This patchset adds support for Intel's branch monitoring feature. This feature uses heuristics to detect the occurrence of an ROP(Return Oriented Programming) or ROP like(JOP: Jump oriented programming) attack. These heuristics are based off certain performance monitoring statistics, measured dynamically over a short configurable window period. ROP is a malware trend in which the attacker can compromise a return pointer held on the stack to redirect execution to a different desired instruction. Currently, only the Cannonlake family of Intel processors support this feature. This feature is enabled by CONFIG_PERF_EVENTS_INTEL_BM. Once the kernel is compiled with CONFIG_PERF_EVENTS_INTEL_BM=y on a Cannonlake system, the following perf events are added which can be viewed with perf list: intel_bm/branch-misp/ [Kernel PMU event] intel_bm/call-ret/ [Kernel PMU event] intel_bm/far-branch/ [Kernel PMU event] intel_bm/indirect-branch-misp/ [Kernel PMU event] intel_bm/ret-misp/ [Kernel PMU event] intel_bm/rets/ [Kernel PMU event] A perf-based kernel driver has been used to monitor the occurrence of one of the 6 branch monitoring events. There are 2 counters that each can select between one of these events for evaluation over a specified instruction window size (0 to 1023). For each counter, a threshold value (0 to 127) can be configured to set a point at which an interrupt is generated. Each task can monitor a maximum of 2 events at any given time. Apart from the kernel driver, this patchset adds CPUID of Cannonlake processors to Intel family list and the Documentation/x86/intel_bm.txt file with some information about Intel Branch monitoring. Changes V0->V1: 1. Used the 'is_sampling_event' function 2. Added support to monitor 2 events for every task 3. Corrected typos 4. Added a lock to prevent race condition in concurrent perf_event_open()s 5. Got rid of start()/stop() and added its functionality in add()/del() 6. Removed read() callback as it was not doing anything. 6. Removed code for sampling events as we do not support sampling. 7. Added 'id' member to hw_perf_event::intel_bm to track which counter the event is using. 8. Moved MSR accesses to the add()/del() callbacks Megha Dey (3): x86/cpu/intel: Add Cannonlake to Intel family perf/x86/intel/bm.c: Add Intel Branch Monitoring support x86, bm: Add documentation on Intel Branch Monitoring Documentation/x86/intel_bm.txt | 216 +++++++++++++ arch/x86/events/Kconfig | 10 + arch/x86/events/intel/Makefile | 2 + arch/x86/events/intel/bm.c | 618 ++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/intel-family.h | 2 + arch/x86/include/asm/msr-index.h | 5 + arch/x86/include/asm/processor.h | 4 + include/linux/perf_event.h | 9 +- kernel/events/core.c | 16 + 9 files changed, 881 insertions(+), 1 deletion(-) create mode 100644 Documentation/x86/intel_bm.txt create mode 100644 arch/x86/events/intel/bm.c -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
