.
The mini kprobes stack can store up to two active kprobes.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Determine instruction fixup details in resume_execution, no need to do
it beforehand. Remove fixup, ilen and reg from arch_specific_insn.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the definition of the helper structure ins_replace_args to the
only place where it is used and drop the old member as it is not needed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The saved interrupt mask and the saved control registers are only
relevant while single stepping is set up. A secondary kprobe while
kprobe single stepping is active may not occur. That makes is safe
to remove the save and restore of kprobe_saved_imask / kprobe_save_ctl
from save_previous_kprobe and restore_previous_kprobe.
Move all single step related code to two functions, enable_singlestep
and disable_singlestep.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove special case of a kprobe on a breakpoint while a relocated
instruction is single stepped. The only instruction that may cause
a fault while kprobe single stepping is active is the relocated
instruction. There is no kprobe on the instruction slot retrieved
with get_insn_slot().
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This fixes the same problem as described in the patch "nohz: fix
printk_needs_cpu() return value on offline cpus" for the arch_needs_cpu()
primitive:
arch_needs_cpu() may return 1 if called on offline cpus. When a cpu gets
offlined it schedules the idle process which, before killing its own cpu,
will call tick_nohz_stop_sched_tick().
That function in turn will call arch_needs_cpu() in order to check if the
local tick can be disabled. On offline cpus this function should naturally
return 0 since regardless if the tick gets disabled or not the cpu will be
dead short after. That is besides the fact that __cpu_disable() should already
have made sure that no interrupts on the offlined cpu will be delivered anyway.
In this case it prevents tick_nohz_stop_sched_tick() to call
select_nohz_load_balancer(). No idea if that really is a problem. However what
made me debug this is that on 2.6.32 the function get_nohz_load_balancer() is
used within __mod_timer() to select a cpu on which a timer gets enqueued.
If arch_needs_cpu() returns 1 then the nohz_load_balancer cpu doesn't get
updated when a cpu gets offlined. It may contain the cpu number of an offline
cpu. In turn timers get enqueued on an offline cpu and not very surprisingly
they never expire and cause system hangs.
This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses
get_nohz_timer_target() which doesn't have that problem. However there might
be other problems because of the too early exit tick_nohz_stop_sched_tick()
in case a cpu goes offline.
This specific bug was indrocuded with 3c5d92a0 "nohz: Introduce
arch_needs_cpu".
In this case a cpu hotplug notifier is used to fix the issue in order to keep
the normal/fast path small. All we need to do is to clear the condition that
makes arch_needs_cpu() return 1 since it is just a performance improvement
which is supposed to keep the local tick running for a short period if a cpu
goes idle. Nothing special needs to be done except for clearing the condition.
Cc: stable@kernel.org
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
On each machine check all registers are revalidated. The save area for
the clock comparator however only contains the upper most seven bytes
of the former contents, if valid.
Therefore the machine check handler uses a store clock instruction to
get the current time and writes that to the clock comparator register
which in turn will generate an immediate timer interrupt.
However within the lowcore the expected time of the next timer
interrupt is stored. If the interrupt happens before that time the
handler won't be called. In turn the clock comparator won't be
reprogrammed and therefore the interrupt condition stays pending which
causes an interrupt loop until the expected time is reached.
On NOHZ machines this can result in unresponsive machines since the
time of the next expected interrupted can be a couple of days in the
future.
To fix this just revalidate the clock comparator register with the
expected value.
In addition the special handling for udelay must be changed as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Analog to git commit 737480a0d5
fix the return address of subsequent kretprobes when multiple
kretprobes are set on the same function.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Execute the kprobe exception and fault handler with interrupts disabled.
To disable the interrupts only while a single step is in progress is not
good enough, a kprobe from interrupt context while another kprobe is
handled can confuse the internal house keeping.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix kprobes after git commit 1e54622e04
broke it. The kprobe_handler is now called with interrupts in the state
at the time of the breakpoint. The single step of the replaced instruction
is done with interrupts off which makes it necessary to enable and disable
the interupts in the kprobes code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CLOCK_* defines in asm-offsets.c are only used for the vdso code
however in the meantime they cause other trouble.
Just rename them to get permanently rid of this:
In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0,
from arch/s390/mm/fault.c:33:
include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined
include/linux/time.h:286:0: note: this is the location of the previous definition
include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined
include/linux/time.h:287:0: note: this is the location of the previous definition
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix cpu masks for 'topology=off' case. Folding of the scheduling domains
happen in such a way that everything belongs to the MC domain instead
of the CPU doimain.
This should fix a performance regression introduced with
eafd2b6d "[S390] topology: use default MC domain initializer" and also
makes sure we have the same behavious as if CONFIG_SCHED_MC was not
selected at all.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This allows us to easily check for performance differences seen with
!CONFIG_SCHED_MC and topology=off.
Actually there shouldn't be any (besides a small overhead because of
additional code).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add machine type for zEnterprise 196 to elf platform detection.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Export the cpu configuration topology via sysinfo. Two new lines are
introduced:
CPU Topology HW: 0 0 0 4 6 4
CPU Topology SW: 0 0 0 0 4 24
The HW line describes the cpu topology nesting levels when the maximum
nesting level is used to get the corresponding SYSIB.
The SW line describes what Linux is actually using. In this case it
supports only two levels (CONFIG_SCHED_BOOK off) and therefore the
hardware folded the two lower levels in the SYSIB response block.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the topology sysinfo SYSIB definitions to the proper place in
asm/sysinfo.h where they should be.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move cpu topology facility detection to early setup code where it
should be.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Switch default value of the kernel parameter 'topology' from off to on.
Various performance measurements have finally shown that there are no
(known) regressions anywhere.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Up to now print_cpu_info() uses the cpu address stored in it's local
lowcore to print a message to the console. The cpu address in the
lowcore is (in this case) however not the physical cpu address of the
local cpu. It's the address of the cpu that issued the sigp restart
which started the local cpu.
Fix this by using the store cpu address instruction instead.
It's not that anybody really cares since this is broken since more than
ten years...
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The ieee_instruction_pointer can not be read from user space anymore
since git commit 613e1def6b, the ptrace
interface always returns zero. Remove it from the thread_struct. It
is still present in the user_regs_struct for compatability reasons.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Do the setup of the stack overflow argument for the sixth system
call parameter right before the branch to the system call function.
That simplifies the system call parameter access code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Read external interrupts parameters from the lowcore in the first
level interrupt handler in entry[64].S.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Read all required fields for program checks from the lowcore in the
first level interrupt handler in entry[64].S. If the context that
caused the fault was enabled for interrupts we can now re-enable the
irqs in entry[64].S.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a kernel config option for the IBM zEnterprise 196. This will
produce faster code on newer compilers using the -march=z196 option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Display machine capacity adjustment indicator and capacity
change reason if available in /proc/sysinfo.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is no difference if cpu_die is called from enabled or disabled
context. Except that the fast_gup code might be called via
cpu_die -> idle_task_exit -> __mm_drop -> crst_table_free. Which in
turn grabs and releases a spinlock using the _bh ops, which is not
allowed in irq disabled context, since spin_unlock_bh will
unconditionally enable interrupts again.
To get rid of the warning emitted by the softirq code just move the
code to enabled context.
In this case this doesn't fix a bug, we just get rid of a warning.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-irqflags:
Fix IRQ flag handling naming
MIPS: Add missing #inclusions of <linux/irq.h>
smc91x: Add missing #inclusion of <linux/irq.h>
Drop a couple of unnecessary asm/system.h inclusions
SH: Add missing consts to sys_execve() declaration
Blackfin: Rename IRQ flags handling functions
Blackfin: Add missing dep to asm/irqflags.h
Blackfin: Rename DES PC2() symbol to avoid collision
Blackfin: Split the BF532 BFIN_*_FIO_FLAG() functions to their own header
Blackfin: Split PLL code from mach-specific cdef headers
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
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
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.
However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling. That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.
Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.
So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.
Future fixups:
- move the module list handling code into kernel/module.c where it
belongs.
- get rid of 'module_bug_list' and just use the regular list of modules
(called 'modules' - imagine that) that we already create and maintain
for other reasons.
Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the extended cpu topology information that z11 machines provide
to improve the scheduler's decision making.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100831082844.604956770@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The tlb flushing code uses the mm_users field of the mm_struct to
decide if each page table entry needs to be flushed individually with
IPTE or if a global flush for the mm_struct is sufficient after all page
table updates have been done. The comment for mm_users says "How many
users with user space?" but the /proc code increases mm_users after it
found the process structure by pid without creating a new user process.
Which makes mm_users useless for the decision between the two tlb
flusing methods. The current code can be confused to not flush tlb
entries by a concurrent access to /proc files if e.g. a fork is in
progres. The solution for this problem is to make the tlb flushing
logic independent from the mm_users field.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
fix this build error:
arch/s390/kernel/process.c:272: error: conflicting types for 'sys_execve'
arch/s390/kernel/entry.h:45: error: previous declaration of 'sys_execve' was here
make[1]: *** [arch/s390/kernel/process.o] Error 1
make: *** [arch/s390/kernel] Error 2
introduced by d7627467b7
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark arguments to certain system calls as being const where they should be but
aren't. The list includes:
(*) The filename arguments of various stat syscalls, execve(), various utimes
syscalls and some mount syscalls.
(*) The filename arguments of some syscall helpers relating to the above.
(*) The buffer argument of various write syscalls.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 485d527686 "sys_personality: change
sys_personality() to accept "unsigned int" instead of u_long" changed
the syscall interface for sys_personality.
Just follow the common code change in our arch code to avoid confusion.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change default load address of the initrd in case of IPL from reader.
The new load address is directly behind the kernel image.
This way we can see immediatly if there are any problems with the code
which tries to rescue the initrd in case the bootmem bitmap would
overlap with the initrd.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
um: Fix read_persistent_clock fallout
kgdb: Do not access xtime directly
powerpc: Clean up obsolete code relating to decrementer and timebase
powerpc: Rework VDSO gettimeofday to prevent time going backwards
clocksource: Add __clocksource_updatefreq_hz/khz methods
x86: Convert common clocksources to use clocksource_register_hz/khz
timekeeping: Make xtime and wall_to_monotonic static
hrtimer: Cleanup direct access to wall_to_monotonic
um: Convert to use read_persistent_clock
timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset
powerpc: Cleanup xtime usage
powerpc: Simplify update_vsyscall
time: Kill off CONFIG_GENERIC_TIME
time: Implement timespec_add
x86: Fix vtime/file timestamp inconsistencies
Trivial conflicts in Documentation/feature-removal-schedule.txt
Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as
per Thomas' earlier merge commit 47916be4e2 ("Merge branch
'powerpc.cherry-picks' into timers/clocksource")
The etr events switch-to-local and sync-check disable the synchronous clock
and schedule a work queue that tries to get the clock back into sync.
If another switch-to-local or sync-check event occurs while the work queue
function etr_work_fn still runs the eacr.es bit and the clock_sync_word can
become inconsistent because check_sync_clock only uses the clock_sync_word
to determine if the clock is in sync or not. The second pass of the
etr_work_fn will reset the eacr.es bit but will leave the clock_sync_word
intact. Fix this race by moving the reset of the eacr.es bit into the
switch-to-local and sync-check functions and by checking the eacr.es bit
as well to decide if the clock needs to be synced.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case user space is single stepped (PER) the program check handler
claims too early that IRQs are enabled on the return path.
Subsequent checks will notice that the IRQ mask in the PSW and
what lockdep thinks the IRQ mask should be do not correlate and
therefore will print a warning to the console and disable lockdep.
Fix this by doing all the work within the correct context.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
update_vsyscall() did not provide the wall_to_monotoinc offset,
so arch specific implementations tend to reference wall_to_monotonic
directly. This limits future cleanups in the timekeeping core, so
this patch fixes the update_vsyscall interface to provide
wall_to_monotonic, allowing wall_to_monotonic to be made static
as planned in Documentation/feature-removal-schedule.txt
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tony Luck <tony.luck@intel.com>
LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When unregistering kprobes, kprobes calls module_free() and
always passes NULL for the mod parameter. Add a check to
prevent NULL pointer dereferences.
See commit 740a8de079 for more details.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
kbuild: Revert part of e8d400a to resolve a conflict
kbuild: Fix checking of scm-identifier variable
gconfig: add support to show hidden options that have prompts
menuconfig: add support to show hidden options which have prompts
gconfig: remove show_debug option
gconfig: remove dbg_print_ptype() and dbg_print_stype()
kconfig: fix zconfdump()
kconfig: some small fixes
add random binaries to .gitignore
kbuild: Include gen_initramfs_list.sh and the file list in the .d file
kconfig: recalc symbol value before showing search results
.gitignore: ignore *.lzo files
headerdep: perlcritic warning
scripts/Makefile.lib: Align the output of LZO
kbuild: Generate modules.builtin in make modules_install
Revert "kbuild: specify absolute paths for cscope"
kbuild: Do not unnecessarily regenerate modules.builtin
headers_install: use local file handles
headers_check: fix perl warnings
export_report: fix perl warnings
...
By the previous modification, the cpu notifier can return encapsulate
errno value. This converts the cpu notifiers for s390.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This config option enables or disables three single instructions
which aren't expensive. This is too fine grained.
Besided that everybody who uses kvm would enable it anyway in order
to debug performance problems.
Just remove it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The probed instructions will be executed in a single stepped and irq
disabled context. Therefore the results of stnsm, stosm and epsw would
be wrong if probed.
So let's just disallow probing of these functions. If really needed a
fixup could be written for each of them, but I doubt it's worth it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Heiko Carstens