linux-stable.git/arch/sparc/kernel, branch linux-3.16.y

jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}

2019-05-22T22:15:03+00:00

commit 76b235c6bcb16062d663e2ee96db0b69f2e6bc14 upstream.

Since we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.

This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.

This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()")

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

sparc32: Fix inverted invalid_frame_pointer checks on sigreturns

2019-02-11T17:53:16+00:00

commit 07b5ab3f71d318e52c18cc3b73c1d44c908aacfa upstream.

Signed-off-by: Andreas Larsson 
Signed-off-by: David S. Miller 
Cc: Guenter Roeck 
Signed-off-by: Ben Hutchings

sparc64: Fix return from trap window fill crashes.

2017-10-12T14:28:14+00:00

[ Upstream commit 7cafc0b8bf130f038b0ec2dcdd6a9de6dc59b65a ]

We must handle data access exception as well as memory address unaligned
exceptions from return from trap window fill faults, not just normal
TLB misses.

Otherwise we can get an OOPS that looks like this:

ld-linux.so.2(36808): Kernel bad sw trap 5 [#1]
CPU: 1 PID: 36808 Comm: ld-linux.so.2 Not tainted 4.6.0 #34
task: fff8000303be5c60 ti: fff8000301344000 task.ti: fff8000301344000
TSTATE: 0000004410001601 TPC: 0000000000a1a784 TNPC: 0000000000a1a788 Y: 00000002    Not tainted
TPC: 
g0: fff8000024fc8248 g1: 0000000000db04dc g2: 0000000000000000 g3: 0000000000000001
g4: fff8000303be5c60 g5: fff800030e672000 g6: fff8000301344000 g7: 0000000000000001
o0: 0000000000b95ee8 o1: 000000000000012b o2: 0000000000000000 o3: 0000000200b9b358
o4: 0000000000000000 o5: fff8000301344040 sp: fff80003013475c1 ret_pc: 0000000000a1a77c
RPC: 
l0: 00000000000007ff l1: 0000000000000000 l2: 000000000000005f l3: 0000000000000000
l4: fff8000301347e98 l5: fff8000024ff3060 l6: 0000000000000000 l7: 0000000000000000
i0: fff8000301347f60 i1: 0000000000102400 i2: 0000000000000000 i3: 0000000000000000
i4: 0000000000000000 i5: 0000000000000000 i6: fff80003013476a1 i7: 0000000000404d4c
I7: 
Call Trace:
 [0000000000404d4c] user_rtt_fill_fixup+0x6c/0x7c

The window trap handlers are slightly clever, the trap table entries for them are
composed of two pieces of code.  First comes the code that actually performs
the window fill or spill trap handling, and then there are three instructions at
the end which are for exception processing.

The userland register window fill handler is:

	add	%sp, STACK_BIAS + 0x00, %g1;		\
	ldxa	[%g1 + %g0] ASI, %l0;			\
	mov	0x08, %g2;				\
	mov	0x10, %g3;				\
	ldxa	[%g1 + %g2] ASI, %l1;			\
	mov	0x18, %g5;				\
	ldxa	[%g1 + %g3] ASI, %l2;			\
	ldxa	[%g1 + %g5] ASI, %l3;			\
	add	%g1, 0x20, %g1;				\
	ldxa	[%g1 + %g0] ASI, %l4;			\
	ldxa	[%g1 + %g2] ASI, %l5;			\
	ldxa	[%g1 + %g3] ASI, %l6;			\
	ldxa	[%g1 + %g5] ASI, %l7;			\
	add	%g1, 0x20, %g1;				\
	ldxa	[%g1 + %g0] ASI, %i0;			\
	ldxa	[%g1 + %g2] ASI, %i1;			\
	ldxa	[%g1 + %g3] ASI, %i2;			\
	ldxa	[%g1 + %g5] ASI, %i3;			\
	add	%g1, 0x20, %g1;				\
	ldxa	[%g1 + %g0] ASI, %i4;			\
	ldxa	[%g1 + %g2] ASI, %i5;			\
	ldxa	[%g1 + %g3] ASI, %i6;			\
	ldxa	[%g1 + %g5] ASI, %i7;			\
	restored;					\
	retry; nop; nop; nop; nop;			\
	b,a,pt	%xcc, fill_fixup_dax;			\
	b,a,pt	%xcc, fill_fixup_mna;			\
	b,a,pt	%xcc, fill_fixup;

And the way this works is that if any of those memory accesses
generate an exception, the exception handler can revector to one of
those final three branch instructions depending upon which kind of
exception the memory access took.  In this way, the fault handler
doesn't have to know if it was a spill or a fill that it's handling
the fault for.  It just always branches to the last instruction in
the parent trap's handler.

For example, for a regular fault, the code goes:

winfix_trampoline:
	rdpr	%tpc, %g3
	or	%g3, 0x7c, %g3
	wrpr	%g3, %tnpc
	done

All window trap handlers are 0x80 aligned, so if we "or" 0x7c into the
trap time program counter, we'll get that final instruction in the
trap handler.

On return from trap, we have to pull the register window in but we do
this by hand instead of just executing a "restore" instruction for
several reasons.  The largest being that from Niagara and onward we
simply don't have enough levels in the trap stack to fully resolve all
possible exception cases of a window fault when we are already at
trap level 1 (which we enter to get ready to return from the original
trap).

This is executed inline via the FILL_*_RTRAP handlers.  rtrap_64.S's
code branches directly to these to do the window fill by hand if
necessary.  Now if you look at them, we'll see at the end:

	    ba,a,pt    %xcc, user_rtt_fill_fixup;
	    ba,a,pt    %xcc, user_rtt_fill_fixup;
	    ba,a,pt    %xcc, user_rtt_fill_fixup;

And oops, all three cases are handled like a fault.

This doesn't work because each of these trap types (data access
exception, memory address unaligned, and faults) store their auxiliary
info in different registers to pass on to the C handler which does the
real work.

So in the case where the stack was unaligned, the unaligned trap
handler sets up the arg registers one way, and then we branched to
the fault handler which expects them setup another way.

So the FAULT_TYPE_* value ends up basically being garbage, and
randomly would generate the backtrace seen above.

Reported-by: Nick Alcock 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

sparc: Harden signal return frame checks.

2017-10-12T14:28:13+00:00

[ Upstream commit d11c2a0de2824395656cf8ed15811580c9dd38aa ]

All signal frames must be at least 16-byte aligned, because that is
the alignment we explicitly create when we build signal return stack
frames.

All stack pointers must be at least 8-byte aligned.

Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

sparc/PCI: Fix for panic while enabling SR-IOV

2017-10-12T14:28:13+00:00

[ Upstream commit d0c31e02005764dae0aab130a57e9794d06b824d ]

We noticed this panic while enabling SR-IOV in sparc.

mlx4_core: Mellanox ConnectX core driver v2.2-1 (Jan  1 2015)
mlx4_core: Initializing 0007:01:00.0
mlx4_core 0007:01:00.0: Enabling SR-IOV with 5 VFs
mlx4_core: Initializing 0007:01:00.1
Unable to handle kernel NULL pointer dereference
insmod(10010): Oops [#1]
CPU: 391 PID: 10010 Comm: insmod Not tainted
		4.1.12-32.el6uek.kdump2.sparc64 #1
TPC: 
I7: <__mlx4_init_one+0x324/0x500 [mlx4_core]>
Call Trace:
 [00000000104c5ea4] __mlx4_init_one+0x324/0x500 [mlx4_core]
 [00000000104c613c] mlx4_init_one+0xbc/0x120 [mlx4_core]
 [0000000000725f14] local_pci_probe+0x34/0xa0
 [0000000000726028] pci_call_probe+0xa8/0xe0
 [0000000000726310] pci_device_probe+0x50/0x80
 [000000000079f700] really_probe+0x140/0x420
 [000000000079fa24] driver_probe_device+0x44/0xa0
 [000000000079fb5c] __device_attach+0x3c/0x60
 [000000000079d85c] bus_for_each_drv+0x5c/0xa0
 [000000000079f588] device_attach+0x88/0xc0
 [000000000071acd0] pci_bus_add_device+0x30/0x80
 [0000000000736090] virtfn_add.clone.1+0x210/0x360
 [00000000007364a4] sriov_enable+0x2c4/0x520
 [000000000073672c] pci_enable_sriov+0x2c/0x40
 [00000000104c2d58] mlx4_enable_sriov+0xf8/0x180 [mlx4_core]
 [00000000104c49ac] mlx4_load_one+0x42c/0xd40 [mlx4_core]
Disabling lock debugging due to kernel taint
Caller[00000000104c5ea4]: __mlx4_init_one+0x324/0x500 [mlx4_core]
Caller[00000000104c613c]: mlx4_init_one+0xbc/0x120 [mlx4_core]
Caller[0000000000725f14]: local_pci_probe+0x34/0xa0
Caller[0000000000726028]: pci_call_probe+0xa8/0xe0
Caller[0000000000726310]: pci_device_probe+0x50/0x80
Caller[000000000079f700]: really_probe+0x140/0x420
Caller[000000000079fa24]: driver_probe_device+0x44/0xa0
Caller[000000000079fb5c]: __device_attach+0x3c/0x60
Caller[000000000079d85c]: bus_for_each_drv+0x5c/0xa0
Caller[000000000079f588]: device_attach+0x88/0xc0
Caller[000000000071acd0]: pci_bus_add_device+0x30/0x80
Caller[0000000000736090]: virtfn_add.clone.1+0x210/0x360
Caller[00000000007364a4]: sriov_enable+0x2c4/0x520
Caller[000000000073672c]: pci_enable_sriov+0x2c/0x40
Caller[00000000104c2d58]: mlx4_enable_sriov+0xf8/0x180 [mlx4_core]
Caller[00000000104c49ac]: mlx4_load_one+0x42c/0xd40 [mlx4_core]
Caller[00000000104c5f90]: __mlx4_init_one+0x410/0x500 [mlx4_core]
Caller[00000000104c613c]: mlx4_init_one+0xbc/0x120 [mlx4_core]
Caller[0000000000725f14]: local_pci_probe+0x34/0xa0
Caller[0000000000726028]: pci_call_probe+0xa8/0xe0
Caller[0000000000726310]: pci_device_probe+0x50/0x80
Caller[000000000079f700]: really_probe+0x140/0x420
Caller[000000000079fa24]: driver_probe_device+0x44/0xa0
Caller[000000000079fb08]: __driver_attach+0x88/0xa0
Caller[000000000079d90c]: bus_for_each_dev+0x6c/0xa0
Caller[000000000079f29c]: driver_attach+0x1c/0x40
Caller[000000000079e35c]: bus_add_driver+0x17c/0x220
Caller[00000000007a02d4]: driver_register+0x74/0x120
Caller[00000000007263fc]: __pci_register_driver+0x3c/0x60
Caller[00000000104f62bc]: mlx4_init+0x60/0xcc [mlx4_core]
Kernel panic - not syncing: Fatal exception
Press Stop-A (L1-A) to return to the boot prom
---[ end Kernel panic - not syncing: Fatal exception

Details:
Here is the call sequence
virtfn_add->__mlx4_init_one->dma_set_mask->dma_supported

The panic happened at line 760(file arch/sparc/kernel/iommu.c)

758 int dma_supported(struct device *dev, u64 device_mask)
759 {
760         struct iommu *iommu = dev->archdata.iommu;
761         u64 dma_addr_mask = iommu->dma_addr_mask;
762
763         if (device_mask >= (1UL << 32UL))
764                 return 0;
765
766         if ((device_mask & dma_addr_mask) == dma_addr_mask)
767                 return 1;
768
769 #ifdef CONFIG_PCI
770         if (dev_is_pci(dev))
771		return pci64_dma_supported(to_pci_dev(dev), device_mask);
772 #endif
773
774         return 0;
775 }
776 EXPORT_SYMBOL(dma_supported);

Same panic happened with Intel ixgbe driver also.

SR-IOV code looks for arch specific data while enabling
VFs. When VF device is added, driver probe function makes set
of calls to initialize the pci device. Because the VF device is
added different way than the normal PF device(which happens via
of_create_pci_dev for sparc), some of the arch specific initialization
does not happen for VF device.  That causes panic when archdata is
accessed.

To fix this, I have used already defined weak function
pcibios_setup_device to copy archdata from PF to VF.
Also verified the fix.

Signed-off-by: Babu Moger 
Signed-off-by: Sowmini Varadhan 
Reviewed-by: Ethan Zhao 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

sparc64: Fix sparc64_set_context stack handling.

2017-10-12T14:28:13+00:00

[ Upstream commit 397d1533b6cce0ccb5379542e2e6d079f6936c46 ]

Like a signal return, we should use synchronize_user_stack() rather
than flush_user_windows().

Reported-by: Ilya Malakhov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

sparc64: Fix bootup regressions on some Kconfig combinations.

2017-10-12T14:28:13+00:00

[ Upstream commit 49fa5230462f9f2c4e97c81356473a6bdf06c422 ]

The system call tracing bug fix mentioned in the Fixes tag
below increased the amount of assembler code in the sequence
of assembler files included by head_64.S

This caused to total set of code to exceed 0x4000 bytes in
size, which overflows the expression in head_64.S that works
to place swapper_tsb at address 0x408000.

When this is violated, the TSB is not properly aligned, and
also the trap table is not aligned properly either.  All of
this together results in failed boots.

So, do two things:

1) Simplify some code by using ba,a instead of ba/nop to get
   those bytes back.

2) Add a linker script assertion to make sure that if this
   happens again the build will fail.

Fixes: 1a40b95374f6 ("sparc: Fix system call tracing register handling.")
Reported-by: Meelis Roos 
Reported-by: Joerg Abraham 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

sparc: Fix system call tracing register handling.

2017-10-12T14:28:12+00:00

[ Upstream commit 1a40b95374f680625318ab61d81958e949e0afe3 ]

A system call trace trigger on entry allows the tracing
process to inspect and potentially change the traced
process's registers.

Account for that by reloading the %g1 (syscall number)
and %i0-%i5 (syscall argument) values.  We need to be
careful to revalidate the range of %g1, and reload the
system call table entry it corresponds to into %l7.

Reported-by: Mike Frysinger 
Signed-off-by: David S. Miller 
Tested-by: Mike Frysinger 
Signed-off-by: Ben Hutchings

mm: larger stack guard gap, between vmas

2017-07-02T16:13:02+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 
[Hugh Dickins: Backported to 3.16]
Signed-off-by: Ben Hutchings

sparc: leon: Fix a retry loop in leon_init_timers()

2017-03-16T02:26:34+00:00

commit 601e6e3cc5bf6adb7d076fe24d10f6191a25ba9b upstream.

The original code causes a static checker warning because it has a
continue inside a do { } while (0); loop.  In that context, a continue
and a break are equivalent.  The intent was to go back to the start of
the loop so the continue was a bug.

I've added a retry label at the start and changed the continue to a goto
retry.  Then I removed the do { } while (0) loop and pulled the code in
one indent level.

Fixes: 2791c1a43900 ("SPARC/LEON: added support for selecting Timer Core and Timer within core")
Signed-off-by: Dan Carpenter 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings