linux-stable.git/arch/parisc/include, branch linux-4.1.y

parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel

2018-03-01T00:32:20+00:00

[ Upstream commit 88776c0e70be0290f8357019d844aae15edaa967 ]

Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."

Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.

As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.

This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.

Signed-off-by: Helge Deller 
Cc:  # v4.0+
Signed-off-by: Sasha Levin

parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs

2017-07-31T17:37:54+00:00

[ Upstream commit 33f9e02495d15a061f0c94ef46f5103a2d0c20f3 ]

Enabling parport pc driver on a B2600 (and probably other 64bit PARISC
systems) produced following BUG:

CPU: 0 PID: 1 Comm: swapper Not tainted 4.12.0-rc5-30198-g1132d5e #156
task: 000000009e050000 task.stack: 000000009e04c000

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001101111111100001111 Not tainted
r00-03  000000ff0806ff0f 000000009e04c990 0000000040871b78 000000009e04cac0
r04-07  0000000040c14de0 ffffffffffffffff 000000009e07f098 000000009d82d200
r08-11  000000009d82d210 0000000000000378 0000000000000000 0000000040c345e0
r12-15  0000000000000005 0000000040c345e0 0000000000000000 0000000040c9d5e0
r16-19  0000000040c345e0 00000000f00001c4 00000000f00001bc 0000000000000061
r20-23  000000009e04ce28 0000000000000010 0000000000000010 0000000040b89e40
r24-27  0000000000000003 0000000000ffffff 000000009d82d210 0000000040c14de0
r28-31  0000000000000000 000000009e04ca90 000000009e04cb40 0000000000000000
sr00-03  0000000000000000 0000000000000000 0000000000000000 0000000000000000
sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000404aece0 00000000404aece4
 IIR: 03ffe01f    ISR: 0000000010340000  IOR: 000001781304cac8
 CPU:        0   CR30: 000000009e04c000 CR31: 00000000e2976de2
 ORIG_R28: 0000000000000200
 IAOQ[0]: sba_dma_supported+0x80/0xd0
 IAOQ[1]: sba_dma_supported+0x84/0xd0
 RP(r2): parport_pc_probe_port+0x178/0x1200

Cause is a call to dma_coerce_mask_and_coherenet in parport_pc_probe_port,
which PARISC DMA API doesn't handle very nicely. This commit gives back
DMA_ERROR_CODE for DMA API calls, if device isn't capable of DMA
transaction.

Cc:  # v3.13+
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header

2017-03-06T22:31:12+00:00

[ Upstream commit 2ad5d52d42810bed95100a3d912679d8864421ec ]

In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if
BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin.

Solve this problem by using __BITS_PER_LONG instead.  Since we now
#include asm/bitsperlong.h avoid further potential userspace pollution
by moving the #define of SHIFT_PER_LONG to bitops.h which is not
exported to userspace.

This patch unbreaks compiling qemu on hppa/parisc.

Signed-off-by: Helge Deller 
Cc: 
Signed-off-by: Sasha Levin

parisc: fix copy_from_user()

2016-10-03T01:14:04+00:00

[ Upstream commit aace880feea38875fbc919761b77e5732a3659ef ]

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

parisc: Fix order of EREFUSED define in errno.h

2016-08-31T23:21:09+00:00

[ Upstream commit 3eb53b20d7bd1374598cfb1feaa081fcac0e76cd ]

When building gccgo in userspace, errno.h gets parsed and the go include file
sysinfo.go is generated.

Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED
is defined later on in errno.h, this leads to go complaining that EREFUSED
isn't defined yet.

Fix this trivial problem by moving the define of EREFUSED down after
ECONNREFUSED in errno.h (and clean up the indenting while touching this line).

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

parisc: Unbreak handling exceptions from kernel modules

2016-04-20T05:08:54+00:00

[ Upstream commit 2ef4dfd9d9f288943e249b78365a69e3ea3ec072 ]

Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.

When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.

Noticed-by: Mikulas Patocka 
Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

parisc: Fix __ARCH_SI_PREAMBLE_SIZE

2016-02-03T20:31:09+00:00

[ Upstream commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 ]

On a 64bit kernel build the compiler aligns the _sifields union in the
struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define
compensates for this alignment and thus fixes the wait testcase of the
strace package.

The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that
_sigchld.si_stime variable is missed to be copied and thus after a
copy_siginfo() will have uninitialized values.

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

parisc: mm: Fix a memory leak related to pmd not attached to the pgd

2015-08-10T19:21:50+00:00

commit 4c4ac9a48ac512c6b5a6cca06cfad2ad96e8caaa upstream.

Commit 0e0da48dee8d ("parisc: mm: don't count preallocated pmds")
introduced a memory leak.

After this commit, the 'return' statement in pmd_free is executed in all
cases. Even for pmd that are not attached to the pgd.  So 'free_pages'
can never be called anymore, leading to a memory leak.

Signed-off-by: Christophe JAILLET 
Acked-by: Kirill A. Shutemov 
Acked-by: Mikulas Patocka 
Acked-by: Helge Deller 
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results

2015-08-10T19:21:50+00:00

commit 01ab60570427caa24b9debc369e452e86cd9beb4 upstream.

The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):

swap_free: Unused swap offset entry 00000004
BUG: Bad page map in process mysqld pte:00000100 pmd:019bbec5
addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
Backtrace:
[<0000000040173eb0>] show_stack+0x20/0x38
[<0000000040444424>] dump_stack+0x9c/0x110
[<00000000402a0d38>] print_bad_pte+0x1a8/0x278
[<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
[<00000000402a4090>] zap_page_range+0xf0/0x198
[<00000000402ba2a4>] SyS_madvise+0x404/0x8c0

Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.

It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.

In looking at the kernel code, I found the following problems:

1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.

The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.

I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.

Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.

Signed-off-by: John David Anglin
Signed-off-by: Helge Deller
Signed-off-by: Greg Kroah-Hartman

parisc,metag: Fix crashes due to stack randomization on stack-grows-upwards architectures

2015-05-12T20:03:44+00:00

On architectures where the stack grows upwards (CONFIG_STACK_GROWSUP=y,
currently parisc and metag only) stack randomization sometimes leads to crashes
when the stack ulimit is set to lower values than STACK_RND_MASK (which is 8 MB
by default if not defined in arch-specific headers).

The problem is, that when the stack vm_area_struct is set up in fs/exec.c, the
additional space needed for the stack randomization (as defined by the value of
STACK_RND_MASK) was not taken into account yet and as such, when the stack
randomization code added a random offset to the stack start, the stack
effectively got smaller than what the user defined via rlimit_max(RLIMIT_STACK)
which then sometimes leads to out-of-stack situations and crashes.

This patch fixes it by adding the maximum possible amount of memory (based on
STACK_RND_MASK) which theoretically could be added by the stack randomization
code to the initial stack size. That way, the user-defined stack size is always
guaranteed to be at minimum what is defined via rlimit_max(RLIMIT_STACK).

This bug is currently not visible on the metag architecture, because on metag
STACK_RND_MASK is defined to 0 which effectively disables stack randomization.

The changes to fs/exec.c are inside an "#ifdef CONFIG_STACK_GROWSUP"
section, so it does not affect other platformws beside those where the
stack grows upwards (parisc and metag).

Signed-off-by: Helge Deller 
Cc: linux-parisc@vger.kernel.org
Cc: James Hogan 
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org # v3.16+