kernel/linux.git/arch, branch linux-5.9.y

x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled

2020-12-21T12:28:21+00:00

commit 06c5fe9b12dde1b62821f302f177c972bb1c81f9 upstream The MBA software controller (mba_sc) is a feedback loop which periodically reads MBM counters and tries to restrict the bandwidth below a user-specified value. It tags along the MBM counter overflow handler to do the updates with 1s interval in mbm_update() and update_mba_bw(). The purpose of mbm_update() is to periodically read the MBM counters to make sure that the hardware counter doesn't wrap around more than once between user samplings. mbm_update() calls __mon_event_count() for local bandwidth updating when mba_sc is not enabled, but calls mbm_bw_count() instead when mba_sc is enabled. __mon_event_count() will not be called for local bandwidth updating in MBM counter overflow handler, but it is still called when reading MBM local bandwidth counter file 'mbm_local_bytes', the call path is as below: rdtgroup_mondata_show() mon_event_read() mon_event_count() __mon_event_count() In __mon_event_count(), m->chunks is updated by delta chunks which is calculated from previous MSR value (m->prev_msr) and current MSR value. When mba_sc is enabled, m->chunks is also updated in mbm_update() by mistake by the delta chunks which is calculated from m->prev_bw_msr instead of m->prev_msr. But m->chunks is not used in update_mba_bw() in the mba_sc feedback loop. When reading MBM local bandwidth counter file, m->chunks was changed unexpectedly by mbm_bw_count(). As a result, the incorrect local bandwidth counter which calculated from incorrect m->chunks is shown to the user. Fix this by removing incorrect m->chunks updating in mbm_bw_count() in MBM counter overflow handler, and always calling __mon_event_count() in mbm_update() to make sure that the hardware local bandwidth counter doesn't wrap around. Test steps: # Run workload with aggressive memory bandwidth (e.g., 10 GB/s) git clone https://github.com/intel/intel-cmt-cat && cd intel-cmt-cat && make ./tools/membw/membw -c 0 -b 10000 --read # Enable MBA software controller mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl # Create control group c1 mkdir /sys/fs/resctrl/c1 # Set MB throttle to 6 GB/s echo "MB:0=6000;1=6000" > /sys/fs/resctrl/c1/schemata # Write PID of the workload to tasks file echo `pidof membw` > /sys/fs/resctrl/c1/tasks # Read local bytes counters twice with 1s interval, the calculated # local bandwidth is not as expected (approaching to 6 GB/s): local_1=`cat /sys/fs/resctrl/c1/mon_data/mon_L3_00/mbm_local_bytes` sleep 1 local_2=`cat /sys/fs/resctrl/c1/mon_data/mon_L3_00/mbm_local_bytes` echo "local b/w (bytes/s):" `expr $local_2 - $local_1` Before fix: local b/w (bytes/s): 11076796416 After fix: local b/w (bytes/s): 5465014272 Fixes: ba0f26d8529c (x86/intel_rdt/mba_sc: Prepare for feedback loop) Signed-off-by: Xiaochen Shen Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Cc: Link: https://lkml.kernel.org/r/1607063279-19437-1-git-send-email-xiaochen.shen@intel.com Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

x86/resctrl: Remove unused struct mbm_state::chunks_bw

2020-12-21T12:28:21+00:00

commit abe8f12b44250d02937665033a8b750c1bfeb26e upstream Nothing reads struct mbm_states's chunks_bw value, its a copy of chunks. Remove it. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Reinette Chatre Link: https://lkml.kernel.org/r/20200708163929.2783-2-james.morse@arm.com Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

KVM: mmu: Fix SPTE encoding of MMIO generation upper half

2020-12-21T12:28:20+00:00

commit 34c0f6f2695a2db81e09a3ab7bdb2853f45d4d3d upstream. Commit cae7ed3c2cb0 ("KVM: x86: Refactor the MMIO SPTE generation handling") cleaned up the computation of MMIO generation SPTE masks, however it introduced a bug how the upper part was encoded: SPTE bits 52-61 were supposed to contain bits 10-19 of the current generation number, however a missing shift encoded bits 1-10 there instead (mostly duplicating the lower part of the encoded generation number that then consisted of bits 1-9). In the meantime, the upper part was shrunk by one bit and moved by subsequent commits to become an upper half of the encoded generation number (bits 9-17 of bits 0-17 encoded in a SPTE). In addition to the above, commit 56871d444bc4 ("KVM: x86: fix overlap between SPTE_MMIO_MASK and generation") has changed the SPTE bit range assigned to encode the generation number and the total number of bits encoded but did not update them in the comment attached to their defines, nor in the KVM MMU doc. Let's do it here, too, since it is too trivial thing to warrant a separate commit. Fixes: cae7ed3c2cb0 ("KVM: x86: Refactor the MMIO SPTE generation handling") Signed-off-by: Maciej S. Szmigiero Message-Id: <156700708db2a5296c5ed7a8b9ac71f1e9765c85.1607129096.git.maciej.szmigiero@oracle.com> Cc: stable@vger.kernel.org [Reorganize macros so that everything is computed from the bit ranges. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86/kprobes: Fix optprobe to detect INT3 padding correctly

2020-12-16T09:58:38+00:00

commit 0d07c0ec4381f630c801539c79ad8dcc627f6e4a upstream. Commit 7705dc855797 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes") changed the padding bytes between functions from NOP to INT3. However, when optprobe decodes a target function it finds INT3 and gives up the jump optimization. Instead of giving up any INT3 detection, check whether the rest of the bytes to the end of the function are INT3. If all of them are INT3, those come from the linker. In that case, continue the optprobe jump optimization. [ bp: Massage commit message. ] Fixes: 7705dc855797 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes") Reported-by: Adam Zabrocki Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/160767025681.3880685.16021570341428835411.stgit@devnote2 Signed-off-by: Greg Kroah-Hartman

x86/apic/vector: Fix ordering in vector assignment

2020-12-16T09:58:38+00:00

commit 190113b4c6531c8e09b31d5235f9b5175cbb0f72 upstream. Prarit reported that depending on the affinity setting the ' irq $N: Affinity broken due to vector space exhaustion.' message is showing up in dmesg, but the vector space on the CPUs in the affinity mask is definitely not exhausted. Shung-Hsi provided traces and analysis which pinpoints the problem: The ordering of trying to assign an interrupt vector in assign_irq_vector_any_locked() is simply wrong if the interrupt data has a valid node assigned. It does: 1) Try the intersection of affinity mask and node mask 2) Try the node mask 3) Try the full affinity mask 4) Try the full online mask Obviously #2 and #3 are in the wrong order as the requested affinity mask has to take precedence. In the observed cases #1 failed because the affinity mask did not contain CPUs from node 0. That made it allocate a vector from node 0, thereby breaking affinity and emitting the misleading message. Revert the order of #2 and #3 so the full affinity mask without the node intersection is tried before actually affinity is broken. If no node is assigned then only the full affinity mask and if that fails the full online mask is tried. Fixes: d6ffc6ac83b1 ("x86/vector: Respect affinity mask in irq descriptor") Reported-by: Prarit Bhargava Reported-by: Shung-Hsi Yu Signed-off-by: Thomas Gleixner Tested-by: Shung-Hsi Yu Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87ft4djtyp.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/membarrier: Get rid of a dubious optimization

2020-12-16T09:58:38+00:00

commit a493d1ca1a03b532871f1da27f8dbda2b28b04c4 upstream. sync_core_before_usermode() had an incorrect optimization. If the kernel returns from an interrupt, it can get to usermode without IRET. It just has to schedule to a different task in the same mm and do SYSRET. Fortunately, there were no callers of sync_core_before_usermode() that could have had in_irq() or in_nmi() equal to true, because it's only ever called from the scheduler. While at it, clarify a related comment. Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Mathieu Desnoyers Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/5afc7632be1422f91eaf7611aaaa1b5b8580a086.1607058304.git.luto@kernel.org Signed-off-by: Greg Kroah-Hartman

x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP

2020-12-16T09:58:38+00:00

commit 29ac40cbed2bc06fa218ca25d7f5e280d3d08a25 upstream. The PAT bit is in different locations for 4k and 2M/1G page table entries. Add a definition for _PAGE_LARGE_CACHE_MASK to represent the three caching bits (PWT, PCD, PAT), similar to _PAGE_CACHE_MASK for 4k pages, and use it in the definition of PMD_FLAGS_DEC_WP to get the correct PAT index for write-protected pages. Fixes: 6ebcb060713f ("x86/mm: Add support to encrypt the kernel in-place") Signed-off-by: Arvind Sankar Signed-off-by: Borislav Petkov Tested-by: Tom Lendacky Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20201111160946.147341-1-nivedita@alum.mit.edu Signed-off-by: Greg Kroah-Hartman

s390: fix irq state tracing

2020-12-16T09:58:34+00:00

[ Upstream commit b1cae1f84a0f609a34ebcaa087fbecef32f69882 ] With commit 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") common code calls arch_cpu_idle() with a lockdep state that tells irqs are on. This doesn't work very well for s390: psw_idle() will enable interrupts to wait for an interrupt. As soon as an interrupt occurs the interrupt handler will verify if the old context was psw_idle(). If that is the case the interrupt enablement bits in the old program status word will be cleared. A subsequent test in both the external as well as the io interrupt handler checks if in the old context interrupts were enabled. Due to the above patching of the old program status word it is assumed the old context had interrupts disabled, and therefore a call to TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in turn makes lockdep incorrectly "think" that interrupts are enabled within the interrupt handler. Fix this by unconditionally calling TRACE_IRQS_OFF when entering interrupt handlers. Also call unconditionally TRACE_IRQS_ON when leaving interrupts handlers. This leaves the special psw_idle() case, which now returns with interrupts disabled, but has an "irqs on" lockdep state. So callers of psw_idle() must adjust the state on their own, if required. This is currently only __udelay_disabled(). Fixes: 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") Acked-by: Peter Zijlstra (Intel) Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

arm64: tegra: Disable the ACONNECT for Jetson TX2

2020-12-16T09:58:33+00:00

[ Upstream commit fb319496935b7475a863a00c76895e8bb3216704 ] Commit ff4c371d2bc0 ("arm64: defconfig: Build ADMA and ACONNECT driver") enable the Tegra ADMA and ACONNECT drivers and this is causing resume from system suspend to fail on Jetson TX2. Resume is failing because the ACONNECT driver is being resumed before the BPMP driver, and the ACONNECT driver is attempting to power on a power-domain that is provided by the BPMP. While a proper fix for the resume sequencing problem is identified, disable the ACONNECT for Jetson TX2 temporarily to avoid breaking system suspend. Please note that ACONNECT driver is used by the Audio Processing Engine (APE) on Tegra, but because there is no mainline support for APE on Jetson TX2 currently, disabling the ACONNECT does not disable any useful feature at the moment. Signed-off-by: Jon Hunter Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

sched/idle: Fix arch_cpu_idle() vs tracing

2020-12-16T09:58:32+00:00

[ Upstream commit 58c644ba512cfbc2e39b758dd979edd1d6d00e27 ] We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mark Rutland Tested-by: Mark Rutland Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org Signed-off-by: Sasha Levin