linux-toradex.git/arch/arm64, branch v4.4.134

arm64: spinlock: Fix theoretical trylock() A-B-A with LSE atomics

2018-05-30T05:48:56+00:00

[ Upstream commit 202fb4ef81e3ec765c23bd1e6746a5c25b797d0e ]

If the spinlock "next" ticket wraps around between the initial LDR
and the cmpxchg in the LSE version of spin_trylock, then we can erroneously
think that we have successfuly acquired the lock because we only check
whether the next ticket return by the cmpxchg is equal to the owner ticket
in our updated lock word.

This patch fixes the issue by performing a full 32-bit check of the lock
word when trying to determine whether or not the CASA instruction updated
memory.

Reported-by: Catalin Marinas 
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas 
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

arm64: Add work around for Arm Cortex-A55 Erratum 1024718

2018-05-26T06:48:49+00:00

commit ece1397cbc89c51914fae1aec729539cfd8bd62b upstream.

Some variants of the Arm Cortex-55 cores (r0p0, r0p1, r1p0) suffer
from an erratum 1024718, which causes incorrect updates when DBM/AP
bits in a page table entry is modified without a break-before-make
sequence. The work around is to skip enabling the hardware DBM feature
on the affected cores. The hardware Access Flag management features
is not affected. There are some other cores suffering from this
errata, which could be added to the midr_list to trigger the work
around.

Cc: Catalin Marinas 
Cc: ckadabi@codeaurora.org
Reviewed-by: Dave Martin 
Signed-off-by: Suzuki K Poulose 
Signed-off-by: Will Deacon 
Signed-off-by: Suzuki K Poulose 
Signed-off-by: Greg Kroah-Hartman

arm64: introduce mov_q macro to move a constant into a 64-bit register

2018-05-26T06:48:49+00:00

commit 30b5ba5cf333cc650e474eaf2cc1ae91bc7cf89f upstream.

Implement a macro mov_q that can be used to move an immediate constant
into a 64-bit register, using between 2 and 4 movz/movk instructions
(depending on the operand)

Acked-by: Catalin Marinas 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Will Deacon 
Signed-off-by: Suzuki K Poulose 
Signed-off-by: Greg Kroah-Hartman

arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage

2018-04-13T17:50:15+00:00

[ Upstream commit 5f16a046f8e144c294ef98cd29d9458b5f8273e5 ]

FUTEX_OP_OPARG_SHIFT instructs the futex code to treat the 12-bit oparg
field as a shift value, potentially leading to a left shift value that
is negative or with an absolute value that is significantly larger then
the size of the type. UBSAN chokes with:

================================================================================
UBSAN: Undefined behaviour in ./arch/arm64/include/asm/futex.h:60:13
shift exponent -1 is negative
CPU: 1 PID: 1449 Comm: syz-executor0 Not tainted 4.11.0-rc4-00005-g977eb52-dirty #11
Hardware name: linux,dummy-virt (DT)
Call trace:
[] dump_backtrace+0x0/0x538 arch/arm64/kernel/traps.c:73
[] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:228
[] __dump_stack lib/dump_stack.c:16 [inline]
[] dump_stack+0x120/0x188 lib/dump_stack.c:52
[] ubsan_epilogue+0x18/0x98 lib/ubsan.c:164
[] __ubsan_handle_shift_out_of_bounds+0x250/0x294 lib/ubsan.c:421
[] futex_atomic_op_inuser arch/arm64/include/asm/futex.h:60 [inline]
[] futex_wake_op kernel/futex.c:1489 [inline]
[] do_futex+0x137c/0x1740 kernel/futex.c:3231
[] SYSC_futex kernel/futex.c:3281 [inline]
[] SyS_futex+0x114/0x268 kernel/futex.c:3249
[] el0_svc_naked+0x24/0x28
================================================================================
syz-executor1 uses obsolete (PF_INET,SOCK_PACKET)
sock: process `syz-executor0' is using obsolete setsockopt SO_BSDCOMPAT

This patch attempts to fix some of this by:

  * Making encoded_op an unsigned type, so we can shift it left even if
    the top bit is set.

  * Casting to signed prior to shifting right when extracting oparg
    and cmparg

  * Consider only the bottom 5 bits of oparg when using it as a left-shift
    value.

Whilst I think this catches all of the issues, I'd much prefer to remove
this stuff, as I think it's unused and the bugs are copy-pasted between
a bunch of architectures.

Reviewed-by: Robin Murphy 
Signed-off-by: Will Deacon 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

arm64: avoid overflow in VA_START and PAGE_OFFSET

2018-04-08T09:51:58+00:00

commit 82cd588052815eb4146f9f7c5347ca5e32c56360 upstream.

The bitmask used to define these values produces overflow, as seen by
this compiler warning:

arch/arm64/kernel/head.S:47:8: warning:
      integer overflow in preprocessor expression
  #elif (PAGE_OFFSET & 0x1fffff) != 0
         ^~~~~~~~~~~
arch/arm64/include/asm/memory.h:52:46: note:
      expanded from macro 'PAGE_OFFSET'
  #define PAGE_OFFSET             (UL(0xffffffffffffffff) << (VA_BITS -
1))
                                      ~~~~~~~~~~~~~~~~~~  ^

It would be preferrable to use GENMASK_ULL() instead, but it's not set
up to be used from assembly (the UL() macro token pastes UL suffixes
when not included in assembly sources).

