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2009-07-11x86: Remove spurious printk level from segfault messageRoland Dreier
Since commit 5fd29d6c ("printk: clean up handling of log-levels and newlines"), the kernel logs segfaults like: <6>gnome-power-man[24509]: segfault at 20 ip 00007f9d4950465a sp 00007fffbb50fc70 error 4 in libgobject-2.0.so.0.2103.0[7f9d494f7000+45000] with the extra "<6>" being KERN_INFO. This happens because the printk in show_signal_msg() started with KERN_CONT and then used "%s" to pass in the real level; and KERN_CONT is no longer an empty string, and printk only pays attention to the level at the very beginning of the format string. Therefore, remove the KERN_CONT from this printk, since it is now actively causing problems (and never really made any sense). Signed-off-by: Roland Dreier <roland@digitalvampire.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <874otjitkj.fsf@shaolin.home.digitalvampire.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-08Remove multiple KERN_ prefixes from printk formatsJoe Perches
Commit 5fd29d6ccbc98884569d6f3105aeca70858b3e0f ("printk: clean up handling of log-levels and newlines") changed printk semantics. printk lines with multiple KERN_<level> prefixes are no longer emitted as before the patch. <level> is now included in the output on each additional use. Remove all uses of multiple KERN_<level>s in formats. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-21Move FAULT_FLAG_xyz into handle_mm_fault() callersLinus Torvalds
This allows the callers to now pass down the full set of FAULT_FLAG_xyz flags to handle_mm_fault(). All callers have been (mechanically) converted to the new calling convention, there's almost certainly room for architectures to clean up their code and then add FAULT_FLAG_RETRY when that support is added. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-20Merge 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: (45 commits) x86, mce: fix error path in mce_create_device() x86: use zalloc_cpumask_var for mce_dev_initialized x86: fix duplicated sysfs attribute x86: de-assembler-ize asm/desc.h i386: fix/simplify espfix stack switching, move it into assembly i386: fix return to 16-bit stack from NMI handler x86, ioapic: Don't call disconnect_bsp_APIC if no APIC present x86: Remove duplicated #include's x86: msr.h linux/types.h is only required for __KERNEL__ x86: nmi: Add Intel processor 0x6f4 to NMI perfctr1 workaround x86, mce: mce_intel.c needs <asm/apic.h> x86: apic/io_apic.c: dmar_msi_type should be static x86, io_apic.c: Work around compiler warning x86: mce: Don't touch THERMAL_APIC_VECTOR if no active APIC present x86: mce: Handle banks == 0 case in K7 quirk x86, boot: use .code16gcc instead of .code16 x86: correct the conversion of EFI memory types x86: cap iomem_resource to addressable physical memory x86, mce: rename _64.c files which are no longer 64-bit-specific x86, mce: mce.h cleanup ... Manually fix up trivial conflict in arch/x86/mm/fault.c
2009-06-16x86: mm: Read cr2 before prefetching the mmap_lockIngo Molnar
Prefetch instructions can generate spurious faults on certain models of older CPUs. The faults themselves cannot be stopped and they can occur pretty much anywhere - so the way we solve them is that we detect certain patterns and ignore the fault. There is one small path of code where we must not take faults though: the #PF handler execution leading up to the reading of the CR2 (the faulting address). If we take a fault there then we destroy the CR2 value (with that of the prefetching instruction's) and possibly mishandle user-space or kernel-space pagefaults. It turns out that in current upstream we do exactly that: prefetchw(&mm->mmap_sem); /* Get the faulting address: */ address = read_cr2(); This is not good. So turn around the order: first read the cr2 then prefetch the lock address. Reading cr2 is plenty fast (2 cycles) so delaying the prefetch by this amount shouldnt be a big issue performance-wise. [ And this might explain a mystery fault.c warning that sometimes occurs on one an old AMD/Semptron based test-system i have - which does have such prefetch problems. ] Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <npiggin@suse.de> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> LKML-Reference: <20090616030522.GA22162@Krystal> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15x86: add hooks for kmemcheckVegard Nossum
The hooks that we modify are: - Page fault handler (to handle kmemcheck faults) - Debug exception handler (to hide pages after single-stepping the instruction that caused the page fault) Also redefine memset() to use the optimized version if kmemcheck is enabled. (Thanks to Pekka Enberg for minimizing the impact on the page fault handler.) As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable the optimized xor code, and rely instead on the generic C implementation in order to avoid false-positive warnings. Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no> [whitespace fixlet] Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
2009-06-11Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/irqinit.c arch/x86/kernel/irqinit_64.c arch/x86/kernel/traps.c arch/x86/mm/fault.c include/linux/sched.h kernel/exit.c
2009-06-11perf_counter: Standardize event namesPeter Zijlstra
Pure renames only, to PERF_COUNT_HW_* and PERF_COUNT_SW_*. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-10Merge branch 'x86-xen-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits) xen: cache cr0 value to avoid trap'n'emulate for read_cr0 xen/x86-64: clean up warnings about IST-using traps xen/x86-64: fix breakpoints and hardware watchpoints xen: reserve Xen start_info rather than e820 reserving xen: add FIX_TEXT_POKE to fixmap lguest: update lazy mmu changes to match lguest's use of kvm hypercalls xen: honour VCPU availability on boot xen: add "capabilities" file xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet xen/sys/hypervisor: change writable_pt to features xen: add /sys/hypervisor support xen/xenbus: export xenbus_dev_changed xen: use device model for suspending xenbus devices xen: remove suspend_cancel hook xen/dev-evtchn: clean up locking in evtchn xen: export ioctl headers to userspace xen: add /dev/xen/evtchn driver xen: add irq_from_evtchn xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction ...
2009-05-03x86, mm: fault.c, use printk_once() in is_errata93()Ingo Molnar
Andrew pointed out that the 'once' variable has a needlessly function-global scope. We can in fact eliminate it completely, via the use of printk_once(). [ Impact: cleanup ] Reported-by: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-08perf_counter: allow for data addresses to be recordedPeter Zijlstra
Paul suggested we allow for data addresses to be recorded along with the traditional IPs as power can provide these. For now, only the software pagefault events provide data addresses, but in the future power might as well for some events. x86 doesn't seem capable of providing this atm. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> LKML-Reference: <20090408130409.394816925@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06perf_counter: provide major/minor page fault software eventsPeter Zijlstra
Provide separate sw counters for major and minor page faults. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06perf_counter: provide pagefault software eventsPeter Zijlstra
We use the generic software counter infrastructure to provide page fault events. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-30x86/mm: further cleanups of fault.c's include file sectionIngo Molnar
Impact: cleanup Eliminate more than 20 unnecessary #include lines in fault.c Also fix include file dependency bug in asm/traps.h. (this was masked before, by implicit inclusion) Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <tip-56aea8468746e673a4bf50b6a13d97b2d1cbe1e8@git.kernel.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com>
2009-03-29x86/paravirt: remove lazy mode in interruptsJeremy Fitzhardinge
Impact: simplification, robustness Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE when in an interrupt. This prevents interrupt code from accidentally inheriting an outer lazy state, and instead does everything synchronously. Outer batched operations are left deferred. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-02-22x86, mm: fault.c, simplify kmmio_fault(), cleanupIngo Molnar
Clarify the kmmio_fault() comment. Acked-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-20x86, mm: fault.c, update copyrightsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, give another attempt at prefetch handing before SIGBUSIngo Molnar
Impact: extend prefetch handling on 64-bit Currently there's an extra is_prefetch() check done in do_sigbus(), which we only do on 32 bits. This is a last-ditch check before we terminate a task, so it's worth giving prefetch instructions another chance - should none of our existing quirks have caught a prefetch instruction related spurious fault. The only risk is if a prefetch causes a real sigbus, in that case we'll not OOM but try another fault. But this code has been on 32-bit for a long time, so it should be fine in practice. So do this on 64-bit too - and thus remove one more #ifdef. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, remove #ifdef from fault_in_kernel_space()Ingo Molnar
Impact: cleanup Removal of an #ifdef in fault_in_kernel_space(), by making use of the new TASK_SIZE_MAX symbol which is now available on 32-bit too. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAXIngo Molnar
Impact: cleanup Rename TASK_SIZE64 to TASK_SIZE_MAX, and provide the define on 32-bit too. (mapped to TASK_SIZE) This allows 32-bit code to make use of the (former-) TASK_SIZE64 symbol as well, in a clean way. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, remove #ifdef from do_page_fault()Ingo Molnar
Impact: cleanup do_page_fault() has this ugly #ifdef in its prototype: #ifdef CONFIG_X86_64 asmlinkage #endif void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) Replace it with 'dotraplinkage' which maps to exactly the above construct: nothing on 32-bit and asmlinkage on 64-bit. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, unify oops handlingIngo Molnar
Impact: add oops-recursion check to 32-bit Unify the oops state-machine, to the 64-bit version. It is slightly more careful in that it does a recursion check in oops_begin(), and is thus more likely to show the relevant oops. It also means that 32-bit will print one more line at the end of pagefault triggered oopses: printk(KERN_EMERG "CR2: %016lx\n", address); Which is generally good information to be seen in partial-dump digital-camera jpegs ;-) The downside is the somewhat more complex critical path. Both variants have been tested well meanwhile by kernel developers crashing their boxes so i dont think this is a practical worry. This removes 3 ugly #ifdefs from no_context() and makes the function a lot nicer read. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, unify oops printingIngo Molnar
Impact: refine/extend page fault related oops printing on 64-bit - honor the pause_on_oops logic on 64-bit too - print out NX fault warnings on 64-bit as well - factor out the NX fault message to make it git-greppable and readable Note that this means that we do the PF_INSTR check on 32-bit non-PAE as well where it should not occur ... normally. Cannot hurt. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, reorder functionsIngo Molnar
Impact: cleanup Avoid a couple more #ifdefs by moving fundamentally non-unifiable functions into a single #ifdef 32-bit / #else / #endif block in fault.c: vmalloc*(), dump_pagetable(), check_vm8086_mode(). No code changed: text data bss dec hex filename 4618 32 24 4674 1242 fault.o.before 4618 32 24 4674 1242 fault.o.after Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm, kprobes: fault.c, simplify notify_page_fault()Ingo Molnar
Impact: cleanup Remove an #ifdef from notify_page_fault(). The function still compiles to nothing in the !CONFIG_KPROBES case. Introduce kprobes_built_in() and kprobe_fault_handler() helpers to allow this - they returns 0 if !CONFIG_KPROBES. No code changed: text data bss dec hex filename 4618 32 24 4674 1242 fault.o.before 4618 32 24 4674 1242 fault.o.after Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, simplify kmmio_fault()Ingo Molnar
Impact: cleanup Remove an #ifdef from kmmio_fault() - we can do this by providing default implementations for is_kmmio_active() and kmmio_handler(). The compiler optimizes it all away in the !CONFIG_MMIOTRACE case. Also, while at it, clean up mmiotrace.h a bit: - standard header guards - standard vertical spaces for structure definitions No code changed (both with mmiotrace on and off in the config): text data bss dec hex filename 2947 12 12 2971 b9b fault.o.before 2947 12 12 2971 b9b fault.o.after Cc: Pekka Paalanen <pq@iki.fi> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, enable PF_RSVD checks on 32-bit tooIngo Molnar
Impact: improve page fault handling robustness The 'PF_RSVD' flag (bit 3) of the page-fault error_code is a relatively recent addition to x86 CPUs, so the 32-bit do_fault() implementation never had it. This flag gets set when the CPU detects nonzero values in any reserved bits of the page directory entries. Extend the existing 64-bit check for PF_RSVD in do_page_fault() to 32-bit too. If we detect such a fault then we print a more informative oops and the pagetables. This unifies the code some more, removes an ugly #ifdef and improves the 32-bit page fault code robustness a bit. It slightly increases the 32-bit kernel text size. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, factor out the vm86 fault checkIngo Molnar
Impact: cleanup Instead of an ugly, open-coded, #ifdef-ed vm86 related legacy check in do_page_fault(), put it into the check_v8086_mode() helper function and merge it with an existing #ifdef. Also, simplify the code flow a tiny bit in the helper. No code changed: arch/x86/mm/fault.o: text data bss dec hex filename 2711 12 12 2735 aaf fault.o.before 2711 12 12 2735 aaf fault.o.after Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c, refactor/simplify the is_prefetch() codeIngo Molnar
Impact: no functionality changed Factor out the opcode checker into a helper inline. The code got a tiny bit smaller: text data bss dec hex filename 4632 32 24 4688 1250 fault.o.before 4618 32 24 4674 1242 fault.o.after And it got cleaner / easier to review as well. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21x86, mm: fault.c cleanupIngo Molnar
Impact: cleanup, no code changed Clean up various small details, which can be correctness checked automatically: - tidy up the include file section - eliminate unnecessary includes - introduce show_signal_msg() to clean up code flow - standardize the code flow - standardize comments and other style details - more cleanups, pointed out by checkpatch No code changed on either 32-bit nor 64-bit: arch/x86/mm/fault.o: text data bss dec hex filename 4632 32 24 4688 1250 fault.o.before 4632 32 24 4688 1250 fault.o.after the md5 changed due to a change in a single instruction: 2e8a8241e7f0d69706776a5a26c90bc0 fault.o.before.asm c5c3d36e725586eb74f0e10692f0193e fault.o.after.asm Because a __LINE__ reference in a WARN_ONCE() has changed. On 32-bit a few stack offsets changed - no code size difference nor any functionality difference. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-20Merge branch 'tip/x86/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into x86/mm
2009-02-20x86: check PMD in spurious_fault handlerSteven Rostedt
Impact: fix to prevent hard lockup on bad PMD permissions If the PMD does not have the correct permissions for a page access, but the PTE does, the spurious fault handler will mistake the fault as a lazy TLB transaction. This will result in an infinite loop of: fault -> spurious_fault check (pass) -> return to code -> fault This patch adds a check and a warn on if the PTE passes the permissions but the PMD does not. [ Updated: Ingo Molnar suggested using WARN_ONCE with some text ] Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-13Merge branch 'x86/untangle2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen into x86/headers Conflicts: arch/x86/include/asm/page.h arch/x86/include/asm/pgtable.h arch/x86/mach-voyager/voyager_smp.c arch/x86/mm/fault.c
2009-02-13Merge branch 'x86/mm' into x86/coreIngo Molnar
2009-02-13Merge branch 'linus' into x86/apicIngo Molnar
Conflicts: arch/x86/kernel/acpi/boot.c arch/x86/mm/fault.c
2009-02-11Merge commit 'remotes/tip/x86/paravirt' into x86/untangle2Jeremy Fitzhardinge
* commit 'remotes/tip/x86/paravirt': (175 commits) xen: use direct ops on 64-bit xen: make direct versions of irq_enable/disable/save/restore to common code xen: setup percpu data pointers xen: fix 32-bit build resulting from mmu move x86/paravirt: return full 64-bit result x86, percpu: fix kexec with vmlinux x86/vmi: fix interrupt enable/disable/save/restore calling convention. x86/paravirt: don't restore second return reg xen: setup percpu data pointers x86: split loading percpu segments from loading gdt x86: pass in cpu number to switch_to_new_gdt() x86: UV fix uv_flush_send_and_wait() x86/paravirt: fix missing callee-save call on pud_val x86/paravirt: use callee-saved convention for pte_val/make_pte/etc x86/paravirt: implement PVOP_CALL macros for callee-save functions x86/paravirt: add register-saving thunks to reduce caller register pressure x86/paravirt: selectively save/restore regs around pvops calls x86: fix paravirt clobber in entry_64.S x86/pvops: add a paravirt_ident functions to allow special patching xen: move remaining mmu-related stuff into mmu.c ... Conflicts: arch/x86/mach-voyager/voyager_smp.c arch/x86/mm/fault.c
2009-02-06Merge branch 'linus' into x86/mmIngo Molnar
Conflicts: arch/x86/mm/fault.c
2009-02-05prevent kprobes from catching spurious page faultsMasami Hiramatsu
Prevent kprobes from catching spurious faults which will cause infinite recursive page-fault and memory corruption by stack overflow. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-04x86: mm: introduce helper function in fault.cHiroshi Shimamoto
Impact: cleanup Introduce helper function fault_in_kernel_address() to make editors happy. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-29x86: add might_sleep() to do_page_fault()Peter Zijlstra
Impact: widen debug checks VirtualBox calls do_page_fault() from an atomic context but runs into a might_sleep() way pas this point, cure that. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', ↵Ingo Molnar
'x86/doc', 'x86/header-fixes', 'x86/mm', 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core
2009-01-21x86: optimise page fault entry, cleanupJohannes Weiner
tsk is already assigned to current, drop the redundant second assignment. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21Merge branch 'x86/mm' into core/percpuIngo Molnar
Conflicts: arch/x86/mm/fault.c
2009-01-20x86: optimise x86's do_page_fault (C entry point for the page fault path)Nick Piggin
Impact: cleanup, restructure code to improve assembly gcc isn't _all_ that smart about spilling registers to stack or reusing stack slots, even with branch annotations. do_page_fault contained a lot of functionality, so split unlikely paths into their own functions, and mark them as noinline just to be sure. I consider this actually to be somewhat of a cleanup too: the main function now contains about half the number of lines so the normal path is easier to read, while the error cases are also nicely split away. Also, ensure the order of arguments to functions is always the same: regs, addr, error_code. This can reduce code size a tiny bit, and just looks neater too. And add a couple of branch annotations. Before: do_page_fault: subq $360, %rsp #, After: do_page_fault: subq $56, %rsp #, bloat-o-meter: add/remove: 8/0 grow/shrink: 0/1 up/down: 2222/-1680 (542) function old new delta __bad_area_nosemaphore - 506 +506 no_context - 474 +474 vmalloc_fault - 424 +424 spurious_fault - 358 +358 mm_fault_error - 272 +272 bad_area_access_error - 89 +89 bad_area - 89 +89 bad_area_nosemaphore - 10 +10 do_page_fault 2464 784 -1680 Yes, the total size increases by 542 bytes, due to the extra function calls. But these will very rarely be called (except for vmalloc_fault) in a normal workload. Importantly, do_page_fault is less than 1/3rd it's original size, and touches far less stack. Existing gotos and branch hints did move a lot of the infrequently used text out of the fastpath, but that's even further improved after this patch. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18Merge branch 'core/percpu' into stackprotectorIngo Molnar
Conflicts: arch/x86/include/asm/pda.h arch/x86/include/asm/system.h Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12x86: avoid theoretical vmalloc fault loopAndi Kleen
Ajith Kumar noticed: I was going through the vmalloc fault handling for x86_64 and am unclear about the following lines in the vmalloc_fault() function. pgd = pgd_offset(current->mm ?: &init_mm, address); pgd_ref = pgd_offset_k(address); Here the intention is to get the pgd corresponding to the current process and sync it up with the pgd in init_mm(obtained from pgd_offset_k). However, for kernel threads current->mm is NULL and hence pgd = pgd_offset(init_mm, address) = pgd_ref which means the fault handler returns without setting the pgd entry in the MM structure in the context of which the kernel thread has faulted. This could lead to never-ending faults and busy looping of kernel threads like pdflush. So, shouldn't the pgd = pgd_offset(current->mm ?: &init_mm, address); be pgd = pgd_offset(current->active_mm ?: &init_mm, address); We can use active_mm unconditionally because it should be always set. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06mm: invoke oom-killer from page faultNick Piggin
Rather than have the pagefault handler kill a process directly if it gets a VM_FAULT_OOM, have it call into the OOM killer. With increasingly sophisticated oom behaviour (cpusets, memory cgroups, oom killing throttling, oom priority adjustment or selective disabling, panic on oom, etc), it's silly to unconditionally kill the faulting process at page fault time. Create a hook for pagefault oom path to call into instead. Only converted x86 and uml so far. [akpm@linux-foundation.org: make __out_of_memory() static] [akpm@linux-foundation.org: fix comment] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jeff Dike <jdike@addtoit.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-31Merge branch 'linus' into stackprotectorIngo Molnar
Conflicts: arch/x86/include/asm/pda.h kernel/fork.c
2008-12-28Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits) sched, trace: update trace_sched_wakeup() tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3 Revert "x86: disable X86_PTRACE_BTS" ring-buffer: prevent false positive warning ring-buffer: fix dangling commit race ftrace: enable format arguments checking x86, bts: memory accounting x86, bts: add fork and exit handling ftrace: introduce tracing_reset_online_cpus() helper tracing: fix warnings in kernel/trace/trace_sched_switch.c tracing: fix warning in kernel/trace/trace.c tracing/ring-buffer: remove unused ring_buffer size trace: fix task state printout ftrace: add not to regex on filtering functions trace: better use of stack_trace_enabled for boot up code trace: add a way to enable or disable the stack tracer x86: entry_64 - introduce FTRACE_ frame macro v2 tracing/ftrace: add the printk-msg-only option tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp() x86, bts: correctly report invalid bts records ... Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits being already partly merged by the SH merge.
2008-12-28Merge branch 'x86-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (246 commits) x86: traps.c replace #if CONFIG_X86_32 with #ifdef CONFIG_X86_32 x86: PAT: fix address types in track_pfn_vma_new() x86: prioritize the FPU traps for the error code x86: PAT: pfnmap documentation update changes x86: PAT: move track untrack pfnmap stubs to asm-generic x86: PAT: remove follow_pfnmap_pte in favor of follow_phys x86: PAT: modify follow_phys to return phys_addr prot and return value x86: PAT: clarify is_linear_pfn_mapping() interface x86: ia32_signal: remove unnecessary declaration x86: common.c boot_cpu_stack and boot_exception_stacks should be static x86: fix intel x86_64 llc_shared_map/cpu_llc_id anomolies x86: fix warning in arch/x86/kernel/microcode_amd.c x86: ia32.h: remove unused struct sigfram32 and rt_sigframe32 x86: asm-offset_64: use rt_sigframe_ia32 x86: sigframe.h: include headers for dependency x86: traps.c declare functions before they get used x86: PAT: update documentation to cover pgprot and remap_pfn related changes - v3 x86: PAT: add pgprot_writecombine() interface for drivers - v3 x86: PAT: change pgprot_noncached to uc_minus instead of strong uc - v3 x86: PAT: implement track/untrack of pfnmap regions for x86 - v3 ...