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* x86, mm: fault.c, remove #ifdef from do_page_fault()Ingo Molnar2009-02-20
| | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, unify oops handlingIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, unify oops printingIngo Molnar2009-02-20
| | | | | | | | | | | | | | 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>
* x86, mm: fault.c, reorder functionsIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | 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>
* x86, mm, kprobes: fault.c, simplify notify_page_fault()Ingo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, simplify kmmio_fault()Ingo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, enable PF_RSVD checks on 32-bit tooIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, factor out the vm86 fault checkIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c, refactor/simplify the is_prefetch() codeIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | 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>
* x86, mm: fault.c cleanupIngo Molnar2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'tip/x86/urgent' of ↵Ingo Molnar2009-02-20
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into x86/mm
| * x86: check PMD in spurious_fault handlerSteven Rostedt2009-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'x86/untangle2' of ↵Ingo Molnar2009-02-13
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * \ Merge commit 'remotes/tip/x86/paravirt' into x86/untangle2Jeremy Fitzhardinge2009-02-11
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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
* | | Merge branch 'x86/mm' into x86/coreIngo Molnar2009-02-13
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| * | | Merge branch 'linus' into x86/mmIngo Molnar2009-02-06
| |\| | | | | | | | | | | | | | | | | | Conflicts: arch/x86/mm/fault.c
| * | | x86: mm: introduce helper function in fault.cHiroshi Shimamoto2009-02-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | x86: add might_sleep() to do_page_fault()Peter Zijlstra2009-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | Merge branch 'linus' into x86/apicIngo Molnar2009-02-13
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | Conflicts: arch/x86/kernel/acpi/boot.c arch/x86/mm/fault.c
| * | | prevent kprobes from catching spurious page faultsMasami Hiramatsu2009-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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*---. \ \ \ Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', ↵Ingo Molnar2009-01-28
|\ \ \ \ \ \ | | | |/ / / | | |/| / / | | | |/ / | |_|_| / |/| | | 'x86/doc', 'x86/header-fixes', 'x86/mm', 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core
| | | * x86: optimise page fault entry, cleanupJohannes Weiner2009-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | Merge branch 'x86/mm' into core/percpuIngo Molnar2009-01-21
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | Conflicts: arch/x86/mm/fault.c
| * | | x86: optimise x86's do_page_fault (C entry point for the page fault path)Nick Piggin2009-01-20
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | Merge branch 'core/percpu' into stackprotectorIngo Molnar2009-01-18
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | x86: avoid theoretical vmalloc fault loopAndi Kleen2009-01-12
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * mm: invoke oom-killer from page faultNick Piggin2009-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'linus' into stackprotectorIngo Molnar2008-12-31
|\| | | | | | | | | | | Conflicts: arch/x86/include/asm/pda.h kernel/fork.c
| * Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds2008-12-28
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
| | *-. Merge commit 'v2.6.28-rc7'; branch 'x86/dumpstack' into tracing/ftraceIngo Molnar2008-12-03
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge x86/dumpstack into tracing/ftrace because upcoming ftrace changes depend on cleanups already in x86/dumpstack. Also merge to latest upstream -rc.
| | * | | trace: add the MMIO-tracer to the tracer menu, cleanupPekka Paalanen2008-10-27
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup We can remove MMIOTRACE_HOOKS and replace it with just MMIOTRACE. MMIOTRACE_HOOKS is a remnant from the time when I thought that something else could also use the kmmio facilities. Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'x86-core-for-linus' of ↵Linus Torvalds2008-12-28
| |\ \ \ | | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| | * | x86, dumpstack: let signr=0 signal no do_exitAlexander van Heukelum2008-10-22
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change oops_end such that signr=0 signals that do_exit is not to be called. Currently, each use of __die is soon followed by a call to oops_end and 'regs' is set to NULL if oops_end is expected not to call do_exit. Change all such pairs to set signr=0 instead. On x86_64 oops_end is used 'bare' in die_nmi; use signr=0 instead of regs=NULL there, too. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * / CRED: Wrap task credential accesses in the x86 archDavid Howells2008-11-13
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: James Morris <jmorris@namei.org>
| * Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2008-10-16
| |\ | | | | | | | | | | | | | | | | | | | | | | | | 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: fix compat-vdso x86/mm: unify init task OOM handling x86/mm: do not trigger a kernel warning if user-space disables interrupts and generates a page fault
| | * x86/mm: unify init task OOM handlingIngo Molnar2008-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus noticed that the "again:" versus "survive:" OOM logic for the init task was arbitrarily different. The 64-bit codepath is the better one, because it correctly re-lookups the vma after having dropped the ->mmap_sem. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
| | * x86/mm: do not trigger a kernel warning if user-space disables interrupts ↵Linus Torvalds2008-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and generates a page fault Arjan reported a spike in the following bug pattern in v2.6.27: http://www.kerneloops.org/searchweek.php?search=lock_page which happens because hwclock started triggering warnings due to a (correct) might_sleep() check in the MM code. The warning occurs because hwclock uses this dubious sequence of code to run "atomic" code: static unsigned long atomic(const char *name, unsigned long (*op)(unsigned long), unsigned long arg) { unsigned long v; __asm__ volatile ("cli"); v = (*op)(arg); __asm__ volatile ("sti"); return v; } Then it pagefaults in that "atomic" section, triggering the warning. There is no way the kernel could provide "atomicity" in this path, a page fault is a cannot-continue machine event so the kernel has to wait for the page to be filled in. Even if it was just a minor fault we'd have to take locks and might have to spend quite a bit of time with interrupts disabled - not nice to irq latencies in general. So instead just enable interrupts in the pagefault path unconditionally if we come from user-space, and handle the fault. Also, while touching this code, unify some trivial parts of the x86 VM paths at the same time. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'linus' into stackprotectorIngo Molnar2008-10-15
|\| | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/Makefile include/asm-x86/pda.h
| * | traps: x86: remove trace_hardirqs_fixup from pagefault handlerAlexander van Heukelum2008-10-13
| |/ | | | | | | | | | | | | | | | | | | | | | | The last use of trace_hardirqs_fixup is unnecessary, because the trap is taken with interrupt off on i386 as well as x86_64, and the irq-tracer is notified of this from the assembly code. trace_hardirqs_fixup and trace_hardirqs_fixup_flags are removed from include/asm-x86/irqflags.h as they are no longer used. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Merge branch 'linus' into x86/xenIngo Molnar2008-10-12
| |\ | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/process_64.c arch/x86/xen/enlighten.c
| | * x86: mm/fault.c declare do_page_fault before they get usedJaswinder Singh2008-07-23
| | | | | | | | | | | | | | | | | | | | | | | | declared do_page_fault() in asm-x86/trap.h for both X86_32 and X86_64 removed do_invalid_op declaration from mm/fault.c as it is already declared in asm-x86/trap.h Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
| * | x86: adjust vmalloc_sync_all() for Xen (2nd try)Jan Beulich2008-09-06
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Since the fourth PDPT entry cannot be shared under Xen, vmalloc_sync_all() must iterate over pmd-s rather than pgd-s here. Luckily, the code isn't used for native PAE (SHARED_KERNEL_PMD is 1) and the change is benign to non-PAE. Also do a little more cleanup in that function. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
| * Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar2008-07-14
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * Merge branch 'linus' into tracing/mmiotraceIngo Molnar2008-07-07
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| | * | x86: mmiotrace full patch, preview 1Pekka Paalanen2008-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmmio.c handles the list of mmio probes with callbacks, list of traced pages, and attaching into the page fault handler and die notifier. It arms, traps and disarms the given pages, this is the core of mmiotrace. mmio-mod.c is a user interface, hooking into ioremap functions and registering the mmio probes. It also decodes the required information from trapped mmio accesses via the pre and post callbacks in each probe. Currently, hooking into ioremap functions works by redefining the symbols of the target (binary) kernel module, so that it calls the traced versions of the functions. The most notable changes done since the last discussion are: - kmmio.c is a built-in, not part of the module - direct call from fault.c to kmmio.c, removing all dynamic hooks - prepare for unregistering probes at any time - make kmmio re-initializable and accessible to more than one user - rewrite kmmio locking to remove all spinlocks from page fault path Can I abuse call_rcu() like I do in kmmio.c:unregister_kmmio_probe() or is there a better way? The function called via call_rcu() itself calls call_rcu() again, will this work or break? There I need a second grace period for RCU after the first grace period for page faults. Mmiotrace itself (mmio-mod.c) is still a module, I am going to attack that next. At some point I will start looking into how to make mmiotrace a tracer component of ftrace (thanks for the hint, Ingo). Ftrace should make the user space part of mmiotracing as simple as 'cat /debug/trace/mmio > dump.txt'. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | x86: explicit call to mmiotrace in do_page_fault()Pekka Paalanen2008-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The custom page fault handler list is replaced with a single function pointer. All related functions and variables are renamed for mmiotrace. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: pq@iki.fi Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | x86: add a list for custom page fault handlers.Pekka Paalanen2008-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provides kernel modules a way to register custom page fault handlers. On every page fault this will call a list of registered functions. The functions may handle the fault and force do_page_fault() to return immediately. This functionality is similar to the now removed page fault notifiers. Custom page fault handlers are used by debugging and reverse engineering tools. Mmiotrace is one such tool and a patch to add it into the tree will follow. The custom page fault handlers are called earlier in do_page_fault() than the page fault notifiers were. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | x86: simplify vmalloc_sync_allJeremy Fitzhardinge2008-07-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmalloc_sync_all() is only called from register_die_notifier and alloc_vm_area. Neither is on any performance-critical paths, so vmalloc_sync_all() itself is not on any hot paths. Given that the optimisations in vmalloc_sync_all add a fair amount of code and complexity, and are fairly hard to evaluate for correctness, it's better to just remove them to simplify the code rather than worry about its absolute performance. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: xen-devel <xen-devel@lists.xensource.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| *---. \ \ Merge branches 'x86/mmio', 'x86/delay', 'x86/idle', 'x86/oprofile', ↵Ingo Molnar2008-07-08
| |\ \ \ \ \ | | | |_|/ / | | |/| | / | | | | |/ | | | |/| 'x86/debug', 'x86/ptrace' and 'x86/amd-iommu' into x86/devel
| | | | * x86: small unifications of address printingVegard Nossum2008-07-01
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'man 3 printf' tells me that %p should be printed as if by %#x, but this is not true for the kernel, which does not use the '0x' prefix for the %p conversion specifier. A small cast to (void *) is also prettier than #ifdef/#else/#endif. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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