- 11 1月, 2006 1 次提交
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由 Anil S Keshavamurthy 提交于
Since Kprobes runtime exception handlers is now lock free as this code path is now using RCU to walk through the list, there is no need for the register/unregister{_kprobe} to use spin_{lock/unlock}_isr{save/restore}. The serialization during registration/unregistration is now possible using just a mutex. In the above process, this patch also fixes a minor memory leak for x86_64 and powerpc. Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 13 12月, 2005 1 次提交
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由 Keshavamurthy Anil S 提交于
When multiple probes are registered at the same address and if due to some recursion (probe getting triggered within a probe handler), we skip calling pre_handlers and just increment nmissed field. The below patch make sure it walks the list for multiple probes case. Without the below patch we get incorrect results of nmissed count for multiple probe case. Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 07 11月, 2005 4 次提交
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Reorganize the preempt_disable/enable calls to eliminate the extra preempt depth. Changes based on Paul McKenney's review suggestions for the kprobes RCU changeset. Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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Changes to the arch kprobes infrastructure to take advantage of the locking changes introduced by usage of RCU for synchronization. All handlers are now run without any locks held, so they have to be re-entrant or provide their own synchronization. Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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I386 changes to track kprobe execution on a per-cpu basis. We now track the kprobe state machine independently on each cpu, using an arch specific kprobe control block. Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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The following set of patches are aimed at improving kprobes scalability. We currently serialize kprobe registration, unregistration and handler execution using a single spinlock - kprobe_lock. With these changes, kprobe handlers can run without any locks held. It also allows for simultaneous kprobe handler executions on different processors as we now track kprobe execution on a per processor basis. It is now necessary that the handlers be re-entrant since handlers can run concurrently on multiple processors. All changes have been tested on i386, ia64, ppc64 and x86_64, while sparc64 has been compile tested only. The patches can be viewed as 3 logical chunks: patch 1: Reorder preempt_(dis/en)able calls patches 2-7: Introduce per_cpu data areas to track kprobe execution patches 8-9: Use RCU to synchronize kprobe (un)registration and handler execution. Thanks to Maneesh Soni, James Keniston and Anil Keshavamurthy for their review and suggestions. Thanks again to Anil, Hien Nguyen and Kevin Stafford for testing the patches. This patch: Reorder preempt_disable/enable() calls in arch kprobes files in preparation to introduce locking changes. No functional changes introduced by this patch. Signed-off-by: NAnanth N Mavinakayahanalli <ananth@in.ibm.com> Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 08 9月, 2005 3 次提交
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由 Keshavamurthy Anil S 提交于
This patch fixes a race condition where in system used to hang or sometime crash within minutes when kprobes are inserted on ISR routine and a task routine. The fix has been stress tested on i386, ia64, pp64 and on x86_64. To reproduce the problem insert kprobes on schedule() and do_IRQ() functions and you should see hang or system crash. Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Jim Keniston 提交于
This patch fixes a bug in kprobes's handling of a corner case on i386 and x86_64. On an SMP system, if one CPU unregisters a kprobe just after another CPU hits that probepoint, kprobe_handler() on the latter CPU sees that the kprobe has been unregistered, and attempts to let the CPU continue as if the probepoint hadn't been hit. The bug is that on i386 and x86_64, we were neglecting to set the IP back to the beginning of the probed instruction. This could cause an oops or crash. This bug doesn't exist on ppc64 and ia64, where a breakpoint instruction leaves the IP pointing to the beginning of the instruction. I don't know about sparc64. (Dave, could you please advise?) This fix has been tested on i386 and x86_64 SMP systems. To reproduce the problem, set one CPU to work registering and unregistering a kprobe repeatedly, and another CPU pounding the probepoint in a tight loop. Acked-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NJim Keniston <jkenisto@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Prasanna S Panchamukhi 提交于
This patch contains the i386 architecture specific changes to prevent the possible race conditions. Signed-off-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 06 7月, 2005 1 次提交
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由 Rusty Lynch 提交于
The following renames arch_init, a kprobes function for performing any architecture specific initialization, to arch_init_kprobes in order to cleanup the namespace. Also, this patch adds arch_init_kprobes to sparc64 to fix the sparc64 kprobes build from the last return probe patch. Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 28 6月, 2005 1 次提交
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由 Rusty Lynch 提交于
The following patch contains the i386 specific changes for the new return probe design. Changes include: * Removing the architecture specific functions for querying a return probe instance off a stack address * Complete rework onf arch_prepare_kretprobe() and trampoline_probe_handler() * Removing trampoline_post_handler() * Adding arch_init() so that now we handle registering the return probe trampoline instead of kernel/kprobes.c doing it Signed-off-by: NRusty Lynch <rusty.lynch@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 24 6月, 2005 4 次提交
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由 Prasanna S Panchamukhi 提交于
This patch includes i386 architecture specific changes to support temporary disarming on reentrancy of probes. Signed-of-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Hien Nguyen 提交于
This patch moves the lock/unlock of the arch specific kprobe_flush_task() to the non-arch specific kprobe_flusk_task(). Signed-off-by: NHien Nguyen <hien@us.ibm.com> Acked-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Rusty Lynch 提交于
The architecture independent code of the current kprobes implementation is arming and disarming kprobes at registration time. The problem is that the code is assuming that arming and disarming is a just done by a simple write of some magic value to an address. This is problematic for ia64 where our instructions look more like structures, and we can not insert break points by just doing something like: *p->addr = BREAKPOINT_INSTRUCTION; The following patch to 2.6.12-rc4-mm2 adds two new architecture dependent functions: * void arch_arm_kprobe(struct kprobe *p) * void arch_disarm_kprobe(struct kprobe *p) and then adds the new functions for each of the architectures that already implement kprobes (spar64/ppc64/i386/x86_64). I thought arch_[dis]arm_kprobe was the most descriptive of what was really happening, but each of the architectures already had a disarm_kprobe() function that was really a "disarm and do some other clean-up items as needed when you stumble across a recursive kprobe." So... I took the liberty of changing the code that was calling disarm_kprobe() to call arch_disarm_kprobe(), and then do the cleanup in the block of code dealing with the recursive kprobe case. So far this patch as been tested on i386, x86_64, and ppc64, but still needs to be tested in sparc64. Signed-off-by: NRusty Lynch <rusty.lynch@intel.com> Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Hien Nguyen 提交于
This patch adds function-return probes to kprobes for the i386 architecture. This enables you to establish a handler to be run when a function returns. 1. API Two new functions are added to kprobes: int register_kretprobe(struct kretprobe *rp); void unregister_kretprobe(struct kretprobe *rp); 2. Registration and unregistration 2.1 Register To register a function-return probe, the user populates the following fields in a kretprobe object and calls register_kretprobe() with the kretprobe address as an argument: kp.addr - the function's address handler - this function is run after the ret instruction executes, but before control returns to the return address in the caller. maxactive - The maximum number of instances of the probed function that can be active concurrently. For example, if the function is non- recursive and is called with a spinlock or mutex held, maxactive = 1 should be enough. If the function is non-recursive and can never relinquish the CPU (e.g., via a semaphore or preemption), NR_CPUS should be enough. maxactive is used to determine how many kretprobe_instance objects to allocate for this particular probed function. If maxactive <= 0, it is set to a default value (if CONFIG_PREEMPT maxactive=max(10, 2 * NR_CPUS) else maxactive=NR_CPUS) For example: struct kretprobe rp; rp.kp.addr = /* entrypoint address */ rp.handler = /*return probe handler */ rp.maxactive = /* e.g., 1 or NR_CPUS or 0, see the above explanation */ register_kretprobe(&rp); The following field may also be of interest: nmissed - Initialized to zero when the function-return probe is registered, and incremented every time the probed function is entered but there is no kretprobe_instance object available for establishing the function-return probe (i.e., because maxactive was set too low). 2.2 Unregister To unregiter a function-return probe, the user calls unregister_kretprobe() with the same kretprobe object as registered previously. If a probed function is running when the return probe is unregistered, the function will return as expected, but the handler won't be run. 3. Limitations 3.1 This patch supports only the i386 architecture, but patches for x86_64 and ppc64 are anticipated soon. 3.2 Return probes operates by replacing the return address in the stack (or in a known register, such as the lr register for ppc). This may cause __builtin_return_address(0), when invoked from the return-probed function, to return the address of the return-probes trampoline. 3.3 This implementation uses the "Multiprobes at an address" feature in 2.6.12-rc3-mm3. 3.4 Due to a limitation in multi-probes, you cannot currently establish a return probe and a jprobe on the same function. A patch to remove this limitation is being tested. This feature is required by SystemTap (http://sourceware.org/systemtap), and reflects ideas contributed by several SystemTap developers, including Will Cohen and Ananth Mavinakayanahalli. Signed-off-by: NHien Nguyen <hien@us.ibm.com> Signed-off-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NFrederik Deweerdt <frederik.deweerdt@laposte.net> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 06 5月, 2005 1 次提交
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由 Prasanna S Panchamukhi 提交于
Kprobes could not handle the insertion of a probe on the ret/lret instruction and used to oops after single stepping since kprobes was modifying eip/rip incorrectly. Adjustment of eip/rip is not required after single stepping in case of ret/lret instruction, because eip/rip points to the correct location after execution of the ret/lret instruction. This patch fixes the above problem. Signed-off-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 17 4月, 2005 1 次提交
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由 Linus Torvalds 提交于
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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