Commit Graph

91 Commits

Author SHA1 Message Date
Linus Torvalds a0b09f2d6f Random number generator updates for Linux 6.0-rc1.
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Merge tag 'random-6.0-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:
 "Though there's been a decent amount of RNG-related development during
  this last cycle, not all of it is coming through this tree, as this
  cycle saw a shift toward tackling early boot time seeding issues,
  which took place in other trees as well.

  Here's a summary of the various patches:

   - The CONFIG_ARCH_RANDOM .config option and the "nordrand" boot
     option have been removed, as they overlapped with the more widely
     supported and more sensible options, CONFIG_RANDOM_TRUST_CPU and
     "random.trust_cpu". This change allowed simplifying a bit of arch
     code.

   - x86's RDRAND boot time test has been made a bit more robust, with
     RDRAND disabled if it's clearly producing bogus results. This would
     be a tip.git commit, technically, but I took it through random.git
     to avoid a large merge conflict.

   - The RNG has long since mixed in a timestamp very early in boot, on
     the premise that a computer that does the same things, but does so
     starting at different points in wall time, could be made to still
     produce a different RNG state. Unfortunately, the clock isn't set
     early in boot on all systems, so now we mix in that timestamp when
     the time is actually set.

   - User Mode Linux now uses the host OS's getrandom() syscall to
     generate a bootloader RNG seed and later on treats getrandom() as
     the platform's RDRAND-like faculty.

   - The arch_get_random_{seed_,}_long() family of functions is now
     arch_get_random_{seed_,}_longs(), which enables certain platforms,
     such as s390, to exploit considerable performance advantages from
     requesting multiple CPU random numbers at once, while at the same
     time compiling down to the same code as before on platforms like
     x86.

   - A small cleanup changing a cmpxchg() into a try_cmpxchg(), from
     Uros.

   - A comment spelling fix"

More info about other random number changes that come in through various
architecture trees in the full commentary in the pull request:

  https://lore.kernel.org/all/20220731232428.2219258-1-Jason@zx2c4.com/

* tag 'random-6.0-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  random: correct spelling of "overwrites"
  random: handle archrandom with multiple longs
  um: seed rng using host OS rng
  random: use try_cmpxchg in _credit_init_bits
  timekeeping: contribute wall clock to rng on time change
  x86/rdrand: Remove "nordrand" flag in favor of "random.trust_cpu"
  random: remove CONFIG_ARCH_RANDOM
2022-08-02 17:31:35 -07:00
Jason A. Donenfeld 0b9ba6135d um: seed rng using host OS rng
UML generally does not provide access to special CPU instructions like
RDRAND, and execution tends to be rather deterministic, with no real
hardware interrupts, making good randomness really very hard, if not
all together impossible. Not only is this a security eyebrow raiser, but
it's also quite annoying when trying to do various pieces of UML-based
automation that takes a long time to boot, if ever.

Fix this by trivially calling getrandom() in the host and using that
seed as "bootloader randomness", which initializes the rng immediately
at UML boot.

The old behavior can be restored the same way as on any other arch, by
way of CONFIG_TRUST_BOOTLOADER_RANDOMNESS=n or
random.trust_bootloader=0. So seen from that perspective, this just
makes UML act like other archs, which is positive in its own right.

Additionally, wire up arch_get_random_{int,long}() in the same way, so
that reseeds can also make use of the host RNG, controllable by
CONFIG_TRUST_CPU_RANDOMNESS and random.trust_cpu, per usual.

Cc: stable@vger.kernel.org
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-07-18 15:04:04 +02:00
Peter Zijlstra 564d998106 um: Add missing apply_returns()
Implement apply_returns() stub for UM, just like all the other patching
routines.

Fixes: 15e67227c4 ("x86: Undo return-thunk damage")
Reported-by: Randy Dunlap <rdunlap@infradead.org)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Ys%2Ft45l%2FgarIrD0u@worktop.programming.kicks-ass.net
2022-07-14 13:40:21 +02:00
Peter Zijlstra ed53a0d971 x86/alternative: Use .ibt_endbr_seal to seal indirect calls
Objtool's --ibt option generates .ibt_endbr_seal which lists
superfluous ENDBR instructions. That is those instructions for which
the function is never indirectly called.

Overwrite these ENDBR instructions with a NOP4 such that these
function can never be indirect called, reducing the number of viable
ENDBR targets in the kernel.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.822545231@infradead.org
2022-03-15 10:32:47 +01:00
Vincent Whitchurch b31297f04e um: Add devicetree support
Add a dtb=<filename> option to boot UML with a devicetree blob.  This
can be used for testing driver code using UML.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
[rw: Add dependency on CONFIG_OF]
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-22 20:35:01 +01:00
Peter Zijlstra 7508500900 x86/alternative: Implement .retpoline_sites support
Rewrite retpoline thunk call sites to be indirect calls for
spectre_v2=off. This ensures spectre_v2=off is as near to a
RETPOLINE=n build as possible.

This is the replacement for objtool writing alternative entries to
ensure the same and achieves feature-parity with the previous
approach.

One noteworthy feature is that it relies on the thunks to be in
machine order to compute the register index.

Specifically, this does not yet address the Jcc __x86_indirect_thunk_*
calls generated by clang, a future patch will add this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.232495794@infradead.org
2021-10-28 23:25:27 +02:00
Linus Torvalds dcf3c935dd This pull request contains the following changes for UML:
- Support for optimized routines based on the host CPU
 - Support for PCI via virtio
 - Various fixes
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Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Support for optimized routines based on the host CPU

 - Support for PCI via virtio

 - Various fixes

* tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: remove unneeded semicolon in um_arch.c
  um: Remove the repeated declaration
  um: fix error return code in winch_tramp()
  um: fix error return code in slip_open()
  um: Fix stack pointer alignment
  um: implement flush_cache_vmap/flush_cache_vunmap
  um: add a UML specific futex implementation
  um: enable the use of optimized xor routines in UML
  um: Add support for host CPU flags and alignment
  um: allow not setting extra rpaths in the linux binary
  um: virtio/pci: enable suspend/resume
  um: add PCI over virtio emulation driver
  um: irqs: allow invoking time-travel handler multiple times
  um: time-travel/signals: fix ndelay() in interrupt
  um: expose time-travel mode to userspace side
  um: export signals_enabled directly
  um: remove unused smp_sigio_handler() declaration
  lib: add iomem emulation (logic_iomem)
  um: allow disabling NO_IOMEM
2021-07-09 10:19:13 -07:00
Andy Shevchenko f39650de68 kernel.h: split out panic and oops helpers
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
  Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:04 -07:00
Wan Jiabing 1aee020155 um: remove unneeded semicolon in um_arch.c
Fix following coccicheck warning:
./arch/um/kernel/um_arch.c:284:34-35: Unneeded semicolon

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-06-19 10:02:50 +02:00
Anton Ivanov d8fb32f479 um: Add support for host CPU flags and alignment
1. Reflect host cpu flags into the UML instance so they can
be used to select the correct implementations for xor, crypto, etc.

2. Reflect host cache alignment into UML instance. This is
important when running 32 bit on a 64 bit host as 32 bit by
default aligns to 32 while the actual alignment should be 64.
Ditto for some Xeons which align at 128.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-06-17 22:01:26 +02:00
Johannes Berg bfc58e2b98 um: remove process stub VMA
This mostly reverts the old commit 3963333fe6 ("uml: cover stubs
with a VMA") which had added a VMA to the existing PTEs. However,
there's no real reason to have the PTEs in the first place and the
VMA cannot be 'fixed' in place, which leads to bugs that userspace
could try to unmap them and be forcefully killed, or such. Also,
there's a bit of an ugly hole in userspace's address space.

Simplify all this: just install the stub code/page at the top of
the (inner) address space, i.e. put it just above TASK_SIZE. The
pages are simply hard-coded to be mapped in the userspace process
we use to implement an mm context, and they're out of reach of the
inner mmap/munmap/mprotect etc. since they're above TASK_SIZE.

Getting rid of the VMA also makes vma_merge() no longer hit one of
the VM_WARN_ON()s there because we installed a VMA while the code
assumes the stack VMA is the first one.

It also removes a lockdep warning about mmap_sem usage since we no
longer have uml_setup_stubs() and thus no longer need to do any
manipulation that would require mmap_sem in activate_mm().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:37:38 +01:00
Thomas Meyer d7ffac3363 um: stdio_console: Make preferred console
The addition of the "ttynull" console driver did break the ordering of the
UML stdio console driver.
The UML stdio console driver is added in late_initcall (7), whereby the
ttynull driver is added in device_initcall (6), which always does make the
ttynull driver the default console.

Fix it by explicitly adding the UML stdio console as the preferred console,
in case no 'console=' command line option was specified.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:37 +01:00
Johannes Berg 1fb1abc836 um: Fix build w/o CONFIG_PM_SLEEP
uml_pm_wake() is unconditionally called from the SIGUSR1 wakeup
handler since that's in the userspace portion of UML, and thus
a bit tricky to ifdef out. Since pm_system_wakeup() can always
be called (but may be an empty inline), also simply always have
uml_pm_wake() to fix the build.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-14 21:15:32 +01:00
Johannes Berg a374b7cb1e um: Support suspend to RAM
With all the previous bits in place, we can now also support
suspend to RAM, in the sense that everything is suspended,
not just most, including userspace, processes like in s2idle.

Since um_idle_sleep() now waits forever, we can simply call
that to "suspend" the system.

As before, you can wake it up using SIGUSR1 since we're just
in a pause() call that only needs to return.

In order to implement selective resume from certain devices,
and not have any arbitrary device interrupt wake up, suspend
interrupts by removing SIGIO notification (O_ASYNC) from all
the FDs that are not supposed to wake up the system. However,
swap out the handler so we don't actually handle the SIGIO as
an interrupt.

Since we're in pause(), the mere act of receiving SIGIO wakes
us up, and then after things have been restored enough, re-set
O_ASYNC for all previously suspended FDs, reinstall the proper
SIGIO handler, and send SIGIO to self to process anything that
might now be pending.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:49 +01:00
Johannes Berg 92dcd3d318 um: Allow PM with suspend-to-idle
In order to be able to experiment with suspend in UML, add the
minimal work to be able to suspend (s2idle) an instance of UML,
and be able to wake it back up from that state with the USR1
signal sent to the main UML process.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:46 +01:00
Joe Perches 33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Mike Rapoport e31cf2f4ca mm: don't include asm/pgtable.h if linux/mm.h is already included
Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include <linux/mm.h>") ; do
		sed -i -e '/include <asm\/pgtable.h>/ d' $f
	done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Peter Zijlstra 88fc078a7a x86/module: Use text_poke() for late relocations
Because of late module patching, a livepatch module needs to be able to
apply some of its relocations well after it has been loaded.  Instead of
playing games with module_{dis,en}able_ro(), use existing text poking
mechanisms to apply relocations after module loading.

So far only x86, s390 and Power have HAVE_LIVEPATCH but only the first
two also have STRICT_MODULE_RWX.

This will allow removal of the last module_disable_ro() usage in
livepatch.  The ultimate goal is to completely disallow making
executable mappings writable.

[ jpoimboe: Split up patches.  Use mod state to determine whether
	    memcpy() can be used.  Implement text_poke() for UML. ]

Cc: x86@kernel.org
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-05-08 00:12:43 +02:00
Alex Dewar 0d1fb0a47c um: Add SPDX headers to files in arch/um/kernel/
Convert files to use SPDX header. All files are licensed under the
GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:17 +02:00
Erel Geron 5d38f32499 um: drivers: Add virtio vhost-user driver
This module allows virtio devices to be used over a vhost-user socket.

Signed-off-by: Erel Geron <erelx.geron@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:15 +02:00
David Howells 0500871f21 Construct init thread stack in the linker script rather than by union
Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2018-01-09 23:21:02 +00:00
Linus Torvalds 4ecd4ff55a Merge branch 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
 "Mostly fixes for UML:

   - First round of fixes for PTRACE_GETRESET/SETREGSET

   - A printf vs printk cleanup

   - Minor improvements"

* 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Correctly check for PTRACE_GETRESET/SETREGSET
  um: v2: Use generic NOTES macro
  um: Add kerneldoc for userspace_tramp() and start_userspace()
  um: Add kerneldoc for segv_handler
  um: stub-data.h: remove superfluous include
  um: userspace - be more verbose in ptrace set regs error
  um: add dummy ioremap and iounmap functions
  um: Allow building and running on older hosts
  um: Avoid longjmp/setjmp symbol clashes with libpthread.a
  um: console: Ignore console= option
  um: Use os_warn to print out pre-boot warning/error messages
  um: Add os_warn() for pre-boot warning/error messages
  um: Use os_info for the messages on normal path
  um: Add os_info() for pre-boot information messages
  um: Use printk instead of printf in make_uml_dir
2017-07-15 10:49:33 -07:00
Masami Hiramatsu 0936d4f3d5 um: Use os_warn to print out pre-boot warning/error messages
Use os_warn() instead of printf/fprintf to print out
pre-boot warning/error messages to stderr.
Note that the help message and version message are
kept to print out to stdout, because user explicitly
specifies those options to get such information.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-07-05 23:18:25 +02:00
Masami Hiramatsu d3878bb800 um: Use os_info for the messages on normal path
Use os_info() for printing out the messages on the
normal execution path.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-07-05 23:17:42 +02:00
Tobias Klauser 6474924e2b arch: remove unused macro/function thread_saved_pc()
The only user of thread_saved_pc() in non-arch-specific code was removed
in commit 8243d55977 ("sched/core: Remove pointless printout in
sched_show_task()").  Remove the implementations as well.

Some architectures use thread_saved_pc() in their arch-specific code.
Leave their thread_saved_pc() intact.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-28 16:13:57 -07:00
Masami Hiramatsu 5b4236e17c um: Fix to call read_initrd after init_bootmem
Since read_initrd() invokes alloc_bootmem() for allocating
memory to load initrd image, it must be called after init_bootmem.

This makes read_initrd() called directly from setup_arch()
after init_bootmem() and mem_total_pages().

Cc: <stable@vger.kernel.org>
Fixes: b63236972e ("um: Setup physical memory in setup_arch()")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-05-03 22:38:16 +02:00
Ingo Molnar 9164bb4a18 sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h>
Update all usage sites first.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:38 +01:00
Richard Weinberger b63236972e um: Setup physical memory in setup_arch()
Currently UML sets up physical memory very early,
long before setup_arch() was called by the kernel main
function.
This can cause problems when code paths in UML's memory setup
code assume that the kernel is already running.
i.e. when kmemleak is enabled it will evaluate current()
in free_bootmem(). That early current() is undefined and
UML explodes.

Solve the problem by setting up physical memory in setup_arch(),
at this stage the kernel has materialized and basic infrastructure
such as current() works.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-08-04 00:00:46 +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
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
Richard Weinberger 28fa468f53 um: Remove broken SMP support
At times where UML used the TT mode to operate it had
kind of SMP support. It never got finished nor was
stable.
Let's rip out that cruft and stop confusing developers
which do tree-wide SMP cleanups.

If someone wants SMP support UML it has do be done from scratch.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:00:58 +02:00
Richard Weinberger d0b5e15f0c um: Remove SKAS3/4 support
Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.

With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:00:53 +02:00
Honggang Li 9e6a57d2cd um: delete unnecessary bootmem struct page array
1) uml kernel bootmem managed through bootmem_data->node_bootmem_map,
not the struct page array, so the array is unnecessary.

2) the bootmem struct page array has been pointed by a *local* pointer,
struct page *map, in init_maps function. The array can be accessed only
in init_maps's scope. As a result, uml kernel wastes about 1% of total
memory.

Signed-off-by: Honggang Li <enjoymindful@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2014-10-13 17:15:09 +02:00
Geert Uytterhoeven 33a7d42999 um: Remove unused declarations from <as-layout.h>
_end is used, but it's already provided by <asm/sections.h>, so use that.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>
2013-11-17 11:39:22 +01:00
Richard Weinberger 9d1ee8ce92 um: Rewrite show_stack()
Currently on UML stack traces are not very reliable and both
x86 and x86_64 have their on implementations.
This patch unifies both and adds support to outline unreliable
functions calls.

Signed-off-by: Richard Weinberger <richard@nod.at>
2013-11-17 11:27:25 +01:00
Al Viro 37185b3324 um: get rid of pointless include "..." where include <...> will do
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2012-10-09 22:28:45 +02:00
Thomas Gleixner 5b408241e9 um: Use generic init_task
Same code. Use the generic version.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/20120503085035.592937512@linutronix.de
2012-05-05 13:00:26 +02:00
Al Viro 73395a0002 um: distribute exports to where exported stuff is defined
ksyms.c is down to the stuff defined in various USER_OBJS

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2011-11-02 14:15:36 +01:00
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 60a2988aea uml: physical memory shouldn't include initial stack
The top of physical memory should be below the initial process stack, not the
top of the address space, at least for as long as the stack isn't known to the
kernel VM system and appropriately reserved.

Cc: "Christopher S. Aker" <caker@theshore.net>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.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 96cee3044d uml: style fixes
A few random style fixes.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:21 -07:00
WANG Cong 3af9c5bed1 arch/um/kernel/um_arch.c: some small improvements
Make some small improvements for arch/um/kernel/um_arch.c.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:28 -07:00
Jeff Dike 536788fe2d uml: runtime host VMSPLIT detection
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>
2008-02-08 09:22:42 -08:00
Jeff Dike c5d4bb171c uml: style fixes in arch/um/kernel
Joe Perches noticed some printks in smp.c that needed fixing.

While I was in there, I did the usual tidying in arch/um/kernel, which
should be fairly style-clean at this point:
	copyright updates
	emacs formatting comments removal
	include tidying
	style fixes

Cc: Joe Perches <joe@perches.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>
2008-02-05 09:44:30 -08:00
Jeff Dike 0983a88b9f uml: install panic notifier earlier
It turns out that if there's a panic early enough, UML will just sit there in
the LED-blinking loop because the panic notifier hadn't been installed yet.

This patch installs it earlier.

It also fixes the problem which exposed the hang, namely that if you give UML
a zero-sized initrd, it will ask alloc_bootmem for zero bytes, and that will
cause the panic.

While I was in initrd.c, I gave it a style makeover.

Prompted by checkpatch, I moved a couple extern declarations of uml_exitcode
to kern_util.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>
2008-02-05 09:44:29 -08:00
Jeff Dike 42a2b54ce8 uml: clean up TASK_SIZE usage
Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.

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>
2008-02-05 09:44:29 -08:00
Karol Swietlicki 6b7e967484 uml: convert functions to void
This patch changes a few functions into returning void.  The return values
were not used anyway, so I think it should not be a problem.  Also removed a
little leftover bit from TT mode.

Signed-off-by: Karol Swietlicki <magotari@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>
2008-02-05 09:44:26 -08:00