Make the tracepoints more robust, making them solid enough to handle compiler
changes by not relying on anything based on compiler-specific behavior with
respect to structure alignment. Implement an approach proposed by David Miller:
use an array of const pointers to refer to the individual structures, and export
this pointer array through the linker script rather than the structures per se.
It will consume 32 extra bytes per tracepoint (24 for structure padding and 8
for the pointers), but are less likely to break due to compiler changes.

History:

commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
added the aligned(32) type and variable attribute to the tracepoint structures
to deal with gcc happily aligning statically defined structures on 32-byte
multiples.

One attempt was to use a 8-byte alignment for tracepoint structures by applying
both the variable and type attribute to tracepoint structures definitions and
declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5.

The reason is that the "aligned" attribute only specify the _minimum_ alignment
for a structure, leaving both the compiler and the linker free to align on
larger multiples. Because tracepoint.c expects the structures to be placed as an
array within each section, up-alignment cause NULL-pointer exceptions due to the
extra unexpected padding.

(this patch applies on top of -tip)
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
LKML-Reference: <20110126222622.GA10794@Krystal>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently the trace_event structures are placed in the _ftrace_events
section, and at link time, the linker makes one large array of all
the trace_event structures. On boot up, this array is read (much like
the initcall sections) and the events are processed.

The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.

A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).

Instead of packing the structures into an array, the structures' addresses
are now put into the _ftrace_event section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).

By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.

The _ftrace_event section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: NDavid Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently only drivers that are built as modules have their versions
shown in /sys/module/<module_name>/version, but this information might
also be useful for built-in drivers as well. This especially important
for drivers that do not define any parameters - such drivers, if
built-in, are completely invisible from userspace.

This patch changes MODULE_VERSION() macro so that in case when we are
compiling built-in module, version information is stored in a separate
section. Kernel then uses this data to create 'version' sysfs attribute
in the same fashion it creates attributes for module parameters.
Signed-off-by: NDmitry Torokhov <dtor@vmware.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The readmostly section should end at a cacheline aligned address,
otherwise the last several data might share cachline with other data and
make the readmostly data still have cache bounce.

For example, in ia64, secpath_cachep is the last readmostly data, and it
shares cacheline with init_uts_ns.

a000000100e80480 d secpath_cachep
a000000100e80488 D init_uts_ns
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds support for linking device tree blob(s) into
vmlinux. Modifies asm-generic/vmlinux.lds.h to add linking
.dtb sections into vmlinux. To maintain compatiblity with the of/fdt
driver code platforms MUST copy the blob to a non-init memory location
before the kernel frees the .init.* sections in the image.

Modifies scripts/Makefile.lib to add a kbuild command to
compile DTS files to device tree blobs and a rule to create objects to
wrap the blobs for linking.

STRUCT_ALIGNMENT is defined in vmlinux.lds.h for use in the rule to
create wrapper objects for the dtb in Makefile.lib.  The
STRUCT_ALIGN() macro in vmlinux.lds.h is modified to use the
STRUCT_ALIGNMENT definition.

The DTB's are placed on 32 byte boundries to allow parsing the blob
with driver/of/fdt.c during early boot without having to copy the blob
to get the structure alignment GCC expects.

A DTB is linked in by adding the DTB object to the list of objects to
be linked into vmlinux in the archtecture specific Makefile using
   obj-y += foo.dtb.o
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: NMichal Marek <mmarek@suse.cz>
[grant.likely@secretlab.ca: cleaned up whitespace inconsistencies]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

The new init ramfs format (cpio based) requires an alignment of 4 (per the
documentation and per the source files themselves).  As for compressed
sources, the decompressors can all deal with unaligned buffers.

The cpio source is also found in the __init sections of the kernel, so
once they are read and expanded into a tmpfs, the source is freed.  That
means there is no need to force page alignment here either.

This has been used on Blackfin systems for many releases without issue.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the recent change "net: remove time limit in process_backlog()", the
softnet_data variable changed from "DEFINE_PER_CPU()" to
"DEFINE_PER_CPU_ALIGNED()" which moved it from the .data section to the
.data.shared_align section.  I'm not saying this patch is wrong, just that
is what caused me to notice this larger problem.  No one else in the
kernel is using this aligned macro variant, so I imagine that's why no one
has noticed yet.

Since .data..shared_align isn't declared in any vmlinux files that I can
see, the linker just places it last.  This "just works" for most people,
but when building a ROM kernel on Blackfin systems, it causes section
overlap errors:

bfin-uclinux-ld.real:
	section .init.data [00000000202e06b8 -> 00000000202e48b7] overlaps
	section .data.shared_aligned [00000000202e06b8 -> 00000000202e0723]

I imagine other arches which support the ROM config option and thus do
funky placement would see similar issues ...

On x86, it is stuck in a dedicated section at the end:
 [8] .data             PROGBITS ffffffff810ec000 2ec0000303a8 00 WA 0 0 4096
 [9] .data.shared_alig PROGBITS ffffffff8111c3c0 31c3c00000c8 00 WA 0 0 64

So make sure we include this section in the DATA_DATA macro so that it is
placed in the right location.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Checkin c957ef2c had inconsistent
ordering of .data..percpu..page_aligned and .data..percpu..readmostly;
the still-broken version affected x86-32 at least.

The page aligned version really must be page aligned...
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>

Add a new readmostly percpu section and API.  This can be used to
avoid dirtying data lines which are generally not written to, which is
especially important for data which may be accessed by processors
other than the one for which the percpu area belongs to.

[ hpa: moved it *after* the page-aligned section, for obvious
  reasons. ]
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
LKML-Reference: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The size of a built-in initramfs is calculated in init/initramfs.c by
"__initramfs_end - __initramfs_start".  Those symbols are defined in the
linker script include/asm-generic/vmlinux.lds.h:

#define INIT_RAM_FS                                                     \
        . = ALIGN(PAGE_SIZE);                                           \
        VMLINUX_SYMBOL(__initramfs_start) = .;                          \
        *(.init.ramfs)                                                  \
        VMLINUX_SYMBOL(__initramfs_end) = .;

If the initramfs file has an odd number of bytes, the "__initramfs_end"
symbol points to an odd address, for example, the symbols in the
System.map might look like:

    0000000000572000 T __initramfs_start
    00000000005bcd05 T __initramfs_end	  <-- odd address

At least on s390 this causes a problem:

Certain s390 instructions, especially instructions for loading addresses
(larl) or branch addresses must be on even addresses.  The compiler loads
the symbol addresses with the "larl" instruction.  This instruction sets
the last bit to 0 and, therefore, for odd size files, the calculated size
is one byte less than it should be:

    0000000000540a9c <populate_rootfs>:
      540a9c:     eb cf f0 78 00 24       stmg    %r12,%r15,120(%r15),
      540aa2:     c0 10 00 01 8a af       larl    %r1,572000 <__initramfs_start>
      540aa8:     c0 c0 00 03 e1 2e       larl    %r12,5bcd04 <initramfs_end>
                                                  (Instead of  5bcd05)
      ...
      540abe:     1b c1                   sr      %r12,%r1

To fix the problem, this patch introduces the global variable
__initramfs_size, which is calculated in the "usr/initramfs_data.S" file.
The populate_rootfs() function can then use the start marker of the
.init.ramfs section and the value of __initramfs_size for loading the
initramfs.  Because the start marker and size is sufficient, the
__initramfs_end symbol is no longer needed and is removed.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Acked-by: NMichal Marek <mmarek@suse.cz>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>

[ cleaned up some formating ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

gcc 4.4.4 will complain if you use a .discard section for both text and
data ("causes a section type conflict").  Add support for ".discard.*"
sections, and use .discard.text for a dummy function in the x86
RESERVE_BRK() macro.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

The .data..init_task output section was missing
a load offset causing a popwerpc target to fail to boot.

Sean MacLennan tracked it down to the definition of
INIT_TASK_DATA_SECTION().

There are only two users of INIT_TASK_DATA_SECTION()
in the kernel today: cris and popwerpc.
cris do not support relocatable kernels and is thus not
impacted by this change.

Fix INIT_TASK_DATA_SECTION() to specify load offset like
all other output sections.
Reported-by: NSean MacLennan <smaclennan@pikatech.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We define a number of symbols in the linker scipt like this:

    __start_syscalls_metadata = .;
    *(__syscalls_metadata)

But we do not know the alignment of "." when we assign
the __start_syscalls_metadata symbol.
gcc started to uses bigger alignment for structs (32 bytes),
so we saw situations where the linker due to alignment
constraints increased the value of "." after the symbol assignment.

This resulted in boot fails.

Fix this by forcing a 32 byte alignment of "." before the
assignment.

This patch introduces the forced alignment for
ftrace_events and syscalls_metadata.
It may be required in more places.
Reported-by: NZeev Tarantov <zeev.tarantov@gmail.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
LKML-Reference: <20100710063459.GA14596@merkur.ravnborg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Markers have been removed, but we forgot to remove their
section.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Modify the way how RapidIO switch operations are declared.  Multiple
assignments through the linker script replaced by single initialization
call.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add RapidIO Port-Write message handling in the context of Error
   Management Extensions Specification Rev.1.3.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Tested-by: NThomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

The next commit will require the use of MODULE_SYMBOL_PREFIX in
.tmp_exports-asm.S.  Currently it is mixed in with C structure
definitions in "asm/module.h".  Move the definition of this arch option
into Kconfig, so it can be easily accessed by any code.

This also lets modpost.c use the same definition.  Previously modpost
relied on a hardcoded list of architectures in mk_elfconfig.c.

A build test for blackfin, one of the two MODULE_SYMBOL_PREFIX archs,
showed the generated code was unchanged.  vmlinux was identical save
for build ids, and an apparently randomized suffix on a single "__key"
symbol in the kallsyms data).
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Mike Frysinger <vapier@gentoo.org> (blackfin)
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The old RW_DATA_SECTION had INIT_TASK_DATA (which was
more-than-PAGE_SIZE-aligned), followed by a bunch of small alignment
stuff, followed by more PAGE_SIZE-aligned stuff, so you wasted memory
in the middle of .data re-aligning back up to PAGE_SIZE.

This patch sorts the sections by alignment requirements, which should
pack them essentially optimally.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__start_mcount_loc[] is unused after init, yet occupies RAM forever
as part of .rodata.  152kiB is typical on a 64-bit architecture.  Instead,
__start_mcount_loc should be in the interval [__init_begin, __init_end)
so that the space is reclaimed after init.

__start_mcount_loc[] is generated during the load portion
of kernel build, and is used only by ftrace_init().  ftrace_init is declared
'__init' and is in .init.text, which is freed after init.
__start_mcount_loc is placed into .rodata by a call to MCOUNT_REC inside
the RO_DATA macro of include/asm-generic/vmlinux.lds.h.  The array *is*
read-only, but more importantly it is not used after init.  So the call to
MCOUNT_REC should be moved from RO_DATA to INIT_DATA.

This patch has been tested on x86_64 with CONFIG_DEBUG_PAGEALLOC=y
which verifies that the address range never is accessed after init.
Signed-off-by: NJohn Reiser <jreiser@BitWagon.com>
LKML-Reference: <4A6DF0B6.7080402@bitwagon.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The BSS section macros in vmlinux.lds.h currently place the .sbss
input section outside the bounds of [__bss_start, __bss_end].  On all
architectures except for microblaze that handle both .sbss and
__bss_start/__bss_end, this is wrong: the .sbss input section is
within the range [__bss_start, __bss_end].  Relatedly, the example
code at the top of the file actually has __bss_start/__bss_end defined
twice; I believe the right fix here is to define them in the
BSS_SECTION macro but not in the BSS macro.

Another problem with the current macros is that several
architectures have an ALIGN(4) or some other small number just before
__bss_stop in their linker scripts.  The BSS_SECTION macro currently
hardcodes this to 4; while it should really be an argument.  It also
ignores its sbss_align argument; fix that.

mn10300 is the only user at present of any of the macros touched by
this patch.  It looks like mn10300 actually was incorrectly converted
to use the new BSS() macro (the alignment of 4 prior to conversion was
a __bss_stop alignment, but the argument to the BSS macro is a start
alignment).  So fix this as well.

