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>
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>
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>
Prior to this commit, it was impossible to use relative path to
include Makefiles from the top level Makefile because the option
"--include-dir=$(srctree)" becomes effective when Make enters into
sub Makefiles.
To use relative path in any places, this commit moves the option
above the "sub-make" target.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
In an O= build, rely on the generated Makefile to call the main Makefile
properly. When building in the source tree, we do not need to specify
the -C and O= either. This fixes the problem when $(objtree) is a
relative path and the -C changes the directory.
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
On UML SUBARCH can be x86, x86_64 and i386 and if it is x86
we use uname -m to select a defconfig.
Therefore we can no longer use -mcmodel=large only if SUBARCH
is x86_64.
Reported-and-tested-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
arch/um/defconfig only lists one default configuration, and that applies
only to the i386 architecture. Replace it with two minimal
configuration files generated using `make savedefconfig`:
i386_defconfig and x86_64_defconfig
The build scripts now require two updates:
1. um's Kconfig (arch/x86/um/Kconfig) should specify an ARCH_DEFCONFIG
section explicitly pointing to these scripts if the required
variables are set. Take care to remove the DEFCONFIG_LIST section
defined in the included file arch/um/Kconfig.common.
2. um's Makefile (arch/um/Makefile) should set KBUILD_DEFCONFIG properly
for the top-level Makefile to pick up. Copy the logic in
arch/x86/Makefile to properly pick the defconfig file depending on
the actual architecture; except we're working with $SUBARCH here,
instead of $ARCH.
Now, you can do:
$ ARCH=um make defconfig
$ ARCH=um make
and successfully build User-Mode Linux on an x86_64 box in default
configuration.
Cc: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.
Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.
The userspace set (represented by the USERINCLUDE make variable) contains:
-I $(srctree)/arch/$(hdr-arch)/include/uapi
-I arch/$(hdr-arch)/include/generated/uapi
-I $(srctree)/include/uapi
-I include/generated/uapi
-include $(srctree)/include/linux/kconfig.h
and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:
-I $(srctree)/arch/$(hdr-arch)/include
-I arch/$(hdr-arch)/include/generated
-I $(srctree)/include
-I include --- if not building in the source tree
plus everything in the USERINCLUDE set.
Then use USERINCLUDE in building the x86 boot code.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Move the final link of vmlinux to a script to improve
readability and maintainability of the code.
The Makefile fragments used to link vmlinux has over the
years seen far too many changes and the logic had become
hard to follow.
As the process by nature is serialized there was
nothing gained including this in the Makefile.
"um" has special link requirments - and the
only way to handle this was to hard-code the linking
of "um" in the script.
This was better than trying to modularize it only for the
benefit of "um" anyway.
The shell script has been improved after input from:
Arnaud Lacombe <lacombar@gmail.com>
Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Michal Marek <mmarek@suse.cz>
x86_64 UML is unable to load modules if more than 504MiB
of memory are used.
This happens because on x86_64 the UML process has a quite high
start address (typically around 0x6000000).
If UML's memory is larger than 504MiB VMALLOC_START happens to be after
0x8000000. This is no problem unless one loads a module which was built
with R_X86_64_32S relocations.
Symbols with a location > 0x8000000 cannot be used with R_X86_64_32S
To deal with this x86_64 UML has to be compiled with -mcmodel=large
such that no R_X86_64_32S relocations are used.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: 전하늘 <allskyee@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[richard@nod.at: Re-export SUBARCH in arch/um/Makefile]
Signed-off-by: Richard Weinberger <richard@nod.at>
$(KBUILD_SRC) is not defined without O=, use $(srctree).
Reported-and-tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
In case we need generated header files for the values in
user-offsets.h, make sure we build generated header files before
user-offsets.s is built.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Run the "archheaders" target for the host architecture, for
architectures (like x86, now) that want to generate some of the
necessary header files.
Add $(HOST_DIR)/include/generated to the include path so we then pick
them up.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
richard@nod.at:
Fixes:
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/libc.a(strrchr.o): In function `rindex':
(.text+0x0): multiple definition of `strrchr'
If both STATIC_LINK and UML_NET_VDE are set to "y" libc's strrchr may
clash with the kernel implementation.
This workaround comes originally from Jeff Dike:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=494995#35
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The simplest method was to add an extra asm-offsets.h
file in arch/$ARCH/include/asm that references the generated file.
We can now migrate the architectures one-by-one to reference
the generated file direct - and when done we can delete the
temporary arch/$ARCH/include/asm/asm-offsets.h file.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Albin Tonnerre <albin.tonnerre@free-electrons.com> reported:
Bash 4 filters out variables which contain a dot in them.
This happends to be the case of CPPFLAGS_vmlinux.lds.
This is rather unfortunate, as it now causes
build failures when using SHELL=/bin/bash to compile,
or when bash happens to be used by make (eg when it's /bin/sh)
Remove the common definition of CPPFLAGS_vmlinux.lds by
pushing relevant stuff to either Makefile.build or the
arch specific kernel/Makefile where we build the linker script.
This is also nice cleanup as we move the information out where
it is used.
Notes for the different architectures touched:
arm - we use an already exported symbol
cris - we use a config symbol aleady available
[Not build tested]
mips - the jiffies complexity has moved to vmlinux.lds.S where we need it.
Added a few variables to CPPFLAGS - they are only used by
the linker script.
[Not build tested]
powerpc - removed assignment that is not needed
[not build tested]
sparc - simplified it using $(BITS)
um - introduced a few new exported variables to deal with this
xtensa - added options to CPP invocation
[not build tested]
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
We need to make asm-offsets.h contents visible for objects built
with userland headers. Instead of creating a symlink, just have the
file with equivalent include (relative to location of header) created
once. That kills the last symlink used in arch/um builds.
Additionally, both generated headers can become dependencies of
archprepare now, killing the misuse of prepare.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Teach scripts/kconfig/Makefile and top-level Makefile that arch/*/Makefile
is allowed to say Kconfig := <whatever I want instead of arch/blah/Kconfig>.
Rewrite arch/um/Kconfig and arch/um/Kconfig.<subarch> so that the latter
would be top-level one (and include the pieces of the former).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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>
Long-term we want to split system.h and include barriers part from
underlying target; for now copy that part to sysdep.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* turn asm/ldt.h into ldt.h; update the (very few) users
* take host_ldt.h into sysdep, kill symlink mess
* includes of asm/arch/ldt.h turn into asm/ldt.h now
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
a) the only difference between sigcontext and sysdep/sigcontext
is that the former contains externs for two long-dead functions.
Removed, switched the only user to sysdep/sigcontext
b) asm/sigcontext.h is removable - that of underlying architecture
would get used.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
We can't just plop asm/* into it - userland helpers are built with it
in search path and seeing asm/* show up there suddenly would be a bad
idea.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
There are various constraints on the use of unit-at-a-time:
- i386 uses no-unit-at-a-time for pre-4.0 (not 4.3)
- x86_64 uses unit-at-a-time always
Uli reported a crash on x86_64 with gcc 4.1.2 with unit-at-a-time,
resulting in commit c0a18111e5
Ingo reported a gcc internal error with gcc 4.3 with no-unit-at-a-timem,
resulting in 22eecde2f9
Benny Halevy is seeing extern inlines not resolved with gcc 4.3 with
no-unit-at-a-time
This patch reintroduces unit-at-a-time for gcc >= 4.0, bringing back the
possibility of Uli's crash. If that happens, we'll debug it.
I started seeing both the internal compiler errors and unresolved
inlines on Fedora 9. This patch fixes both problems, without so far
reintroducing the crash reported by Uli.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Benny Halevy <bhalevy@panasas.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 22eecde2f9. Uli
reports that it breaks UML on x86-64 with the Fedora 8 gcc (gcc 4.1.2),
causing a crash on startup. See
http://marc.info/?l=linux-kernel&m=121011722806093&w=2
for a trace.
Reported-by: Ulrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
this is what caused gcc 4.3 to throw an internal error when
OPTIMIZE_INLINING was enabled ...
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is
needed on i386 if UML is to run on hosts with varying VMSPLITs without
recompilation.
TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of
an include of pgtable.h from processor.h, which can cause include loops.
On i386, task_size is calculated early in boot by probing the address space in
a binary search to figure out where the boundary between usable and non-usable
memory is. This tries to make sure that a page that is considered to be in
userspace is, or can be made, read-write. I'm concerned about a system-global
VDSO page in kernel memory being hit and considered to be a userspace page.
On x86_64, task_size is just the old value of CONFIG_TOP_ADDR.
A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced
by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it
irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in
arch/um/Makefile are also gone.
I noticed and fixed a missing extern in os.h when adding os_get_task_size.
Note: This has been revised to fix the 32-bit UML on 64-bit host bug that
Miklos ran into.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
TOPDIR is obsolete, use srctree instead. This patch removes TOPDIR from all
UML Makefiles.
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: WANG Cong <xiyou.wangcong@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>
UML still needed some work in order to allow CFLAGS to be passed in from the
command line.
USER_CFLAGS is produced from KBUILD_CFLAGS in part by removing all the -I
switches. This is so that kernel headers don't accidentally get pulled into
libc files. However, a common use of command-line CFLAGS would be to add -I
switches to the build. This patch specifically adds any command-line -I flags
back to USER_CFLAGS.
I also corrected the spelling of LFLAGS to LDFLAGS.
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>
Allow LFLAGS to be given to make and have the expected effect.
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>
include/asm-um/arch points to the non-existed include/asm-i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@karaya.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
symlinks to directories in the non-O= case were lacking -n, which meant
that, when the link already existed, a new link pointing at itself was
created in the target directory.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anton Ivanov