ARM: Blacklist GCC 4.8.0 to GCC 4.8.2 - PR58854

These stock GCC versions miscompile the kernel by incorrectly optimising
the function epilogue code - by first increasing the stack pointer, and
then loading entries from below the stack.  This means that an opportune
interrupt or exception will corrupt the current function's saved state,
which may result in the parent function seeing different register
values.

As this bug has been known to result in corrupted filesystems, and these
buggy compiler versions seem to be frequently used, we have little
option but to blacklist these compiler versions.

Distributions may have fixed PR58854, but as their compilers are totally
indistinguishable from the buggy versions, it is unfortunate that this
also results in those also being blacklisted.  Given the filesystem
corruption potential of the original, this is the lesser evil.  People
who want to build with their fixed compiler versions will need to adjust
the kernel source.  (Distros need to think about the implications of
fixing such a compiler bug, and consider how to ensure that their fixed
compiler versions can be detected if they wish to avoid this.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
nfsd4: fix response size estimation for OP_SEQUENCE

We added this new estimator function but forgot to hook it up.  The
effect is that NFSv4.1 (and greater) won't do zero-copy reads.

The estimate was also wrong by 8 bytes.

Fixes: ccae70a9ee41 "nfsd4: estimate sequence response size"
Cc: stable@vger.kernel.org
Reported-by: Chuck Lever <chucklever@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
ARM: fix some printk formats

GCC 4.9 complains if we take the difference of two pointers, and it's
printed with "%d".  Fix this by using the proper flag - "t" for
ptrdiff_t.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
nfsd4: fix crash on unknown operation number

Unknown operation numbers are caught in nfsd4_decode_compound() which
sets op->opnum to OP_ILLEGAL and op->status to nfserr_op_illegal.  The
error causes the main loop in nfsd4_proc_compound() to skip most
processing.  But nfsd4_proc_compound also peeks ahead at the next
operation in one case and doesn't take similar precautions there.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
ftrace: Set ops->old_hash on modifying what an ops hooks to

The code that checks for trampolines when modifying function hooks
tests against a modified ops "old_hash". But the ops old_hash pointer
is not being updated before the changes are made, making it possible
to not find the right hash to the callback and possibly causing
ftrace to break in accounting and disable itself.

Have the ops set its old_hash before the modifying takes place.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace: Fix checking of trampoline ftrace_ops in finding trampoline

When modifying code, ftrace has several checks to make sure things
are being done correctly. One of them is to make sure any code it
modifies is exactly what it expects it to be before it modifies it.
In order to do so with the new trampoline logic, it must be able
to find out what trampoline a function is hooked to in order to
see if the code that hooks to it is what's expected.

The logic to find the trampoline from a record (accounting descriptor
for a function that is hooked) needs to only look at the "old_hash"
of an ops that is being modified. The old_hash is the list of function
an ops is hooked to before its update. Since a record would only be
pointing to an ops that is being modified if it was already hooked
before.

Currently, it can pick a modified ops based on its new functions it
will be hooked to, and this picks the wrong trampoline and causes
the check to fail, disabling ftrace.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

ftrace: squash into ordering of ops for modification
zap_pte_range: update addr when forcing flush after TLB batching faiure

When unmapping a range of pages in zap_pte_range, the page being
unmapped is added to an mmu_gather_batch structure for asynchronous
freeing. If we run out of space in the batch structure before the range
has been completely unmapped, then we break out of the loop, force a
TLB flush and free the pages that we have batched so far. If there are
further pages to unmap, then we resume the loop where we left off.

Unfortunately, we forget to update addr when we break out of the loop,
which causes us to truncate the range being invalidated as the end
address is exclusive. When we re-enter the loop at the same address, the
page has already been freed and the pte_present test will fail, meaning
that we do not reconsider the address for invalidation.

This patch fixes the problem by incrementing addr by the PAGE_SIZE
before breaking out of the loop on batch failure.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
 "A couple of ARM fixes.

  We fix some printk formats for ptrdiff_t quantities which cause GCC
  4.9 to complain, and we also blacklist known buggy GCC 4.8.x compilers
  as their miscompilation is serious enough to cause filesystem
  corruption, even through many distros have fixed their versions"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: fix some printk formats
  ARM: Blacklist GCC 4.8.0 to GCC 4.8.2 - PR58854
Merge tag 'trace-fixes-v3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace trampoline accounting fixes from Steven Rostedt:
 "Adding the new code for 3.19, I discovered a couple of minor bugs with
  the accounting of the ftrace_ops trampoline logic.

  One was that the old hash was not updated before calling the modify
  code for an ftrace_ops.  The second bug was what let the first bug go
  unnoticed, as the update would check the current hash for all
  ftrace_ops (where it should only check the old hash for modified
  ones).  This let things work when only one ftrace_ops was registered
  to a function, but could break if more than one was registered
  depending on the order of the look ups.

  The worse thing that can happen if this bug triggers is that the
  ftrace self checks would find an anomaly and shut itself down"

* tag 'trace-fixes-v3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix checking of trampoline ftrace_ops in finding trampoline
  ftrace: Set ops->old_hash on modifying what an ops hooks to
Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux

Pull two nfsd fixes from Bruce Fields:
 "One regression from the 3.16 xdr rewrite, one an older bug exposed by
  a separate bug in the client's new SEEK code"

* 'for-3.18' of git://linux-nfs.org/~bfields/linux:
  nfsd4: fix crash on unknown operation number
  nfsd4: fix response size estimation for OP_SEQUENCE