linux-stable.git/arch/arc, branch v4.4.243

Revert "ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE"

2020-11-10T09:22:21+00:00

This reverts commit 00fdec98d9881bf5173af09aebd353ab3b9ac729.
(but only from 5.2 and prior kernels)

The original commit was a preventive fix based on code-review and was
auto-picked for stable back-port (for better or worse).
It was OK for v5.3+ kernels, but turned up needing an implicit change
68e5c6f073bcf70 "(ARC: entry: EV_Trap expects r10 (vs. r9) to have
 exception cause)" merged in v5.3 which itself was not backported.
So to summarize the stable backport of this patch for v5.2 and prior
kernels is busted and it won't boot.

The obvious solution is backport 68e5c6f073bcf70 but that is a pain as
it doesn't revert cleanly and each of affected kernels (so far v4.19,
v4.14, v4.9, v4.4) needs a slightly different massaged varaint.
So the easier fix is to simply revert the backport from 5.2 and prior.
The issue was not a big deal as it would cause strace to sporadically
not work correctly.

Waldemar Brodkorb first reported this when running ARC uClibc regressions
on latest stable kernels (with offending backport). Once he bisected it,
the analysis was trivial, so thx to him for this.

Reported-by: Waldemar Brodkorb 
Bisected-by: Waldemar Brodkorb 
Cc: stable  # 5.2 and prior
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: stack unwinding: avoid indefinite looping

2020-11-10T09:22:21+00:00

commit 328d2168ca524d501fc4b133d6be076142bd305c upstream.

Currently stack unwinder is a while(1) loop which relies on the dwarf
unwinder to signal termination, which in turn relies on dwarf info to do
so. This in theory could cause an infinite loop if the dwarf info was
somehow messed up or the register contents were etc.

This fix thus detects the excessive looping and breaks the loop.

| Mem: 26184K used, 1009136K free, 0K shrd, 0K buff, 14416K cached
| CPU:  0.0% usr 72.8% sys  0.0% nic 27.1% idle  0.0% io  0.0% irq  0.0% sirq
| Load average: 4.33 2.60 1.11 2/74 139
|   PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
|   133     2 root     SWN      0  0.0   3 22.9 [rcu_torture_rea]
|   132     2 root     SWN      0  0.0   0 22.0 [rcu_torture_rea]
|   131     2 root     SWN      0  0.0   3 21.5 [rcu_torture_rea]
|   126     2 root     RW       0  0.0   2  5.4 [rcu_torture_wri]
|   129     2 root     SWN      0  0.0   0  0.2 [rcu_torture_fak]
|   137     2 root     SW       0  0.0   0  0.2 [rcu_torture_cbf]
|   127     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   138   115 root     R     1464  0.1   2  0.1 top
|   130     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   128     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   115     1 root     S     1472  0.1   1  0.0 -/bin/sh
|   104     1 root     S     1464  0.1   0  0.0 inetd
|     1     0 root     S     1456  0.1   2  0.0 init
|    78     1 root     S     1456  0.1   0  0.0 syslogd -O /var/log/messages
|   134     2 root     SW       0  0.0   2  0.0 [rcu_torture_sta]
|    10     2 root     IW       0  0.0   1  0.0 [rcu_preempt]
|    88     2 root     IW       0  0.0   1  0.0 [kworker/1:1-eve]
|    66     2 root     IW       0  0.0   2  0.0 [kworker/2:2-eve]
|    39     2 root     IW       0  0.0   2  0.0 [kworker/2:1-eve]
| unwinder looping too long, aborting !

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: elf: use right ELF_ARCH

2020-07-22T07:10:03+00:00

commit b7faf971081a4e56147f082234bfff55135305cb upstream.

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE

2020-07-22T07:10:03+00:00

commit 00fdec98d9881bf5173af09aebd353ab3b9ac729 upstream.

Trap handler for syscall tracing reads EFA (Exception Fault Address),
in case strace wants PC of trap instruction (EFA is not part of pt_regs
as of current code).

However this EFA read is racy as it happens after dropping to pure
kernel mode (re-enabling interrupts). A taken interrupt could
context-switch, trigger a different task's trap, clobbering EFA for this
execution context.

Fix this by reading EFA early, before re-enabling interrupts. A slight
side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler.
The trap handler is common to both ARCompact and ARCv2 builds too.

This just came out of code rework/review and no real problem was reported
but is clearly a potential problem specially for strace.

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Fix ICCM & DCCM runtime size checks

2020-06-11T07:21:38+00:00

[ Upstream commit 43900edf67d7ef3ac8909854d75b8a1fba2d570c ]

As of today the ICCM and DCCM size checks are incorrectly using
mismatched units (KiB checked against bytes). The CONFIG_ARC_DCCM_SZ
and CONFIG_ARC_ICCM_SZ are in KiB, but the size calculated in
runtime and stored in cpu->dccm.sz and cpu->iccm.sz is in bytes.

Fix that.

Reported-by: Paul Greco 
Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: define __ALIGN_STR and __ALIGN symbols for ARC

2020-03-20T08:06:22+00:00

commit 8d92e992a785f35d23f845206cf8c6cafbc264e0 upstream.

The default defintions use fill pattern 0x90 for padding which for ARC
generates unintended "ldh_s r12,[r0,0x20]" corresponding to opcode 0x9090

So use ".align 4" which insert a "nop_s" instruction instead.

Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta 
Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: [plat-axs10x]: Add missing multicast filter number to GMAC node

2020-02-14T21:30:01+00:00

commit 7980dff398f86a618f502378fa27cf7e77449afa upstream.

Add a missing property to GMAC node so that multicast filtering works
correctly.

Fixes: 556cc1c5f528 ("ARC: [axs101] Add support for AXS101 SDP (software development platform)")
Acked-by: Alexey Brodkin 
Signed-off-by: Jose Abreu 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: perf: Accommodate big-endian CPU

2019-11-28T17:26:16+00:00

commit 5effc09c4907901f0e71e68e5f2e14211d9a203f upstream.

8-letter strings representing ARC perf events are stores in two
32-bit registers as ASCII characters like that: "IJMP", "IALL", "IJMPTAK" etc.

And the same order of bytes in the word is used regardless CPU endianness.

Which means in case of big-endian CPU core we need to swap bytes to get
the same order as if it was on little-endian CPU.

Otherwise we're seeing the following error message on boot:
------------------------->8----------------------
ARC perf        : 8 counters (32 bits), 40 conditions, [overflow IRQ support]
sysfs: cannot create duplicate filename '/devices/arc_pct/events/pmji'
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  sysfs_warn_dup+0x46/0x58
  sysfs_add_file_mode_ns+0xb2/0x168
  create_files+0x70/0x2a0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at kernel/events/core.c:12144 perf_event_sysfs_init+0x70/0xa0
Failed to register pmu: arc_pct, reason -17
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3
Stack Trace:
  arc_unwind_core+0xd4/0xfc
  dump_stack+0x64/0x80
  __warn+0x9c/0xd4
  warn_slowpath_fmt+0x22/0x2c
  perf_event_sysfs_init+0x70/0xa0
---[ end trace a75fb9a9837bd1ec ]---
------------------------->8----------------------

What happens here we're trying to register more than one raw perf event
with the same name "PMJI". Why? Because ARC perf events are 4 to 8 letters
and encoded into two 32-bit words. In this particular case we deal with 2
events:
 * "IJMP____" which counts all jump & branch instructions
 * "IJMPC___" which counts only conditional jumps & branches

Those strings are split in two 32-bit words this way "IJMP" + "____" &
"IJMP" + "C___" correspondingly. Now if we read them swapped due to CPU core
being big-endian then we read "PMJI" + "____" & "PMJI" + "___C".

And since we interpret read array of ASCII letters as a null-terminated string
on big-endian CPU we end up with 2 events of the same name "PMJI".

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

ARC: export "abort" for modules

2019-09-21T05:12:54+00:00

This is a custom patch (no mainline equivalent) for stable backport only
to address 0-Day kernel test infra ARC 4.x.y builds errors.

The reason for this custom patch as that it is a single patch, touches
only ARC, vs. atleast two 7c2c11b208be09c1, dc8635b78cd8669 which touch
atleast 3 other arches (one long removed) and could potentially have a
fallout.

Reported-by: kbuild test robot 
CC: stable@vger.kernel.org	# 4.4, 4.9
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: configs: Remove CONFIG_INITRAMFS_SOURCE from defconfigs

2019-09-21T05:12:46+00:00

commit 64234961c145606b36eaa82c47b11be842b21049 upstream.

We used to have pre-set CONFIG_INITRAMFS_SOURCE with local path
to intramfs in ARC defconfigs. This was quite convenient for
in-house development but not that convenient for newcomers
who obviusly don't have folders like "arc_initramfs" next to
the Linux source tree. Which leads to quite surprising failure
of defconfig building:
------------------------------->8-----------------------------
  ../scripts/gen_initramfs_list.sh: Cannot open '../../arc_initramfs_hs/'
../usr/Makefile:57: recipe for target 'usr/initramfs_data.cpio.gz' failed
make[2]: *** [usr/initramfs_data.cpio.gz] Error 1
------------------------------->8-----------------------------

So now when more and more people start to deal with our defconfigs
let's make their life easier with removal of CONFIG_INITRAMFS_SOURCE.

Signed-off-by: Alexey Brodkin 
Cc: Kevin Hilman 
Cc: stable@vger.kernel.org
Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
[backport: Fix context conflicts, drop non-existing configuration files]
Signed-off-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman