linux-stable.git/arch/arc/kernel, branch v4.18.2 Linux kernel stable tree ARC: Improve cmpxchg syscall implementation 2018-07-09T18:22:05+00:00 Peter Zijlstra peterz@infradead.org 2018-06-19T14:22:05+00:00 e8708786d4fe21c043d38d760f768949a3d71185 This is used in configs lacking hardware atomics to emulate atomic r-m-w for user space, implemented by disabling preemption in kernel. However there are issues in current implementation: 1. Process not terminated if invalid user pointer passed: i.e. __get_user() failed. 2. The reason for this patch was __put_user() failure not being handled either, specifically for the COW break scenario. The zero page is initially wired up and read from __get_user() succeeds. A subsequent write by __put_user() induces a Protection Violation, but COW can't finish as Linux page fault handler is disabled due to preempt disable. And what's worse is we silently return the stale value to user space. Fix this specific case by re-enabling preemption and explicitly fixing up the fault and retrying the whole sequence over. Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-arch@vger.kernel.org Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote the changelog] 
This is used in configs lacking hardware atomics to emulate atomic r-m-w
for user space, implemented by disabling preemption in kernel.

However there are issues in current implementation:

1. Process not terminated if invalid user pointer passed:
   i.e. __get_user() failed.

2. The reason for this patch was __put_user() failure not being handled
   either, specifically for the COW break scenario.
   The zero page is initially wired up and read from __get_user()
   succeeds. A subsequent write by __put_user() induces a
   Protection Violation, but COW can't finish as Linux page fault
   handler is disabled due to preempt disable.
   And what's worse is we silently return the stale value to user space.
   Fix this specific case by re-enabling preemption and explicitly
   fixing up the fault and retrying the whole sequence over.

Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote the changelog]
ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP 2018-06-20T23:12:06+00:00 Alexey Brodkin Alexey.Brodkin@synopsys.com 2017-11-29T08:21:45+00:00 2f24ef7413a4d91657ef04e77c27ce0b313e6c95 machine_desc->init_per_cpu() hook is supposed to be per cpu initialization and would seem to apply equally to UP and/or SMP. Infact the comment in header file seems to suggest it works for UP too, which was not the case and this patch. This enables !CONFIG_SMP build for platforms such as hsdk. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: trimmeed changelog] 
machine_desc->init_per_cpu() hook is supposed to be per cpu
initialization and would seem to apply  equally to UP and/or SMP.
Infact the comment in header file seems to suggest it works for
UP too, which was not the case and this patch.

This enables !CONFIG_SMP build for platforms such as hsdk.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: trimmeed changelog]
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-04-06T18:07:08+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-04-06T18:07:08+00:00 9022ca6b1129da44e3d5c4fa779b8bb9ceabe2ce Pull misc vfs updates from Al Viro: "Assorted stuff, including Christoph's I_DIRTY patches" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: move I_DIRTY_INODE to fs.h ubifs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call ntfs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call gfs2: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) calls fs: fold open_check_o_direct into do_dentry_open vfs: Replace stray non-ASCII homoglyph characters with their ASCII equivalents vfs: make sure struct filename->iname is word-aligned get rid of pointless includes of fs_struct.h [poll] annotate SAA6588_CMD_POLL users 
Pull misc vfs updates from Al Viro:
 "Assorted stuff, including Christoph's I_DIRTY patches"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: move I_DIRTY_INODE to fs.h
  ubifs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call
  ntfs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call
  gfs2: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) calls
  fs: fold open_check_o_direct into do_dentry_open
  vfs: Replace stray non-ASCII homoglyph characters with their ASCII equivalents
  vfs: make sure struct filename->iname is word-aligned
  get rid of pointless includes of fs_struct.h
  [poll] annotate SAA6588_CMD_POLL users
Merge tag 'arc-4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc 2018-03-01T22:32:23+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-03-01T22:32:23+00:00 2120447b5dbda530a5c13cbc77cf20336465a5b4 Pull ARC fixes from Vineet Gupta: - MCIP aka ARconnect fixes for SMP builds [Euginey] - preventive fix for SLC (L2 cache) flushing [Euginey] - Kconfig default fix [Ulf Magnusson] - trailing semicolon fixes [Luis de Bethencourt] - other assorted minor fixes * tag 'arc-4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: setup cpu possible mask according to possible-cpus dts property ARC: mcip: update MCIP debug mask when the new cpu came online ARC: mcip: halt GFRC counter when ARC cores halt ARCv2: boot log: fix HS48 release number arc: dts: use 'atmel' as manufacturer for at24 in axs10x_mb ARC: Fix malformed ARC_EMUL_UNALIGNED default ARC: boot log: Fix trailing semicolon ARC: dw2 unwind: Fix trailing semicolon ARC: Enable fatal signals on boot for dev platforms ARCv2: Don't pretend we may set L-bit in STATUS32 with kflag instruction ARCv2: cache: fix slc_entire_op: flush only instead of flush-n-inv 
Pull ARC fixes from Vineet Gupta:

 - MCIP aka ARconnect fixes for SMP builds [Euginey]

 - preventive fix for SLC (L2 cache) flushing [Euginey]

 - Kconfig default fix [Ulf Magnusson]

 - trailing semicolon fixes [Luis de Bethencourt]

 - other assorted minor fixes

* tag 'arc-4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: setup cpu possible mask according to possible-cpus dts property
  ARC: mcip: update MCIP debug mask when the new cpu came online
  ARC: mcip: halt GFRC counter when ARC cores halt
  ARCv2: boot log: fix HS48 release number
  arc: dts: use 'atmel' as manufacturer for at24 in axs10x_mb
  ARC: Fix malformed ARC_EMUL_UNALIGNED default
  ARC: boot log: Fix trailing semicolon
  ARC: dw2 unwind: Fix trailing semicolon
  ARC: Enable fatal signals on boot for dev platforms
  ARCv2: Don't pretend we may set L-bit in STATUS32 with kflag instruction
  ARCv2: cache: fix slc_entire_op: flush only instead of flush-n-inv
ARC: setup cpu possible mask according to possible-cpus dts property 2018-02-28T18:45:32+00:00 Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com 2018-02-23T16:41:54+00:00 a29a25275452c97fe35815f1eb9564f2a07a1965 As we have option in u-boot to set CPU mask for running linux, we want to pass information to kernel about CPU cores should be brought up. So we patch kernel dtb in u-boot to set possible-cpus property. This also allows us to have correctly setuped MCIP debug mask. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> 
As we have option in u-boot to set CPU mask for running linux,
we want to pass information to kernel about CPU cores should
be brought up. So we patch kernel dtb in u-boot to set
possible-cpus property.

This also allows us to have correctly setuped MCIP debug mask.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: mcip: update MCIP debug mask when the new cpu came online 2018-02-28T18:45:31+00:00 Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com 2018-02-23T16:41:53+00:00 f3205de98db2fc8083796dd5ad81b191e436fab8 As of today we use hardcoded MCIP debug mask, so if we launch kernel via debugger and kick fever cores than HW has all cpus hang at the momemt of setup MCIP debug mask. So update MCIP debug mask when the new cpu came online, instead of use hardcoded MCIP debug mask. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> 
As of today we use hardcoded MCIP debug mask, so if we launch
kernel via debugger and kick fever cores than HW has all cpus
hang at the momemt of setup MCIP debug mask.

So update MCIP debug mask when the new cpu came online, instead of
use hardcoded MCIP debug mask.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: mcip: halt GFRC counter when ARC cores halt 2018-02-28T18:45:31+00:00 Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com 2018-02-23T16:41:52+00:00 07423d00a2b2a71a97e4287d9262cb83c4c4c89f In SMP systems, GFRC is used for clocksource. However by default the counter keeps running even when core is halted (say when debugging via a JTAG debugger). This confuses Linux timekeeping and triggers flase RCU stall splat such as below: | [ARCLinux]# while true; do ./shm_open_23-1.run-test ; done | Running with 1000 processes for 1000 objects | hrtimer: interrupt took 485060 ns | | create_cnt: 1000 | Running with 1000 processes for 1000 objects | [ARCLinux]# INFO: rcu_preempt self-detected stall on CPU | 2-...: (1 GPs behind) idle=a01/1/0 softirq=135770/135773 fqs=0 | INFO: rcu_preempt detected stalls on CPUs/tasks: | 0-...: (1 GPs behind) idle=71e/0/0 softirq=135264/135264 fqs=0 | 2-...: (1 GPs behind) idle=a01/1/0 softirq=135770/135773 fqs=0 | 3-...: (1 GPs behind) idle=4e0/0/0 softirq=134304/134304 fqs=0 | (detected by 1, t=13648 jiffies, g=31493, c=31492, q=1) Starting from ARC HS v3.0 it's possible to tie GFRC to state of up-to 4 ARC cores with help of GFRC's CORE register where we set a mask for cores which state we need to rely on. We update cpu mask every time new cpu came online instead of using hardcoded one or using mask generated from "possible_cpus" as we want it set correctly even if we run kernel on HW which has fewer cores than expected (or we launch kernel via debugger and kick fever cores than HW has) Note that GFRC halts when all cores have halted and thus relies on programming of Inter-Core-dEbug register to halt all cores when one halts. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog] 
In SMP systems, GFRC is used for clocksource. However by default the
counter keeps running even when core is halted (say when debugging via a
JTAG debugger). This confuses Linux timekeeping and triggers flase RCU stall
splat such as below:

| [ARCLinux]# while true; do ./shm_open_23-1.run-test ; done
| Running with 1000 processes for 1000 objects
| hrtimer: interrupt took 485060 ns
|
| create_cnt: 1000
| Running with 1000 processes for 1000 objects
| [ARCLinux]# INFO: rcu_preempt self-detected stall on CPU
|       2-...: (1 GPs behind) idle=a01/1/0 softirq=135770/135773 fqs=0
| INFO: rcu_preempt detected stalls on CPUs/tasks:
| 	0-...: (1 GPs behind) idle=71e/0/0 softirq=135264/135264 fqs=0
|	2-...: (1 GPs behind) idle=a01/1/0 softirq=135770/135773 fqs=0
|	3-...: (1 GPs behind) idle=4e0/0/0 softirq=134304/134304 fqs=0
|	(detected by 1, t=13648 jiffies, g=31493, c=31492, q=1)

Starting from ARC HS v3.0 it's possible to tie GFRC to state of up-to 4
ARC cores with help of GFRC's CORE register where we set a mask for
cores which state we need to rely on.

We update cpu mask every time new cpu came online instead of using
hardcoded one or using mask generated from "possible_cpus" as we
want it set correctly even if we run kernel on HW which has fewer cores
than expected (or we launch kernel via debugger and kick fever cores
than HW has)

Note that GFRC halts when all cores have halted and thus relies on
programming of Inter-Core-dEbug register to halt all cores when one
halts.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
ARCv2: boot log: fix HS48 release number 2018-02-28T18:45:30+00:00 Vineet Gupta vgupta@synopsys.com 2018-02-21T23:10:02+00:00 701eda01cbd212bae2f7d29cf14322bd49b94657 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> 
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
get rid of pointless includes of fs_struct.h 2018-02-22T19:28:50+00:00 Al Viro viro@zeniv.linux.org.uk 2018-02-22T19:28:50+00:00 304ec482f562885b178b370cd50340447585d1c0 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
treewide/trivial: Remove ';;$' typo noise 2018-02-22T09:59:33+00:00 Ingo Molnar mingo@kernel.org 2018-02-22T09:54:55+00:00 ed7158bae41044ff696e9aafd5ada46d391a5a2e On lkml suggestions were made to split up such trivial typo fixes into per subsystem patches: --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height) struct efi_uga_draw_protocol *uga = NULL, *first_uga; efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; unsigned long nr_ugas; - u32 *handles = (u32 *)uga_handle;; + u32 *handles = (u32 *)uga_handle; efi_status_t status = EFI_INVALID_PARAMETER; int i; This patch is the result of the following script: $ sed -i 's/;;$/;/g' $(git grep -E ';;$' | grep "\.[ch]:" | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq) ... followed by manual review to make sure it's all good. Splitting this up is just crazy talk, let's get over with this and just do it. Reported-by: Pavel Machek <pavel@ucw.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:

  --- a/arch/x86/boot/compressed/eboot.c
  +++ b/arch/x86/boot/compressed/eboot.c
  @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
          struct efi_uga_draw_protocol *uga = NULL, *first_uga;
          efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
          unsigned long nr_ugas;
  -       u32 *handles = (u32 *)uga_handle;;
  +       u32 *handles = (u32 *)uga_handle;
          efi_status_t status = EFI_INVALID_PARAMETER;
          int i;

This patch is the result of the following script:

  $ sed -i 's/;;$/;/g' $(git grep -E ';;$'  | grep "\.[ch]:"  | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)

... followed by manual review to make sure it's all good.

Splitting this up is just crazy talk, let's get over with this and just do it.

Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>