linux-toradex.git/arch/sparc, branch v4.4.136

sparc64: Fix build warnings with gcc 7.

2018-06-06T14:46:23+00:00

commit 0fde7ad71ee371ede73b3f326e58f9e8d102feb6 upstream.

arch/sparc/kernel/ds.c: In function ‘register_services’:
arch/sparc/kernel/ds.c:912:3: error: ‘strcpy’: writing at least 1 byte
into a region of size 0 overflows the destination

Reported-by: Anatoly Pugachev 
Signed-off-by: David S. Miller 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

sparc64: Make atomic_xchg() an inline function rather than a macro.

2018-05-30T05:49:08+00:00

[ Upstream commit d13864b68e41c11e4231de90cf358658f6ecea45 ]

This avoids a lot of -Wunused warnings such as:

====================
kernel/debug/debug_core.c: In function ‘kgdb_cpu_enter’:
./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value]
 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

./arch/sparc/include/asm/atomic_64.h:86:30: note: in expansion of macro ‘xchg’
 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
                              ^~~~
kernel/debug/debug_core.c:508:4: note: in expansion of macro ‘atomic_xchg’
    atomic_xchg(&kgdb_active, cpu);
    ^~~~~~~~~~~
====================

Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50+00:00

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby 
Signed-off-by: Thomas Gleixner 
Acked-by: Russell King 
Acked-by: Michael Ellerman  (powerpc)
Acked-by: Heiko Carstens  [s390]
Acked-by: Chris Metcalf  [for tile]
Reviewed-by: Darren Hart (VMware) 
Reviewed-by: Will Deacon  [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker 
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt 
Cc: Max Filippov 
Cc: Paul Mackerras 
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn 
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato 
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Catalin Marinas 
Cc: Matt Turner 
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu 
Cc: Arnd Bergmann 
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson 
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky 
Cc: Stafford Horne 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson 
Cc: Chris Zankel 
Cc: Michal Simek 
Cc: Tony Luck 
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta 
Cc: Ralf Baechle 
Cc: Richard Kuo 
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" 
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

sparc64: ldc abort during vds iso boot

2018-04-13T17:50:20+00:00

[ Upstream commit 6c95483b768c62f8ee933ae08a1bdbcb78b5410f ]

Orabug: 20902628

When an ldc control-only packet is received during data exchange in
read_nonraw(), a new rx head is calculated but the rx queue head is not
actually advanced (rx_set_head() is not called) and a branch is taken to
'no_data' at which point two things can happen depending on the value
of the newly calculated rx head and the current rx tail:

- If the rx queue is determined to be not empty, then the wrong packet
  is picked up.

- If the rx queue is determined to be empty, then a read error (EAGAIN)
  is eventually returned since it is falsely assumed that more data was
  expected.

The fix is to update the rx head and return in case of a control only
packet during data exchange.

Signed-off-by: Jagannathan Raman 
Reviewed-by: Aaron Young 
Reviewed-by: Alexandre Chartre 
Reviewed-by: Bijan Mottahedeh 
Reviewed-by: Liam Merwick 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sparc64/mm: set fields in deferred pages

2017-12-16T09:33:55+00:00

[ Upstream commit 2a20aa171071a334d80c4e5d5af719d8374702fc ]

Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().

With deferred struct page feature enabled there is a case where we set
some fields prior to initializing:

mem_init() {
     register_page_bootmem_info();
     free_all_bootmem();
     ...
}

When register_page_bootmem_info() is called only non-deferred struct
pages are initialized.  But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.

mem_init
register_page_bootmem_info
register_page_bootmem_info_node
 get_page_bootmem
  .. setting fields here ..
  such as: page->freelist = (void *)type;

free_all_bootmem()
free_low_memory_core_early()
 for_each_reserved_mem_region()
  reserve_bootmem_region()
   init_reserved_page() <- Only if this is deferred reserved page
    __init_single_pfn()
     __init_single_page()
      memset(0) <-- Loose the set fields here

We end up with similar issue as in the previous patch, where currently
we do not observe problem as memory is zeroed.  But, if flag asserts are
changed we can start hitting issues.

Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.

The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.

Link: http://lkml.kernel.org/r/20171013173214.27300-4-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin 
Reviewed-by: Steven Sistare 
Reviewed-by: Daniel Jordan 
Reviewed-by: Bob Picco 
Acked-by: David S. Miller 
Acked-by: Michal Hocko 
Cc: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Ard Biesheuvel 
Cc: Catalin Marinas 
Cc: Christian Borntraeger 
Cc: Dmitry Vyukov 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Matthew Wilcox 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Sam Ravnborg 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

security/keys: add CONFIG_KEYS_COMPAT to Kconfig

2017-11-18T10:11:07+00:00

commit 47b2c3fff4932e6fc17ce13d51a43c6969714e20 upstream.

CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.

At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.

This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.

[DH: Modified to remove arm64 compat enablement also as requested by Eric
 Biggers]

Signed-off-by: Bilal Amarni 
Signed-off-by: David Howells 
Reviewed-by: Arnd Bergmann 
cc: Eric Biggers 
Signed-off-by: James Morris 
Cc: James Cowgill 
Signed-off-by: Greg Kroah-Hartman

sparc64: Migrate hvcons irq to panicked cpu

2017-10-21T15:09:05+00:00

[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]

On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sparc64: Prevent perf from running during super critical sections

2017-08-13T02:29:09+00:00

commit fc290a114fc6034b0f6a5a46e2fb7d54976cf87a upstream.

This fixes another cause of random segfaults and bus errors that may
occur while running perf with the callgraph option.

Critical sections beginning with spin_lock_irqsave() raise the interrupt
level to PIL_NORMAL_MAX (14) and intentionally do not block performance
counter interrupts, which arrive at PIL_NMI (15).

But some sections of code are "super critical" with respect to perf
because the perf_callchain_user() path accesses user space and may cause
TLB activity as well as faults as it unwinds the user stack.

One particular critical section occurs in switch_mm:

        spin_lock_irqsave(&mm->context.lock, flags);
        ...
        load_secondary_context(mm);
        tsb_context_switch(mm);
        ...
        spin_unlock_irqrestore(&mm->context.lock, flags);

If a perf interrupt arrives in between load_secondary_context() and
tsb_context_switch(), then perf_callchain_user() could execute with
the context ID of one process, but with an active TSB for a different
process. When the user stack is accessed, it is very likely to
incur a TLB miss, since the h/w context ID has been changed. The TLB
will then be reloaded with a translation from the TSB for one process,
but using a context ID for another process. This exposes memory from
one process to another, and since it is a mapping for stack memory,
this usually causes the new process to crash quickly.

This super critical section needs more protection than is provided
by spin_lock_irqsave() since perf interrupts must not be allowed in.

Since __tsb_context_switch already goes through the trouble of
disabling interrupts completely, we fix this by moving the secondary
context load down into this better protected region.

Orabug: 25577560

Signed-off-by: Dave Aldridge 
Signed-off-by: Rob Gardner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sparc64: Measure receiver forward progress to avoid send mondo timeout

2017-08-11T16:08:56+00:00

[ Upstream commit 9d53caec84c7c5700e7c1ed744ea584fff55f9ac ]

A large sun4v SPARC system may have moments of intensive xcall activities,
usually caused by unmapping many pages on many CPUs concurrently. This can
flood receivers with CPU mondo interrupts for an extended period, causing
some unlucky senders to hit send-mondo timeout. This problem gets worse
as cpu count increases because sometimes mappings must be invalidated on
all CPUs, and sometimes all CPUs may gang up on a single CPU.

But a busy system is not a broken system. In the above scenario, as long
as the receiver is making forward progress processing mondo interrupts,
the sender should continue to retry.

This patch implements the receiver's forward progress meter by introducing
a per cpu counter 'cpu_mondo_counter[cpu]' where 'cpu' is in the range
of 0..NR_CPUS. The receiver increments its counter as soon as it receives
a mondo and the sender tracks the receiver's counter. If the receiver has
stopped making forward progress when the retry limit is reached, the sender
declares send-mondo-timeout and panic; otherwise, the receiver is allowed
to keep making forward progress.

In addition, it's been observed that PCIe hotplug events generate Correctable
Errors that are handled by hypervisor and then OS. Hypervisor 'borrows'
a guest cpu strand briefly to provide the service. If the cpu strand is
simultaneously the only cpu targeted by a mondo, it may not be available
for the mondo in 20msec, causing SUN4V mondo timeout. It appears that 1 second
is the agreed wait time between hypervisor and guest OS, this patch makes
the adjustment.

Orabug: 25476541
Orabug: 26417466

Signed-off-by: Jane Chu 
Reviewed-by: Steve Sistare 
Reviewed-by: Anthony Yznaga 
Reviewed-by: Rob Gardner 
Reviewed-by: Thomas Tai 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

mm: larger stack guard gap, between vmas

2017-06-26T05:13:11+00:00

commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov 
Original-patch-by: Michal Hocko 
Signed-off-by: Hugh Dickins 
Acked-by: Michal Hocko 
Tested-by: Helge Deller  # parisc
Signed-off-by: Linus Torvalds 
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes]
Signed-off-by: Willy Tarreau 
[gkh: minor build fixes for 4.4]
Signed-off-by: Greg Kroah-Hartman