Commit Graph

1822 Commits

Author SHA1 Message Date
Anton Ivanov 2eb5f31bc4 um: Switch clocksource to hrtimers
UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.

This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.

Fixes:
 - crashes when hosts suspends/resumes
 - broken userspace timers - effecive ~40Hz instead
   of what they should be. Note - this modifies skas behavior
   by no longer setting an itimer per clone(). Timer events
   are relayed instead.
 - kernel network packet scheduling disciplines
 - tcp behaviour especially under load
 - various timer related corner cases

Finally, overall responsiveness of userspace is better.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
[rw: massaged commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:54:49 +01:00
Saurabh Sengar e17c6d77b2 um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held
since GFP_KERNEL with GFP_ATOMIC while spinlock is held,
as code while holding a spinlock should be atomic.
GFP_KERNEL may sleep and can cause deadlock,
where as GFP_ATOMIC may fail but certainly avoids deadlockdex f70dd54..d898f6c 100644

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:51:00 +01:00
Richard Weinberger 70c8205f40 um: Report host OOM more nicely
If UML runs on the host side out of memory, report this
condition more nicely.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:49:12 +01:00
Richard Weinberger f10e6d652b um: Get rid of open coded NR_SYSCALLS
We can use __NR_syscall_max.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:49:10 +01:00
Richard Weinberger 1d80f0cda1 um: Store syscall number after syscall_trace_enter()
To support changing syscall numbers we have to store
it after syscall_trace_enter().

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:49:09 +01:00
Richard Weinberger 44011b897a um: Define PTRACE_OLDSETOPTIONS
...such that processes within UML can do a ptrace(PTRACE_OLDSETOPTIONS, ...)

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 22:49:09 +01:00
Richard Weinberger 56b88a3bf9 um: Fix kernel mode fault condition
We have to exclude memory locations <= PAGE_SIZE from
the condition and let the kernel mode fault path catch it.
Otherwise a kernel NULL pointer exception will be reported
as a kernel user space access.

Fixes: d2313084e2 (um: Catch unprotected user memory access)
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19 22:53:37 +02:00
Richard Weinberger 6b1873371c um: Fix waitpid() usage in helper code
If UML is executing a helper program it is using
waitpid() with the __WCLONE flag to wait for the program
as the helper is executed from a clone()'ed thread.
While using __WCLONE is perfectly fine for clone()'ed
childs it won't detect terminated childs if the helper
has issued an execve().

We have to use __WALL to wait for both clone()'ed and
regular childs to detect the termination before and
after an execve().

Reported-and-tested-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19 22:53:37 +02:00
Richard Weinberger 0b5aedfe0e um: Fix out-of-tree build
Commit 30b11ee9a (um: Remove copy&paste code from init.h)
uncovered an issue wrt. out-of-tree builds.
For out-of-tree builds, we must not rely on relative paths.
Before 30b11ee9a it worked by chance as no host code included
generated header files.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19 22:53:36 +02:00
Linus Torvalds 30c44659f4 Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures
2015-10-04 16:31:13 +01:00
Linus Torvalds 5e359bf221 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "Rather large, but nothing exiting:

   - new range check for settimeofday() to prevent that boot time
     becomes negative.
   - fix for file time rounding
   - a few simplifications of the hrtimer code
   - fix for the proc/timerlist code so the output of clock realtime
     timers is accurate
   - more y2038 work
   - tree wide conversion of clockevent drivers to the new callbacks"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
  hrtimer: Handle failure of tick_init_highres() gracefully
  hrtimer: Unconfuse switch_hrtimer_base() a bit
  hrtimer: Simplify get_target_base() by returning current base
  hrtimer: Drop return code of hrtimer_switch_to_hres()
  time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
  time: Introduce current_kernel_time64()
  time: Introduce struct itimerspec64
  time: Add the common weak version of update_persistent_clock()
  time: Always make sure wall_to_monotonic isn't positive
  time: Fix nanosecond file time rounding in timespec_trunc()
  timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
  cris/time: Migrate to new 'set-state' interface
  kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
  xtensa/time: Migrate to new 'set-state' interface
  unicore/time: Migrate to new 'set-state' interface
  um/time: Migrate to new 'set-state' interface
  sparc/time: Migrate to new 'set-state' interface
  sh/localtimer: Migrate to new 'set-state' interface
  score/time: Migrate to new 'set-state' interface
  s390/time: Migrate to new 'set-state' interface
  ...
2015-09-01 14:04:50 -07:00
Viresh Kumar 71b5280b79 um/time: Migrate to new 'set-state' interface
Migrate um driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: user-mode-linux-user@lists.sourceforge.net
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:41:06 +02:00
Ingo Molnar 5b929bd11d Merge branch 'x86/urgent' into x86/asm, before applying dependent patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-31 10:23:35 +02:00
Laurent Dufour f2abeef9fd mm: clean up per architecture MM hook header files
Commit 2ae416b142 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.

As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.

The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:53 -07:00
Chris Metcalf a6e2f029ae Make asm/word-at-a-time.h available on all architectures
Added the x86 implementation of word-at-a-time to the
generic version, which previously only supported big-endian.

Omitted the x86-specific load_unaligned_zeropad(), which in
any case is also not present for the existing BE-only
implementation of a word-at-a-time, and is only used under
CONFIG_DCACHE_WORD_ACCESS.

Added as a "generic-y" to the Kbuilds of all architectures
that didn't previously have it.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-07-08 16:41:55 -04:00
Ingo Molnar ccaee5f851 um: Fix do_signal() prototype
Once x86 exports its do_signal(), the prototypes will clash.

Fix the clash and also improve the code a bit: remove the
unnecessary kern_do_signal() indirection. This allows
interrupt_end() to share the 'regs' parameter calculation.

Also remove the unused return code to match x86.

Minimally build and boot tested.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/67c57eac09a589bac3c6c5ff22f9623ec55a184a.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-07 10:58:54 +02:00
Linus Torvalds 02201e3f1b Minor merge needed, due to function move.
Main excitement here is Peter Zijlstra's lockless rbtree optimization to
 speed module address lookup.  He found some abusers of the module lock
 doing that too.
 
 A little bit of parameter work here too; including Dan Streetman's breaking
 up the big param mutex so writing a parameter can load another module (yeah,
 really).  Unfortunately that broke the usual suspects, !CONFIG_MODULES and
 !CONFIG_SYSFS, so those fixes were appended too.
 
 Cheers,
 Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...
2015-07-01 10:49:25 -07:00
Linus Torvalds 21dc2e6c6d Merge branch 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:

 - remove hppfs ("HonePot ProcFS")

 - initial support for musl libc

 - uaccess cleanup

 - random cleanups and bug fixes all over the place

* 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (21 commits)
  um: Don't pollute kernel namespace with uapi
  um: Include sys/types.h for makedev(), major(), minor()
  um: Do not use stdin and stdout identifiers for struct members
  um: Do not use __ptr_t type for stack_t's .ss pointer
  um: Fix mconsole dependency
  um: Handle tracehook_report_syscall_entry() result
  um: Remove copy&paste code from init.h
  um: Stop abusing __KERNEL__
  um: Catch unprotected user memory access
  um: Fix warning in setup_signal_stack_si()
  um: Rework uaccess code
  um: Add uaccess.h to ldt.c
  um: Add uaccess.h to syscalls_64.c
  um: Add asm/elf.h to vma.c
  um: Cleanup mem_32/64.c headers
  um: Remove hppfs
  um: Move syscall() declaration into os.h
  um: kernel: ksyms: Export symbol syscall() for fixing modpost issue
  um/os-Linux: Use char[] for syscall_stub declarations
  um: Use char[] for linker script address declarations
  ...
2015-06-28 13:55:08 -07:00
Linus Torvalds d87823813f Char/Misc driver patches for 4.2-rc1
Here's the big char/misc driver pull request for 4.2-rc1.
 
 Lots of mei, extcon, coresight, uio, mic, and other driver updates in
 here.  Full details in the shortlog.  All of these have been in
 linux-next for some time with no reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here's the big char/misc driver pull request for 4.2-rc1.

  Lots of mei, extcon, coresight, uio, mic, and other driver updates in
  here.  Full details in the shortlog.  All of these have been in
  linux-next for some time with no reported problems"

* tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (176 commits)
  mei: me: wait for power gating exit confirmation
  mei: reset flow control on the last client disconnection
  MAINTAINERS: mei: add mei_cl_bus.h to maintained file list
  misc: sram: sort and clean up included headers
  misc: sram: move reserved block logic out of probe function
  misc: sram: add private struct device and virt_base members
  misc: sram: report correct SRAM pool size
  misc: sram: bump error message level on unclean driver unbinding
  misc: sram: fix device node reference leak on error
  misc: sram: fix enabled clock leak on error path
  misc: mic: Fix reported static checker warning
  misc: mic: Fix randconfig build error by including errno.h
  uio: pruss: Drop depends on ARCH_DAVINCI_DA850 from config
  uio: pruss: Add CONFIG_HAS_IOMEM dependence
  uio: pruss: Include <linux/sizes.h>
  extcon: Redefine the unique id of supported external connectors without 'enum extcon' type
  char:xilinx_hwicap:buffer_icap - change 1/0 to true/false for bool type variable in function buffer_icap_set_configuration().
  Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion
  parport: check exclusive access before register
  w1: use correct lock on error in w1_seq_show()
  ...
2015-06-26 14:51:15 -07:00
Linus Torvalds ad90fb9751 Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block
Pull asm/scatterlist.h removal from Jens Axboe:
 "We don't have any specific arch scatterlist anymore, since parisc
  finally switched over.  Kill the include"

* 'for-4.2/sg' of git://git.kernel.dk/linux-block:
  remove scatterlist.h generation from arch Kbuild files
  remove <asm/scatterlist.h>
2015-06-25 15:22:36 -07:00
Richard Weinberger da028d5e54 um: Don't pollute kernel namespace with uapi
Don't include ptrace uapi stuff in arch headers, it will
pollute the kernel namespace and conflict with existing
stuff.
In this case it fixes clashes with common names like R8.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25 22:44:11 +02:00
Hans-Werner Hilse 8eeba4e9a7 um: Include sys/types.h for makedev(), major(), minor()
The functions in question are not part of the POSIX standard,
documentation however hints that the corresponding header shall
be sys/types.h. C libraries other than glibc, namely musl, did
not include that header via other ways and complained.

Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25 22:42:21 +02:00
Hans-Werner Hilse f9bb3b5947 um: Do not use stdin and stdout identifiers for struct members
stdin, stdout and stderr are macros according to C89/C99.
Thus do not use them as struct member identifiers to avoid
bad results from macro expansion.

Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25 22:42:19 +02:00
Hans-Werner Hilse 9a75551aea um: Do not use __ptr_t type for stack_t's .ss pointer
__ptr_t type is a glibc-specific type, while the generally
documented type is a void*. That's what other C libraries use,
too.

Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25 22:42:17 +02:00
Laurent Dufour 2ae416b142 mm: new mm hook framework
CRIU is recreating the process memory layout by remapping the checkpointee
memory area on top of the current process (criu).  This includes remapping
the vDSO to the place it has at checkpoint time.

However some architectures like powerpc are keeping a reference to the
vDSO base address to build the signal return stack frame by calling the
vDSO sigreturn service.  So once the vDSO has been moved, this reference
is no more valid and the signal frame built later are not usable.

This patch serie is introducing a new mm hook framework, and a new
arch_remap hook which is called when mremap is done and the mm lock still
hold.  The next patch is adding the vDSO remap and unmap tracking to the
powerpc architecture.

This patch (of 3):

This patch introduces a new set of header file to manage mm hooks:
- per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
- a generic header (include/linux/mm-arch-hooks.h)

The architecture which need to overwrite a hook as to redefine it in its
header file, while architecture which doesn't need have nothing to do.

The default hooks are defined in the generic header and are used in the
case the architecture is not defining it.

In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
be moved here.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:41 -07:00
Dan Streetman b51d23e4e9 module: add per-module param_lock
Add a "param_lock" mutex to each module, and update params.c to use
the correct built-in or module mutex while locking kernel params.
Remove the kparam_block_sysfs_r/w() macros, replace them with direct
calls to kernel_param_[un]lock(module).

The kernel param code currently uses a single mutex to protect
modification of any and all kernel params.  While this generally works,
there is one specific problem with it; a module callback function
cannot safely load another module, i.e. with request_module() or even
with indirect calls such as crypto_has_alg().  If the module to be
loaded has any of its params configured (e.g. with a /etc/modprobe.d/*
config file), then the attempt will result in a deadlock between the
first module param callback waiting for modprobe, and modprobe trying to
lock the single kernel param mutex to set the new module's param.

This fixes that by using per-module mutexes, so that each individual module
is protected against concurrent changes in its own kernel params, but is
not blocked by changes to other module params.  All built-in modules
continue to use the built-in mutex, since they will always be loaded at
runtime and references (e.g. request_module(), crypto_has_alg()) to them
will never cause load-time param changing.

This also simplifies the interface used by modules to block sysfs access
to their params; while there are currently functions to block and unblock
sysfs param access which are split up by read and write and expect a single
kernel param to be passed, their actual operation is identical and applies
to all params, not just the one passed to them; they simply lock and unlock
the global param mutex.  They are replaced with direct calls to
kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or
if the module is built-in, it locks the built-in mutex.

Suggested-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-23 15:27:38 +09:30
Richard Weinberger 1eb7c6c70e um: Fix mconsole dependency
mconsole depends on CONFIG_PROC_FS.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 23:27:26 +02:00
Richard Weinberger 5334cdae40 um: Handle tracehook_report_syscall_entry() result
tracehook_report_syscall_entry() is allowed to fail,
in case of failure we have to abort the current syscall.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 22:59:03 +02:00
Richard Weinberger 30b11ee9ae um: Remove copy&paste code from init.h
As we got rid of the __KERNEL__ abuse, we can directly
include linux/compiler.h now.
This also allows gcc 5 to build UML.

Reported-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 22:17:08 +02:00
Richard Weinberger 298e20ba8c um: Stop abusing __KERNEL__
Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 22:05:32 +02:00
Richard Weinberger d2313084e2 um: Catch unprotected user memory access
If the kernel tries to access user memory without copy_from_user()
a trap will happen as kernel and userspace run in different processes
on the host side. Currently this special page fault cannot be resolved
and will happen over and over again. As result UML will lockup.
This patch allows the page fault code to detect that situation and
causes a panic() such that the root cause of the unprotected memory
access can be found and fixed.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 19:21:51 +02:00
Richard Weinberger f8d65d27e6 um: Rework uaccess code
Rework UML's uaccess code to reuse as much as possible
from asm-generic/uaccess.c.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 17:32:36 +02:00
Richard Weinberger f74a14e870 um: Remove hppfs
hppfs (honeypot procfs) was an attempt to use UML as honeypot.
It was never stable nor in heavy use.

As Al Viro and Christoph Hellwig pointed some major issues out
it is better to let it die.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:23:08 +02:00
Richard Weinberger 89520d9996 um: Move syscall() declaration into os.h
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:14:07 +02:00
Chen Gang a791b1565f um: kernel: ksyms: Export symbol syscall() for fixing modpost issue
syscall() is implemented in libc.so/a (e.g. for glibc, in "syscall.o"),
so for normal ".o" files, it is undefined, neither can be found within
kernel wide, so will break modpost.

Since ".o" files is OK, can simply export 'syscall' symbol, let modpost
know about that, then can fix this issue.

The related error (with allmodconfig under um):

    MODPOST 1205 modules
  ERROR: "syscall" [fs/hostfs/hostfs.ko] undefined!

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:14:07 +02:00
Nicolas Iooss 5f32943b5e um/os-Linux: Use char[] for syscall_stub declarations
When declaring __syscall_stub_start, use the same type in UML userspace
code as in arch/um/include/asm/sections.h.

While at it, also declare batch_syscall_stub as char[].

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:14:07 +02:00
Nicolas Iooss 05eacfd00c um: Use char[] for linker script address declarations
The linker script defines some variables which are declared either with
type char[] in include/asm-generic/sections.h or with a meaningless
integer type in arch/um/include/asm/sections.h.

Fix this inconsistency by declaring every variable char[].

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:14:06 +02:00
Nicolas Iooss d5f20be7ca um: Create asm/sections.h
arch/um/kernel/dyn.lds.S and arch/um/kernel/uml.lds.S define some
UML-specific symbols.  These symbols are used in the kernel part of UML
with extern declarations.

Move these declarations to a new header, asm/sections.h, like other
architectures do.

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31 13:14:05 +02:00
Alan 7879b1d94b um,ethertap: use strncpy
[um maintainers appear to be vanished]

I can't prove the case pointed out in
https://bugzilla.kernel.org/show_bug.cgi?id=82341
is correct so let us play safe.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:24:35 -07:00
Christoph Hellwig c546d5db75 remove scatterlist.h generation from arch Kbuild files
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:14:34 -06:00
Peter Zijlstra fbc9f16a23 mm/fault, um: Fix compile error
A missing include file caused build fail.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zijlstra (Intel) <peterz@infradead.org>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Fixes: 70ffdb9393 ("mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 15:42:25 +02:00
David Hildenbrand 70ffdb9393 mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler
Introduce faulthandler_disabled() and use it to check for irq context and
disabled pagefaults (via pagefault_disable()) in the pagefault handlers.

Please note that we keep the in_atomic() checks in place - to detect
whether in irq context (in which case preemption is always properly
disabled).

In contrast, preempt_disable() should never be used to disable pagefaults.
With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt
counter, and therefore the result of in_atomic() differs.
We validate that condition by using might_fault() checks when calling
might_sleep().

Therefore, add a comment to faulthandler_disabled(), describing why this
is needed.

faulthandler_disabled() and pagefault_disable() are defined in
linux/uaccess.h, so let's properly add that include to all relevant files.

This patch is based on a patch from Thomas Gleixner.

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:15 +02:00
Linus Torvalds fa2e5c073a Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc
Pull exec domain removal from Richard Weinberger:
 "This series removes execution domain support from Linux.

  The idea behind exec domains was to support different ABIs.  The
  feature was never complete nor stable.  Let's rip it out and make the
  kernel signal handling code less complicated"

* 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits)
  arm64: Removed unused variable
  sparc: Fix execution domain removal
  Remove rest of exec domains.
  arch: Remove exec_domain from remaining archs
  arc: Remove signal translation and exec_domain
  xtensa: Remove signal translation and exec_domain
  xtensa: Autogenerate offsets in struct thread_info
  x86: Remove signal translation and exec_domain
  unicore32: Remove signal translation and exec_domain
  um: Remove signal translation and exec_domain
  tile: Remove signal translation and exec_domain
  sparc: Remove signal translation and exec_domain
  sh: Remove signal translation and exec_domain
  s390: Remove signal translation and exec_domain
  mn10300: Remove signal translation and exec_domain
  microblaze: Remove signal translation and exec_domain
  m68k: Remove signal translation and exec_domain
  m32r: Remove signal translation and exec_domain
  m32r: Autogenerate offsets in struct thread_info
  frv: Remove signal translation and exec_domain
  ...
2015-04-15 13:53:55 -07:00
Linus Torvalds e44740c1a9 Merge tag 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
 - hostfs saw a face lifting
 - old/broken stuff was removed (SMP, HIGHMEM, SKAS3/4)
 - random cleanups and bug fixes

* tag 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (26 commits)
  um: Print minimum physical memory requirement
  um: Move uml_postsetup in the init_thread stack
  um: add a kmsg_dumper
  x86, UML: fix integer overflow in ELF_ET_DYN_BASE
  um: hostfs: Reduce number of syscalls in readdir
  um: Remove broken highmem support
  um: Remove broken SMP support
  um: Remove SKAS3/4 support
  um: Remove ppc cruft
  um: Remove ia64 cruft
  um: Remove dead code from stacktrace
  hostfs: No need to box and later unbox the file mode
  hostfs: Use page_offset()
  hostfs: Set page flags in hostfs_readpage() correctly
  hostfs: Remove superfluous initializations in hostfs_open()
  hostfs: hostfs_open: Reset open flags upon each retry
  hostfs: Remove superfluous test in hostfs_open()
  hostfs: Report append flag in ->show_options()
  hostfs: Use __getname() in follow_link
  hostfs: Remove open coded strcpy()
  ...
2015-04-15 13:49:27 -07:00
Linus Torvalds b422b75875 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:
 "Here is the first round of kbuild changes for v4.1-rc1:

   - kallsyms fix for ARM and cleanup

   - make dep(end) removed (developers have no sense of nostalgia these
     days...)

   - include Makefiles by relative path

   - stop useless rebuilds of asm-offsets.h and bounds.h"

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  Kbuild: kallsyms: drop special handling of pre-3.0 GCC symbols
  Kbuild: kallsyms: ignore veneers emitted by the ARM linker
  kbuild: ia64: use $(src)/Makefile.gate rather than particular path
  kbuild: include $(src)/Makefile rather than $(obj)/Makefile
  kbuild: use relative path more to include Makefile
  kbuild: use relative path to include Makefile
  kbuild: do not add $(bounds-file) and $(offsets-file) to targets
  kbuild: remove warning about "make depend"
  kbuild: Don't reset timestamps in include/generated if not needed
2015-04-15 11:19:18 -07:00
Kirill A. Shutemov 6b8ce2a1a4 um: expose number of page table levels
We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:02 -07:00
Thomas Meyer fe205bdd13 um: Print minimum physical memory requirement
Print a more sensible message about the minimum physical memory
requirement.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:17:46 +02:00
Thomas Meyer 33bbc30654 um: Move uml_postsetup in the init_thread stack
atomic_notifier_chain_register() and uml_postsetup() do call kernel code
that rely on the "current" kernel macro and a valid task_struct resp.
thread_info struct. Give those functions a valid stack by moving
uml_postsetup() in the init_thread stack. This moves enables a panic()
call in this early code to generate a valid stacktrace, instead of
crashing.
E.g. when an UML kernel is started with an initrd but too few physical
memory the panic() call get's actually processed.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:17:44 +02:00
Thomas Meyer 04a418495e um: add a kmsg_dumper
Add a kmsg_dumper, that dumps the kmsg buffer to stdout, when no console
is available. This an enables the printing of early panic() calls
triggered in uml_postsetup().
When a panic() call happens so early in the UML kernel no
earlyprintk/console is available yet, but with a kmsg_dumper in place
the kernel message buffer will be outputted to the user, to give a
better hint, of what the failure was.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:17:37 +02:00
Richard Weinberger a98a6d864d um: Remove broken highmem support
Highmem was always buggy and experimental on UML(i386).
In times where 64 bit computers are default we can
remove that experimental code.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:01:02 +02:00