Pull vfs file system parameter updates from Al Viro:
"Saner fs_parser.c guts and data structures. The system-wide registry
of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
the horror switch() in fs_parse() that would have to grow another case
every time something got added to that system-wide registry.
New syntax types can be added by filesystems easily now, and their
namespace is that of functions - not of system-wide enum members. IOW,
they can be shared or kept private and if some turn out to be widely
useful, we can make them common library helpers, etc., without having
to do anything whatsoever to fs_parse() itself.
And we already get that kind of requests - the thing that finally
pushed me into doing that was "oh, and let's add one for timeouts -
things like 15s or 2h". If some filesystem really wants that, let them
do it. Without somebody having to play gatekeeper for the variants
blessed by direct support in fs_parse(), TYVM.
Quite a bit of boilerplate is gone. And IMO the data structures make a
lot more sense now. -200LoC, while we are at it"
* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
tmpfs: switch to use of invalfc()
cgroup1: switch to use of errorfc() et.al.
procfs: switch to use of invalfc()
hugetlbfs: switch to use of invalfc()
cramfs: switch to use of errofc() et.al.
gfs2: switch to use of errorfc() et.al.
fuse: switch to use errorfc() et.al.
ceph: use errorfc() and friends instead of spelling the prefix out
prefix-handling analogues of errorf() and friends
turn fs_param_is_... into functions
fs_parse: handle optional arguments sanely
fs_parse: fold fs_parameter_desc/fs_parameter_spec
fs_parser: remove fs_parameter_description name field
add prefix to fs_context->log
ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
new primitive: __fs_parse()
switch rbd and libceph to p_log-based primitives
struct p_log, variants of warnf() et.al. taking that one instead
teach logfc() to handle prefices, give it saner calling conventions
get rid of cg_invalf()
...
Unused now.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- three fixes and a cleanup for the resctrl code
- a HyperV fix
- a fix to /proc/kcore contents in live debugging sessions
- a fix for the x86 decoder opcode map"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/decoder: Add TEST opcode to Group3-2
x86/resctrl: Clean up unused function parameter in mkdir path
x86/resctrl: Fix a deadlock due to inaccurate reference
x86/resctrl: Fix use-after-free due to inaccurate refcount of rdtgroup
x86/resctrl: Fix use-after-free when deleting resource groups
x86/hyper-v: Add "polling" bit to hv_synic_sint
x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y
Unfortunately, GCC 9.1 is expected to be be released without support for
MPX. This means that there was only a relatively small window where
folks could have ever used MPX. It failed to gain wide adoption in the
industry, and Linux was the only mainstream OS to ever support it widely.
Support for the feature may also disappear on future processors.
This set completes the process that we started during the 5.4 merge window.
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Merge tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx
Pull x86 MPX removal from Dave Hansen:
"MPX requires recompiling applications, which requires compiler
support. Unfortunately, GCC 9.1 is expected to be be released without
support for MPX. This means that there was only a relatively small
window where folks could have ever used MPX. It failed to gain wide
adoption in the industry, and Linux was the only mainstream OS to ever
support it widely.
Support for the feature may also disappear on future processors.
This set completes the process that we started during the 5.4 merge
window when the MPX prctl()s were removed. XSAVE support is left in
place, which allows MPX-using KVM guests to continue to function"
* tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx:
x86/mpx: remove MPX from arch/x86
mm: remove arch_bprm_mm_init() hook
x86/mpx: remove bounds exception code
x86/mpx: remove build infrastructure
x86/alternatives: add missing insn.h include
Pull x86 mtrr updates from Ingo Molnar:
"Two changes: restrict /proc/mtrr to CAP_SYS_ADMIN, plus a cleanup"
* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mtrr: Require CAP_SYS_ADMIN for all access
x86/mtrr: Get rid of mtrr_seq_show() forward declaration
Pull x86 cpu-features updates from Ingo Molnar:
"The biggest change in this cycle was a large series from Sean
Christopherson to clean up the handling of VMX features. This both
fixes bugs/inconsistencies and makes the code more coherent and
future-proof.
There are also two cleanups and a minor TSX syslog messages
enhancement"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/cpu: Remove redundant cpu_detect_cache_sizes() call
x86/cpu: Print "VMX disabled" error message iff KVM is enabled
KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs
perf/x86: Provide stubs of KVM helpers for non-Intel CPUs
KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits
KVM: VMX: Check for full VMX support when verifying CPU compatibility
KVM: VMX: Use VMX feature flag to query BIOS enabling
KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR
x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured
x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl()
x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs
x86/vmx: Introduce VMX_FEATURES_*
x86/cpu: Clear VMX feature flag if VMX is not fully enabled
x86/zhaoxin: Use common IA32_FEAT_CTL MSR initialization
x86/centaur: Use common IA32_FEAT_CTL MSR initialization
x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked
x86/intel: Initialize IA32_FEAT_CTL MSR at boot
tools/x86: Sync msr-index.h from kernel sources
selftests, kvm: Replace manual MSR defs with common msr-index.h
...
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups all around the map"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Remove amd_get_topology_early()
x86/tsc: Remove redundant assignment
x86/crash: Use resource_size()
x86/cpu: Add a missing prototype for arch_smt_update()
x86/nospec: Remove unused RSB_FILL_LOOPS
x86/vdso: Provide missing include file
x86/Kconfig: Correct spelling and punctuation
Documentation/x86/boot: Fix typo
x86/boot: Fix a comment's incorrect file reference
x86/process: Remove set but not used variables prev and next
x86/Kconfig: Fix Kconfig indentation
Pull x86 resource control updates from Ingo Molnar:
"The main change in this tree is the extension of the resctrl procfs
ABI with a new file that helps tooling to navigate from tasks back to
resctrl groups: /proc/{pid}/cpu_resctrl_groups.
Also fix static key usage for certain feature combinations and
simplify the task exit resctrl case"
* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Add task resctrl information display
x86/resctrl: Check monitoring static key in the MBM overflow handler
x86/resctrl: Do not reconfigure exiting tasks
Pull EFI updates from Ingo Molnar:
"The main changes in this cycle were:
- Cleanup of the GOP [graphics output] handling code in the EFI stub
- Complete refactoring of the mixed mode handling in the x86 EFI stub
- Overhaul of the x86 EFI boot/runtime code
- Increase robustness for mixed mode code
- Add the ability to disable DMA at the root port level in the EFI
stub
- Get rid of RWX mappings in the EFI memory map and page tables,
where possible
- Move the support code for the old EFI memory mapping style into its
only user, the SGI UV1+ support code.
- plus misc fixes, updates, smaller cleanups.
... and due to interactions with the RWX changes, another round of PAT
cleanups make a guest appearance via the EFI tree - with no side
effects intended"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
efi/x86: Disable instrumentation in the EFI runtime handling code
efi/libstub/x86: Fix EFI server boot failure
efi/x86: Disallow efi=old_map in mixed mode
x86/boot/compressed: Relax sed symbol type regex for LLVM ld.lld
efi/x86: avoid KASAN false positives when accessing the 1: 1 mapping
efi: Fix handling of multiple efi_fake_mem= entries
efi: Fix efi_memmap_alloc() leaks
efi: Add tracking for dynamically allocated memmaps
efi: Add a flags parameter to efi_memory_map
efi: Fix comment for efi_mem_type() wrt absent physical addresses
efi/arm: Defer probe of PCIe backed efifb on DT systems
efi/x86: Limit EFI old memory map to SGI UV machines
efi/x86: Avoid RWX mappings for all of DRAM
efi/x86: Don't map the entire kernel text RW for mixed mode
x86/mm: Fix NX bit clearing issue in kernel_map_pages_in_pgd
efi/libstub/x86: Fix unused-variable warning
efi/libstub/x86: Use mandatory 16-byte stack alignment in mixed mode
efi/libstub/x86: Use const attribute for efi_is_64bit()
efi: Allow disabling PCI busmastering on bridges during boot
efi/x86: Allow translating 64-bit arguments for mixed mode calls
...
and improvements:
- Update the cached HLE state when the TSX state is changed via the new
control register. This ensures feature bit consistency.
- Exclude the new Zhaoxin CPUs from Spectre V2 and SWAPGS vulnerabilities.
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Merge tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner:
"The performance deterioration departement provides a few non-scary
fixes and improvements:
- Update the cached HLE state when the TSX state is changed via the
new control register. This ensures feature bit consistency.
- Exclude the new Zhaoxin CPUs from Spectre V2 and SWAPGS
vulnerabilities"
* tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation/swapgs: Exclude Zhaoxin CPUs from SWAPGS vulnerability
x86/speculation/spectre_v2: Exclude Zhaoxin CPUs from SPECTRE_V2
x86/cpu: Update cached HLE state on write to TSX_CTRL_CPUID_CLEAR
Pull RAS updates from Borislav Petkov:
- Misc fixes to the MCE code all over the place, by Jan H. Schönherr.
- Initial support for AMD F19h and other cleanups to amd64_edac, by
Yazen Ghannam.
- Other small cleanups.
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
EDAC/mce_amd: Make fam_ops static global
EDAC/amd64: Drop some family checks for newer systems
EDAC/amd64: Add family ops for Family 19h Models 00h-0Fh
x86/amd_nb: Add Family 19h PCI IDs
EDAC/mce_amd: Always load on SMCA systems
x86/MCE/AMD, EDAC/mce_amd: Add new Load Store unit McaType
x86/mce: Fix use of uninitialized MCE message string
x86/mce: Fix mce=nobootlog
x86/mce: Take action on UCNA/Deferred errors again
x86/mce: Remove mce_inject_log() in favor of mce_log()
x86/mce: Pass MCE message to mce_panic() on failed kernel recovery
x86/mce/therm_throt: Mark throttle_active_work() as __maybe_unused
... and fold its function body into its single call site.
No functional changes:
# arch/x86/kernel/cpu/amd.o:
text data bss dec hex filename
5994 385 1 6380 18ec amd.o.before
5994 385 1 6380 18ec amd.o.after
md5:
99ec6daa095b502297884e949c520f90 amd.o.before.asm
99ec6daa095b502297884e949c520f90 amd.o.after.asm
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200123165811.5288-1-bp@alien8.de
From: Dave Hansen <dave.hansen@linux.intel.com>
MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).
This removes all the remaining (dead at this point) MPX handling
code remaining in the tree. The only remaining code is the XSAVE
support for MPX state which is currently needd for KVM to handle
VMs which might use MPX.
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Commit
334b0f4e9b ("x86/resctrl: Fix a deadlock due to inaccurate reference")
changed the argument to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
within mkdir_rdt_prepare(). That change resulted in an unused function
parameter to mkdir_rdt_prepare().
Clean up the unused function parameter in mkdir_rdt_prepare() and its
callers rdtgroup_mkdir_mon() and rdtgroup_mkdir_ctrl_mon().
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1578500886-21771-5-git-send-email-xiaochen.shen@intel.com
There is a race condition which results in a deadlock when rmdir and
mkdir execute concurrently:
$ ls /sys/fs/resctrl/c1/mon_groups/m1/
cpus cpus_list mon_data tasks
Thread 1: rmdir /sys/fs/resctrl/c1
Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1
3 locks held by mkdir/48649:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170
#2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
4 locks held by rmdir/48652:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0
#2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120
#3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
Thread 1 is deleting control group "c1". Holding rdtgroup_mutex,
kernfs_remove() removes all kernfs nodes under directory "c1"
recursively, then waits for sub kernfs node "mon_groups" to drop active
reference.
Thread 2 is trying to create a subdirectory "m1" in the "mon_groups"
directory. The wrapper kernfs_iop_mkdir() takes an active reference to
the "mon_groups" directory but the code drops the active reference to
the parent directory "c1" instead.
As a result, Thread 1 is blocked on waiting for active reference to drop
and never release rdtgroup_mutex, while Thread 2 is also blocked on
trying to get rdtgroup_mutex.
Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir)
(rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1)
------------------------- -------------------------
kernfs_iop_mkdir
/*
* kn: "m1", parent_kn: "mon_groups",
* prgrp_kn: parent_kn->parent: "c1",
*
* "mon_groups", parent_kn->active++: 1
*/
kernfs_get_active(parent_kn)
kernfs_iop_rmdir
/* "c1", kn->active++ */
kernfs_get_active(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
/* "c1", kn->active-- */
kernfs_break_active_protection(kn)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
sentry->flags = RDT_DELETED
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
kernfs_get(kn)
kernfs_remove(rdtgrp->kn)
__kernfs_remove
/* "mon_groups", sub_kn */
atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active)
kernfs_drain(sub_kn)
/*
* sub_kn->active == KN_DEACTIVATED_BIAS + 1,
* waiting on sub_kn->active to drop, but it
* never drops in Thread 2 which is blocked
* on getting rdtgroup_mutex.
*/
Thread 1 hangs here ---->
wait_event(sub_kn->active == KN_DEACTIVATED_BIAS)
...
rdtgroup_mkdir
rdtgroup_mkdir_mon(parent_kn, prgrp_kn)
mkdir_rdt_prepare(parent_kn, prgrp_kn)
rdtgroup_kn_lock_live(prgrp_kn)
atomic_inc(&rdtgrp->waitcount)
/*
* "c1", prgrp_kn->active--
*
* The active reference on "c1" is
* dropped, but not matching the
* actual active reference taken
* on "mon_groups", thus causing
* Thread 1 to wait forever while
* holding rdtgroup_mutex.
*/
kernfs_break_active_protection(
prgrp_kn)
/*
* Trying to get rdtgroup_mutex
* which is held by Thread 1.
*/
Thread 2 hangs here ----> mutex_lock
...
The problem is that the creation of a subdirectory in the "mon_groups"
directory incorrectly releases the active protection of its parent
directory instead of itself before it starts waiting for rdtgroup_mutex.
This is triggered by the rdtgroup_mkdir() flow calling
rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the
parent control group ("c1") as argument. It should be called with kernfs
node "mon_groups" instead. What is currently missing is that the
kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp.
Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then
it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
instead. And then it operates on the same rdtgroup structure but handles
the active reference of kernfs node "mon_groups" to prevent deadlock.
The same changes are also made to the "mon_data" directories.
This results in some unused function parameters that will be cleaned up
in follow-up patch as the focus here is on the fix only in support of
backporting efforts.
Fixes: c7d9aac613 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-4-git-send-email-xiaochen.shen@intel.com
There is a race condition in the following scenario which results in an
use-after-free issue when reading a monitoring file and deleting the
parent ctrl_mon group concurrently:
Thread 1 calls atomic_inc() to take refcount of rdtgrp and then calls
kernfs_break_active_protection() to drop the active reference of kernfs
node in rdtgroup_kn_lock_live().
In Thread 2, kernfs_remove() is a blocking routine. It waits on all sub
kernfs nodes to drop the active reference when removing all subtree
kernfs nodes recursively. Thread 2 could block on kernfs_remove() until
Thread 1 calls kernfs_break_active_protection(). Only after
kernfs_remove() completes the refcount of rdtgrp could be trusted.
Before Thread 1 calls atomic_inc() and kernfs_break_active_protection(),
Thread 2 could call kfree() when the refcount of rdtgrp (sentry) is 0
instead of 1 due to the race.
In Thread 1, in rdtgroup_kn_unlock(), referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_mondata_show) Thread 2 (rdtgroup_rmdir)
-------------------------------- -------------------------
rdtgroup_kn_lock_live
/*
* kn active protection until
* kernfs_break_active_protection(kn)
*/
rdtgrp = kernfs_to_rdtgroup(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry->waitcount should be 1
* but is 0 now due to the race.
*/
kfree(sentry)*[1]
/*
* Only after kernfs_remove()
* completes, the refcount of
* rdtgrp could be trusted.
*/
atomic_inc(&rdtgrp->waitcount)
/* kn->active-- */
kernfs_break_active_protection(kn)
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
/*
* Blocking routine, wait for
* all sub kernfs nodes to drop
* active reference in
* kernfs_break_active_protection.
*/
kernfs_remove(rdtgrp->kn)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
mutex_lock
mon_event_read
rdtgroup_kn_unlock
mutex_unlock
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
/* kn->active++ */
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
Fix it by moving free_all_child_rdtgrp() to after kernfs_remove() in
rdtgroup_rmdir_ctrl() to ensure it has the accurate refcount of rdtgrp.
Fixes: f3cbeacaa0 ("x86/intel_rdt/cqm: Add rmdir support")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-3-git-send-email-xiaochen.shen@intel.com
A resource group (rdtgrp) contains a reference count (rdtgrp->waitcount)
that indicates how many waiters expect this rdtgrp to exist. Waiters
could be waiting on rdtgroup_mutex or some work sitting on a task's
workqueue for when the task returns from kernel mode or exits.
The deletion of a rdtgrp is intended to have two phases:
(1) while holding rdtgroup_mutex the necessary cleanup is done and
rdtgrp->flags is set to RDT_DELETED,
(2) after releasing the rdtgroup_mutex, the rdtgrp structure is freed
only if there are no waiters and its flag is set to RDT_DELETED. Upon
gaining access to rdtgroup_mutex or rdtgrp, a waiter is required to check
for the RDT_DELETED flag.
When unmounting the resctrl file system or deleting ctrl_mon groups,
all of the subdirectories are removed and the data structure of rdtgrp
is forcibly freed without checking rdtgrp->waitcount. If at this point
there was a waiter on rdtgrp then a use-after-free issue occurs when the
waiter starts running and accesses the rdtgrp structure it was waiting
on.
See kfree() calls in [1], [2] and [3] in these two call paths in
following scenarios:
(1) rdt_kill_sb() -> rmdir_all_sub() -> free_all_child_rdtgrp()
(2) rdtgroup_rmdir() -> rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
There are several scenarios that result in use-after-free issue in
following:
Scenario 1:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdt_kill_sb() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdt_kill_sb)
------------------------------- ----------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
mutex_lock
rmdir_all_sub
/*
* sentry and rdtgrp are freed
* without checking refcount
*/
free_all_child_rdtgrp
kfree(sentry)*[1]
kfree(rdtgrp)*[2]
mutex_unlock
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1] or [2].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
Scenario 2:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdtgroup_rmdir() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdtgroup_rmdir)
------------------------------- -------------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry is freed without
* checking refcount
*/
kfree(sentry)*[3]
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [3].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
If CONFIG_DEBUG_SLAB=y, Slab corruption on kmalloc-2k can be observed
like following. Note that "0x6b" is POISON_FREE after kfree(). The
corrupted bits "0x6a", "0x64" at offset 0x424 correspond to
waitcount member of struct rdtgroup which was freed:
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c5b0d000, len=2048
420: 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkjkkkkkkkkkkk
Single bit error detected. Probably bad RAM.
Run memtest86+ or a similar memory test tool.
Next obj: start=ffff9504c5b0d800, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c58ab800, len=2048
420: 6b 6b 6b 6b 64 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkdkkkkkkkkkkk
Prev obj: start=ffff9504c58ab000, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Fix this by taking reference count (waitcount) of rdtgrp into account in
the two call paths that currently do not do so. Instead of always
freeing the resource group it will only be freed if there are no waiters
on it. If there are waiters, the resource group will have its flags set
to RDT_DELETED.
It will be left to the waiter to free the resource group when it starts
running and finding that it was the last waiter and the resource group
has been removed (rdtgrp->flags & RDT_DELETED) since. (1) rdt_kill_sb()
-> rmdir_all_sub() -> free_all_child_rdtgrp() (2) rdtgroup_rmdir() ->
rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
Fixes: f3cbeacaa0 ("x86/intel_rdt/cqm: Add rmdir support")
Fixes: 60cf5e101f ("x86/intel_rdt: Add mkdir to resctrl file system")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-2-git-send-email-xiaochen.shen@intel.com
Both functions call init_intel_cacheinfo() which computes L2 and L3 cache
sizes from CPUID(4). But then they also call cpu_detect_cache_sizes() a
bit later which computes ->x86_tlbsize and L2 size from CPUID(80000006).
However, the latter call is not needed because
- on these CPUs, CPUID(80000006).EBX for ->x86_tlbsize is reserved
- CPUID(80000006).ECX for the L2 size has the same result as CPUID(4)
Therefore, remove the latter call to simplify the code.
[ bp: Rewrite commit message. ]
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1579075257-6985-1-git-send-email-TonyWWang-oc@zhaoxin.com
Monitoring tools that want to find out which resctrl control and monitor
groups a task belongs to must currently read the "tasks" file in every
group until they locate the process ID.
Add an additional file /proc/{pid}/cpu_resctrl_groups to provide this
information:
1) res:
mon:
resctrl is not available.
2) res:/
mon:
Task is part of the root resctrl control group, and it is not associated
to any monitor group.
3) res:/
mon:mon0
Task is part of the root resctrl control group and monitor group mon0.
4) res:group0
mon:
Task is part of resctrl control group group0, and it is not associated
to any monitor group.
5) res:group0
mon:mon1
Task is part of resctrl control group group0 and monitor group mon1.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jinshi Chen <jinshi.chen@intel.com>
Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- a resctrl fix for uninitialized objects found by debugobjects
- a resctrl memory leak fix
- fix the unintended re-enabling of the of SME and SEV CPU flags if
memory encryption was disabled at bootup via the MSR space"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Ensure clearing of SME/SEV features is maintained
x86/resctrl: Fix potential memory leak
x86/resctrl: Fix an imbalance in domain_remove_cpu()
Currently, there are three static keys in the resctrl file system:
rdt_mon_enable_key and rdt_alloc_enable_key indicate if the monitoring
feature and the allocation feature are enabled, respectively. The
rdt_enable_key is enabled when either the monitoring feature or the
allocation feature is enabled.
If no monitoring feature is present (either hardware doesn't support a
monitoring feature or the feature is disabled by the kernel command line
option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key
is disabled.
MBM is a monitoring feature. The MBM overflow handler intends to
check if the monitoring feature is not enabled for fast return.
So check the rdt_mon_enable_key in it instead of the rdt_enable_key as
former is the more accurate check.
[ bp: Massage commit message. ]
Fixes: e33026831b ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1576094705-13660-1-git-send-email-xiaochen.shen@intel.com
New Zhaoxin family 7 CPUs are not affected by the SWAPGS vulnerability. So
mark these CPUs in the cpu vulnerability whitelist accordingly.
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579227872-26972-3-git-send-email-TonyWWang-oc@zhaoxin.com
New Zhaoxin family 7 CPUs are not affected by SPECTRE_V2. So define a
separate cpu_vuln_whitelist bit NO_SPECTRE_V2 and add these CPUs to the cpu
vulnerability whitelist.
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579227872-26972-2-git-send-email-TonyWWang-oc@zhaoxin.com
/proc/cpuinfo currently reports Hardware Lock Elision (HLE) feature to
be present on boot cpu even if it was disabled during the bootup. This
is because cpuinfo_x86->x86_capability HLE bit is not updated after TSX
state is changed via the new MSR IA32_TSX_CTRL.
Update the cached HLE bit also since it is expected to change after an
update to CPUID_CLEAR bit in MSR IA32_TSX_CTRL.
Fixes: 95c5824f75 ("x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default")
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/2529b99546294c893dfa1c89e2b3e46da3369a59.1578685425.git.pawan.kumar.gupta@linux.intel.com
If the SME and SEV features are present via CPUID, but memory encryption
support is not enabled (MSR 0xC001_0010[23]), the feature flags are cleared
using clear_cpu_cap(). However, if get_cpu_cap() is later called, these
feature flags will be reset back to present, which is not desired.
Change from using clear_cpu_cap() to setup_clear_cpu_cap() so that the
clearing of the flags is maintained.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.16.x-
Link: https://lkml.kernel.org/r/226de90a703c3c0be5a49565047905ac4e94e8f3.1579125915.git.thomas.lendacky@amd.com
Add support for a new version of the Load Store unit bank type as
indicated by its McaType value, which will be present in future SMCA
systems.
Add the new (HWID, MCATYPE) tuple. Reuse the same name, since this is
logically the same to the user.
Also, add the new error descriptions to edac_mce_amd.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200110015651.14887-2-Yazen.Ghannam@amd.com
Don't print an error message about VMX being disabled by BIOS if KVM,
the sole user of VMX, is disabled. E.g. if KVM is disabled and the MSR
is unlocked, the kernel will intentionally disable VMX when locking
feature control and then complain that "BIOS" disabled VMX.
Fixes: ef4d3bf198 ("x86/cpu: Clear VMX feature flag if VMX is not fully enabled")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200114202545.20296-1-sean.j.christopherson@intel.com
It is relatively easy to trigger the following boot splat on an Ice Lake
client platform. The call stack is like:
kernel BUG at kernel/timer/timer.c:1152!
Call Trace:
__queue_delayed_work
queue_delayed_work_on
therm_throt_process
intel_thermal_interrupt
...
The reason is that a CPU's thermal interrupt is enabled prior to
executing its hotplug onlining callback which will initialize the
throttling workqueues.
Such a race can lead to therm_throt_process() accessing an uninitialized
therm_work, leading to the above BUG at a very early bootup stage.
Therefore, unmask the thermal interrupt vector only after having setup
the workqueues completely.
[ bp: Heavily massage commit message and correct comment formatting. ]
Fixes: f6656208f0 ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200107004116.59353-1-chuansheng.liu@intel.com
Add a new feature flag, X86_FEATURE_MSR_IA32_FEAT_CTL, to track whether
IA32_FEAT_CTL has been initialized. This will allow KVM, and any future
subsystems that depend on IA32_FEAT_CTL, to rely purely on cpufeatures
to query platform support, e.g. allows a future patch to remove KVM's
manual IA32_FEAT_CTL MSR checks.
Various features (on platforms that support IA32_FEAT_CTL) are dependent
on IA32_FEAT_CTL being configured and locked, e.g. VMX and LMCE. The
MSR is always configured during boot, but only if the CPU vendor is
recognized by the kernel. Because CPUID doesn't incorporate the current
IA32_FEAT_CTL value in its reporting of relevant features, it's possible
for a feature to be reported as supported in cpufeatures but not truly
enabled, e.g. if the CPU supports VMX but the kernel doesn't recognize
the CPU.
As a result, without the flag, KVM would see VMX as supported even if
IA32_FEAT_CTL hasn't been initialized, and so would need to manually
read the MSR and check the various enabling bits to avoid taking an
unexpected #GP on VMXON.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-14-sean.j.christopherson@intel.com
Set the synthetic VMX cpufeatures, which need to be kept to preserve
/proc/cpuinfo's ABI, in the common IA32_FEAT_CTL initialization code.
Remove the vendor code that manually sets the synthetic flags.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-13-sean.j.christopherson@intel.com
Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo. Don't
print VMX flags if no bits are set in word 0, which holds Pin Controls.
Pin Control's INTR and NMI exiting are fundamental pillars of VMX, if
they are not supported then the CPU is broken, it does not actually
support VMX, or the kernel wasn't built with support for the target CPU.
Print the features in a dedicated "vmx flags" line to avoid polluting
the common "flags" and to avoid having to prefix all flags with "vmx_",
which results in horrendously long names.
Keep synthetic VMX flags in cpufeatures to preserve /proc/cpuinfo's ABI
for those flags. This means that "flags" and "vmx flags" will have
duplicate entries for tpr_shadow (virtual_tpr), vnmi, ept, flexpriority,
vpid and ept_ad, but caps the pollution of "flags" at those six VMX
features. The vendor-specific code that populates the synthetic flags
will be consolidated in a future patch to further minimize the lasting
damage.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-12-sean.j.christopherson@intel.com
Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill
the capabilities during IA32_FEAT_CTL MSR initialization.
Make the VMX capabilities dependent on IA32_FEAT_CTL and
X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't
possibly support VMX, or when /proc/cpuinfo is not available.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
Now that IA32_FEAT_CTL is always configured and locked for CPUs that are
known to support VMX[*], clear the VMX capability flag if the MSR is
unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't
set the appropriate VMX enable bit.
[*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's
still possible for IA32_FEAT_CTL to be left unlocked when VMX is
supported by the CPU. This is not fatal, and will be addressed in a
future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
Use the recently added IA32_FEAT_CTL MSR initialization sequence to
opportunistically enable VMX support when running on a Zhaoxin CPU.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-8-sean.j.christopherson@intel.com
Use the recently added IA32_FEAT_CTL MSR initialization sequence to
opportunistically enable VMX support when running on a Centaur CPU.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-7-sean.j.christopherson@intel.com
Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is
left unlocked by BIOS. Configuring feature control at boot time paves
the way for similar enabling of other features, e.g. Software Guard
Extensions (SGX).
Temporarily leave equivalent KVM code in place in order to avoid
introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing
KVM's code would leave the MSR unlocked on those CPUs and would break
existing functionality if people are loading kvm_intel on Centaur and/or
Zhaoxin. Defer enablement of the boot-time configuration on Centaur and
Zhaoxin to future patches to aid bisection.
Note, Local Machine Check Exceptions (LMCE) are also supported by the
kernel and enabled via feature control, but the kernel currently uses
LMCE if and only if the feature is explicitly enabled by BIOS. Keep
the current behavior to avoid introducing bugs, future patches can opt
in to opportunistic enabling if it's deemed desirable to do so.
Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support
VMX, so that other existing and future kernel code that queries the MSR
can assume it's locked.
Start from a clean slate when constructing the value to write to
IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not
to enable random features or fault on the WRMSR.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
As pointed out by Boris, the defines for bits in IA32_FEATURE_CONTROL
are quite a mouthful, especially the VMX bits which must differentiate
between enabling VMX inside and outside SMX (TXT) operation. Rename the
MSR and its bit defines to abbreviate FEATURE_CONTROL as FEAT_CTL to
make them a little friendlier on the eyes.
Arguably, the MSR itself should keep the full IA32_FEATURE_CONTROL name
to match Intel's SDM, but a future patch will add a dedicated Kconfig,
file and functions for the MSR. Using the full name for those assets is
rather unwieldy, so bite the bullet and use IA32_FEAT_CTL so that its
nomenclature is consistent throughout the kernel.
Opportunistically, fix a few other annoyances with the defines:
- Relocate the bit defines so that they immediately follow the MSR
define, e.g. aren't mistaken as belonging to MISC_FEATURE_CONTROL.
- Add whitespace around the block of feature control defines to make
it clear they're all related.
- Use BIT() instead of manually encoding the bit shift.
- Use "VMX" instead of "VMXON" to match the SDM.
- Append "_ENABLED" to the LMCE (Local Machine Check Exception) bit to
be consistent with the kernel's verbiage used for all other feature
control bits. Note, the SDM refers to the LMCE bit as LMCE_ON,
likely to differentiate it from IA32_MCG_EXT_CTL.LMCE_EN. Ignore
the (literal) one-off usage of _ON, the SDM is simply "wrong".
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-2-sean.j.christopherson@intel.com
When writing a pid to file "tasks", a callback function move_myself() is
queued to this task to be called when the task returns from kernel mode
or exits. The purpose of move_myself() is to activate the newly assigned
closid and/or rmid associated with this task. This activation is done by
calling resctrl_sched_in() from move_myself(), the same function that is
called when switching to this task.
If this work is successfully queued but then the task enters PF_EXITING
status (e.g., receiving signal SIGKILL, SIGTERM) prior to the
execution of the callback move_myself(), move_myself() still calls
resctrl_sched_in() since the task status is not currently considered.
When a task is exiting, the data structure of the task itself will
be freed soon. Calling resctrl_sched_in() to write the register that
controls the task's resources is unnecessary and it implies extra
performance overhead.
Add check on task status in move_myself() and return immediately if the
task is PF_EXITING.
[ bp: Massage. ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1578500026-21152-1-git-send-email-xiaochen.shen@intel.com
The function mce_severity() is not required to update its msg argument.
In fact, mce_severity_amd() does not, which makes mce_no_way_out()
return uninitialized data, which may be used later for printing.
Assuming that implementations of mce_severity() either always or never
update the msg argument (which is currently the case), it is sufficient
to initialize the temporary variable in mce_no_way_out().
While at it, avoid printing a useless "Unknown".
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200103150722.20313-4-jschoenh@amazon.de
Since commit
8b38937b7a ("x86/mce: Do not enter deferred errors into the generic
pool twice")
the mce=nobootlog option has become mostly ineffective (after being only
slightly ineffective before), as the code is taking actions on MCEs left
over from boot when they have a usable address.
Move the check for MCP_DONTLOG a bit outward to make it effective again.
Also, since commit
011d826111 ("RAS: Add a Corrected Errors Collector")
the two branches of the remaining "if" at the bottom of machine_check_poll()
do same. Unify them.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200103150722.20313-3-jschoenh@amazon.de
Commit
fa92c58694 ("x86, mce: Support memory error recovery for both UCNA
and Deferred error in machine_check_poll")
added handling of UCNA and Deferred errors by adding them to the ring
for SRAO errors.
Later, commit
fd4cf79fcc ("x86/mce: Remove the MCE ring for Action Optional errors")
switched storage from the SRAO ring to the unified pool that is still
in use today. In order to only act on the intended errors, a filter
for MCE_AO_SEVERITY is used -- effectively removing handling of
UCNA/Deferred errors again.
Extend the severity filter to include UCNA/Deferred errors again.
Also, generalize the naming of the notifier from SRAO to UC to capture
the extended scope.
Note, that this change may cause a message like the following to appear,
as the same address may be reported as SRAO and as UCNA:
Memory failure: 0x5fe3284: already hardware poisoned
Technically, this is a return to previous behavior.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200103150722.20313-2-jschoenh@amazon.de
set_cache_qos_cfg() is leaking memory when the given level is not
RDT_RESOURCE_L3 or RDT_RESOURCE_L2. At the moment, this function is
called with only valid levels but move the allocation after the valid
level checks in order to make it more robust and future proof.
[ bp: Massage commit message. ]
Fixes: 99adde9b37 ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20200102165844.133133-1-shakeelb@google.com
A system that supports resource monitoring may have multiple resources
while not all of these resources are capable of monitoring. Monitoring
related state is initialized only for resources that are capable of
monitoring and correspondingly this state should subsequently only be
removed from these resources that are capable of monitoring.
domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
is true where it will initialize d->mbm_over. However,
domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
all resources, even those that never initialized d->mbm_over because
they are not capable of monitoring. Hence, it triggers a debugobjects
warning when offlining CPUs because those timer debugobjects are never
initialized:
ODEBUG: assert_init not available (active state 0) object type:
timer_list hint: 0x0
WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484
debug_print_object
Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS I40 05/23/2018
RIP: 0010:debug_print_object
Call Trace:
debug_object_assert_init
del_timer
try_to_grab_pending
cancel_delayed_work
resctrl_offline_cpu
cpuhp_invoke_callback
cpuhp_thread_fun
smpboot_thread_fn
kthread
ret_from_fork
Fixes: e33026831b ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: tj@kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191211033042.2188-1-cai@lca.pw
The mutex in mce_inject_log() became unnecessary with commit
5de97c9f6d ("x86/mce: Factor out and deprecate the /dev/mcelog driver"),
though the original reason for its presence only vanished with commit
7298f08ea8 ("x86/mcelog: Get rid of RCU remnants").
Drop the mutex. And as that makes mce_inject_log() identical to mce_log(),
get rid of the former in favor of the latter.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191210000733.17979-7-jschoenh@amazon.de
Linus Torvalds