20 Sep, 2007
1 commit
-
This patch fixes a crash caused by an interrupt coming in when an IRQ stack
is being torn down. When this happens, handle_signal will loop, setting up
the IRQ stack again because the tearing down had finished, and handling
whatever signals had come in.However, to_irq_stack returns a mask of pending signals to be handled, plus
bit zero is set if the IRQ stack was already active, and thus shouldn't be
torn down. This causes a problem because when handle_signal goes around
the loop, sig will be zero, and to_irq_stack will duly set bit zero in the
returned mask, faking handle_signal into believing that it shouldn't tear
down the IRQ stack and return thread_info pointers back to their original
values.This will eventually cause a crash, as the IRQ stack thread_info will
continue pointing to the original task_struct and an interrupt will look
into it after it has been freed.The fix is to stop passing a signal number into to_irq_stack. Rather, the
pending signals mask is initialized beforehand with the bit for sig already
set. References to sig in to_irq_stack can be replaced with references to
the mask.[akpm@linux-foundation.org: use UL]
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Aug, 2007
1 commit
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Fix a class of bugs in the UML linker scripts which caused section boundary
variables to sometimes not line up with their sections.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jul, 2007
1 commit
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Remove fs.h from mm.h. For this,
1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
2) Add back fs.h or less bloated headers (err.h) to files that need it.As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
rebuilt down to 3444 (-12.3%).Cross-compile tested without regressions on my two usual configs and (sigh):
alpha arm-mx1ads mips-bigsur powerpc-ebony
alpha-allnoconfig arm-neponset mips-capcella powerpc-g5
alpha-defconfig arm-netwinder mips-cobalt powerpc-holly
alpha-up arm-netx mips-db1000 powerpc-iseries
arm arm-ns9xxx mips-db1100 powerpc-linkstation
arm-assabet arm-omap_h2_1610 mips-db1200 powerpc-lite5200
arm-at91rm9200dk arm-onearm mips-db1500 powerpc-maple
arm-at91rm9200ek arm-picotux200 mips-db1550 powerpc-mpc7448_hpc2
arm-at91sam9260ek arm-pleb mips-ddb5477 powerpc-mpc8272_ads
arm-at91sam9261ek arm-pnx4008 mips-decstation powerpc-mpc8313_rdb
arm-at91sam9263ek arm-pxa255-idp mips-e55 powerpc-mpc832x_mds
arm-at91sam9rlek arm-realview mips-emma2rh powerpc-mpc832x_rdb
arm-ateb9200 arm-realview-smp mips-excite powerpc-mpc834x_itx
arm-badge4 arm-rpc mips-fulong powerpc-mpc834x_itxgp
arm-carmeva arm-s3c2410 mips-ip22 powerpc-mpc834x_mds
arm-cerfcube arm-shannon mips-ip27 powerpc-mpc836x_mds
arm-clps7500 arm-shark mips-ip32 powerpc-mpc8540_ads
arm-collie arm-simpad mips-jazz powerpc-mpc8544_ds
arm-corgi arm-spitz mips-jmr3927 powerpc-mpc8560_ads
arm-csb337 arm-trizeps4 mips-malta powerpc-mpc8568mds
arm-csb637 arm-versatile mips-mipssim powerpc-mpc85xx_cds
arm-ebsa110 i386 mips-mpc30x powerpc-mpc8641_hpcn
arm-edb7211 i386-allnoconfig mips-msp71xx powerpc-mpc866_ads
arm-em_x270 i386-defconfig mips-ocelot powerpc-mpc885_ads
arm-ep93xx i386-up mips-pb1100 powerpc-pasemi
arm-footbridge ia64 mips-pb1500 powerpc-pmac32
arm-fortunet ia64-allnoconfig mips-pb1550 powerpc-ppc64
arm-h3600 ia64-bigsur mips-pnx8550-jbs powerpc-prpmc2800
arm-h7201 ia64-defconfig mips-pnx8550-stb810 powerpc-ps3
arm-h7202 ia64-gensparse mips-qemu powerpc-pseries
arm-hackkit ia64-sim mips-rbhma4200 powerpc-up
arm-integrator ia64-sn2 mips-rbhma4500 s390
arm-iop13xx ia64-tiger mips-rm200 s390-allnoconfig
arm-iop32x ia64-up mips-sb1250-swarm s390-defconfig
arm-iop33x ia64-zx1 mips-sead s390-up
arm-ixp2000 m68k mips-tb0219 sparc
arm-ixp23xx m68k-amiga mips-tb0226 sparc-allnoconfig
arm-ixp4xx m68k-apollo mips-tb0287 sparc-defconfig
arm-jornada720 m68k-atari mips-workpad sparc-up
arm-kafa m68k-bvme6000 mips-wrppmc sparc64
arm-kb9202 m68k-hp300 mips-yosemite sparc64-allnoconfig
arm-ks8695 m68k-mac parisc sparc64-defconfig
arm-lart m68k-mvme147 parisc-allnoconfig sparc64-up
arm-lpd270 m68k-mvme16x parisc-defconfig um-x86_64
arm-lpd7a400 m68k-q40 parisc-up x86_64
arm-lpd7a404 m68k-sun3 powerpc x86_64-allnoconfig
arm-lubbock m68k-sun3x powerpc-cell x86_64-defconfig
arm-lusl7200 mips powerpc-celleb x86_64-up
arm-mainstone mips-atlas powerpc-chrp32Signed-off-by: Alexey Dobriyan
Signed-off-by: Linus Torvalds
25 Jul, 2007
1 commit
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2.6.23-rc1 turned up another batch of references from non-__init code to
__init code. In most cases, these were missing __init annotations. In one
case (os_drop_memory), the annotation was present but wrong.init_maps is __init, but for some reason was being very careful about the
mechanism by which it allocated memory, checking whether it was OK to use
kmalloc (at this point in the boot, it definitely isn't) and using either
alloc_bootmem_low_pages or kmalloc/vmalloc. So, the kmalloc/vmalloc code is
removed.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
1 commit
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This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer. This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Russell King
Cc: Ian Molton
Cc: Bryan Wu
Cc: Mikael Starvik
Cc: David Howells
Cc: Yoshinori Sato
Cc: "Luck, Tony"
Cc: Hirokazu Takata
Cc: Geert Uytterhoeven
Cc: Roman Zippel
Cc: Greg Ungerer
Cc: Matthew Wilcox
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Heiko Carstens
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: Kazumoto Kojima
Cc: Richard Curnow
Cc: William Lee Irwin III
Cc: "David S. Miller"
Cc: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Cc: Miles Bader
Cc: Chris Zankel
Acked-by: Kyle McMartin
Acked-by: Haavard Skinnemoen
Acked-by: Ralf Baechle
Acked-by: Andi Kleen
Signed-off-by: Andrew Morton
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds
18 Jul, 2007
2 commits
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Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.Signed-off-by: Alexey Dobriyan
Cc: Christoph Hellwig
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Identical implementations of PTRACE_PEEKDATA go into generic_ptrace_peekdata()
function.Signed-off-by: Alexey Dobriyan
Cc: Christoph Hellwig
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jul, 2007
1 commit
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UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h had made kernel constants available for a long time, so there
is no need for these wrappers any more. Rather, userspace code calls kmalloc
directly with the userspace versions of the gfp flags.kmalloc isn't a real procedure, so I had to essentially copy the inline
wrapper around __kmalloc.vmalloc also had its own wrapper for no good reason. This is now gone.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Jun, 2007
1 commit
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Include linux/kernel.h wherever simple_strtoul is used. This kills a
compile warning in stderr_console.c and potential ones in the other files.This also fixes a bunch of style violations in exitcode.c.
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 May, 2007
2 commits
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With this consolidation we can now modify the .data
section definition in one spot for all archs.Signed-off-by: Sam Ravnborg
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Move definition of .text section to asm-generic.
Signed-off-by: Sam Ravnborg
11 May, 2007
4 commits
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Add a separate IRQ stack. This differs from i386 in having the entire
interrupt run on a separate stack rather than starting on the normal kernel
stack and switching over once some preparation has been done. The underlying
mechanism, is of course, sigaltstack.Another difference is that interrupts that happen in userspace are handled on
the normal kernel stack. These cause a wait wakeup instead of a signal
delivery so there is no point in trying to switch stacks for these. There's
no other stuff on the stack, so there is no extra stack consumption.This quirk makes it possible to have the entire interrupt run on a separate
stack - process preemption (and calls to schedule()) happens on a normal
kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought.The IRQ stack for CPU 0 is declared in the same way as the initial kernel
stack. IRQ stacks for other CPUs will be allocated dynamically.An extra field was added to the thread_info structure. When the active
thread_info is copied to the IRQ stack, the real_thread field points back to
the original stack. This makes it easy to tell where to copy the thread_info
struct back to when the interrupt is finished. It also serves as a marker of
a nested interrupt. It is NULL for the first interrupt on the stack, and
non-NULL for any nested interrupts.Care is taken to behave correctly if a second interrupt comes in when the
thread_info structure is being set up or taken down. I could just disable
interrupts here, but I don't feel like giving up any of the performance gained
by not flipping signals on and off.If an interrupt comes in during these critical periods, the handler can't run
because it has no idea what shape the stack is in. So, it sets a bit for its
signal in a global mask and returns. The outer handler will deal with this
signal itself.Atomicity is had with xchg. A nested interrupt that needs to bail out will
xchg its signal mask into pending_mask and repeat in case yet another
interrupt hit at the same time, until the mask stabilizes.The outermost interrupt will set up the thread_info and xchg a zero into
pending_mask when it is done. At this point, nested interrupts will look at
->real_thread and see that no setup needs to be done. They can just continue
normally.Similar care needs to be taken when exiting the outer handler. If another
interrupt comes in while it is copying the thread_info, it will drop a bit
into pending_mask. The outer handler will check this and if it is non-zero,
will loop, set up the stack again, and handle the interrupt.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Some tidying of the irq code before introducing irq stacks. Mostly
style fixes, but the timer handler calls the timer code directly
rather than going through the generic sig_handler_common_skas.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that we have UM_THREAD_SIZE, we can replace the calculations in
user-space code (an earlier patch took care of the kernel side of the
house).Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Replaced task_protections with stack_protections since they do the same
thing, and task_protections was misnamed anyway.This needs THREAD_SIZE, so that's imported via common-offsets.h
Also tidied up the code in the vicinity.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 May, 2007
1 commit
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These haven't been fixed for ages. Just make comments out of them.
arch/um/kernel/skas/process.c:181:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:187:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:194:2: warning: #warning need to loop over
+userspace_pids in kill_off_processes_skasSigned-off-by: Miklos Szeredi
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 May, 2007
1 commit
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The ever-vigilant users of linode.com noticed that an idle 2.6 UML has a
persistent load average of ~.4.It turns out that because the UML timer handler processed softirqs before
actually delivering the tick, the tick was counted in the context of the idle
thread about half the time.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2007
23 commits
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With the current timekeeping, !CONFIG_UML_REAL_TIME_CLOCK has
inconsistent behavior. Previously, gettimeofday could be (and was)
isolated from the clock ticking. Now, it's not, so when
CONFIG_UML_REAL_TIME_CLOCK is disabled, gettimeofday must progress in
lockstep with the clock, making it fully virtual.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It turns out that the message complaining about a lack of tmpfs space
on the host can be misunderstood as referring to the UML.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When doing a full address space flush, only look at areas covered by a VMA.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
More trimming of the page fault path.
Permissions are passed around in a single int rather than one bit per
int. The permission values are copied from libc so that they can be
passed to mmap and mprotect without any further conversion.The register sets used by do_syscall_stub and copy_context_skas0 are
initialized once, at boot time, rather than once per call.wait_stub_done checks whether it is getting the signals it expects by
comparing the wait status to a mask containing bits for the signals of
interest rather than comparing individually to the signal numbers. It
also has one check for a wait failure instead of two. The caller is
expected to do the initial continue of the stub. This gets rid of an
argument and some logic. The fname argument is gone, as that can be
had from a stack trace.user_signal() is collapsed into userspace() as it is basically one or
two lines of code afterwards.The physical memory remapping stuff is gone, as it is unused.
flush_tlb_page is inlined.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I missed removing another piece of debugging in an earlier patch.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Give the page fault code a specialized path. There is only one page to look
at, so there's no point in going into the general page table walking code.
There's only going to be one host operation, so there are no opportunities for
merging. So, we go straight to the pte we want, figure out what needs doing,
and do it.While I was in here, I fixed the wart where the address passed to unmap was a
void *, but an unsigned long to map and protect.This gives me just under 10% on a kernel build.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Rename os_{read_write}_file_k back to os_{read_write}_file, delete
the originals and their bogus infrastructure, and fix all the callers.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I accidentally left the remnants of some debugging in an earlier patch.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Formatting fixes ahead of renaming os_{read_write}_file_k to
os_{read_write}_file and fixing all the callers.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Convert all remaining os_{read_write}_file users to use the simple
{read,write} wrappers, os_{read_write}_file_k.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Dump core after a panic. This will provide better debugging information than
is currently available.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch starts the removal of a very old, very broken piece of code. This
stems from the problem of passing a userspace buffer into read() or write() on
the host. If that buffer had not yet been faulted in, read and write will
return -EFAULT.To avoid this problem, the solution was to fault the buffer in before the
system call by touching the pages that hold the buffer by doing a copy-user of
a byte to each page. This is obviously bogus, but it does usually work, in tt
mode, since the kernel and process are in the same address space and userspace
addresses can be accessed directly in the kernel.In skas mode, where the kernel and process are in separate address spaces, it
is completely bogus because the userspace address, which is invalid in the
kernel, is passed into the system call instead of the corresponding physical
address, which would be valid. Here, it appears that this code, on every host
read() or write(), tries to fault in a random process page. This doesn't seem
to cause any correctness problems, but there is a performance impact. This
patch, and the ones following, result in a 10-15% performance gain on a kernel
build.This code can't be immediately tossed out because when it is, you can't log
in. Apparently, there is some code in the console driver which depends on
this somehow.However, we can start removing it by switching the code which does I/O using
kernel addresses to using plain read() and write(). This patch introduces
os_read_file_k and os_write_file_k for use with kernel buffers and converts
all call locations which use obvious kernel buffers to use them. These
include I/O using buffers which are local variables which are on the stack or
kmalloc-ed. Later patches will handle the less obvious cases, followed by a
mass conversion back to the original interface.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The previous page table walking code was horribly inefficient. This patch
replaces it with code taken from elsewhere in the kernel.Forking from bash is now ~5% faster and page faults are handled ~10% faster.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Locking commentary.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commentary about missing locking.
Also got rid of uml_start because it was pointless.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If there's a segfault inside the kernel, we want a dump of the registers at
the point of the segfault, not the registers at the point of calling panic or
the last userspace registers.sig_handler_common_skas now uses a static register set in the case of a
SIGSEGV to avoid messing up the process registers if the segfault turns out to
be non-fatal.The architecture sigcontext-to-pt_regs copying code was repurposed to copy
data out of the SEGV stack frame.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Tidying in preparation for the segfault register dumping patch which follows.
void * pointers are changed to union uml_pt_regs *. This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs. This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.Whitespace and other style fixes.
There's also a errno printk fix.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
kernel_thread() should just return an error value on do_fork failure, not
panic.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
userspace code used to have to call the kernelspace function page_size() in
order to determine the value of the kernel's PAGE_SIZE. Since this is now
available directly from kern_constants.h as UM_KERN_PAGE_SIZE, page_size() can
be deleted and calls changed to use the constant.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up arch/um/kernel/process.c:
- lots of return(x); -> return x; conversions
- a number of the small functions are either unused, in which case they are
gone, along any declarations in a header, or could be made static.- current_pid is ifdefed on CONFIG_MODE_TT and its declaration is ifdefed on
both CONFIG_MODE_TT and UML_CONFIG_MODE_TT because we don't know whether
it's being used in a userspace or kernel file.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
flush_thread doesn't need to do a full page table walk in order to clear the
address space. It knows what the end result needs to be, so it can call unmap
directly.This results in a 10-20% speedup in an exec from bash.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Robert P. J. Day
Acked-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The build started finding calls from non-init to init functions. These are
just cases of init functions not being properly marked, so this patch fixes
that.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
