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  1. 18 12月, 2017 2 次提交
  3. 05 12月, 2017 2 次提交
  5. 14 11月, 2017 1 次提交
  7. 12 11月, 2017 1 次提交
    • X
      x86/intel_rdt: Fix a silent failure when writing zero value schemata · 2244645a
      由 Xiaochen Shen 提交于 
      Writing an invalid schemata with no domain values (e.g., "(L3|MB):"),
results in a silent failure, i.e. the last_cmd_status returns OK,

Check for an empty value and set the result string with a proper error
message and return -EINVAL.

Before the fix:
 # mkdir /sys/fs/resctrl/p1

 # echo "L3:" > /sys/fs/resctrl/p1/schemata
 (silent failure)
 # cat /sys/fs/resctrl/info/last_cmd_status
 ok

 # echo "MB:" > /sys/fs/resctrl/p1/schemata
 (silent failure)
 # cat /sys/fs/resctrl/info/last_cmd_status
 ok

After the fix:
 # mkdir /sys/fs/resctrl/p1

 # echo "L3:" > /sys/fs/resctrl/p1/schemata
 -bash: echo: write error: Invalid argument
 # cat /sys/fs/resctrl/info/last_cmd_status
 Missing 'L3' value

 # echo "MB:" > /sys/fs/resctrl/p1/schemata
 -bash: echo: write error: Invalid argument
 # cat /sys/fs/resctrl/info/last_cmd_status
 Missing 'MB' value

[ Tony: This is an unintended side effect of the patch earlier to allow the
    	user to just write the value they want to change.  While allowing
    	user to specify less than all of the values, it also allows an
    	empty value. ]

Fixes: c4026b7b ("x86/intel_rdt: Implement "update" mode when writing schemata file")
Signed-off-by: NXiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lkml.kernel.org/r/20171110191624.20280-1-tony.luck@intel.com
      2244645a
  9. 11 11月, 2017 1 次提交
  11. 10 11月, 2017 2 次提交
  13. 08 11月, 2017 1 次提交
    • R
      x86/umip: Enable User-Mode Instruction Prevention at runtime · aa35f896
      由 Ricardo Neri 提交于 
      User-Mode Instruction Prevention (UMIP) is enabled by setting/clearing a
bit in %cr4.

It makes sense to enable UMIP at some point while booting, before user
spaces come up. Like SMAP and SMEP, is not critical to have it enabled
very early during boot. This is because UMIP is relevant only when there is
a user space to be protected from. Given these similarities, UMIP can be
enabled along with SMAP and SMEP.

At the moment, UMIP is disabled by default at build time. It can be enabled
at build time by selecting CONFIG_X86_INTEL_UMIP. If enabled at build time,
it can be disabled at run time by adding clearcpuid=514 to the kernel
parameters.
Signed-off-by: NRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: ricardo.neri@intel.com
Link: http://lkml.kernel.org/r/1509935277-22138-10-git-send-email-ricardo.neri-calderon@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      aa35f896
  15. 07 11月, 2017 2 次提交
  17. 03 11月, 2017 2 次提交
    • R
      x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo · 941f5f0f
      由 Rafael J. Wysocki 提交于 
      Commit 890da9cf (Revert "x86: do not use cpufreq_quick_get() for
/proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous
behavior of "cpu MHz" in /proc/cpuinfo on x86 due to some changes
made after the commit it has reverted.

To address this, make the code in question use arch_freq_get_on_cpu()
which also is used by cpufreq for reporting the current frequency of
CPUs and since that function doesn't really depend on cpufreq in any
way, drop the CONFIG_CPU_FREQ dependency for the object file
containing it.

Also refactor arch_freq_get_on_cpu() somewhat to avoid IPIs and
return cached values right away if it is called very often over a
short time (to prevent user space from triggering IPI storms through
it).

Fixes: 890da9cf (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Cc: stable@kernel.org   # 4.13 - together with 890da9cfSigned-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      941f5f0f
    • L
      Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"" · 890da9cf
      由 Linus Torvalds 提交于 
      This reverts commit 51204e06.

There wasn't really any good reason for it, and people are complaining
(rightly) that it broke existing practice.

Cc: Len Brown <len.brown@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      890da9cf
  19. 02 11月, 2017 5 次提交
    • T
      x86/cpuid: Replace set/clear_bit32() · 06dd688d
      由 Thomas Gleixner 提交于 
      Peter pointed out that the set/clear_bit32() variants are broken in various
aspects.

Replace them with open coded set/clear_bit() and type cast
cpu_info::x86_capability as it's done in all other places throughout x86.

Fixes: 0b00de85 ("x86/cpuid: Add generic table for CPUID dependencies")
Reported-by: NPeter Ziljstra <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
      06dd688d
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      由 Greg Kroah-Hartman 提交于 
      Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
    • A
      x86/entry/64: Stop initializing TSS.sp0 at boot · 20bb8344
      由 Andy Lutomirski 提交于 
      In my quest to get rid of thread_struct::sp0, I want to clean up or
remove all of its readers.  Two of them are in cpu_init() (32-bit and
64-bit), and they aren't needed.  This is because we never enter
userspace at all on the threads that CPUs are initialized in.

Poison the initial TSS.sp0 and stop initializing it on CPU init.

The comment text mostly comes from Dave Hansen.  Thanks!
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ee4a00540ad28c6cff475fbcc7769a4460acc861.1509609304.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      20bb8344
    • A
      x86/entry/64: Pass SP0 directly to load_sp0() · da51da18
      由 Andy Lutomirski 提交于 
      load_sp0() had an odd signature:

  void load_sp0(struct tss_struct *tss, struct thread_struct *thread);

Simplify it to:

  void load_sp0(unsigned long sp0);

Also simplify a few get_cpu()/put_cpu() sequences to
preempt_disable()/preempt_enable().
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2655d8b42ed940aa384fe18ee1129bbbcf730a08.1509609304.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      da51da18
    • B
      x86/mcelog: Get rid of RCU remnants · 7298f08e
      由 Borislav Petkov 提交于 
      Jeremy reported a suspicious RCU usage warning in mcelog.

/dev/mcelog is called in process context now as part of the notifier
chain and doesn't need any of the fancy RCU and lockless accesses which
it did in atomic context.

Axe it all in favor of a simple mutex synchronization which cures the
problem reported.

Fixes: 5de97c9f ("x86/mce: Factor out and deprecate the /dev/mcelog driver")
Reported-by: NJeremy Cline <jcline@redhat.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-and-tested-by: NTony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: linux-edac@vger.kernel.org
Cc: Laura Abbott <labbott@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171101164754.xzzmskl4ngrqc5br@pd.tnic
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1498969
      7298f08e
  21. 31 10月, 2017 1 次提交
  23. 21 10月, 2017 3 次提交
    • R
      x86/intel_rdt: Fix potential deadlock during resctrl mount · 87943db7
      由 Reinette Chatre 提交于 
      Sai reported a warning during some MBA tests:

[  236.755559] ======================================================
[  236.762443] WARNING: possible circular locking dependency detected
[  236.769328] 4.14.0-rc4-yocto-standard #8 Not tainted
[  236.774857] ------------------------------------------------------
[  236.781738] mount/10091 is trying to acquire lock:
[  236.787071]  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8117f892>] static_key_enable+0x12/0x30
[  236.797058]
               but task is already holding lock:
[  236.803552]  (&type->s_umount_key#37/1){+.+.}, at: [<ffffffff81208b2f>] sget_userns+0x32f/0x520
[  236.813247]
               which lock already depends on the new lock.

[  236.822353]
               the existing dependency chain (in reverse order) is:
[  236.830686]
               -> #4 (&type->s_umount_key#37/1){+.+.}:
[  236.837756]        __lock_acquire+0x1100/0x11a0
[  236.842799]        lock_acquire+0xdf/0x1d0
[  236.847363]        down_write_nested+0x46/0x80
[  236.852310]        sget_userns+0x32f/0x520
[  236.856873]        kernfs_mount_ns+0x7e/0x1f0
[  236.861728]        rdt_mount+0x30c/0x440
[  236.866096]        mount_fs+0x38/0x150
[  236.870262]        vfs_kern_mount+0x67/0x150
[  236.875015]        do_mount+0x1df/0xd50
[  236.879286]        SyS_mount+0x95/0xe0
[  236.883464]        entry_SYSCALL_64_fastpath+0x18/0xad
[  236.889183]
               -> #3 (rdtgroup_mutex){+.+.}:
[  236.895292]        __lock_acquire+0x1100/0x11a0
[  236.900337]        lock_acquire+0xdf/0x1d0
[  236.904899]        __mutex_lock+0x80/0x8f0
[  236.909459]        mutex_lock_nested+0x1b/0x20
[  236.914407]        intel_rdt_online_cpu+0x3b/0x4a0
[  236.919745]        cpuhp_invoke_callback+0xce/0xb80
[  236.925177]        cpuhp_thread_fun+0x1c5/0x230
[  236.930222]        smpboot_thread_fn+0x11a/0x1e0
[  236.935362]        kthread+0x152/0x190
[  236.939536]        ret_from_fork+0x27/0x40
[  236.944097]
               -> #2 (cpuhp_state-up){+.+.}:
[  236.950199]        __lock_acquire+0x1100/0x11a0
[  236.955241]        lock_acquire+0xdf/0x1d0
[  236.959800]        cpuhp_issue_call+0x12e/0x1c0
[  236.964845]        __cpuhp_setup_state_cpuslocked+0x13b/0x2f0
[  236.971242]        __cpuhp_setup_state+0xa7/0x120
[  236.976483]        page_writeback_init+0x43/0x67
[  236.981623]        pagecache_init+0x38/0x3b
[  236.986281]        start_kernel+0x3c6/0x41a
[  236.990931]        x86_64_start_reservations+0x2a/0x2c
[  236.996650]        x86_64_start_kernel+0x72/0x75
[  237.001793]        verify_cpu+0x0/0xfb
[  237.005966]
               -> #1 (cpuhp_state_mutex){+.+.}:
[  237.012364]        __lock_acquire+0x1100/0x11a0
[  237.017408]        lock_acquire+0xdf/0x1d0
[  237.021969]        __mutex_lock+0x80/0x8f0
[  237.026527]        mutex_lock_nested+0x1b/0x20
[  237.031475]        __cpuhp_setup_state_cpuslocked+0x54/0x2f0
[  237.037777]        __cpuhp_setup_state+0xa7/0x120
[  237.043013]        page_alloc_init+0x28/0x30
[  237.047769]        start_kernel+0x148/0x41a
[  237.052425]        x86_64_start_reservations+0x2a/0x2c
[  237.058145]        x86_64_start_kernel+0x72/0x75
[  237.063284]        verify_cpu+0x0/0xfb
[  237.067456]
               -> #0 (cpu_hotplug_lock.rw_sem){++++}:
[  237.074436]        check_prev_add+0x401/0x800
[  237.079286]        __lock_acquire+0x1100/0x11a0
[  237.084330]        lock_acquire+0xdf/0x1d0
[  237.088890]        cpus_read_lock+0x42/0x90
[  237.093548]        static_key_enable+0x12/0x30
[  237.098496]        rdt_mount+0x406/0x440
[  237.102862]        mount_fs+0x38/0x150
[  237.107035]        vfs_kern_mount+0x67/0x150
[  237.111787]        do_mount+0x1df/0xd50
[  237.116058]        SyS_mount+0x95/0xe0
[  237.120233]        entry_SYSCALL_64_fastpath+0x18/0xad
[  237.125952]
               other info that might help us debug this:

[  237.134867] Chain exists of:
                 cpu_hotplug_lock.rw_sem --> rdtgroup_mutex --> &type->s_umount_key#37/1

[  237.148425]  Possible unsafe locking scenario:

[  237.155015]        CPU0                    CPU1
[  237.160057]        ----                    ----
[  237.165100]   lock(&type->s_umount_key#37/1);
[  237.169952]                                lock(rdtgroup_mutex);
[  237.176641]
lock(&type->s_umount_key#37/1);
[  237.184287]   lock(cpu_hotplug_lock.rw_sem);
[  237.189041]
                *** DEADLOCK ***

When the resctrl filesystem is mounted the locks must be acquired in the
same order as was done when the cpus came online:

     cpu_hotplug_lock before rdtgroup_mutex.

This also requires to switch the static_branch_enable() calls to the
_cpulocked variant because now cpu hotplug lock is held already.

[ tglx: Switched to cpus_read_[un]lock ]
Reported-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Tested-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Acked-by: NVikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Link: https://lkml.kernel.org/r/9c41b91bc2f47d9e95b62b213ecdb45623c47a9f.1508490116.git.reinette.chatre@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      87943db7
    • R
      x86/intel_rdt: Fix potential deadlock during resctrl unmount · 36b6f9fc
      由 Reinette Chatre 提交于 
      Lockdep warns about a potential deadlock:

[   66.782842] ======================================================
[   66.782888] WARNING: possible circular locking dependency detected
[   66.782937] 4.14.0-rc2-test-test+ #48 Not tainted
[   66.782983] ------------------------------------------------------
[   66.783052] umount/336 is trying to acquire lock:
[   66.783117]  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff81032395>] rdt_kill_sb+0x215/0x390
[   66.783193]
               but task is already holding lock:
[   66.783244]  (rdtgroup_mutex){+.+.}, at: [<ffffffff810321b6>] rdt_kill_sb+0x36/0x390
[   66.783305]
               which lock already depends on the new lock.

[   66.783364]
               the existing dependency chain (in reverse order) is:
[   66.783419]
               -> #3 (rdtgroup_mutex){+.+.}:
[   66.783467]        __lock_acquire+0x1293/0x13f0
[   66.783509]        lock_acquire+0xaf/0x220
[   66.783543]        __mutex_lock+0x71/0x9b0
[   66.783575]        mutex_lock_nested+0x1b/0x20
[   66.783610]        intel_rdt_online_cpu+0x3b/0x430
[   66.783649]        cpuhp_invoke_callback+0xab/0x8e0
[   66.783687]        cpuhp_thread_fun+0x7a/0x150
[   66.783722]        smpboot_thread_fn+0x1cc/0x270
[   66.783764]        kthread+0x16e/0x190
[   66.783794]        ret_from_fork+0x27/0x40
[   66.783825]
               -> #2 (cpuhp_state){+.+.}:
[   66.783870]        __lock_acquire+0x1293/0x13f0
[   66.783906]        lock_acquire+0xaf/0x220
[   66.783938]        cpuhp_issue_call+0x102/0x170
[   66.783974]        __cpuhp_setup_state_cpuslocked+0x154/0x2a0
[   66.784023]        __cpuhp_setup_state+0xc7/0x170
[   66.784061]        page_writeback_init+0x43/0x67
[   66.784097]        pagecache_init+0x43/0x4a
[   66.784131]        start_kernel+0x3ad/0x3f7
[   66.784165]        x86_64_start_reservations+0x2a/0x2c
[   66.784204]        x86_64_start_kernel+0x72/0x75
[   66.784241]        verify_cpu+0x0/0xfb
[   66.784270]
               -> #1 (cpuhp_state_mutex){+.+.}:
[   66.784319]        __lock_acquire+0x1293/0x13f0
[   66.784355]        lock_acquire+0xaf/0x220
[   66.784387]        __mutex_lock+0x71/0x9b0
[   66.784419]        mutex_lock_nested+0x1b/0x20
[   66.784454]        __cpuhp_setup_state_cpuslocked+0x52/0x2a0
[   66.784497]        __cpuhp_setup_state+0xc7/0x170
[   66.784535]        page_alloc_init+0x28/0x30
[   66.784569]        start_kernel+0x148/0x3f7
[   66.784602]        x86_64_start_reservations+0x2a/0x2c
[   66.784642]        x86_64_start_kernel+0x72/0x75
[   66.784678]        verify_cpu+0x0/0xfb
[   66.784707]
               -> #0 (cpu_hotplug_lock.rw_sem){++++}:
[   66.784759]        check_prev_add+0x32f/0x6e0
[   66.784794]        __lock_acquire+0x1293/0x13f0
[   66.784830]        lock_acquire+0xaf/0x220
[   66.784863]        cpus_read_lock+0x3d/0xb0
[   66.784896]        rdt_kill_sb+0x215/0x390
[   66.784930]        deactivate_locked_super+0x3e/0x70
[   66.784968]        deactivate_super+0x40/0x60
[   66.785003]        cleanup_mnt+0x3f/0x80
[   66.785034]        __cleanup_mnt+0x12/0x20
[   66.785070]        task_work_run+0x8b/0xc0
[   66.785103]        exit_to_usermode_loop+0x94/0xa0
[   66.786804]        syscall_return_slowpath+0xe8/0x150
[   66.788502]        entry_SYSCALL_64_fastpath+0xab/0xad
[   66.790194]
               other info that might help us debug this:

[   66.795139] Chain exists of:
                 cpu_hotplug_lock.rw_sem --> cpuhp_state --> rdtgroup_mutex

[   66.800035]  Possible unsafe locking scenario:

[   66.803267]        CPU0                    CPU1
[   66.804867]        ----                    ----
[   66.806443]   lock(rdtgroup_mutex);
[   66.808002]                                lock(cpuhp_state);
[   66.809565]                                lock(rdtgroup_mutex);
[   66.811110]   lock(cpu_hotplug_lock.rw_sem);
[   66.812608]
                *** DEADLOCK ***

[   66.816983] 2 locks held by umount/336:
[   66.818418]  #0:  (&type->s_umount_key#35){+.+.}, at: [<ffffffff81229738>] deactivate_super+0x38/0x60
[   66.819922]  #1:  (rdtgroup_mutex){+.+.}, at: [<ffffffff810321b6>] rdt_kill_sb+0x36/0x390

When the resctrl filesystem is unmounted the locks should be obtain in the
locks in the same order as was done when the cpus came online:

      cpu_hotplug_lock before rdtgroup_mutex.

This also requires to switch the static_branch_disable() calls to the
_cpulocked variant because now cpu hotplug lock is held already.

[ tglx: Switched to cpus_read_[un]lock ]
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Acked-by: NVikas Shivappa <vikas.shivappa@linux.intel.com>
Acked-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/cc292e76be073f7260604651711c47b09fd0dc81.1508490116.git.reinette.chatre@intel.com
      36b6f9fc
    • R
      x86/intel_rdt: Initialize bitmask of shareable resource if CDP enabled · 95953034
      由 Reinette Chatre 提交于 
      The platform informs via CPUID.(EAX=0x10, ECX=res#):EBX[31:0] (valid res#
are only 1 for L3 and 2 for L2) which unit of the allocation may be used by
other entities in the platform. This information is valid whether CDP (Code
and Data Prioritization) is enabled or not.

Ensure that the bitmask of shareable resource is initialized when CDP is
enabled.

Fixes: 0dd2d749 ("x86/intel_rdt: Show bitmask of shareable resource with other executing units"
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NVikas Shivappa <vikas.shivappa@linux.intel.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/815747bddc820ca221a8924edaf4d1a7324547e4.1508490116.git.reinette.chatre@intel.com
      95953034
  25. 19 10月, 2017 1 次提交
  27. 18 10月, 2017 1 次提交
  29. 17 10月, 2017 2 次提交
  31. 16 10月, 2017 1 次提交
  33. 14 10月, 2017 1 次提交
  35. 05 10月, 2017 4 次提交
  37. 04 10月, 2017 1 次提交
    • J
      x86/boot: Spell out "boot CPU" for BP · a1652bb8
      由 Jean Delvare 提交于 
      It's not obvious to everybody that BP stands for boot processor. At
least it was not for me. And BP is also a CPU register on x86, so it
is ambiguous. Spell out "boot CPU" everywhere instead.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      a1652bb8
  39. 27 9月, 2017 5 次提交
  41. 18 9月, 2017 1 次提交