Commit Graph

305 Commits

Author SHA1 Message Date
Al Viro 966e803ab1 um: unify ptrace_user.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:27 +01:00
Al Viro 1bbd5f21f4 um: merge os-Linux/tls.c into arch/x86/um/os-Linux/tls.c
it's i386-specific; moreover, analogs on other targets have
incompatible interface - PTRACE_GET_THREAD_AREA does exist
elsewhere, but struct user_desc does *not*

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:17 +01:00
Al Viro 510c72a3cf um: take chan_*.h and line.h to arch/um/drivers
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:12 +01:00
Al Viro 17e052093b um: take register_winch_irq() into the caller of is_skas_winch()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:11 +01:00
Al Viro 5c48b108ec um: take arch/um/sys-x86 to arch/x86/um
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:05 +01:00
Al Viro 62982ad6b0 um: sysdep/barrier.h is not used for anything
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:01 +01:00
Al Viro 0de021f797 um: shared/process.h is empty now; kill it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:00 +01:00
Al Viro ab1c0cc7c9 um: finish conversion to mcontext_t
now we don't mix host and guest signal frame layouts anymore; moreover,
we don't need host's struct sigcontext at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:59 +01:00
Al Viro 248b74c79e um: start switching the references to host mcontext_t to its userland type
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:59 +01:00
Al Viro 05c46db4d7 um: take userland definition of barrier() to user.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:58 +01:00
Al Viro 00361683ce um: fill the handlers array at build time
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:57 +01:00
Al Viro e87df986ed um: simplify set_handler()
For one thing, we always block the same signals (IRQ ones - IO, WINCH, VTALRM),
so there's no need to pass sa_mask elements in arguments.  For another, the
flags depend only on whether it's an IRQ signal or not (we add SA_RESTART
for them).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:56 +01:00
Al Viro d5c7e8b4ec um: don't bother blocking SIGARLM and SIGUSR1
We used to generate those, but we hadn't done that for a long
time.  No need to bother blocking them for signal handlers.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:55 +01:00
Al Viro 9b25fcbdc6 um: switch stub_segv_handler to SA_SIGINFO variant, get rid of magic crap in there
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:54 +01:00
Al Viro 51d3474905 um: merge arch/um/os-Linux/sys-{i386,x86_64}
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:53 +01:00
Al Viro 7eb122555c um: merge hard_handler() instances, switch to use of SA_SIGINFO
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:52 +01:00
Al Viro 5d40de0f6e um: kill dead code around uaccess
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:52 +01:00
Al Viro 078073a3d4 um: -include user.h for USER_OBJ, trim includes
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:14:44 +01:00
Ingo van Lil fbfe9c847e um: Save FPU registers between task switches
Some time ago Jeff prepared 42daba3165 ("uml: stop saving process FP
state") for UML to stop saving the process FP state between task
switches.  The assumption was that since with SKAS0 every guest process
runs inside a host process context the host OS will take care of keeping
the proper FP state.

Unfortunately this is not true for multi-threaded applications, where
all guest threads share a single host process context yet all may use
the FPU on their own.  Although I haven't verified it I suspect things
to be even worse in SKAS3 mode where all guest processes run inside a
single host process.

The patch reintroduces the saving and restoring of the FP context
between task switches.

[richard@nod.at: Ingo posted this patch in 2009, sadly it was never applied
and got lost. Now in 2011 the problem was reported by Gunnar.]

Signed-off-by: Ingo van Lil <inguin@gmx.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: <gunnarlindroth@hotmail.com>
Tested-by: <gunnarlindroth@hotmail.com>
Cc: Stanislav Meduna <stano@meduna.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-14 18:09:37 -07:00
Richard Weinberger b743ac54e5 um: disable scan_elf_aux() on x86_64
Reusing the host's vDSO makes only sense on x86_32.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:13 -07:00
Davidlohr Bueso 2a6d0ac182 uml: free resources
When creating the temp file there's a memory and file descriptor leak upon
error.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:13 -07:00
Vitaliy Ivanov 2fdf213092 uml: helper.c warning corrections
Fix this warning:

  arch/um/os-Linux/helper.c: In function `helper_child':
  arch/um/os-Linux/helper.c:38:7: warning: ignoring return value of `write', declared with attribute warn_unused_result

[richard@nod.at: happens only with -D_FORTIFY_SOURCE=2]
Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:13 -07:00
Richard Weinberger f956b3e40a um: fix _FORTIFY_SOURCE=2 support for kernel modules
When UML is compiled with _FORTIFY_SOURCE we have to export all _chk()
functions which are used in modules.  For now it's only the case for
__sprintf_chk().

Tested-by: Florian Fainelli <florian@openwrt.org>
Reported-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:12 -07:00
Richard Weinberger db271cf03f um: fix crash while os_dump_core()
os_dump_core() emits SIGTERM to terminate all UML processes.  Kernel
threads have to exit on SIGTERM instead of calling last_ditch_exit().
Multiple calls to last_ditch_exit() can cause a crash.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:42 -07:00
Richard Weinberger d634f194d4 um: add earlyprintk support
User Mode Linux can also benefit from earlyprintk.  UML's earlyprintk
writes kernel messages directly to stdout.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:41 -07:00
Richard Weinberger 2525e70d49 um: remove SIGHUP handler
The UML kernel ignores SIGHUP anyway.  This handler is in vain.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:40 -07:00
Richard Weinberger 0ce451acb1 um: fix UML_LIB_PATH
UML_LIB_PATH is hardcoded to /usr/lib/uml/, on 64bit systems UML_LIB_PATH
needs to be /usr/lib64/uml/.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:40 -07:00
Richard Weinberger b2db21997f um: fix abort
os_dump_core() uses abort() to terminate UML in case of an fatal error.

glibc's abort() calls raise(SIGABRT) which makes use of tgkill().
tgkill() has no effect within UML's kernel threads because they are not
pthreads.  As fallback abort() executes an invalid instruction to
terminate the process.  Therefore UML gets killed by SIGSEGV and leaves a
ugly log entry in the host's kernel ring buffer.

To get rid of this we use our own abort routine.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-18 02:55:23 -07:00
Richard Weinberger 482db6df17 um: fix global timer issue when using CONFIG_NO_HZ
This fixes a issue which was introduced by fe2cc53e ("uml: track and make
up lost ticks").

timeval_to_ns() returns long long and not int.  Due to that UML's timer
did not work properlt and caused timer freezes.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:03 -07:00
Al Viro 005a59ec74 Deal with missing exports for hostfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:25 -04:00
Liu Aleaxander fb967ecc58 um: os-linux/mem.c needs sys/stat.h
The os-linux/mem.c file calls fchmod function, which is declared in sys/stat.h
header file, so include it.  Fixes build breakage under FC13.

Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-29 15:29:32 -07:00
Jan Kiszka 7f3c1fa4c3 uml: Fix build breakage after slab.h changes
We now have to to include linux/slab.h explicitly for kmalloc &
friends.  Files that build against host headers already get their
prototypes via um_malloc.h, linux/slab.h may even be unavailable.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-04-19 17:46:23 +09:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jaswinder Singh Rajput edf382bc6d includecheck fix: um, helper.c
fix the following 'make includecheck' warning:

  arch/um/os-Linux/helper.c: linux/limits.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: jdike@addtoit.com
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1247064950.4382.45.camel@ht.satnam>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
2009-09-20 15:59:20 +05:30
WANG Cong 5062910a06 uml: improve error messages
These error messages are from check_sysemu(), not check_ptrace().

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:16 -07:00
akpm@linux-foundation.org 00699e8472 uml: fix WARNING: vmlinux: 'memcpy' exported twice
Fix the following warning on x86_64:

LD vmlinux.o
MODPOST vmlinux.o
WARNING: vmlinux: 'memcpy' exported twice. Previous export was in vmlinux

For x86_64, this symbol is already exported from arch/um/sys-x86_64/ksyms.c.

Reported-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Tested-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-12 16:20:23 -07:00
Wang Chen 17c324fa80 um: Kill directly reference of netdev->priv
Simply replace netdev->priv with netdev_priv().

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04 15:07:33 -08:00
Al Viro ec82c32d45 x86, um: get rid of arch/um/os symlink
we can get DEV_NULL defined for arch/um/drivers/null.c in less
convoluted ways, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:22 -07:00
Al Viro 887c57d480 x86, um: get rid of excessive includes of uml-config.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:22 -07:00
Adrian Bunk d2efa6d5ce uml: remove the dead TTY_LOG code
Remove the dead CONFIG_TTY_LOG (no kconfig option).

Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:30 -07:00
WANG Cong 99764fa4ce UML: make several more things static
- Make some variables and functions static, since they don't need to be
  global.

- Remove an unused function - arch/um/kernel/time.c::sched_clock().

- Clean the style a bit as complained by checkpatch.pl.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:24 -07:00
Jeff Dike f1ef9167ca uml: work around broken host PTRACE_SYSEMU
Fedora broke PTRACE_SYSEMU again, and UML crashes as a result when it
doesn't need to.  This patch makes the PTRACE_SYSEMU check fail gracefully
and makes UML fall back to PTRACE_SYSCALL.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 18:05:40 -07:00
Jeff Dike 14c8a77e1b uml: remove include of asm/user.h
I allowed an include of asm/user.h to sneak back in.  This patch replaces
it with sys/user.h.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 18:05:40 -07:00
Ingo Molnar b6d8adf477 uml: PATH_MAX needs limits.h
Include limits.h to get a definition of PATH_MAX.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:10 -07:00
Jeff Dike 3d5ede6f77 uml: stub needs to tolerate SIGWINCH
We lost the marking of SIGWINCH as being OK to receive during stub
execution, causing a panic should that happen.

Cc: Benedict Verheyen <benedict.verheyen@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:10 -07:00
Tom Spink 40fb16a360 uml: deal with inaccessible address space start
This patch makes os_get_task_size locate the bottom of the address space,
as well as the top.  This is for systems which put a lower limit on mmap
addresses.  It works by manually scanning pages from zero onwards until a
valid page is found.

Because the bottom of the address space may not be zero, it's not
sufficient to assume the top of the address space is the size of the
address space.  The size is the difference between the top address and
bottom address.

[jdike@addtoit.com: changed the name to reflect that this function is
supposed to return the top of the process address space, not its size and
changed the return value to reflect that.  Also some minor formatting
changes]
Signed-off-by: Tom Spink <tspink@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:10 -07:00
Jeff Dike 06e1e4ffbd uml: deal with host time going backwards
Protection against the host's time going backwards (eg, ntp activity on
the host) by keeping track of the time at the last tick and if it's
greater than the current time, keep time stopped until the host catches
up.

Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:10 -07:00
Al Viro 3787fa6df5 fix include order in sys-i386/registers.c
We want sys/ptrace.h before any includes of linux/ptrace.h and
asm/user.h pulls the latter.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-21 16:55:58 -07:00
Jeff Dike fe2cc53ee0 uml: track and make up lost ticks
Alarm delivery could be noticably late in the !CONFIG_NOHZ case because lost
ticks weren't being taken into account.  This is now treated more carefully,
with the time between ticks being calculated and the appropriate number of
ticks delivered to the timekeeping system.

Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00
Jeff Dike 5d33e4d7fd uml: random driver fixes
The random driver would essentially hang if the host's /dev/random returned
-EAGAIN.  There was a test of need_resched followed by a schedule inside the
loop, but that didn't help and it's the wrong way to work anyway.

The right way is to ask for an interrupt when there is input available from
the host and handle it then rather than polling.

Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup
when there's randomness available again and sleeps.  The interrupt routine
just wakes up whatever processes are sleeping on host_read_wait.

There is an atomic_t, host_sleep_count, which counts the number of processes
waiting for randomness.  When this reaches zero, the interrupt is disabled.

An added complication is that async I/O notification was only recently added
to /dev/random (by me), so essentially all hosts will lack it.  So, we use the
sigio workaround here, which is to have a separate thread poll on the
descriptor and send an interrupt when there is input on it.  This mechanism is
activated when a process gets -EAGAIN (activating this multiple times is
harmless, if a bit wasteful) and deactivated by the last process still
waiting.

The module name was changed from "random" to "hw_random" in order for udev to
recognize it.

The sigio workaround needed some changes.  sigio_broken was added for cases
when we know that async notification doesn't work.  This is now called from
maybe_sigio_broken, which deals with pts devices.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:22 -07:00