BMC/Intel-BMC/linux.git/arch/x86/include/asm/traps.h, branch dev

x86/mce/amd: Introduce deferred error interrupt handler

2015-05-07T08:23:32+00:00

Deferred errors indicate error conditions that were not corrected, but require no action from S/W (or action is optional).These errors provide info about a latent UC MCE that can occur when a poisoned data is consumed by the processor. Processors that report these errors can be configured to generate APIC interrupts to notify OS about the error. Provide an interrupt handler in this patch so that OS can catch these errors as and when they happen. Currently, we simply log the errors and exit the handler as S/W action is not mandated. Signed-off-by: Aravind Gopalakrishnan Cc: Tony Luck Cc: x86-ml Cc: linux-edac Link: http://lkml.kernel.org/r/1430913538-1415-5-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov

x86, traps: Add ist_begin_non_atomic and ist_end_non_atomic

2015-01-02T18:22:46+00:00

In some IST handlers, if the interrupt came from user mode, we can safely enable preemption. Add helpers to do it safely. This is intended to be used my the memory failure code in do_machine_check. Acked-by: Borislav Petkov Signed-off-by: Andy Lutomirski

x86, traps: Track entry into and exit from IST context

2015-01-02T18:22:46+00:00

We currently pretend that IST context is like standard exception context, but this is incorrect. IST entries from userspace are like standard exceptions except that they use per-cpu stacks, so they are atomic. IST entries from kernel space are like NMIs from RCU's perspective -- they are not quiescent states even if they interrupted the kernel during a quiescent state. Add and use ist_enter and ist_exit to track IST context. Even though x86_32 has no IST stacks, we track these interrupts the same way. This fixes two issues: - Scheduling from an IST interrupt handler will now warn. It would previously appear to work as long as we got lucky and nothing overwrote the stack frame. (I don't know of any bugs in this that would trigger the warning, but it's good to be on the safe side.) - RCU handling in IST context was dangerous. As far as I know, only machine checks were likely to trigger this, but it's good to be on the safe side. Note that the machine check handlers appears to have been missing any context tracking at all before this patch. Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Frédéric Weisbecker Signed-off-by: Andy Lutomirski

x86_64, traps: Stop using IST for #SS

2014-11-23T21:56:19+00:00

On a 32-bit kernel, this has no effect, since there are no IST stacks. On a 64-bit kernel, #SS can only happen in user code, on a failed iret to user space, a canonical violation on access via RSP or RBP, or a genuine stack segment violation in 32-bit kernel code. The first two cases don't need IST, and the latter two cases are unlikely fatal bugs, and promoting them to double faults would be fine. This fixes a bug in which the espfix64 code mishandles a stack segment violation. This saves 4k of memory per CPU and a tiny bit of code. Signed-off-by: Andy Lutomirski Reviewed-by: Thomas Gleixner Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

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

2014-06-13T02:18:49+00:00

Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...

Merge branch 'perf/kprobes' into perf/core

2014-06-05T10:26:50+00:00

Conflicts: arch/x86/kernel/traps.c The kprobes enhancements are fully cooked, ship them upstream. Signed-off-by: Ingo Molnar

x86: fix page fault tracing when KVM guest support enabled

2014-05-22T15:47:17+00:00

I noticed on some of my systems that page fault tracing doesn't work: cd /sys/kernel/debug/tracing echo 1 > events/exceptions/enable cat trace; # nothing shows up I eventually traced it down to CONFIG_KVM_GUEST. At least in a KVM VM, enabling that option breaks page fault tracing, and disabling fixes it. I tried on some old kernels and this does not appear to be a regression: it never worked. There are two page-fault entry functions today. One when tracing is on and another when it is off. The KVM code calls do_page_fault() directly instead of calling the traced version: > dotraplinkage void __kprobes > do_async_page_fault(struct pt_regs *regs, unsigned long > error_code) > { > enum ctx_state prev_state; > > switch (kvm_read_and_reset_pf_reason()) { > default: > do_page_fault(regs, error_code); > break; > case KVM_PV_REASON_PAGE_NOT_PRESENT: I'm also having problems with the page fault tracing on bare metal (same symptom of no trace output). I'm unsure if it's related. Steven had an alternative to this which has zero overhead when tracing is off where this includes the standard noops even when tracing is disabled. I'm unconvinced that the extra complexity of his apporach: http://lkml.kernel.org/r/20140508194508.561ed220@gandalf.local.home is worth it, expecially considering that the KVM code is already making page fault entry slower here. This solution is dirt-simple. Cc: Thomas Gleixner Cc: x86@kernel.org Cc: Peter Zijlstra Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: Paolo Bonzini Signed-off-by: Dave Hansen Acked-by: "H. Peter Anvin" Acked-by: Steven Rostedt Signed-off-by: Paolo Bonzini

x86/traps: Make math_error() static

2014-05-14T11:57:26+00:00

Trivial, make math_error() static. Signed-off-by: Oleg Nesterov

kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation

2014-04-24T08:26:38+00:00

Use NOKPROBE_SYMBOL macro for protecting functions from kprobes instead of __kprobes annotation under arch/x86. This applies nokprobe_inline annotation for some cases, because NOKPROBE_SYMBOL() will inhibit inlining by referring the symbol address. This just folds a bunch of previous NOKPROBE_SYMBOL() cleanup patches for x86 to one patch. Signed-off-by: Masami Hiramatsu Link: http://lkml.kernel.org/r/20140417081814.26341.51656.stgit@ltc230.yrl.intra.hitachi.co.jp Cc: Andrew Morton Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Dave Hansen Cc: Fernando Luis Vázquez Cao Cc: Gleb Natapov Cc: Jason Wang Cc: Jesper Nilsson Cc: Jiri Kosina Cc: Jiri Olsa Cc: Jiri Slaby Cc: Johannes Weiner Cc: Jonathan Lebon Cc: Kees Cook Cc: Matt Fleming Cc: Michel Lespinasse Cc: Paolo Bonzini Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Paul Mackerras Cc: Raghavendra K T Cc: Rusty Russell Cc: Seiji Aguchi Cc: Srivatsa Vaddagiri Cc: Tejun Heo Cc: Vineet Gupta Signed-off-by: Ingo Molnar

x86, trace: Register exception handler to trace IDT

2013-11-08T22:15:45+00:00

This patch registers exception handlers for tracing to a trace IDT. To implemented it in set_intr_gate(), this patch does followings. - Register the exception handlers to the trace IDT by prepending "trace_" to the handler's names. - Also, newly introduce trace_page_fault() to add tracepoints in a subsequent patch. Signed-off-by: Seiji Aguchi Link: http://lkml.kernel.org/r/52716DEC.5050204@hds.com Signed-off-by: H. Peter Anvin