linux-stable.git/arch/arc/kernel, branch v5.4.239

ARC: entry: fix syscall_trace_exit argument

2022-04-27T11:50:49+00:00

commit b1c6ecfdd06907554518ec384ce8e99889d15193 upstream.

Function syscall_trace_exit expects pointer to pt_regs. However
r0 is also used to keep syscall return value. Restore pointer
to pt_regs before calling syscall_trace_exit.

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

ARC: wireup clone3 syscall

2021-09-12T06:56:40+00:00

commit bd71c453db91ecb464405411f2821d040f2a0d44 upstream.

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

ARC: Fix CONFIG_STACKDEPOT

2021-09-03T08:08:12+00:00

[ Upstream commit bf79167fd86f3b97390fe2e70231d383526bd9cc ]

Enabling CONFIG_STACKDEPOT results in the following build error.

arc-elf-ld: lib/stackdepot.o: in function `filter_irq_stacks':
stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end'

Other architectures address this problem by adding IRQENTRY_TEXT and
SOFTIRQENTRY_TEXT to the text segment, so do the same here.

Signed-off-by: Guenter Roeck 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARCv2: save ABI registers across signal handling

2021-06-23T12:41:29+00:00

commit 96f1b00138cb8f04c742c82d0a7c460b2202e887 upstream.

ARCv2 has some configuration dependent registers (r30, r58, r59) which
could be targetted by the compiler. To keep the ABI stable, these were
unconditionally part of the glibc ABI
(sysdeps/unix/sysv/linux/arc/sys/ucontext.h:mcontext_t) however we
missed populating them (by saving/restoring them across signal
handling).

This patch fixes the issue by
 - adding arcv2 ABI regs to kernel struct sigcontext
 - populating them during signal handling

Change to struct sigcontext might seem like a glibc ABI change (although
it primarily uses ucontext_t:mcontext_t) but the fact is
 - it has only been extended (existing fields are not touched)
 - the old sigcontext was ABI incomplete to begin with anyways

Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/53
Cc: 
Tested-by: kernel test robot 
Reported-by: Vladimir Isaev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: entry: fix off-by-one error in syscall number validation

2021-05-19T08:08:29+00:00

commit 3433adc8bd09fc9f29b8baddf33b4ecd1ecd2cdc upstream.

We have NR_syscall syscalls from [0 .. NR_syscall-1].
However the check for invalid syscall number is "> NR_syscall" as
opposed to >=. This off-by-one error erronesously allows "NR_syscall"
to be treated as valid syscall causeing out-of-bounds access into
syscall-call table ensuing a crash (holes within syscall table have a
invalid-entry handler but this is beyond the array implementing the
table).

This problem showed up on v5.6 kernel when testing glibc 2.33 (v5.10
kernel capable, includng faccessat2 syscall 439). The v5.6 kernel has
NR_syscalls=439 (0 to 438). Due to the bug, 439 passed by glibc was
not handled as -ENOSYS but processed leading to a crash.

Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/48
Reported-by: Shahab Vahedi 
Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

arc: kernel: Return -EFAULT if copy_to_user() fails

2021-04-21T10:56:13+00:00

[ Upstream commit 46e152186cd89d940b26726fff11eb3f4935b45a ]

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Signed-off-by: Wang Qing 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: stack unwinding: don't assume non-current task is sleeping

2020-12-16T09:56:55+00:00

[ Upstream commit e42404fa10fd11fe72d0a0e149a321d10e577715 ]

To start stack unwinding (SP, PC and BLINK) are needed. When the
explicit execution context (pt_regs etc) is not available, unwinder
assumes the task is sleeping (in __switch_to()) and fetches SP and BLINK
from kernel mode stack.

But this assumption is not true, specially in a SMP system, when top
runs on 1 core, there may be active running processes on all cores.

So when unwinding non courrent tasks, ensure they are NOT running.

And while at it, handle the self unwinding case explicitly.

This came out of investigation of a customer reported hang with
rcutorture+top

Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/31
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: stack unwinding: avoid indefinite looping

2020-11-10T11:37:33+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: perf: redo the pct irq missing in device-tree handling

2020-11-05T10:43:33+00:00

commit 8c42a5c02bec6c7eccf08957be3c6c8fccf9790b upstream.

commit feb92d7d3813456c11dce21 "(ARC: perf: don't bail setup if pct irq
missing in device-tree)" introduced a silly brown-paper bag bug:
The assignment and comparison in an if statement were not bracketed
correctly leaving the order of evaluation undefined.

|
| if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|                           ^^^                         ^^^^

And given such a chance, the compiler will bite you hard, fully entitled
to generating this piece of beauty:

|
| # if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|
| bl.d @platform_get_irq  <-- irq returned in r0
|
| setge r2, r0, 0   	<-- r2 is bool 1 or 0 if irq >= 0 true/false
| brlt.d r0, 0, @.L114
|
| st_s	r2,[sp]    	<-- irq saved is bool 1 or 0, not actual return val
| st	1,[r3,160]   	# arc_pmu.18_29->irq <-- drops bool and assumes 1
|
| # return __request_percpu_irq(irq, handler, 0,
|
| bl.d @__request_percpu_irq;
| mov_s	r0,1	   <-- drops even bool and assumes 1 which fails

With the snafu fixed, everything is as expected.

| bl.d @platform_get_irq	<-- returns irq in r0
|
| mov_s	r2,r0
| brlt.d r2, 0, @.L112
|
| st_s	r0,[sp]			<-- irq isaved is actual return value above
| st	r0,[r13,160]	#arc_pmu.18_27->irq
|
| bl.d @__request_percpu_irq	<-- r0 unchanged so actual irq returned
| add r4,r4,r12	#, tmp363, __ptr

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

ARC: perf: don't bail setup if pct irq missing in device-tree

2020-09-09T17:12:30+00:00

commit feb92d7d3813456c11dce215b3421801a78a8986 upstream.

Current code inadventely bails if hardware supports sampling/overflow
interrupts, but the irq is missing from device tree.

|
| # perf stat -e cycles,instructions,major-faults,minor-faults ../hackbench
| Running with 10 groups 400 process
| Time: 0.921
|
| Performance counter stats for '../hackbench':
|
|         cycles
|         instructions
|                 0      major-faults
|              8679      minor-faults

This need not be as we can still do simple counting based perf stat.
This unborks perf on HSDK-4xD

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