kernel/linux.git/include/uapi/linux/prctl.h, branch v3.16.61

prctl: Add force disable speculation

2018-10-03T03:09:42+00:00

commit 356e4bfff2c5489e016fdb925adbf12a1e3950ee upstream. For certain use cases it is desired to enforce mitigations so they cannot be undone afterwards. That's important for loader stubs which want to prevent a child from disabling the mitigation again. Will also be used for seccomp(). The extra state preserving of the prctl state for SSB is a preparatory step for EBPF dymanic speculation control. Signed-off-by: Thomas Gleixner [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings

prctl: Add speculation control prctls

2018-10-03T03:09:41+00:00

commit b617cfc858161140d69cc0b5cc211996b557a1c7 upstream. Add two new prctls to control aspects of speculation related vulnerabilites and their mitigations to provide finer grained control over performance impacting mitigations. PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature which is selected with arg2 of prctl(2). The return value uses bit 0-2 with the following meaning: Bit Define Description 0 PR_SPEC_PRCTL Mitigation can be controlled per task by PR_SET_SPECULATION_CTRL 1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is disabled 2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is enabled If all bits are 0 the CPU is not affected by the speculation misfeature. If PR_SPEC_PRCTL is set, then the per task control of the mitigation is available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation misfeature will fail. PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which is selected by arg2 of prctl(2) per task. arg3 is used to hand in the control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE. The common return values are: EINVAL prctl is not implemented by the architecture or the unused prctl() arguments are not 0 ENODEV arg2 is selecting a not supported speculation misfeature PR_SET_SPECULATION_CTRL has these additional return values: ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE ENXIO prctl control of the selected speculation misfeature is disabled The first supported controlable speculation misfeature is PR_SPEC_STORE_BYPASS. Add the define so this can be shared between architectures. Based on an initial patch from Tim Chen and mostly rewritten. Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Reviewed-by: Konrad Rzeszutek Wilk [bwh: Backported to 3.16: - Add the documentation directly under Documentation/ since there is no userspace-api subdirectory or reST index - Adjust context] Signed-off-by: Ben Hutchings

mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLE

2014-04-07T23:35:52+00:00

Add VM_INIT_DEF_MASK, to allow us to set the default flags for VMs. It also adds a prctl control which allows us to set the THP disable bit in mm->def_flags so that VMs will pick up the setting as they are created. Signed-off-by: Alex Thorlton Suggested-by: Oleg Nesterov Cc: Gerald Schaefer Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Paolo Bonzini Cc: "Kirill A. Shutemov" Cc: Mel Gorman Acked-by: Rik van Riel Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Andrea Arcangeli Cc: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: Johannes Weiner Cc: David Rientjes Cc: Paolo Bonzini Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

UAPI: (Scripted) Disintegrate include/linux

2012-10-13T09:46:48+00:00

Signed-off-by: David Howells Acked-by: Arnd Bergmann Acked-by: Thomas Gleixner Acked-by: Michael Kerrisk Acked-by: Paul E. McKenney Acked-by: Dave Jones