MIPS is introducing new variants of its O32 ABI which differ in their
handling of floating point, in order to enable a gradual transition
towards a world where mips32 binaries can take advantage of new hardware
features only available when configured for certain FP modes. In order
to do this ELF binaries are being augmented with a new section that
indicates, amongst other things, the FP mode requirements of the binary.
The presence & location of such a section is indicated by a program
header in the PT_LOPROC ... PT_HIPROC range.

In order to allow the MIPS architecture code to examine the program
header & section in question, pass all program headers in this range
to an architecture-specific arch_elf_pt_proc function. This function
may return an error if the header is deemed invalid or unsuitable for
the system, in which case that error will be returned from
load_elf_binary and upwards through the execve syscall.

A means is required for the architecture code to make a decision once
it is known that all such headers have been seen, but before it is too
late to return from an execve syscall. For this purpose the
arch_check_elf function is added, and called once, after all PT_LOPROC
to PT_HIPROC headers have been passed to arch_elf_pt_proc but before
the code which invoked execve has been lost. This enables the
architecture code to make a decision based upon all the headers present
in an ELF binary and its interpreter, as is required to forbid
conflicting FP ABI requirements between an ELF & its interpreter.

In order to allow data to be stored throughout the calls to the above
functions, struct arch_elf_state is introduced.

Finally a variant of the SET_PERSONALITY macro is introduced which
accepts a pointer to the struct arch_elf_state, allowing it to act
based upon state observed from the architecture specific program
headers.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7679/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Load the program headers of an ELF interpreter early enough in
load_elf_binary that they can be examined before it's too late to return
an error from an exec syscall. This patch does not perform any such
checking, it merely lays the groundwork for a further patch to do so.

No functional change is intended.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7675/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

load_elf_binary & load_elf_interp both load program headers from an ELF
executable in the same way, duplicating the code. This patch introduces
a helper function (load_elf_phdrs) which performs this common task &
calls it from both load_elf_binary & load_elf_interp. In addition to
reducing code duplication, this is part of preparing to load the ELF
interpreter headers earlier such that they can be examined before it's
too late to return an error from an exec syscall.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7676/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fix coccinelle warnings.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch_vma_name sucks.  It's a silly hack, and it's annoying to
implement correctly.  In fact, AFAICS, even the straightforward x86
implementation is incorrect (I suspect that it breaks if the vdso
mapping is split or gets remapped).

This adds a new vm_ops->name operation that can replace it.  The
followup patches will remove all uses of arch_vma_name on x86,
fixing a couple of annoyances in the process.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2eee21791bb36a0a408c5c2bdb382a9e6a41ca4a.1400538962.git.luto@amacapital.netSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

load_elf_binary() sets current->mm->def_flags = def_flags and def_flags
is always zero.  Not only this looks strange, this is unnecessary
because mm_init() has already set ->def_flags = 0.
Signed-off-by: NAlex Thorlton <athorlton@sgi.com>
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

uselib hasn't been used since libc5; glibc does not use it.  Support
turning it off.

When disabled, also omit the load_elf_library implementation from
binfmt_elf.c, which only uselib invokes.

bloat-o-meter:
add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785)
function                                     old     new   delta
padzero                                       39      36      -3
uselib_flags                                  20       -     -20
sys_uselib                                   168       -    -168
SyS_uselib                                   168       -    -168
load_elf_library                             426       -    -426

The new CONFIG_USELIB defaults to `y'.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These two defines are unused since the removal of the a.out interpreter
support in the ELF loader in kernel 2.6.25
Signed-off-by: NTodor Minchev <todor@minchev.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

we can't get to do_coredump() if that condition isn't satisfied...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dump_skip to given alignment...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dump_write() analog, takes core_dump_params instead of file,
keeps track of the amount written in cprm->written and checks for
cprm->limit.  Start using it in binfmt_elf.c...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A high setting of max_map_count, and a process core-dumping with a large
enough vm_map_count could result in an NT_FILE note not being written,
and the kernel crashing immediately later because it has assumed
otherwise.

Reproduction of the oops-causing bug described here:

    https://lkml.org/lkml/2013/8/30/50

Rge ussue originated in commit 2aa362c4 ("coredump: extend core dump
note section to contain file names of mapped file") from Oct 4, 2012.

This patch make that section optional in that case.  fill_files_note()
should signify the error, and also let the info struct in
elf_core_dump() be zero-initialized so that we can check for the
optionally written note.

[akpm@linux-foundation.org: avoid abusing E2BIG, remove a couple of not-really-needed local variables]
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: NDan Aloni <alonid@stratoscale.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Reported-by: NMartin MOKREJS <mmokrejs@gmail.com>
Tested-by: NMartin MOKREJS <mmokrejs@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.
Signed-off-by: NMichel Lespinasse <walken@google.com>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cleanup.  Every linux_binfmt->core_dump() sets PF_DUMPCORE, move this into
zap_threads() called by do_coredump().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NMandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The comment I originally added in commit a3defbe5 ("binfmt_elf: fix
PIE execution with randomization disabled") is not really 100% accurate
-- sysctl is not the only way how PF_RANDOMIZE could be forcibly unset
in runtime.

Another option of course is direct modification of personality flags
(i.e.  running through setarch wrapper).

Make the comment more explicit and accurate.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are currently out of free bits in AT_HWCAP. With POWER8, we have
several hardware features that we need to advertise.

Tested on POWER and x86.
Signed-off-by: NMichael Neuling <michael@neuling.org>
Signed-off-by: NNishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Documentation/filesystems/proc.txt says about coredump_filter bitmask,

  Note bit 0-4 doesn't effect any hugetlb memory. hugetlb memory are only
  effected by bit 5-6.

However current code can go into the subsequent flag checks of bit 0-4
for vma(VM_HUGETLB). So this patch inserts 'return' and makes it work
as written in the document.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Reviewed-by: NHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>	[3.7+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The commit "binfmt_elf: cleanups"
(f670d0ec) removed an ifndef elf_map but
this breaks compilation for metag which does define elf_map.

This adds the ifndef back in as it was before, but does not affect the
other cleanups made by that patch.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Acked-by: NMikael Pettersson <mikpe@it.uu.se>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In fill_elf_header(), elf->e_ident[EI_OSABI] is always set to ELF_OSABI,
so remove the unused argument 'osabi'.
Signed-off-by: NZhang Yanfei <zhangyanfei@cn.fujitsu.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>

This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

If elf_core_dump() is called and fill_note_info() fails in the kmalloc()
then it returns 0 but has not yet initialised all the needed fields.  As a
result we do a kfree(randomness) after correctly skipping the thread data.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:

 | effect                 | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump      | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock           | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP

This patch removes reserved_vm counter from mm_struct.  Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.

Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.

remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.

[akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename VM_NODUMP into VM_DONTDUMP: this name matches other negative flags:
VM_DONTEXPAND, VM_DONTCOPY.  Currently this flag used only for
sys_madvise.  The next patch will use it for replacing the outdated flag
VM_RESERVED.

Also forbid madvise(MADV_DODUMP) for special kernel mappings VM_SPECIAL
(VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This note has the following format:

long count     -- how many files are mapped
long page_size -- units for file_ofs
array of [COUNT] elements of
   long start
   long end
   long file_ofs
followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Existing PRSTATUS note contains only si_signo, si_code, si_errno fields
from the siginfo of the signal which caused core to be dumped.

There are tools which try to analyze crashes for possible security
implications, and they want to use, among other data, si_addr field from
the SIGSEGV.

This patch adds a new elf note, NT_SIGINFO, which contains the complete
siginfo_t of the signal which killed the process.
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a preparatory patch for the introduction of NT_SIGINFO elf note.

With this patch we pass "siginfo_t *siginfo" instead of "int signr" to
do_coredump() and put it into coredump_params.  It will be used by the
next patch.  Most changes are simple s/signr/siginfo->si_signo/.
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

load_elf_interp() has interp_map_addr carefully described as
"uninitialized_var" and marked so as to avoid a warning.  However if you
trace the code it is passed into load_elf_interp and then this value is
checked against NULL.

As this return value isn't used this is actually safe but it freaks
various analysis tools that see un-initialized memory addresses being read
before their value is ever defined.

Set it to NULL as a matter of programming good taste if nothing else
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate
memory for info->fields, it frees already allocated stuff and returns
error to its caller, fill_note_info.  Which in turn returns error to its
caller, elf_core_dump.  Which jumps to cleanup label and calls
free_note_info, which will happily try to free all info->fields again.
BOOM.

This is the fix.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Cc: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>