Suggested-by: Ard Biesheuvel 
Suggested-by: Yury Norov 
Suggested-by: Matthias Kaehlcke 
Signed-off-by: Nick Desaulniers 
Signed-off-by: Will Deacon 
[natechancellor: KIMAGE_VADDR doesn't exist]
Signed-off-by: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

mm/vmalloc: add interfaces to free unmapped page table

2018-03-28T16:40:14+00:00

commit b6bdb7517c3d3f41f20e5c2948d6bc3f8897394e upstream.

On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may
create pud/pmd mappings.  A kernel panic was observed on arm64 systems
with Cortex-A75 in the following steps as described by Hanjun Guo.

 1. ioremap a 4K size, valid page table will build,
 2. iounmap it, pte0 will set to 0;
 3. ioremap the same address with 2M size, pgd/pmd is unchanged,
    then set the a new value for pmd;
 4. pte0 is leaked;
 5. CPU may meet exception because the old pmd is still in TLB,
    which will lead to kernel panic.

This panic is not reproducible on x86.  INVLPG, called from iounmap,
purges all levels of entries associated with purged address on x86.  x86
still has memory leak.

The patch changes the ioremap path to free unmapped page table(s) since
doing so in the unmap path has the following issues:

 - The iounmap() path is shared with vunmap(). Since vmap() only
   supports pte mappings, making vunmap() to free a pte page is an
   overhead for regular vmap users as they do not need a pte page freed
   up.

 - Checking if all entries in a pte page are cleared in the unmap path
   is racy, and serializing this check is expensive.

 - The unmap path calls free_vmap_area_noflush() to do lazy TLB purges.
   Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB
   purge.

Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which
clear a given pud/pmd entry and free up a page for the lower level
entries.

This patch implements their stub functions on x86 and arm64, which work
as workaround.

[akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub]
Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com
Fixes: e61ce6ade404e ("mm: change ioremap to set up huge I/O mappings")
Reported-by: Lei Li 
Signed-off-by: Toshi Kani 
Cc: Catalin Marinas 
Cc: Wang Xuefeng 
Cc: Will Deacon 
Cc: Hanjun Guo 
Cc: Michal Hocko 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Borislav Petkov 
Cc: Matthew Wilcox 
Cc: Chintan Pandya 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[ tweak arm64 portion to rely on CONFIG_ARCH_HAVE_HUGE_VMAP - gregkh]
Signed-off-by: Greg Kroah-Hartman

arm64: Disable unhandled signal log messages by default

2018-02-28T09:17:23+00:00

commit 5ee39a71fd89ab7240c5339d04161c44a8e03269 upstream.

aarch64 unhandled signal kernel messages are very verbose, suggesting
them to be more of a debugging aid:

sigsegv[33]: unhandled level 2 translation fault (11) at 0x00000000, esr
0x92000046, in sigsegv[400000+71000]
CPU: 1 PID: 33 Comm: sigsegv Tainted: G        W        4.15.0-rc3+ #3
Hardware name: linux,dummy-virt (DT)
pstate: 60000000 (nZCv daif -PAN -UAO)
pc : 0x4003f4
lr : 0x4006bc
sp : 0000fffffe94a060
x29: 0000fffffe94a070 x28: 0000000000000000
x27: 0000000000000000 x26: 0000000000000000
x25: 0000000000000000 x24: 00000000004001b0
x23: 0000000000486ac8 x22: 00000000004001c8
x21: 0000000000000000 x20: 0000000000400be8
x19: 0000000000400b30 x18: 0000000000484728
x17: 000000000865ffc8 x16: 000000000000270f
x15: 00000000000000b0 x14: 0000000000000002
x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0008000020008008
x9 : 000000000000000f x8 : ffffffffffffffff
x7 : 0004000000000000 x6 : ffffffffffffffff
x5 : 0000000000000000 x4 : 0000000000000000
x3 : 00000000004003e4 x2 : 0000fffffe94a1e8
x1 : 000000000000000a x0 : 0000000000000000

Disable them by default, so they can be enabled using
/proc/sys/debug/exception-trace.

Cc: 
Signed-off-by: Michael Weiser 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

ARM: tegra: select USB_ULPI from EHCI rather than platform

2018-02-25T10:03:51+00:00

commit a262e87ff354f12447bb6268bd63edf7ba1c20e0 upstream.

For historic reasons, the tegra platform selects USB_ULPI from architecture
code, but that hasn't really made sense for a long time, as the only
user of that code is the Tegra EHCI driver that has its own Kconfig
symbol.

This removes the 'select' statements from mach-tegra and drivers/soc/tegra
and adds them with the device driver that actually needs them.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thierry Reding 
[arnd: rebased to 4.4-stable]
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

arm64: Kconfig: select COMPAT_BINFMT_ELF only when BINFMT_ELF is set

2018-02-25T10:03:43+00:00

commit 2e449048a25eb75d48dff12882b93f26d130a1c6 upstream.

Fix warning:
"(COMPAT) selects COMPAT_BINFMT_ELF which has unmet direct dependencies
(COMPAT && BINFMT_ELF)"

Signed-off-by: Kefeng Wang 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman