kernel/linux.git/drivers/base/cpu.c, branch v4.4.151

x86/speculation/l1tf: Add sysfs reporting for l1tf

2018-08-15T15:42:09+00:00

commit 17dbca119312b4e8173d4e25ff64262119fcef38 upstream L1TF core kernel workarounds are cheap and normally always enabled, However they still should be reported in sysfs if the system is vulnerable or mitigated. Add the necessary CPU feature/bug bits. - Extend the existing checks for Meltdowns to determine if the system is vulnerable. All CPUs which are not vulnerable to Meltdown are also not vulnerable to L1TF - Check for 32bit non PAE and emit a warning as there is no practical way for mitigation due to the limited physical address bits - If the system has more than MAX_PA/2 physical memory the invert page workarounds don't protect the system against the L1TF attack anymore, because an inverted physical address will also point to valid memory. Print a warning in this case and report that the system is vulnerable. Add a function which returns the PFN limit for the L1TF mitigation, which will be used in follow up patches for sanity and range checks. [ tglx: Renamed the CPU feature bit to L1TF_PTEINV ] [ dwmw2: Backport to 4.9 (cpufeatures.h, E820) ] Signed-off-by: Andi Kleen Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Acked-by: Dave Hansen Signed-off-by: David Woodhouse Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

x86/bugs: Expose /sys/../spec_store_bypass

2018-07-25T08:18:24+00:00

commit c456442cd3a59eeb1d60293c26cbe2ff2c4e42cf upstream Add the sysfs file for the new vulerability. It does not do much except show the words 'Vulnerable' for recent x86 cores. Intel cores prior to family 6 are known not to be vulnerable, and so are some Atoms and some Xeon Phi. It assumes that older Cyrix, Centaur, etc. cores are immune. Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Reviewed-by: Ingo Molnar Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman Signed-off-by: Srivatsa S. Bhat Reviewed-by: Matt Helsley (VMware) Reviewed-by: Alexey Makhalov Reviewed-by: Bo Gan Signed-off-by: Greg Kroah-Hartman

sysfs/cpu: Add vulnerability folder

2018-01-17T08:35:33+00:00

commit 87590ce6e373d1a5401f6539f0c59ef92dd924a9 upstream. As the meltdown/spectre problem affects several CPU architectures, it makes sense to have common way to express whether a system is affected by a particular vulnerability or not. If affected the way to express the mitigation should be common as well. Create /sys/devices/system/cpu/vulnerabilities folder and files for meltdown, spectre_v1 and spectre_v2. Allow architectures to override the show function. Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Reviewed-by: Konrad Rzeszutek Wilk Cc: Peter Zijlstra Cc: Will Deacon Cc: Dave Hansen Cc: Linus Torvalds Cc: Borislav Petkov Cc: David Woodhouse Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de Signed-off-by: Greg Kroah-Hartman

cpu: Remove bogus __ref annotation of cpu_subsys_online()

2015-08-05T22:18:26+00:00

In commit 0db0628d9012 ("kernel: delete __cpuinit usage from all core kernel files") cpu_up() lost its __cpuinit annotation, vanishing the need for cpu_subsys_online() to have a __ref annotation. Just drop it to be able to catch real section mismatches in the future. Signed-off-by: Mathias Krause Cc: Paul Gortmaker Signed-off-by: Greg Kroah-Hartman

show nohz_full cpus in sysfs

2015-05-20T07:15:09+00:00

Currently there is no way to query which CPUs are in nohz_full mode from userspace. Export the CPU list running in nohz_full mode in sysfs, specifically in the file /sys/devices/system/cpu/nohz_full This can be used by system management tools like libvirt, openstack, and others to ensure proper task placement. Signed-off-by: Rik van Riel Acked-by: Mike Galbraith Acked-by: Chris Metcalf Signed-off-by: Greg Kroah-Hartman

show isolated cpus in sysfs

2015-05-20T07:15:06+00:00

After system bootup, there is no totally reliable way to see which CPUs are isolated, because the kernel may modify the CPUs specified on the isolcpus= kernel command line option. Export the CPU list that actually got isolated in sysfs, specifically in the file /sys/devices/system/cpu/isolated This can be used by system management tools like libvirt, openstack, and others to ensure proper placement of tasks. Suggested-by: Li Zefan Signed-off-by: Rik van Riel Acked-by: Mike Galbraith Acked-by: Chris Metcalf Signed-off-by: Greg Kroah-Hartman

drivers/base: use %*pb[l] to print bitmaps including cpumasks and nodemasks

2015-02-14T05:21:38+00:00

printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. * Line termination only requires one extra space at the end of the buffer. Use PAGE_SIZE - 1 instead of PAGE_SIZE - 2 when formatting. Signed-off-by: Tejun Heo Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers: base: add cpu_device_create to support per-cpu devices

2014-11-07T19:45:00+00:00

This patch adds a new function to create per-cpu devices. This helps in: 1. reusing the device infrastructure to create any cpu related attributes and corresponding sysfs instead of creating and dealing with raw kobjects directly 2. retaining the legacy path(/sys/devices/system/cpu/..) to support existing sysfs ABI 3. avoiding to create links in the bus directory pointing to the device as there would be per-cpu instance of these devices with the same name since dev->bus is not populated to cpu_sysbus on purpose Signed-off-by: Sudeep Holla Tested-by: Stephen Boyd Cc: Greg Kroah-Hartman Cc: David Herrmann Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman

cpumask: factor out show_cpumap into separate helper function

2014-11-07T19:45:00+00:00

Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null terminated buffer with newline. This patch creates a new helper function cpumap_print_to_pagebuf in cpumask.h using newly added bitmap_print_to_pagebuf and consolidates most of those sysfs functions using the new helper function. Signed-off-by: Sudeep Holla Suggested-by: Stephen Boyd Tested-by: Stephen Boyd Acked-by: "Rafael J. Wysocki" Acked-by: Bjorn Helgaas Acked-by: Peter Zijlstra (Intel) Cc: Greg Kroah-Hartman Cc: x86@kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

x86: align x86 arch with generic CPU modalias handling

2014-02-18T20:45:38+00:00

The x86 CPU feature modalias handling existed before it was reimplemented generically. This patch aligns the x86 handling so that it (a) reuses some more code that is now generic; (b) uses the generic format for the modalias module metadata entry, i.e., it now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of the 'x86cpu:vendor:VVVV:family:FFFF:model:MMMM:feature:,XXXX,YYYY' that was used before. Signed-off-by: Ard Biesheuvel Acked-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman