Commit Graph

561949 Commits

Author SHA1 Message Date
Vijay Kumar 079317a65d tty/serial: Skip 'NULL' char after console break when sysrq enabled
When sysrq is triggered from console, serial driver for SUN hypervisor
console receives a console break and enables the sysrq. It expects a valid
sysrq char following with break. Meanwhile if driver receives 'NULL'
ASCII char then it disables sysrq and sysrq handler will never be invoked.

This fix skips calling uart sysrq handler when 'NULL' is received while
sysrq is enabled.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Acked-by: Karl Volz <karl.volz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:13:37 -05:00
Rob Gardner a7c5724b5c sparc64: fix FP corruption in user copy functions
Short story: Exception handlers used by some copy_to_user() and
copy_from_user() functions do not diligently clean up floating point
register usage, and this can result in a user process seeing invalid
values in floating point registers. This sometimes makes the process
fail.

Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions
use floating point registers and VIS alignaddr/faligndata to
accelerate data copying when source and dest addresses don't align
well. Linux uses a lazy scheme for saving floating point registers; It
is not done upon entering the kernel since it's a very expensive
operation. Rather, it is done only when needed. If the kernel ends up
not using FP regs during the course of some trap or system call, then
it can return to user space without saving or restoring them.

The various memcpy functions begin their FP code with VISEntry (or a
variation thereof), which saves the FP regs. They conclude their FP
code with VISExit (or a variation) which essentially marks the FP regs
"clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned
off so that a lazy restore will be triggered when/if the user process
accesses floating point regs again.

The bug is that the user copy variants of memcpy, copy_from_user() and
copy_to_user(), employ an exception handling mechanism to detect faults
when accessing user space addresses, and when this handler is invoked,
an immediate return from the function is forced, and VISExit is not
executed, thus leaving the fprs register in an indeterminate state,
but often with fprs.FPRS_FEF set and one or more dirty bits. This
results in a return to user space with invalid values in the FP regs,
and since fprs.FPRS_FEF is on, no lazy restore occurs.

This bug affects copy_to_user() and copy_from_user() for NG4, NG2,
U3, and U1. All are fixed by using a new exception handler for those
loads and stores that are done during the time between VISEnter and
VISExit.

n.b. In NG4memcpy, the problematic code can be triggered by a copy
size greater than 128 bytes and an unaligned source address.  This bug
is known to be the cause of random user process memory corruptions
while perf is running with the callgraph option (ie, perf record -g).
This occurs because perf uses copy_from_user() to read user stacks,
and may fault when it follows a stack frame pointer off to an
invalid page. Validation checks on the stack address just obscure
the underlying problem.

Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:13:18 -05:00
Rob Gardner 833526941f sparc64: Perf should save/restore fault info
There have been several reports of random processes being killed with
a bus error or segfault during userspace stack walking in perf.  One
of the root causes of this problem is an asynchronous modification to
thread_info fault_address and fault_code, which stems from a perf
counter interrupt arriving during kernel processing of a "benign"
fault, such as a TSB miss. Since perf_callchain_user() invokes
copy_from_user() to read user stacks, a fault is not only possible,
but probable. Validity checks on the stack address merely cover up the
problem and reduce its frequency.

The solution here is to save and restore fault_address and fault_code
in perf_callchain_user() so that the benign fault handler is not
disturbed by a perf interrupt.

Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:12:46 -05:00
Rob Gardner 3f74306ac8 sparc64: Ensure perf can access user stacks
When an interrupt (such as a perf counter interrupt) is delivered
while executing in user space, the trap entry code puts ASI_AIUS in
%asi so that copy_from_user() and copy_to_user() will access the
correct memory. But if a perf counter interrupt is delivered while the
cpu is already executing in kernel space, then the trap entry code
will put ASI_P in %asi, and this will prevent copy_from_user() from
reading any useful stack data in either of the perf_callchain_user_X
functions, and thus no user callgraph data will be collected for this
sample period. An additional problem is that a fault is guaranteed
to occur, and though it will be silently covered up, it wastes time
and could perturb state.

In perf_callchain_user(), we ensure that %asi contains ASI_AIUS
because we know for a fact that the subsequent calls to
copy_from_user() are intended to read the user's stack.

[ Use get_fs()/set_fs() -DaveM ]

Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:10:29 -05:00
Rob Gardner 1ca04a4ce0 sparc64: Don't set %pil in rtrap_nmi too early
Commit 28a1f53 delays setting %pil to avoid potential
hardirq stack overflow in the common rtrap_irq path.
Setting %pil also needs to be delayed in the rtrap_nmi
path for the same reason.

Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:07:16 -05:00
Khalid Aziz 82924e542f sparc64: Add ADI capability to cpu capabilities
Add ADI (Application Data Integrity) capability to cpu capabilities list.
ADI capability allows virtual addresses to be encoded with a tag in
bits 63-60. This tag serves as an access control key for the regions
of virtual address with ADI enabled and a key set on them. Hypervisor
encodes this capability as "adp" in "hwcap-list" property in machine
description.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:05:06 -05:00
Aya Mahfouz 01fd3c2744 tty: serial: constify sunhv_ops structs
Constifies sunhv_ops structures in tty's serial
driver since they are not modified after their
initialization.

Detected and found using Coccinelle.

Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:04:18 -05:00
Mike Kravetz 9bcfd78ac0 sparc: Hook up userfaultfd system call
After hooking up system call, userfaultfd selftest was successful for
both 32 and 64 bit version of test.

Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-23 15:41:13 -05:00
Linus Torvalds 73796d8bf2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix uninitialized variable warnings in nfnetlink_queue, a lot of
    people reported this...  From Arnd Bergmann.

 2) Don't init mutex twice in i40e driver, from Jesse Brandeburg.

 3) Fix spurious EBUSY in rhashtable, from Herbert Xu.

 4) Missing DMA unmaps in mvpp2 driver, from Marcin Wojtas.

 5) Fix race with work structure access in pppoe driver causing
    corruptions, from Guillaume Nault.

 6) Fix OOPS due to sh_eth_rx() not checking whether netdev_alloc_skb()
    actually succeeded or not, from Sergei Shtylyov.

 7) Don't lose flags when settifn IFA_F_OPTIMISTIC in ipv6 code, from
    Bjørn Mork.

 8) VXLAN_HD_RCO defined incorrectly, fix from Jiri Benc.

 9) Fix clock source used for cookies in SCTP, from Marcelo Ricardo
    Leitner.

10) aurora driver needs HAS_DMA dependency, from Geert Uytterhoeven.

11) ndo_fill_metadata_dst op of vxlan has to handle ipv6 tunneling
    properly as well, from Jiri Benc.

12) Handle request sockets properly in xfrm layer, from Eric Dumazet.

13) Double stats update in ipv6 geneve transmit path, fix from Pravin B
    Shelar.

14) sk->sk_policy[] needs RCU protection, and as a result
    xfrm_policy_destroy() needs to free policies using an RCU grace
    period, from Eric Dumazet.

15) SCTP needs to clone ipv6 tx options in order to avoid use after
    free, from Eric Dumazet.

16) Missing kbuild export if ila.h, from Stephen Hemminger.

17) Missing mdiobus_alloc() return value checking in mdio-mux.c, from
    Tobias Klauser.

18) Validate protocol value range in ->create() methods, from Hannes
    Frederic Sowa.

19) Fix early socket demux races that result in illegal dst reuse, from
    Eric Dumazet.

20) Validate socket address length in pptp code, from WANG Cong.

21) skb_reorder_vlan_header() uses incorrect offset and can corrupt
    packets, from Vlad Yasevich.

22) Fix memory leaks in nl80211 registry code, from Ola Olsson.

23) Timeout loop count handing fixes in mISDN, xgbe, qlge, sfc, and
    qlcnic.  From Dan Carpenter.

24) msg.msg_iocb needs to be cleared in recvfrom() otherwise, for
    example, AF_ALG will interpret it as an async call.  From Tadeusz
    Struk.

25) inetpeer_set_addr_v4 forgets to initialize the 'vif' field, from
    Eric Dumazet.

26) rhashtable enforces the minimum table size not early enough,
    breaking how we calculate the per-cpu lock allocations.  From
    Herbert Xu.

27) Fix FCC port lockup in 82xx driver, from Martin Roth.

28) FOU sockets need to be freed using RCU, from Hannes Frederic Sowa.

29) Fix out-of-bounds access in __skb_complete_tx_timestamp() and
    sock_setsockopt() wrt.  timestamp handling.  From WANG Cong.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (117 commits)
  net: check both type and procotol for tcp sockets
  drivers: net: xgene: fix Tx flow control
  tcp: restore fastopen with no data in SYN packet
  af_unix: Revert 'lock_interruptible' in stream receive code
  fou: clean up socket with kfree_rcu
  82xx: FCC: Fixing a bug causing to FCC port lock-up
  gianfar: Don't enable RX Filer if not supported
  net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration
  rhashtable: Fix walker list corruption
  rhashtable: Enforce minimum size on initial hash table
  inet: tcp: fix inetpeer_set_addr_v4()
  ipv6: automatically enable stable privacy mode if stable_secret set
  net: fix uninitialized variable issue
  bluetooth: Validate socket address length in sco_sock_bind().
  net_sched: make qdisc_tree_decrease_qlen() work for non mq
  ser_gigaset: remove unnecessary kfree() calls from release method
  ser_gigaset: fix deallocation of platform device structure
  ser_gigaset: turn nonsense checks into WARN_ON
  ser_gigaset: fix up NULL checks
  qlcnic: fix a timeout loop
  ...
2015-12-17 14:05:22 -08:00
WANG Cong ac5cc97799 net: check both type and procotol for tcp sockets
Dmitry reported the following out-of-bound access:

Call Trace:
 [<ffffffff816cec2e>] __asan_report_load4_noabort+0x3e/0x40
mm/kasan/report.c:294
 [<ffffffff84affb14>] sock_setsockopt+0x1284/0x13d0 net/core/sock.c:880
 [<     inline     >] SYSC_setsockopt net/socket.c:1746
 [<ffffffff84aed7ee>] SyS_setsockopt+0x1fe/0x240 net/socket.c:1729
 [<ffffffff85c18c76>] entry_SYSCALL_64_fastpath+0x16/0x7a
arch/x86/entry/entry_64.S:185

This is because we mistake a raw socket as a tcp socket.
We should check both sk->sk_type and sk->sk_protocol to ensure
it is a tcp socket.

Willem points out __skb_complete_tx_timestamp() needs to fix as well.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:46:32 -05:00
Iyappan Subramanian 67894eec3e drivers: net: xgene: fix Tx flow control
Currently the Tx flow control is based on reading the hardware state,
which is not accurate since it may not reflect the descriptors that
are not yet reached the memory.

To accurately control the Tx flow, changing it to be software based.

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:45:53 -05:00
Eric Dumazet 07e100f984 tcp: restore fastopen with no data in SYN packet
Yuchung tracked a regression caused by commit 57be5bdad7 ("ip: convert
tcp_sendmsg() to iov_iter primitives") for TCP Fast Open.

Some Fast Open users do not actually add any data in the SYN packet.

Fixes: 57be5bdad7 ("ip: convert tcp_sendmsg() to iov_iter primitives")
Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:37:39 -05:00
Rainer Weikusat 3822b5c2fc af_unix: Revert 'lock_interruptible' in stream receive code
With b3ca9b02b0, the AF_UNIX SOCK_STREAM
receive code was changed from using mutex_lock(&u->readlock) to
mutex_lock_interruptible(&u->readlock) to prevent signals from being
delayed for an indefinite time if a thread sleeping on the mutex
happened to be selected for handling the signal. But this was never a
problem with the stream receive code (as opposed to its datagram
counterpart) as that never went to sleep waiting for new messages with the
mutex held and thus, wouldn't cause secondary readers to block on the
mutex waiting for the sleeping primary reader. As the interruptible
locking makes the code more complicated in exchange for no benefit,
change it back to using mutex_lock.

Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:33:47 -05:00
Linus Torvalds ce42af94aa Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
 "Some i915 fixes, one omap fix, one core regression fix.

  Not even enough fixes for a twelve days of xmas song, which seemms
  good"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm: Don't overwrite UNVERFIED mode status to OK
  drm/omap: fix fbdev pix format to support all platforms
  drm/i915: Do a better job at disabling primary plane in the noatomic case.
  drm/i915/skl: Double RC6 WRL always on
  drm/i915/skl: Disable coarse power gating up until F0
  drm/i915: Remove incorrect warning in context cleanup
2015-12-17 11:55:29 -08:00
Will Deacon b4b29f9485 locking/osq: Fix ordering of node initialisation in osq_lock
The Cavium guys reported a soft lockup on their arm64 machine, caused by
commit c55a6ffa62 ("locking/osq: Relax atomic semantics"):

    mutex_optimistic_spin+0x9c/0x1d0
    __mutex_lock_slowpath+0x44/0x158
    mutex_lock+0x54/0x58
    kernfs_iop_permission+0x38/0x70
    __inode_permission+0x88/0xd8
    inode_permission+0x30/0x6c
    link_path_walk+0x68/0x4d4
    path_openat+0xb4/0x2bc
    do_filp_open+0x74/0xd0
    do_sys_open+0x14c/0x228
    SyS_openat+0x3c/0x48
    el0_svc_naked+0x24/0x28

This is because in osq_lock we initialise the node for the current CPU:

    node->locked = 0;
    node->next = NULL;
    node->cpu = curr;

and then publish the current CPU in the lock tail:

    old = atomic_xchg_acquire(&lock->tail, curr);

Once the update to lock->tail is visible to another CPU, the node is
then live and can be both read and updated by concurrent lockers.

Unfortunately, the ACQUIRE semantics of the xchg operation mean that
there is no guarantee the contents of the node will be visible before
lock tail is updated.  This can lead to lock corruption when, for
example, a concurrent locker races to set the next field.

Fixes: c55a6ffa62 ("locking/osq: Relax atomic semantics"):
Reported-by: David Daney <ddaney@caviumnetworks.com>
Reported-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Tested-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1449856001-21177-1-git-send-email-will.deacon@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-17 11:40:29 -08:00
Linus Torvalds d7637d01be Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:

 - Two bug fixes for misuse of PAGE_MASK in scatterlist and dma-debug.
   These are tagged for -stable.  The scatterlist impact is potentially
  corrupted dma addresses on HIGHMEM enabled platforms.

 - A minor locking fix for the NFIT hot-add implementation that is new
   in 4.4-rc.  This would only trigger in the case a hot-add raced
   driver removal.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dma-debug: Fix dma_debug_entry offset calculation
  Revert "scatterlist: use sg_phys()"
  nfit: acpi_nfit_notify(): Do not leave device locked
2015-12-17 11:20:13 -08:00
Hannes Frederic Sowa 3036facbb7 fou: clean up socket with kfree_rcu
fou->udp_offloads is managed by RCU. As it is actually included inside
the fou sockets, we cannot let the memory go out of scope before a grace
period. We either can synchronize_rcu or switch over to kfree_rcu to
manage the sockets. kfree_rcu seems appropriate as it is used by vxlan
and geneve.

Fixes: 23461551c0 ("fou: Support for foo-over-udp RX path")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 19:03:02 -05:00
David S. Miller 4d4f37910b Merge tag 'mac80211-for-davem-2015-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
Johannes Berg says:

====================
Another set of fixes:
 * memory leak fixes (from Ola)
 * operating mode notification spec compliance fix (from Eyal)
 * copy rfkill names in case pointer becomes invalid (myself)
 * two hardware restart fixes (myself)
 * get rid of "limiting TX power" log spam (myself)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 18:33:38 -05:00
Martin Roth 79aa05a24f 82xx: FCC: Fixing a bug causing to FCC port lock-up
The patch fixes FCC port lock-up, which occurs as a result of a bug
during underrun/collision handling. Within the tx_startup() function
in mac-fcc.c, the address of last BD is not calculated correctly.
As a result of wrong calculation of the last BD address, the next
transmitted BD may be set to an area out of the transmit BD ring.
This actually causes to port lock-up and it is not recoverable.

Signed-off-by: Martin Roth <martin.roth@motorolasolutions.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 18:32:35 -05:00
Hamish Martin 7bff47da1e gianfar: Don't enable RX Filer if not supported
After commit 15bf176db1 ("gianfar: Don't enable the Filer w/o the
Parser"), 'TSEC' model controllers (for example as seen on MPC8541E)
always have 8 bytes stripped from the front of received frames.
Only 'eTSEC' gianfar controllers have the RX Filer capability (amongst
other enhancements). Previously this was treated as always enabled
for both 'TSEC' and 'eTSEC' controllers.
In commit 15bf176db1 ("gianfar: Don't enable the Filer w/o the Parser")
a subtle change was made to the setting of 'uses_rxfcb' to effectively
always set it (since 'rx_filer_enable' was always true). This had the
side-effect of always stripping 8 bytes from the front of received frames
on 'TSEC' type controllers.

We now only enable the RX Filer capability on controller types that
support it, thereby avoiding the issue for 'TSEC' type controllers.

Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 18:31:00 -05:00
Daniel Mentz 0354aec19c dma-debug: Fix dma_debug_entry offset calculation
dma-debug uses struct dma_debug_entry to keep track of dma coherent
memory allocation requests. The virtual address is converted into a pfn
and an offset. Previously, the offset was calculated using an incorrect
bit mask.  As a result, we saw incorrect error messages from dma-debug
like the following:

"DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000"

Cacheline 0x03e00000 does not exist on our platform.

Cc: <stable@vger.kernel.org>
Fixes: 0abdd7a81b ("dma-debug: introduce debug_dma_assert_idle()")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-12-16 11:24:26 -08:00
Linus Torvalds a5e90b1b07 Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
 "Further ARM fixes:
   - Anson Huang noticed that we were corrupting a register we shouldn't
     be during suspend on some CPUs.
   - Shengjiu Wang spotted a bug in the 'swp' instruction emulation.
   - Will Deacon fixed a bug in the ASID allocator.
   - Laura Abbott fixed the kernel permission protection to apply to all
     threads running in the system.
   - I've fixed two bugs with the domain access control register
     handling, one to do with printing an appropriate value at oops
     time, and the other to further fix the uaccess_with_memcpy code"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8475/1: SWP emulation: Restore original *data when failed
  ARM: 8471/1: need to save/restore arm register(r11) when it is corrupted
  ARM: fix uaccess_with_memcpy() with SW_DOMAIN_PAN
  ARM: report proper DACR value in oops dumps
  ARM: 8464/1: Update all mm structures with section adjustments
  ARM: 8465/1: mm: keep reserved ASIDs in sync with mm after multiple rollovers
2015-12-16 10:57:24 -08:00
Hannes Frederic Sowa 7bbadd2d10 net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration
Docbook does not like the definition of macros inside a field declaration
and adds a warning. Move the definition out.

Fixes: 79462ad02e ("net: add validation for the socket syscall protocol argument")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 11:44:17 -05:00
Herbert Xu c6ff526829 rhashtable: Fix walker list corruption
The commit ba7c95ea38 ("rhashtable:
Fix sleeping inside RCU critical section in walk_stop") introduced
a new spinlock for the walker list.  However, it did not convert
all existing users of the list over to the new spin lock.  Some
continued to use the old mutext for this purpose.  This obviously
led to corruption of the list.

The fix is to use the spin lock everywhere where we touch the list.

This also allows us to do rcu_rad_lock before we take the lock in
rhashtable_walk_start.  With the old mutex this would've deadlocked
but it's safe with the new spin lock.

Fixes: ba7c95ea38 ("rhashtable: Fix sleeping inside RCU...")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 11:13:14 -05:00
Herbert Xu 3a324606bb rhashtable: Enforce minimum size on initial hash table
William Hua <william.hua@canonical.com> wrote:
>
> I wasn't aware there was an enforced minimum size. I simply set the
> nelem_hint in the rhastable_params struct to 1, expecting it to grow as
> needed. This caused a segfault afterwards when trying to insert an
> element.

OK we're doing the size computation before we enforce the limit
on min_size.

---8<---
We need to do the initial hash table size computation after we
have obtained the correct min_size/max_size parameters.  Otherwise
we may end up with a hash table whose size is outside the allowed
envelope.

Fixes: a998f712f7 ("rhashtable: Round up/down min/max_size to...")
Reported-by: William Hua <william.hua@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 10:44:08 -05:00