linux/arch/x86
Reinette Chatre 80b71c340f x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
The user triggers the creation of a pseudo-locked region when writing
the requested schemata to the schemata resctrl file. The pseudo-locking
of a region is required to be done on a CPU that is associated with the
cache on which the pseudo-locked region will reside. In order to run the
locking code on a specific CPU, the needed CPU has to be selected and
ensured to remain online during the entire locking sequence.

At this time, the cpu_hotplug_lock is not taken during the pseudo-lock
region creation and it is thus possible for a CPU to be selected to run
the pseudo-locking code and then that CPU to go offline before the
thread is able to run on it.

Fix this by ensuring that the cpu_hotplug_lock is taken while the CPU on
which code has to run needs to be controlled. Since the cpu_hotplug_lock
is always taken before rdtgroup_mutex the lock order is maintained.

Fixes: e0bdfe8e36 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: stable <stable@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/b7b17432a80f95a1fa21a1698ba643014f58ad31.1544476425.git.reinette.chatre@intel.com
2018-12-11 21:59:01 +01:00
..
boot x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
configs x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y 2018-10-10 08:29:51 +02:00
crypto crypto: x86/aes-ni - fix build error following fpu template removal 2018-10-08 13:47:02 +08:00
entry x86/vdso: Drop implicit common-page-size linker flag 2018-12-07 18:57:38 +01:00
events perf/x86/intel: Disallow precise_ip on BTS events 2018-11-22 09:45:10 +01:00
hyperv Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 17:54:58 +01:00
ia32
include x86/mm: Fix guard hole handling 2018-12-11 11:19:24 +01:00
kernel x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence 2018-12-11 21:59:01 +01:00
kvm kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb 2018-11-27 12:50:42 +01:00
lib Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 15:24:22 +01:00
math-emu
mm x86/dump_pagetables: Fix LDT remap address marker 2018-12-11 11:19:24 +01:00
net bpf, x32: Fix regression caused by commit 24dea04767 2018-07-26 02:51:12 +02:00
oprofile
pci mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
platform memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
power mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
purgatory kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
ras
realmode
tools x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
um Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix 2018-11-03 23:42:16 +01:00
video
xen x86/mm: Fix guard hole handling 2018-12-11 11:19:24 +01:00
.gitignore
Kbuild
Kconfig x86/Kconfig: Select SCHED_SMT if SMP enabled 2018-11-28 11:57:07 +01:00
Kconfig.cpu x86/cpu: Create Hygon Dhyana architecture support file 2018-09-27 16:14:05 +02:00
Kconfig.debug x86/kconfig: Remove redundant 'default n' lines from all x86 Kconfig's 2018-10-17 08:39:42 +02:00
Makefile x86/build: Fix compiler support check for CONFIG_RETPOLINE 2018-12-05 08:44:02 +01:00
Makefile_32.cpu
Makefile.um kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00