linux-stable.git/arch/arc/include, branch v3.18.136

arc: fix build errors in arc/include/asm/delay.h

2018-09-05T07:16:22+00:00

[ Upstream commit 2423665ec53f2a29191b35382075e9834288a975 ]

Fix build errors in arch/arc/'s delay.h:
- add "extern unsigned long loops_per_jiffy;"
- add  for "u64"

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:61:12: error: 'u64' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) >> 32;
            ^~~

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:63:37: error: 'loops_per_jiffy' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) >> 32;
                                     ^~~~~~~~~~~~~~~

Signed-off-by: Randy Dunlap 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Elad Kanfi 
Cc: Leon Romanovsky 
Cc: Ofer Levi 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARC: mm: allow mprotect to make stack mappings executable

2018-07-28T05:43:17+00:00

commit 93312b6da4df31e4102ce5420e6217135a16c7ea upstream.

mprotect(EXEC) was failing for stack mappings as default vm flags was
missing MAYEXEC.

This was triggered by glibc test suite nptl/tst-execstack testcase

What is surprising is that despite running LTP for years on, we didn't
catch this issue as it lacks a directed test case.

gcc dejagnu tests with nested functions also requiring exec stack work
fine though because they rely on the GNU_STACK segment spit out by
compiler and handled in kernel elf loader.

This glibc case is different as the stack is non exec to begin with and
a dlopen of shared lib with GNU_STACK segment triggers the exec stack
proceedings using a mprotect(PROT_EXEC) which was broken.

CC: stable@vger.kernel.org
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Fix CONFIG_SWAP

2018-07-28T05:43:17+00:00

commit 6e3761145a9ba3ce267c330b6bff51cf6a057b06 upstream.

swap was broken on ARC due to silly copy-paste issue.

We encode offset from swapcache page in __swp_entry() as (off << 13) but
were not decoding back in __swp_offset() as (off >> 13) - it was still
(off << 13).

This finally fixes swap usage on ARC.

| # mkswap /dev/sda2
|
| # swapon -a -e /dev/sda2
| Adding 500728k swap on /dev/sda2.  Priority:-2 extents:1 across:500728k
|
| # free
|              total       used       free     shared    buffers     cached
| Mem:        765104      13456     751648       4736          8       4736
| -/+ buffers/cache:       8712     756392
| Swap:       500728          0     500728

Cc: stable@vger.kernel.org
Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

Make asm/word-at-a-time.h available on all architectures

2017-08-11T16:30:13+00:00

commit a6e2f029ae34f41adb6ae3812c32c5d326e1abd2 upstream.

Added the x86 implementation of word-at-a-time to the
generic version, which previously only supported big-endian.

Omitted the x86-specific load_unaligned_zeropad(), which in
any case is also not present for the existing BE-only
implementation of a word-at-a-time, and is only used under
CONFIG_DCACHE_WORD_ACCESS.

Added as a "generic-y" to the Kbuilds of all architectures
that didn't previously have it.

Signed-off-by: Chris Metcalf 
Signed-off-by: Greg Kroah-Hartman

ARC: uaccess: get_user to zero out dest in cause of fault

2016-10-06T02:40:20+00:00

[ Upstream commit 05d9d0b96e53c52a113fd783c0c97c830c8dc7af ]

Al reported potential issue with ARC get_user() as it wasn't clearing
out destination pointer in case of fault due to bad address etc.

Verified using following

| {
|  	u32 bogus1 = 0xdeadbeef;
|	u64 bogus2 = 0xdead;
|	int rc1, rc2;
|
|  	pr_info("Orig values %x %llx\n", bogus1, bogus2);
|	rc1 = get_user(bogus1, (u32 __user *)0x40000000);
|	rc2 = get_user(bogus2, (u64 __user *)0x50000000);
|	pr_info("access %d %d, new values %x %llx\n",
|		rc1, rc2, bogus1, bogus2);
| }

| [ARCLinux]# insmod /mnt/kernel-module/qtn.ko
| Orig values deadbeef dead
| access -14 -14, new values 0 0

Reported-by: Al Viro 
Cc: Linus Torvalds 
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta 
Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

Revert "ARC: mm: don't loose PTE_SPECIAL in pte_modify()"

2016-09-15T22:55:24+00:00

This reverts commit 77c6ffdbce68688492a31702f67c7dbc4eeedd62.

Signed-off-by: Sasha Levin

ARC: Support syscall ABI v4

2016-09-01T02:05:44+00:00

[ Upstream commit 840c054fd0efb048df6fceb0c46385ec5b66dfe6 ]

The syscall ABI includes the gcc functional calling ABI since a syscall
implies userland caller and kernel callee.

The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in
even-odd register pairs, (potentially punching reg holes when passing such
values as args). This was partly driven by the fact that the double-word
LDD/STD instructions in ARCv2 expect the register alignment and thus gcc
forcing this avoids extra MOV at the cost of a few unused register (which we
have plenty anyways).

This however was rejected as part of upstreaming gcc port to HS. So the new
ABI v4 doesn't enforce the even-odd reg restriction.

Do note that for ARCompact ISA builds v3 and v4 are practically the same in
terms of gcc code generation.

In terms of change management, we infer the new ABI if gcc 6.x onwards
is used for building the kernel.

This also needs a stable backport to enable older kernels to work with
new tools/user-space

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: use correct offset in pt_regs for saving/restoring user mode r25

2016-09-01T02:05:44+00:00

[ Upstream commit 86147e3cfa5e118b61e78f4f0bf29e920dcbd477 ]

User mode callee regs are explicitly collected before signal delivery or
breakpoint trap. r25 is special for kernel as it serves as task pointer,
so user mode value is clobbered very early. It is saved in pt_regs where
generally only scratch (aka caller saved) regs are saved.

The code to access the corresponding pt_regs location had a subtle bug as
it was using load/store with scaling of offset, whereas the offset was already
byte wise correct. So fix this by replacing LD.AS with a standard LD

Cc: 
Signed-off-by: Liav Rehana 
Reviewed-by: Alexey Brodkin 
[vgupta: rewrote title and commit log]
Signed-off-by: Vineet Gupta 

Signed-off-by: Sasha Levin

ARCv2: STAR 9000808988: signals involving Delay Slot

2016-09-01T02:05:44+00:00

[ Upstream commit 0d7b8855a05c099a5c65a8d49a1e604198021f56 ]

Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.

   --------------------->8--------------------------------------
   mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
   munmap(0x200d2000, 24576)               = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
   ---
   potentially unexpected fatal signal 4.
   Path: /munmap01
   CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
   task: 9f1a8000 ti: 9f154000 task.ti: 9f154000

   [ECR   ]: 0x00020100 => Illegal Insn
   [EFA   ]: 0x0001354c
   [BLINK ]: 0x200515d4
   [ERET  ]: 0x1354c
       @off 0x1354c in [/munmap01]
       VMA: 0x00010000 to 0x00018000
   [STAT32]: 0x800802c0
   ...
   --------------------->8--------------------------------------

The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
   installed for SIGSEGV

2. The faulting instruction happened to be in Delay Slot
   00011864 :
      11908:	bl.d       13284 
      1190c:	stb        r16,[r2]

3. kernel sets up the reg file for signal handler and correctly clears
   the DE bit in pt_regs->status32 placeholder

4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
   and it over-writes the above with orig/stale value of status32

5. After RTIE, userspace signal handler executes a non branch
   instruction with DE bit set, triggering Illegal Instruction Exception.

Reported-by: Anton Kolesov 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: Call trace_hardirqs_on() before enabling irqs

2016-09-01T02:05:44+00:00

[ Upstream commit 18b43e89d295cc65151c505c643c98fb2c320e59 ]

trace_hardirqs_on_caller() in lockdep.c expects to be called before, not
after interrupts are actually enabled.

The following comment in kernel/locking/lockdep.c substantiates this
claim:

"
/*
 * We're enabling irqs and according to our state above irqs weren't
 * already enabled, yet we find the hardware thinks they are in fact
 * enabled.. someone messed up their IRQ state tracing.
 */
"

An example can be found in include/linux/irqflags.h:

	do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)

Without this change, we hit the following DEBUG_LOCKS_WARN_ON.

[    7.760000] ------------[ cut here ]------------
[    7.760000] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2711 resume_user_mode_begin+0x48/0xf0
[    7.770000] DEBUG_LOCKS_WARN_ON(!irqs_disabled())
[    7.780000] Modules linked in:
[    7.780000] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-00003-gc668bb9-dirty #366
[    7.790000]
[    7.790000] Stack Trace:
[    7.790000]   arc_unwind_core.constprop.1+0xa4/0x118
[    7.800000]   warn_slowpath_fmt+0x72/0x158
[    7.800000]   resume_user_mode_begin+0x48/0xf0
[    7.810000] ---[ end trace 6f6a7a8fae20d2f0 ]---

Signed-off-by: Daniel Mentz 
Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin