linux/kernel, branch v4.5

memremap: check pfn validity before passing to pfn_to_page()

2016-03-09T23:43:42Z

In memremap's helper function try_ram_remap(), we dereference a struct page pointer that was derived from a PFN that is known to be covered by a 'System RAM' iomem region, and is thus assumed to be a 'valid' PFN, i.e., a PFN that has a struct page associated with it and is covered by the kernel direct mapping. However, the assumption that there is a 1:1 relation between the System RAM iomem region and the kernel direct mapping is not universally valid on all architectures, and on ARM and arm64, 'System RAM' may include regions for which pfn_valid() returns false. Generally speaking, both __va() and pfn_to_page() should only ever be called on PFNs/physical addresses for which pfn_valid() returns true, so add that check to try_ram_remap(). Signed-off-by: Ard Biesheuvel Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sched/kasan: remove stale KASAN poison after hotplug

2016-03-09T23:43:42Z

Functions which the compiler has instrumented for KASAN place poison on the stack shadow upon entry and remove this poision prior to returning. In the case of CPU hotplug, CPUs exit the kernel a number of levels deep in C code. Any instrumented functions on this critical path will leave portions of the stack shadow poisoned. When a CPU is subsequently brought back into the kernel via a different path, depending on stackframe, layout calls to instrumented functions may hit this stale poison, resulting in (spurious) KASAN splats to the console. To avoid this, clear any stale poison from the idle thread for a CPU prior to bringing a CPU online. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Reviewed-by: Andrey Ryabinin Reviewed-by: Ingo Molnar Cc: Alexander Potapenko Cc: Lorenzo Pieralisi Cc: Peter Zijlstra Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: fix mixed zone detection in devm_memremap_pages

2016-03-09T23:43:42Z

The check for whether we overlap "System RAM" needs to be done at section granularity. For example a system with the following mapping: 100000000-37bffffff : System RAM 37c000000-837ffffff : Persistent Memory ...is unable to use devm_memremap_pages() as it would result in two zones colliding within a given section. Signed-off-by: Dan Williams Cc: Ross Zwisler Reviewed-by: Toshi Kani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

list: kill list_force_poison()

2016-03-09T23:43:42Z

Given we have uninitialized list_heads being passed to list_add() it will always be the case that those uninitialized values randomly trigger the poison value. Especially since a list_add() operation will seed the stack with the poison value for later stack allocations to trip over. For example, see these two false positive reports: list_add attempted on force-poisoned entry WARNING: at lib/list_debug.c:34 [..] NIP [c00000000043c390] __list_add+0xb0/0x150 LR [c00000000043c38c] __list_add+0xac/0x150 Call Trace: __list_add+0xac/0x150 (unreliable) __down+0x4c/0xf8 down+0x68/0x70 xfs_buf_lock+0x4c/0x150 [xfs] list_add attempted on force-poisoned entry(0000000000000500), new->next == d0000000059ecdb0, new->prev == 0000000000000500 WARNING: at lib/list_debug.c:33 [..] NIP [c00000000042db78] __list_add+0xa8/0x140 LR [c00000000042db74] __list_add+0xa4/0x140 Call Trace: __list_add+0xa4/0x140 (unreliable) rwsem_down_read_failed+0x6c/0x1a0 down_read+0x58/0x60 xfs_log_commit_cil+0x7c/0x600 [xfs] Fixes: commit 5c2c2587b132 ("mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup") Signed-off-by: Dan Williams Reported-by: Eryu Guan Tested-by: Eryu Guan Cc: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-03-05T00:57:04Z

Pull tracing fix from Steven Rostedt: "A feature was added in 4.3 that allowed users to filter trace points on a tasks "comm" field. But this prevented filtering on a comm field that is within a trace event (like sched_migrate_task). When trying to filter on when a program migrated, this change prevented the filtering of the sched_migrate_task. To fix this, the event fields are examined first, and then the extra fields like "comm" and "cpu" are examined. Also, instead of testing to assign the comm filter function based on the field's name, the generic comm field is given a new filter type (FILTER_COMM). When this field is used to filter the type is checked. The same is done for the cpu filter field. Two new special filter types are added: "COMM" and "CPU". This allows users to still filter the tasks comm for events that have "comm" as one of their fields, in cases that users would like to filter sched_migrate_task on the comm of the task that called the event, and not the comm of the task that is being migrated" * tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Do not have 'comm' filter override event 'comm' field

tracing: Do not have 'comm' filter override event 'comm' field

2016-03-04T14:57:10Z

Commit 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" added a 'comm' filter that will filter events based on the current tasks struct 'comm'. But this now hides the ability to filter events that have a 'comm' field too. For example, sched_migrate_task trace event. That has a 'comm' field of the task to be migrated. echo 'comm == "bash"' > events/sched_migrate_task/filter will now filter all sched_migrate_task events for tasks named "bash" that migrates other tasks (in interrupt context), instead of seeing when "bash" itself gets migrated. This fix requires a couple of changes. 1) Change the look up order for filter predicates to look at the events fields before looking at the generic filters. 2) Instead of basing the filter function off of the "comm" name, have the generic "comm" filter have its own filter_type (FILTER_COMM). Test against the type instead of the name to assign the filter function. 3) Add a new "COMM" filter that works just like "comm" but will filter based on the current task, even if the trace event contains a "comm" field. Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU". Cc: stable@vger.kernel.org # v4.3+ Fixes: 9f61668073a8d "tracing: Allow triggers to filter for CPU ids and process names" Reported-by: Matt Fleming Signed-off-by: Steven Rostedt

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-02-28T15:52:00Z

Pull perf fixes from Thomas Gleixner: "A rather largish series of 12 patches addressing a maze of race conditions in the perf core code from Peter Zijlstra" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Robustify task_function_call() perf: Fix scaling vs. perf_install_in_context() perf: Fix scaling vs. perf_event_enable() perf: Fix scaling vs. perf_event_enable_on_exec() perf: Fix ctx time tracking by introducing EVENT_TIME perf: Cure event->pending_disable race perf: Fix race between event install and jump_labels perf: Fix cloning perf: Only update context time when active perf: Allow perf_release() with !event->ctx perf: Do not double free perf: Close install vs. exit race

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-02-28T15:48:01Z

Pull scheduler fixlet from Thomas Gleixner: "A trivial printk typo fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix trivial typo in printk() message

Merge tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-02-26T04:12:09Z

Pull tracing fix from Steven Rostedt: "Another small bug reported to me by Chunyu Hu. When perf added a "reg" function to the function tracing event (not a tracepoint), it caused that event to be displayed as a tracepoint and could cause errors in tracepoint handling. That was solved by adding a flag to ignore ftrace non-tracepoint events. But that flag was missed when displaying events in available_events, which should only contain tracepoint events. This broke a documented way to enable all events with: cat available_events > set_event As the function non-tracepoint event would cause that to error out. The commit here fixes that by having the available_events file not list events that have the ignore flag set" * tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix showing function event in available_events

Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2016-02-26T02:54:53Z

Pull libnvdimm fixes from Dan Williams: - Two fixes for compatibility with the ACPI 6.1 specification. Without these fixes multi-interface DIMMs will fail to be probed, and address range scrub commands to find memory errors will give results that the kernel will mis-interpret. For multi-interface DIMMs Linux will accept either the original 6.0 implementation or 6.1. For address range scrub we'll only support 6.1 since ACPI formalized this DSM differently than the original example [1] implemented in v4.2. The expectation is that production systems will only ever ship the ACPI 6.1 address range scrub command definition. - The wider async address range scrub work targeting 4.6 discovered that the original synchronous implementation in 4.5 is not sizing its return buffer correctly. - Arnd caught that my recent fix to the size of the pfn_t flags missed updating the flags variable used in the pmem driver. - Toshi found that we mishandle the memremap() return value in devm_memremap(). * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: nvdimm: use 'u64' for pfn flags devm_memremap: Fix error value when memremap failed nfit: update address range scrub commands to the acpi 6.1 format libnvdimm, tools/testing/nvdimm: fix 'ars_status' output buffer sizing nfit: fix multi-interface dimm handling, acpi6.1 compatibility