BMC/Intel-BMC/linux.git/Documentation/admin-guide/kernel-parameters.txt, branch dev-4.19

Merge tag 'v4.19.14' into dev-4.19

2019-01-10T03:32:21+00:00

This is the 4.19.14 stable release

x86/speculation/l1tf: Drop the swap storage limit restriction when l1tf=off

2019-01-09T16:38:41+00:00

commit 5b5e4d623ec8a34689df98e42d038a3b594d2ff9 upstream. Swap storage is restricted to max_swapfile_size (~16TB on x86_64) whenever the system is deemed affected by L1TF vulnerability. Even though the limit is quite high for most deployments it seems to be too restrictive for deployments which are willing to live with the mitigation disabled. We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices which is clearly out of the limit. Drop the swap restriction when l1tf=off is specified. It also doesn't make much sense to warn about too much memory for the l1tf mitigation when it is forcefully disabled by the administrator. [ tglx: Folded the documentation delta change ] Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2") Signed-off-by: Michal Hocko Signed-off-by: Thomas Gleixner Reviewed-by: Pavel Tatashin Reviewed-by: Andi Kleen Acked-by: Jiri Kosina Cc: Linus Torvalds Cc: Dave Hansen Cc: Andi Kleen Cc: Borislav Petkov Cc: Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181113184910.26697-1-mhocko@kernel.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'v4.19.8' into dev-4.19

2018-12-10T23:11:39+00:00

This is the 4.19.8 stable release Signed-off-by: Joel Stanley

x86/speculation: Provide IBPB always command line options

2018-12-05T18:32:04+00:00

commit 55a974021ec952ee460dc31ca08722158639de72 upstream Provide the possibility to enable IBPB always in combination with 'prctl' and 'seccomp'. Add the extra command line options and rework the IBPB selection to evaluate the command instead of the mode selected by the STIPB switch case. Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Jiri Kosina Cc: Tom Lendacky Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: David Woodhouse Cc: Tim Chen Cc: Andi Kleen Cc: Dave Hansen Cc: Casey Schaufler Cc: Asit Mallick Cc: Arjan van de Ven Cc: Jon Masters Cc: Waiman Long Cc: Greg KH Cc: Dave Stewart Cc: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185006.144047038@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/speculation: Add seccomp Spectre v2 user space protection mode

2018-12-05T18:32:04+00:00

commit 6b3e64c237c072797a9ec918654a60e3a46488e2 upstream If 'prctl' mode of user space protection from spectre v2 is selected on the kernel command-line, STIBP and IBPB are applied on tasks which restrict their indirect branch speculation via prctl. SECCOMP enables the SSBD mitigation for sandboxed tasks already, so it makes sense to prevent spectre v2 user space to user space attacks as well. The Intel mitigation guide documents how STIPB works: Setting bit 1 (STIBP) of the IA32_SPEC_CTRL MSR on a logical processor prevents the predicted targets of indirect branches on any logical processor of that core from being controlled by software that executes (or executed previously) on another logical processor of the same core. Ergo setting STIBP protects the task itself from being attacked from a task running on a different hyper-thread and protects the tasks running on different hyper-threads from being attacked. While the document suggests that the branch predictors are shielded between the logical processors, the observed performance regressions suggest that STIBP simply disables the branch predictor more or less completely. Of course the document wording is vague, but the fact that there is also no requirement for issuing IBPB when STIBP is used points clearly in that direction. The kernel still issues IBPB even when STIBP is used until Intel clarifies the whole mechanism. IBPB is issued when the task switches out, so malicious sandbox code cannot mistrain the branch predictor for the next user space task on the same logical processor. Signed-off-by: Jiri Kosina Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Tom Lendacky Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: David Woodhouse Cc: Tim Chen Cc: Andi Kleen Cc: Dave Hansen Cc: Casey Schaufler Cc: Asit Mallick Cc: Arjan van de Ven Cc: Jon Masters Cc: Waiman Long Cc: Greg KH Cc: Dave Stewart Cc: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185006.051663132@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/speculation: Enable prctl mode for spectre_v2_user

2018-12-05T18:32:04+00:00

commit 7cc765a67d8e04ef7d772425ca5a2a1e2b894c15 upstream Now that all prerequisites are in place: - Add the prctl command line option - Default the 'auto' mode to 'prctl' - When SMT state changes, update the static key which controls the conditional STIBP evaluation on context switch. - At init update the static key which controls the conditional IBPB evaluation on context switch. Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Jiri Kosina Cc: Tom Lendacky Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: David Woodhouse Cc: Tim Chen Cc: Andi Kleen Cc: Dave Hansen Cc: Casey Schaufler Cc: Asit Mallick Cc: Arjan van de Ven Cc: Jon Masters Cc: Waiman Long Cc: Greg KH Cc: Dave Stewart Cc: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.958421388@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/speculation: Add command line control for indirect branch speculation

2018-12-05T18:32:03+00:00

commit fa1202ef224391b6f5b26cdd44cc50495e8fab54 upstream Add command line control for user space indirect branch speculation mitigations. The new option is: spectre_v2_user= The initial options are: - on: Unconditionally enabled - off: Unconditionally disabled -auto: Kernel selects mitigation (default off for now) When the spectre_v2= command line argument is either 'on' or 'off' this implies that the application to application control follows that state even if a contradicting spectre_v2_user= argument is supplied. Originally-by: Tim Chen Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Jiri Kosina Cc: Tom Lendacky Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: David Woodhouse Cc: Andi Kleen Cc: Dave Hansen Cc: Casey Schaufler Cc: Asit Mallick Cc: Arjan van de Ven Cc: Jon Masters Cc: Waiman Long Cc: Greg KH Cc: Dave Stewart Cc: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.082720373@linutronix.de Signed-off-by: Greg Kroah-Hartman

/dev/mem: add a devmem kernel parameter to activate the device

2018-12-02T22:31:15+00:00

For security reasons, some configuration needs to run without /dev/mem but on some occasions, to debug HW for instance, it's still useful to be able to reboot the system with access to physical memory. Add a kernel parameter which activates the /dev/mem device only when 'mem.devmem' is enabled. OpenBMC-Staging-Count: 2 Signed-off-by: Cédric Le Goater Signed-off-by: Joel Stanley

USB: Wait for extra delay time after USB_PORT_FEAT_RESET for quirky hub

2018-11-27T15:13:09+00:00

commit 781f0766cc41a9dd2e5d118ef4b1d5d89430257b upstream. Devices connected under Terminus Technology Inc. Hub (1a40:0101) may fail to work after the system resumes from suspend: [ 206.063325] usb 3-2.4: reset full-speed USB device number 4 using xhci_hcd [ 206.143691] usb 3-2.4: device descriptor read/64, error -32 [ 206.351671] usb 3-2.4: device descriptor read/64, error -32 Info for this hub: T: Bus=03 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 2 Spd=480 MxCh= 4 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=1a40 ProdID=0101 Rev=01.11 S: Product=USB 2.0 Hub C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub Some expirements indicate that the USB devices connected to the hub are innocent, it's the hub itself is to blame. The hub needs extra delay time after it resets its port. Hence wait for extra delay, if the device is connected to this quirky hub. Signed-off-by: Kai-Heng Feng Cc: stable Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

x86/earlyprintk: Add a force option for pciserial device

2018-11-27T15:13:00+00:00

[ Upstream commit d2266bbfa9e3e32e3b642965088ca461bd24a94f ] The "pciserial" earlyprintk variant helps much on many modern x86 platforms, but unfortunately there are still some platforms with PCI UART devices which have the wrong PCI class code. In that case, the current class code check does not allow for them to be used for logging. Add a sub-option "force" which overrides the class code check and thus the use of such device can be enforced. [ bp: massage formulations. ] Suggested-by: Borislav Petkov Signed-off-by: Feng Tang Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: "Stuart R . Anderson" Cc: Bjorn Helgaas Cc: David Rientjes Cc: Feng Tang Cc: Frederic Weisbecker Cc: Greg Kroah-Hartman Cc: H Peter Anvin Cc: Ingo Molnar Cc: Jiri Kosina Cc: Jonathan Corbet Cc: Kai-Heng Feng Cc: Kate Stewart Cc: Konrad Rzeszutek Wilk Cc: Peter Zijlstra Cc: Philippe Ombredanne Cc: Thomas Gleixner Cc: Thymo van Beers Cc: alan@linux.intel.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20181002164921.25833-1-feng.tang@intel.com Signed-off-by: Sasha Levin