I'd like acks from Sam and David on this one.  Also CCing Paul, since
he has a patch from me which will need to be updated to use
BSS_SECTION(0, PAGE_SIZE, 4) once this gets merged.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Discarded sections in different archs share some commonality but have
considerable differences.  This led to linker script for each arch
implementing its own /DISCARD/ definition, which makes maintaining
tedious and adding new entries error-prone.

This patch makes all linker scripts to move discard definitions to the
end of the linker script and use the common DISCARDS macro.  As ld
uses the first matching section definition, archs can include default
discarded sections by including them earlier in the linker script.

ia64 is notable because it first throws away some ia64 specific
subsections and then include the rest of the sections into the final
image, so those sections must be discarded before the inclusion.

defconfig compile tested for x86, x86-64, powerpc, powerpc64, ia64,
alpha, sparc, sparc64 and s390.  Michal Simek tested microblaze.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Tested-by: NMichal Simek <monstr@monstr.eu>
Cc: linux-arch@vger.kernel.org
Cc: Michal Simek <monstr@monstr.eu>
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>

The ctors section for each object file is eight byte aligned (on 64 bit).
However the __ctors_start symbol starts at an arbitrary address dependent
on the size of the previous sections.

Therefore the linker may add some zeroes after __ctors_start to make sure
the ctors contents are properly aligned.  However the extra zeroes at the
beginning aren't expected by the code.  When walking the functions
pointers contained in there and extra zeroes are added this may result in
random jumps.  So make sure that the __ctors_start symbol is always
aligned as well.

Fixes this crash on an allyesconfig on s390:

[    0.582482] Kernel BUG at 0000000000000012 [verbose debug info unavailable]
[    0.582489] illegal operation: 0001 [#1] SMP DEBUG_PAGEALLOC
[    0.582496] Modules linked in:
[    0.582501] CPU: 0 Tainted: G        W  2.6.31-rc1-dirty #273
[    0.582506] Process swapper (pid: 1, task: 000000003f218000, ksp: 000000003f2238e8)
[    0.582510] Krnl PSW : 0704200180000000 0000000000000012 (0x12)
[    0.582518]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
[    0.582524] Krnl GPRS: 0000000000036727 0000000000000010 0000000000000001 0000000000000001
[    0.582529]            00000000001dfefa 0000000000000000 0000000000000000 0000000000000040
[    0.582534]            0000000001fff0f0 0000000001790628 0000000002296048 0000000002296048
[    0.582540]            00000000020c438e 0000000001786000 0000000002014a66 000000003f223e60
[    0.582553] Krnl Code:>0000000000000012: 0000                unknown
[    0.582559]            0000000000000014: 0000                unknown
[    0.582564]            0000000000000016: 0000                unknown
[    0.582570]            0000000000000018: 0000                unknown
[    0.582575]            000000000000001a: 0000                unknown
[    0.582580]            000000000000001c: 0000                unknown
[    0.582585]            000000000000001e: 0000                unknown
[    0.582591]            0000000000000020: 0000                unknown
[    0.582596] Call Trace:
[    0.582599] ([<0000000002014a46>] kernel_init+0x622/0x7a0)
[    0.582607]  [<0000000000113e22>] kernel_thread_starter+0x6/0xc
[    0.582615]  [<0000000000113e1c>] kernel_thread_starter+0x0/0xc
[    0.582621] INFO: lockdep is turned off.
[    0.582624] Last Breaking-Event-Address:
[    0.582627]  [<0000000002014a64>] kernel_init+0x640/0x7a0

Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We recently added a INIT_TASK(align) in include/asm-generic/vmlinux.lds.h,
but there is already a macro INIT_TASK in include/linux/init_task.h, which
is quite confusing.  We should switch the macro in the linker script to
INIT_TASK_DATA. (Sorry that I missed this in reviewing the patch).  Since
the macros are new, there is only one user of the INIT_TASK in
vmlinux.lds.h, arch/mn10300/kernel/vmlinux.lds.S.

However, we are currently using INIT_TASK_DATA for laying down an entire
.data.init_task section.  So rename that to INIT_TASK_DATA_SECTION.

I would be worried about changing the meaning of INIT_TASK_DATA, but the
old INIT_TASK_DATA implementation had no users, and in fact if anyone had
tried to use it, it would have failed to compile because it didn't pass
the alignment to the old INIT_TASK.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jesper Nilsson <Jesper.Nilsson@axis.com
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

RW_DATA_SECTION is defined to take 4 different alignment parameters,
while NOSAVE_DATA currently uses a fixed PAGE_SIZE alignment as noted
in the comments.

There are presently no in-tree users of this at present, and I just
stumbled across this while implementing the simplified script on a new
architecture port, which subsequently resulted in a syntax error.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

x86 throws away .discard section but no other archs do.  Also,
.discard is not thrown away while linking modules.  Make every arch
and module linking throw it away.  This will be used to define dummy
variables for percpu declarations and definitions.

This patch is based on Ivan Kokshaysky's alpha percpu patch.

[ Impact: always throw away everything in .discard ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>

In asm-generic/vmlinux.lds.h, name INIT_RAM_FS consistently, no matter the
setting of CONFIG_BLK_DEV_INITRD.  This corrects:

	commit ef53dae8
	Author: Sam Ravnborg <sam@ravnborg.org>
	Date:   Sun Jun 7 20:46:37 2009 +0200
	Subject: Improve vmlinux.lds.h support for arch specific linker scripts
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Call constructors (gcc-generated initcall-like functions) during kernel
start and module load.  Constructors are e.g.  used for gcov data
initialization.

Disable constructor support for usermode Linux to prevent conflicts with
host glibc.
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Updated after review by Tim Abbott.
- Use HEAD_TEXT_SECTION
- Drop use of section-names.h and delete file
- Introduce EXIT_CALL

Deleting section-names.h required a few simple
updates of init.h
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Tim Abbott <tabbott@ksplice.com>

To support alingment of the individual architecture specific linker scripts
provide a set of general definitions in vmlinux.lds.h

With these definitions applied the diverse linekr scripts can be reduced
in line count and their readability are improved - IMO.

A sample linker script is included to give the preferred
order of the sections for the architectures that do not
have any special requirments.

These definitions are also a first step towards eventual
support for -ffunction-sections.
The definitions makes it much easier to do a global
renaming of section names - but the main purpose is
to clean up the linker scripts.

Tim Aboot has provided a lot of inputs to improve
the definitions - all faults are mine.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Tim Abbott <tabbott@mit.edu>

- add .init.rodata to INIT_DATA, and group all initconst flavors
  together
- move strings generated from __setup_param() into .init.rodata
- add .*init.rodata to modpost's sets of init sections
- make modpost warn about references between meminit and cpuinit
  as well as memexit and cpuexit sections (as CPU and memory
  hotplug are independently selectable features)
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

The old refok sections

  .text.init.refok
  .data.init.refok
  .exit.text.refok

have been deprecated since commit
312b1485.  After the other patches in
this patch series nothing is put in these sections, so clean things up
by eliminating all the remaining references to them.
Signed-off-by: NTim Abbott <tabbott@mit.edu>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is preparation for replacing all uses of ".head.text" or
".text.head" in the kernel with macros, so that the section name can
later be changed without having to touch a lot of the kernel.

Since some linker scripts do more complex things than referencing
HEAD_TEXT, we add a HEAD_TEXT_SECTION macro that just contains the
actual name.

I've defined HEAD_TEXT_SECTION in a new header,
include/linux/section-names.h, so that this section name only needs to
appear in one place.  I anticipate creating similar macro structures
for a number of other section names.

The long-term goal here is to be able to change the kernel's magic
section names to those that are compatible with -ffunction-sections
-fdata-sections.  This requires renaming all magic sections with names
of the form ".text.foo".
Signed-off-by: NTim Abbott <tabbott@mit.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>