kernel.git/arch/x86/include/asm/thread_info.h, branch linux-3.17.y

uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME

2014-12-06T23:57:16Z

commit 82975bc6a6df743b9a01810fb32cb65d0ec5d60b upstream. x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but not on non-paranoid returns. I suspect that this is a mistake and that the code only works because int3 is paranoid. Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME from the uprobes code. Reported-by: Oleg Nesterov Acked-by: Srikar Dronamraju Acked-by: Borislav Petkov Signed-off-by: Andy Lutomirski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

sched/idle, x86: Switch from TS_POLLING to TIF_POLLING_NRFLAG

2014-05-08T07:16:56Z

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 Cc: Andy Lutomirski Cc: Jiri Kosina Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Link: http://lkml.kernel.org/n/tip-7yksmqtlv4nfowmlqr1rifoi@git.kernel.org Signed-off-by: Ingo Molnar

x86: Keep thread_info on thread stack in x86_32

2014-03-07T00:56:55Z

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 Cc: Peter Zijlstra Cc: Brian Gerst Signed-off-by: Steven Rostedt 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

x86: Prepare removal of previous_esp from i386 thread_info structure

2014-03-07T00:56:54Z

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 Cc: Peter Zijlstra Cc: Brian Gerst Cc: Robert Richter Signed-off-by: Steven Rostedt 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

x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386

2014-03-07T00:56:54Z

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 Link: http://lkml.kernel.org/r/20140206144321.409045251@goodmis.org Signed-off-by: H. Peter Anvin

x86: Nuke the supervisor_stack field in i386 thread_info

2014-03-07T00:56:54Z

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 Cc: Andrew Morton Cc: Peter Zijlstra Cc: Brian Gerst Signed-off-by: Steven Rostedt 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

x86: Use inline assembler instead of global register variable to get sp

2014-01-30T06:17:17Z

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 Link: http://lkml.kernel.org/r/1382458079-24450-6-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin

preempt: Make PREEMPT_ACTIVE generic

2013-11-13T19:21:47Z

No point in having this bit defined by architecture. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20130917183629.090698799@linutronix.de

sched, x86: Provide a per-cpu preempt_count implementation

2013-09-25T12:07:57Z

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 Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-gzn5rfsf8trgjoqx8hyayy3q@git.kernel.org Signed-off-by: Ingo Molnar

x86: kill TIF_DEBUG

2013-07-03T23:08:01Z

Because it is not used. Signed-off-by: Oleg Nesterov Cc: Benjamin Herrenschmidt Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jan Kratochvil Cc: Michael Neuling Cc: Paul Mackerras Cc: Paul Mundt Cc: Will Deacon Cc: Prasad Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds