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* sched/idle, x86: Switch from TS_POLLING to TIF_POLLING_NRFLAGPeter Zijlstra2014-05-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word. This will allow us, using fetch_or(), to both set NEED_RESCHED and check for POLLING_NRFLAG in a single operation and avoid pointless wakeups. Changing from the non-atomic thread_info::status flags to the atomic thread_info::flags shouldn't be a big issue since most polling state changes were followed/preceded by a full memory barrier anyway. Also, fix up the apm_32 idle function, clearly that was forgotten in the last conversion. The default idle state is !POLLING so just kill the lot. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Link: http://lkml.kernel.org/n/tip-7yksmqtlv4nfowmlqr1rifoi@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Keep thread_info on thread stack in x86_32Steven Rostedt2014-03-061-44/+5
| | | | | | | | | | | | | | | | | | | | | | | | | x86_64 uses a per_cpu variable kernel_stack to always point to the thread stack of current. This is where the thread_info is stored and is accessed from this location even when the irq or exception stack is in use. This removes the complexity of having to maintain the thread info on the stack when interrupts are running and having to copy the preempt_count and other fields to the interrupt stack. x86_32 uses the old method of copying the thread_info from the thread stack to the exception stack just before executing the exception. Having the two different requires #ifdefs and also the x86_32 way is a bit of a pain to maintain. By converting x86_32 to the same method of x86_64, we can remove #ifdefs, clean up the x86_32 code a little, and remove the overhead of the copy. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20110806012354.263834829@goodmis.org Link: http://lkml.kernel.org/r/20140206144321.852942014@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: Prepare removal of previous_esp from i386 thread_info structureSteven Rostedt2014-03-061-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The i386 thread_info contains a previous_esp field that is used to daisy chain the different stacks for dump_stack() (ie. irq, softirq, thread stacks). The goal is to eventual make i386 handling of thread_info the same as x86_64, which means that the thread_info will not be in the stack but as a per_cpu variable. We will no longer depend on thread_info being able to daisy chain different stacks as it will only exist in one location (the thread stack). By moving previous_esp to the end of thread_info and referencing it as an offset instead of using a thread_info field, this becomes a stepping stone to moving the thread_info. The offset to get to the previous stack is rather ugly in this patch, but this is only temporary and the prev_esp will be changed in the next commit. This commit is more for sanity checks of the change. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Robert Richter <rric@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20110806012353.891757693@goodmis.org Link: http://lkml.kernel.org/r/20140206144321.608754481@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386Steven Rostedt (Red Hat)2014-03-061-4/+0
| | | | | | | | | According to a git log -p, GET_THREAD_INFO_WITH_ESP() has only been defined and never been used. Get rid of it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20140206144321.409045251@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: Nuke the supervisor_stack field in i386 thread_infoSteven Rostedt2014-03-061-1/+0
| | | | | | | | | | | | | | | Nothing references the supervisor_stack in the thread_info field, and it does not exist in x86_64. To make the two more the same, it is being removed. Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20110806012353.546183789@goodmis.org Link: http://lkml.kernel.org/r/20140206144321.203619611@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: Use inline assembler instead of global register variable to get spAndi Kleen2014-01-291-3/+5
| | | | | | | | | | | | | | | | | LTO in gcc 4.6/47. has trouble with global register variables. They were used to read the stack pointer. Use a simple inline assembler statement with a mov instead. This also helps LLVM/clang, which does not support global register variables. [ hpa: Ideally this should become a builtin in both gcc and clang. ] v2: More general asm constraint. Fix description (Jan Beulich) Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-6-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* preempt: Make PREEMPT_ACTIVE genericThomas Gleixner2013-11-131-2/+0
| | | | | | | | No point in having this bit defined by architecture. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130917183629.090698799@linutronix.de
* sched, x86: Provide a per-cpu preempt_count implementationPeter Zijlstra2013-09-251-3/+2
| | | | | | | | | | | | | | | | | | | | | | | Convert x86 to use a per-cpu preemption count. The reason for doing so is that accessing per-cpu variables is a lot cheaper than accessing thread_info variables. We still need to save/restore the actual preemption count due to PREEMPT_ACTIVE so we place the per-cpu __preempt_count variable in the same cache-line as the other hot __switch_to() variables such as current_task. NOTE: this save/restore is required even for !PREEMPT kernels as cond_resched() also relies on preempt_count's PREEMPT_ACTIVE to ignore task_struct::state. Also rename thread_info::preempt_count to ensure nobody is 'accidentally' still poking at it. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-gzn5rfsf8trgjoqx8hyayy3q@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: kill TIF_DEBUGOleg Nesterov2013-07-031-3/+1
| | | | | | | | | | | | | | | | | | Because it is not used. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch: Consolidate tsk_is_polling()Thomas Gleixner2013-04-081-2/+0
| | | | | | | | | | | | | | | Move it to a common place. Preparatory patch for implementing set/clear for the idle need_resched poll implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.446034505@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* tracing/syscalls: Allow archs to ignore tracing compat syscallsSteven Rostedt2013-02-121-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tracing of ia32 compat system calls has been a bit of a pain as they use different system call numbers than the 64bit equivalents. I wrote a simple 'lls' program that lists files. I compiled it as a i686 ELF binary and ran it under a x86_64 box. This is the result: echo 0 > /debug/tracing/tracing_on echo 1 > /debug/tracing/events/syscalls/enable echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on grep lls /debug/tracing/trace [.. skipping calls before TS_COMPAT is set ...] lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420) lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000 lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000 lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4) lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000) lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060) lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0 lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2) lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000 lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614) lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0 lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000) lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409279: sys_close(fd: 3) lls-1127 [005] d... 936.421550: sys_close -> 0x200 lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0) lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0 lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802) lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000 lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000) lls-1127 [005] d... 936.421580: sys_capget -> 0x0 lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812) lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000 lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32) lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000 lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0) lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0 lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are obviously incorrect, and confusing. Other efforts have been made to fix this: https://lkml.org/lkml/2012/3/26/367 But the real solution is to rewrite the syscall internals and come up with a fixed solution. One that doesn't require all the kluge that the current solution has. Thus for now, instead of outputting incorrect data, simply ignore them. With this patch the changes now have: #> grep lls /debug/tracing/trace #> Compat system calls simply are not traced. If users need compat syscalls, then they should just use the raw syscall tracepoints. For an architecture to make their compat syscalls ignored, it must define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also define an arch_trace_is_compat_syscall() function that will return true if the current task should ignore tracing the syscall. I want to stress that this change does not affect actual syscalls in any way, shape or form. It is only used within the tracing system and doesn't interfere with the syscall logic at all. The changes are consolidated nicely into trace_syscalls.c and asm/ftrace.h. I had to make one small modification to asm/thread_info.h and that was to remove the include of asm/ftrace.h. As asm/ftrace.h required the current_thread_info() it was causing include hell. That include was added back in 2008 when the function graph tracer was added: commit caf4b323 "tracing, x86: add low level support for ftrace return tracing" It does not need to be included there. Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-10-101-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
| * x86: get rid of TIF_IRET hackeryAl Viro2012-09-201-2/+0
| | | | | | | | | | | | | | | | | | | | TIF_NOTIFY_RESUME will work in precisely the same way; all that is achieved by TIF_IRET is appearing that there's some work to be done, so we end up on the iret exit path. Just use NOTIFY_RESUME. And for execve() do that in 32bit start_thread(), not sys_execve() itself. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | x86: Syscall hooks for userspace RCU extended QSFrederic Weisbecker2012-09-261-3/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | Add syscall slow path hooks to notify syscall entry and exit on CPUs that want to support userspace RCU extended quiescent state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* set_restore_sigmask() is never called without SIGPENDING (and never should be)Al Viro2012-06-011-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helpers: {clear,test,test_and_clear}_restore_sigmask()Al Viro2012-06-011-0/+16
| | | | | | helpers parallel to set_restore_sigmask(), used in the next commits Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'perf-uprobes-for-linus' of ↵Linus Torvalds2012-05-241-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull user-space probe instrumentation from Ingo Molnar: "The uprobes code originates from SystemTap and has been used for years in Fedora and RHEL kernels. This version is much rewritten, reviews from PeterZ, Oleg and myself shaped the end result. This tree includes uprobes support in 'perf probe' - but SystemTap (and other tools) can take advantage of user probe points as well. Sample usage of uprobes via perf, for example to profile malloc() calls without modifying user-space binaries. First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled. If you don't know which function you want to probe you can pick one from 'perf top' or can get a list all functions that can be probed within libc (binaries can be specified as well): $ perf probe -F -x /lib/libc.so.6 To probe libc's malloc(): $ perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0x7eac0) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 Make use of it to create a call graph (as the flat profile is going to look very boring): $ perf record -e probe_libc:malloc -gR make [ perf record: Woken up 173 times to write data ] [ perf record: Captured and wrote 44.190 MB perf.data (~1930712 $ perf report | less 32.03% git libc-2.15.so [.] malloc | --- malloc 29.49% cc1 libc-2.15.so [.] malloc | --- malloc | |--0.95%-- 0x208eb1000000000 | |--0.63%-- htab_traverse_noresize 11.04% as libc-2.15.so [.] malloc | --- malloc | 7.15% ld libc-2.15.so [.] malloc | --- malloc | 5.07% sh libc-2.15.so [.] malloc | --- malloc | 4.99% python-config libc-2.15.so [.] malloc | --- malloc | 4.54% make libc-2.15.so [.] malloc | --- malloc | |--7.34%-- glob | | | |--93.18%-- 0x41588f | | | --6.82%-- glob | 0x41588f ... Or: $ perf report -g flat | less # Overhead Command Shared Object Symbol # ........ ............. ............. .......... # 32.03% git libc-2.15.so [.] malloc 27.19% malloc 29.49% cc1 libc-2.15.so [.] malloc 24.77% malloc 11.04% as libc-2.15.so [.] malloc 11.02% malloc 7.15% ld libc-2.15.so [.] malloc 6.57% malloc ... The core uprobes design is fairly straightforward: uprobes probe points register themselves at (inode:offset) addresses of libraries/binaries, after which all existing (or new) vmas that map that address will have a software breakpoint injected at that address. vmas are COW-ed to preserve original content. The probe points are kept in an rbtree. If user-space executes the probed inode:offset instruction address then an event is generated which can be recovered from the regular perf event channels and mmap-ed ring-buffer. Multiple probes at the same address are supported, they create a dynamic callback list of event consumers. The basic model is further complicated by the XOL speedup: the original instruction that is probed is copied (in an architecture specific fashion) and executed out of line when the probe triggers. The XOL area is a single vma per process, with a fixed number of entries (which limits probe execution parallelism). The API: uprobes are installed/removed via /sys/kernel/debug/tracing/uprobe_events, the API is integrated to align with the kprobes interface as much as possible, but is separate to it. Injecting a probe point is privileged operation, which can be relaxed by setting perf_paranoid to -1. You can use multiple probes as well and mix them with kprobes and regular PMU events or tracepoints, when instrumenting a task." Fix up trivial conflicts in mm/memory.c due to previous cleanup of unmap_single_vma(). * 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf probe: Detect probe target when m/x options are absent perf probe: Provide perf interface for uprobes tracing: Fix kconfig warning due to a typo tracing: Provide trace events interface for uprobes tracing: Extract out common code for kprobes/uprobes trace events tracing: Modify is_delete, is_return from int to bool uprobes/core: Decrement uprobe count before the pages are unmapped uprobes/core: Make background page replacement logic account for rss_stat counters uprobes/core: Optimize probe hits with the help of a counter uprobes/core: Allocate XOL slots for uprobes use uprobes/core: Handle breakpoint and singlestep exceptions uprobes/core: Rename bkpt to swbp uprobes/core: Make order of function parameters consistent across functions uprobes/core: Make macro names consistent uprobes: Update copyright notices uprobes/core: Move insn to arch specific structure uprobes/core: Remove uprobe_opcode_sz uprobes/core: Make instruction tables volatile uprobes: Move to kernel/events/ uprobes/core: Clean up, refactor and improve the code ...
| * uprobes/core: Handle breakpoint and singlestep exceptionsSrikar Dronamraju2012-03-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Uprobes uses exception notifiers to get to know if a thread hit a breakpoint or a singlestep exception. When a thread hits a uprobe or is singlestepping post a uprobe hit, the uprobe exception notifier sets its TIF_UPROBE bit, which will then be checked on its return to userspace path (do_notify_resume() ->uprobe_notify_resume()), where the consumers handlers are run (in task context) based on the defined filters. Uprobe hits are thread specific and hence we need to maintain information about if a task hit a uprobe, what uprobe was hit, the slot where the original instruction was copied for xol so that it can be singlestepped with appropriate fixups. In some cases, special care is needed for instructions that are executed out of line (xol). These are architecture specific artefacts, such as handling RIP relative instructions on x86_64. Since the instruction at which the uprobe was inserted is executed out of line, architecture specific fixups are added so that the thread continues normal execution in the presence of a uprobe. Postpone the signals until we execute the probed insn. post_xol() path does a recalc_sigpending() before return to user-mode, this ensures the signal can't be lost. Uprobes relies on DIE_DEBUG notification to notify if a singlestep is complete. Adds x86 specific uprobe exception notifiers and appropriate hooks needed to determine a uprobe hit and subsequent post processing. Add requisite x86 fixups for xol for uprobes. Specific cases needing fixups include relative jumps (x86_64), calls, etc. Where possible, we check and skip singlestepping the breakpointed instructions. For now we skip single byte as well as few multibyte nop instructions. However this can be extended to other instructions too. Credits to Oleg Nesterov for suggestions/patches related to signal, breakpoint, singlestep handling code. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120313180011.29771.89027.sendpatchset@srdronam.in.ibm.com [ Performed various cleanliness edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-3.5' of ↵Linus Torvalds2012-05-221-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu updates from Tejun Heo: "Contains Alex Shi's three patches to remove percpu_xxx() which overlap with this_cpu_xxx(). There shouldn't be any functional change." * 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: remove percpu_xxx() functions x86: replace percpu_xxx funcs with this_cpu_xxx net: replace percpu_xxx funcs with this_cpu_xxx or __this_cpu_xxx
| * | x86: replace percpu_xxx funcs with this_cpu_xxxAlex Shi2012-05-141-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since percpu_xxx() serial functions are duplicated with this_cpu_xxx(). Removing percpu_xxx() definition and replacing them by this_cpu_xxx() in code. There is no function change in this patch, just preparation for later percpu_xxx serial function removing. On x86 machine the this_cpu_xxx() serial functions are same as __this_cpu_xxx() without no unnecessary premmpt enable/disable. Thanks for Stephen Rothwell, he found and fixed a i386 build error in the patch. Also thanks for Andrew Morton, he kept updating the patchset in Linus' tree. Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Christoph Lameter <cl@gentwo.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | x86: Use common threadinfo allocatorThomas Gleixner2012-05-081-19/+1
| | | | | | | | | | | | | | | | | | | | | | | | The only difference is the free_thread_info function, which frees xstate. Use the new arch_release_task_struct() function instead and switch over to the core allocator. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120505150141.559556763@linutronix.de Cc: x86@kernel.org
* | fork: Remove the weak insanityThomas Gleixner2012-05-081-1/+0
|/ | | | | | | | | | We error out when compiling with gcc4.1.[01] as it miscompiles __weak. The workaround with magic defines is not longer necessary. Make it __weak again. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120505150141.306358267@linutronix.de
* x86: Move is_ia32_task to asm/thread_info.h from asm/compat.hSrikar Dronamraju2012-03-131-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | is_ia32_task() is useful even in !CONFIG_COMPAT cases - utrace will use it for example. Hence move it to a more generic file: asm/thread_info.h Also now is_ia32_task() returns true if CONFIG_X86_32 is defined. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120313140303.17134.1401.sendpatchset@srdronam.in.ibm.com [ Performed minor cleanup ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'x86/x32' into x86/cleanupsIngo Molnar2012-03-131-1/+5
|\ | | | | | | | | | | Merge reason: We are going to merge a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x32: Add a thread flag for x32 processesH. Peter Anvin2012-02-201-0/+2
| | | | | | | | | | | | | | | | An x32 process is *almost* the same thing as a 64-bit process with a 32-bit address limit, but there are a few minor differences -- in particular core dumps are 32 bits and signal handling is different. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * x86: Factor out TIF_IA32 from 32-bit address spaceH. Peter Anvin2012-02-201-1/+3
| | | | | | | | | | | | | | | | | | | | Factor out IA32 (compatibility instruction set) from 32-bit address space in the thread_info flags; this is a precondition patch for x32 support. Originally-by: H. J. Lu <hjl.tools@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org
* | i387: move TS_USEDFPU flag from thread_info to task_structLinus Torvalds2012-02-181-2/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This moves the bit that indicates whether a thread has ownership of the FPU from the TS_USEDFPU bit in thread_info->status to a word of its own (called 'has_fpu') in task_struct->thread.has_fpu. This fixes two independent bugs at the same time: - changing 'thread_info->status' from the scheduler causes nasty problems for the other users of that variable, since it is defined to be thread-synchronous (that's what the "TS_" part of the naming was supposed to indicate). So perfectly valid code could (and did) do ti->status |= TS_RESTORE_SIGMASK; and the compiler was free to do that as separate load, or and store instructions. Which can cause problems with preemption, since a task switch could happen in between, and change the TS_USEDFPU bit. The change to TS_USEDFPU would be overwritten by the final store. In practice, this seldom happened, though, because the 'status' field was seldom used more than once, so gcc would generally tend to generate code that used a read-modify-write instruction and thus happened to avoid this problem - RMW instructions are naturally low fat and preemption-safe. - On x86-32, the current_thread_info() pointer would, during interrupts and softirqs, point to a *copy* of the real thread_info, because x86-32 uses %esp to calculate the thread_info address, and thus the separate irq (and softirq) stacks would cause these kinds of odd thread_info copy aliases. This is normally not a problem, since interrupts aren't supposed to look at thread information anyway (what thread is running at interrupt time really isn't very well-defined), but it confused the heck out of irq_fpu_usable() and the code that tried to squirrel away the FPU state. (It also caused untold confusion for us poor kernel developers). It also turns out that using 'task_struct' is actually much more natural for most of the call sites that care about the FPU state, since they tend to work with the task struct for other reasons anyway (ie scheduling). And the FPU data that we are going to save/restore is found there too. Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to the %esp issue. Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: Raphael Prevost <raphael@buro.asia> Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: Get rid of 'dubious one-bit signed bitfield' sprase warningAnton Vorontsov2012-01-121-2/+2
| | | | | | | | | | | | | | | | This very noisy sparse warning appears on almost every file in the kernel: CHECK init/main.c arch/x86/include/asm/thread_info.h:43:55: error: dubious one-bit signed bitfield arch/x86/include/asm/thread_info.h:44:46: error: dubious one-bit signed bitfield This patch changes sig_on_uaccess_error and uaccess_err flags to unsigned type and thus fixes the warning. Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com> Acked-by: Andy Lutomirski <luto@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'pm-for-linus' of ↵Linus Torvalds2012-01-081-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) PM / Hibernate: Implement compat_ioctl for /dev/snapshot PM / Freezer: fix return value of freezable_schedule_timeout_killable() PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor ... Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused XBT_FORCE_SLEEP bit
| * freezer: remove now unused TIF_FREEZETejun Heo2011-11-211-2/+0
| | | | | | | | | | | | Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-arch@vger.kernel.org
* | x86-64: Slightly shorten line system call entry and exit pathsJan Beulich2011-12-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GET_THREAD_INFO() involves a memory read immediately followed by an "sub" on the value read, in turn (in several cases) immediately followed by a use of the calculated value as the base address of a memory access. This combination of instructions has a non-negligible potential for stalls. In the system call entry point code, however, the (fixed) offset of the stack pointer from the end of the stack is generally known, and hence we can instead avoid the memory load and subtract, and instead do the memory reference using %rsp as the base register. To do so in a legible fashion, introduce a THREAD_INFO() macro which, provided a register (generally %rsp) and the known offset from the end of the stack, produces a suitable memory access operand. The patch attempts to only touch the fast paths (no auditing and alike), but manages to do so only in the 64-bit entry point case; the compatibility mode entry points have so many interdependencies between their various branch targets that it was necessary to also adjust the slow paths to eliminate the risk of having missed some register dependency during code analysis. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/4ED4CD690200007800064075@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86-64: Set siginfo and context on vsyscall emulation faultsAndy Lutomirski2011-12-051-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | To make this work, we teach the page fault handler how to send signals on failed uaccess. This only works for user addresses (kernel addresses will never hit the page fault handler in the first place), so we need to generate signals for those separately. This gets the tricky case right: if the user buffer spans multiple pages and only the second page is invalid, we set cr2 and si_addr correctly. UML relies on this behavior to "fault in" pages as needed. We steal a bit from thread_info.uaccess_err to enable this. Before this change, uaccess_err was a 32-bit boolean value. This fixes issues with UML when vsyscall=emulate. Reported-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: richard -rw- weinberger <richard.weinberger@gmail.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/4c8f91de7ec5cd2ef0f59521a04e1015f11e42b4.1320712291.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-261-1/+1
| | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: NUMA aware alloc_thread_info_node()Eric Dumazet2011-03-221-2/+8
| | | | | | | | | | | | | | | | | | | Add a node parameter to alloc_thread_info(), and change its name to alloc_thread_info_node() This change is needed to allow NUMA aware kthread_create_on_cpu() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'idle-release' of ↵Linus Torvalds2010-05-281-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 * 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6: intel_idle: native hardware cpuidle driver for latest Intel processors ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case acpi_pad: uses MONITOR/MWAIT, so it doesn't need to clear TS_POLLING sched: clarify commment for TS_POLLING ACPI: allow a native cpuidle driver to displace ACPI cpuidle: make cpuidle_curr_driver static cpuidle: add cpuidle_unregister_driver() error check cpuidle: fail to register if !CONFIG_CPU_IDLE
| * sched: clarify commment for TS_POLLINGLen Brown2010-05-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TS_POLLING set tells the scheduler an idle_task will poll need_resched() to look for work. TS_POLLING clear tells resched_task() and wake_up_idle_cpu() that the remote CPU's idle_task is now sleeping in idle, and thus requires a reschedule interrupt notice work. Update the description of TS_POLLING to reflect how it works. "idle task polling need_resched, skip sending interrupt" Wordsmithing-by: Milton Miller <miltonm@bga.com> Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2010-05-201-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits) vlynq: make whole Kconfig-menu dependant on architecture add descriptive comment for TIF_MEMDIE task flag declaration. EEPROM: max6875: Header file cleanup EEPROM: 93cx6: Header file cleanup EEPROM: Header file cleanup agp: use NULL instead of 0 when pointer is needed rtc-v3020: make bitfield unsigned PCI: make bitfield unsigned jbd2: use NULL instead of 0 when pointer is needed cciss: fix shadows sparse warning doc: inode uses a mutex instead of a semaphore. uml: i386: Avoid redefinition of NR_syscalls fix "seperate" typos in comments cocbalt_lcdfb: correct sections doc: Change urls for sparse Powerpc: wii: Fix typo in comment i2o: cleanup some exit paths Documentation/: it's -> its where appropriate UML: Fix compiler warning due to missing task_struct declaration UML: add kernel.h include to signal.c ...
| * | add descriptive comment for TIF_MEMDIE task flag declaration.Andreas Dilger2010-05-141-1/+1
| |/ | | | | | | | | | | Signed-off-by: Andreas Dilger <adilger@dilger.ca> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds2010-05-181-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, fpu: Use static_cpu_has() to implement use_xsave() x86: Add new static_cpu_has() function using alternatives x86, fpu: Use the proper asm constraint in use_xsave() x86, fpu: Unbreak FPU emulation x86: Introduce 'struct fpu' and related API x86: Eliminate TS_XSAVE x86-32: Don't set ignore_fpu_irq in simd exception x86: Merge kernel_math_error() into math_error() x86: Merge simd_math_error() into math_error() x86-32: Rework cache flush denied handler Fix trivial conflict in arch/x86/kernel/process.c
| * | x86: Eliminate TS_XSAVEAvi Kivity2010-05-101-1/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fpu code currently uses current->thread_info->status & TS_XSAVE as a way to distinguish between XSAVE capable processors and older processors. The decision is not really task specific; instead we use the task status to avoid a global memory reference - the value should be the same across all threads. Eliminate this tie-in into the task structure by using an alternative instruction keyed off the XSAVE cpu feature; this results in shorter and faster code, without introducing a global memory reference. [ hpa: in the future, this probably should use an asm jmp ] Signed-off-by: Avi Kivity <avi@redhat.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <1273135546-29690-2-git-send-email-avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, ptrace: Fix block-stepPeter Zijlstra2010-03-261-1/+3
| | | | | | | | | | | | | | | | | | | | Implement ptrace-block-step using TIF_BLOCKSTEP which will set DEBUGCTLMSR_BTF when set for a task while preserving any other DEBUGCTLMSR bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100325135414.017536066@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86, perf, bts, mm: Delete the never used BTS-ptrace codePeter Zijlstra2010-03-261-5/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: get rid of the insane TIF_ABI_PENDING bitH. Peter Anvin2010-01-291-2/+0
| | | | | | | | | | | | | | Now that the previous commit made it possible to do the personality setting at the point of no return, we do just that for ELF binaries. And suddenly all the reasons for that insane TIF_ABI_PENDING bit go away, and we can just make SET_PERSONALITY() just do the obvious thing for a 32-bit compat process. Everything becomes much more straightforward this way. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* core, x86: Add user return notifiersAvi Kivity2009-10-011-2/+5
| | | | | | | | | | | | | | Add a general per-cpu notifier that is called whenever the kernel is about to return to userspace. The notifier uses a thread_info flag and existing checks, so there is no impact on user return or context switch fast paths. This will be used initially to speed up KVM task switching by lazily updating MSRs. Signed-off-by: Avi Kivity <avi@redhat.com> LKML-Reference: <1253342422-13811-1-git-send-email-avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* Merge branch 'x86-percpu-for-linus' of ↵Linus Torvalds2009-09-141-1/+1
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-percpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, percpu: Collect hot percpu variables into one cacheline x86, percpu: Fix DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() x86, percpu: Add 'percpu_read_stable()' interface for cacheable accesses
| * x86, percpu: Add 'percpu_read_stable()' interface for cacheable accessesLinus Torvalds2009-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is very useful for some common things like 'get_current()' and 'get_thread_info()', which can be used multiple times in a function, and where the result is cacheable. tj: Added the magical undocumented "P" modifier to UP __percpu_arg() to force gcc to dereference the pointer value passed in via the "p" input constraint. Without this, percpu_read_stable() returns the address of the percpu variable. Also added comment explaining the difference between percpu_read() and percpu_read_stable(). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | tracing: Rename FTRACE_SYSCALLS for tracepointsJosh Stone2009-08-261-6/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | s/HAVE_FTRACE_SYSCALLS/HAVE_SYSCALL_TRACEPOINTS/g s/TIF_SYSCALL_FTRACE/TIF_SYSCALL_TRACEPOINT/g The syscall enter/exit tracing is no longer specific to just ftrace, so they now have names that reflect their tie to tracepoints instead. Signed-off-by: Josh Stone <jistone@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Jiaying Zhang <jiayingz@google.com> Cc: Martin Bligh <mbligh@google.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> LKML-Reference: <1251150194-1713-2-git-send-email-jistone@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* sched: INIT_PREEMPT_COUNTPeter Zijlstra2009-07-101-1/+1
| | | | | | | | | | | | | | | | | | | | | Pull the initial preempt_count value into a single definition site. Maintainers for: alpha, ia64 and m68k, please have a look, your arch code is funny. The header magic is a bit odd, but similar to the KERNEL_DS one, CPP waits with expanding these macros until the INIT_THREAD_INFO macro itself is expanded, which is in arch/*/kernel/init_task.c where we've already included sched.h so we're good. Cc: tony.luck@intel.com Cc: rth@twiddle.net Cc: geert@linux-m68k.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kmemcheck: add hooks for the page allocatorVegard Nossum2009-06-151-2/+2
| | | | | | | | | | | | | | | This adds support for tracking the initializedness of memory that was allocated with the page allocator. Highmem requests are not tracked. Cc: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> [build fix for !CONFIG_KMEMCHECK] Signed-off-by: Ingo Molnar <mingo@elte.hu> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
* Merge commit 'origin/master' into for-linus/xen/masterJeremy Fitzhardinge2009-04-071-3/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * commit 'origin/master': (4825 commits) Fix build errors due to CONFIG_BRANCH_TRACER=y parport: Use the PCI IRQ if offered tty: jsm cleanups Adjust path to gpio headers KGDB_SERIAL_CONSOLE check for module Change KCONFIG name tty: Blackin CTS/RTS Change hardware flow control from poll to interrupt driven Add support for the MAX3100 SPI UART. lanana: assign a device name and numbering for MAX3100 serqt: initial clean up pass for tty side tty: Use the generic RS485 ioctl on CRIS tty: Correct inline types for tty_driver_kref_get() splice: fix deadlock in splicing to file nilfs2: support nanosecond timestamp nilfs2: introduce secondary super block nilfs2: simplify handling of active state of segments nilfs2: mark minor flag for checkpoint created by internal operation nilfs2: clean up sketch file nilfs2: super block operations fix endian bug ... Conflicts: arch/x86/include/asm/thread_info.h arch/x86/lguest/boot.c drivers/xen/manage.c
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