diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/HOWTO | 20 | ||||
| -rw-r--r-- | Documentation/IPMI.txt | 9 | ||||
| -rw-r--r-- | Documentation/SubmitChecklist | 2 | ||||
| -rw-r--r-- | Documentation/accounting/getdelays.c | 7 | ||||
| -rw-r--r-- | Documentation/accounting/taskstats-struct.txt | 161 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 5 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 4 | ||||
| -rw-r--r-- | Documentation/input/ff.txt | 112 | ||||
| -rw-r--r-- | Documentation/kprobes.txt | 89 | ||||
| -rw-r--r-- | Documentation/lockdep-design.txt | 22 | ||||
| -rw-r--r-- | Documentation/rt-mutex-design.txt | 14 |
11 files changed, 334 insertions, 111 deletions
diff --git a/Documentation/HOWTO b/Documentation/HOWTO index 1d6560413cc..d6f3dd1a346 100644 --- a/Documentation/HOWTO +++ b/Documentation/HOWTO @@ -375,6 +375,26 @@ of information is needed by the kernel developers to help track down the problem. +Managing bug reports +-------------------- + +One of the best ways to put into practice your hacking skills is by fixing +bugs reported by other people. Not only you will help to make the kernel +more stable, you'll learn to fix real world problems and you will improve +your skills, and other developers will be aware of your presence. Fixing +bugs is one of the best ways to earn merit amongst the developers, because +not many people like wasting time fixing other people's bugs. + +To work in the already reported bug reports, go to http://bugzilla.kernel.org. +If you want to be advised of the future bug reports, you can subscribe to the +bugme-new mailing list (only new bug reports are mailed here) or to the +bugme-janitor mailing list (every change in the bugzilla is mailed here) + + http://lists.osdl.org/mailman/listinfo/bugme-new + http://lists.osdl.org/mailman/listinfo/bugme-janitors + + + Mailing lists ------------- diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt index 0256805b548..7756e09ea75 100644 --- a/Documentation/IPMI.txt +++ b/Documentation/IPMI.txt @@ -326,9 +326,12 @@ for events, they will all receive all events that come in. For receiving commands, you have to individually register commands you want to receive. Call ipmi_register_for_cmd() and supply the netfn -and command name for each command you want to receive. Only one user -may be registered for each netfn/cmd, but different users may register -for different commands. +and command name for each command you want to receive. You also +specify a bitmask of the channels you want to receive the command from +(or use IPMI_CHAN_ALL for all channels if you don't care). Only one +user may be registered for each netfn/cmd/channel, but different users +may register for different commands, or the same command if the +channel bitmasks do not overlap. From userland, equivalent IOCTLs are provided to do these functions. diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist index a6cb6ffd293..7ac61f60037 100644 --- a/Documentation/SubmitChecklist +++ b/Documentation/SubmitChecklist @@ -64,3 +64,5 @@ kernel patches. 19: All new userspace interfaces are documented in Documentation/ABI/. See Documentation/ABI/README for more information. + +20: Check that it all passes `make headers_check'. diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c index 795ca3911cc..b11792abd6b 100644 --- a/Documentation/accounting/getdelays.c +++ b/Documentation/accounting/getdelays.c @@ -285,7 +285,7 @@ int main(int argc, char *argv[]) if (maskset) { rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET, TASKSTATS_CMD_ATTR_REGISTER_CPUMASK, - &cpumask, sizeof(cpumask)); + &cpumask, strlen(cpumask) + 1); PRINTF("Sent register cpumask, retval %d\n", rc); if (rc < 0) { printf("error sending register cpumask\n"); @@ -315,7 +315,8 @@ int main(int argc, char *argv[]) } if (msg.n.nlmsg_type == NLMSG_ERROR || !NLMSG_OK((&msg.n), rep_len)) { - printf("fatal reply error, errno %d\n", errno); + struct nlmsgerr *err = NLMSG_DATA(&msg); + printf("fatal reply error, errno %d\n", err->error); goto done; } @@ -383,7 +384,7 @@ done: if (maskset) { rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET, TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK, - &cpumask, sizeof(cpumask)); + &cpumask, strlen(cpumask) + 1); printf("Sent deregister mask, retval %d\n", rc); if (rc < 0) err(rc, "error sending deregister cpumask\n"); diff --git a/Documentation/accounting/taskstats-struct.txt b/Documentation/accounting/taskstats-struct.txt new file mode 100644 index 00000000000..661c797eaf7 --- /dev/null +++ b/Documentation/accounting/taskstats-struct.txt @@ -0,0 +1,161 @@ +The struct taskstats +-------------------- + +This document contains an explanation of the struct taskstats fields. + +There are three different groups of fields in the struct taskstats: + +1) Common and basic accounting fields + If CONFIG_TASKSTATS is set, the taskstats inteface is enabled and + the common fields and basic accounting fields are collected for + delivery at do_exit() of a task. +2) Delay accounting fields + These fields are placed between + /* Delay accounting fields start */ + and + /* Delay accounting fields end */ + Their values are collected if CONFIG_TASK_DELAY_ACCT is set. +3) Extended accounting fields + These fields are placed between + /* Extended accounting fields start */ + and + /* Extended accounting fields end */ + Their values are collected if CONFIG_TASK_XACCT is set. + +Future extension should add fields to the end of the taskstats struct, and +should not change the relative position of each field within the struct. + + +struct taskstats { + +1) Common and basic accounting fields: + /* The version number of this struct. This field is always set to + * TAKSTATS_VERSION, which is defined in <linux/taskstats.h>. + * Each time the struct is changed, the value should be incremented. + */ + __u16 version; + + /* The exit code of a task. */ + __u32 ac_exitcode; /* Exit status */ + + /* The accounting flags of a task as defined in <linux/acct.h> + * Defined values are AFORK, ASU, ACOMPAT, ACORE, and AXSIG. + */ + __u8 ac_flag; /* Record flags */ + + /* The value of task_nice() of a task. */ + __u8 ac_nice; /* task_nice */ + + /* The name of the command that started this task. */ + char ac_comm[TS_COMM_LEN]; /* Command name */ + + /* The scheduling discipline as set in task->policy field. */ + __u8 ac_sched; /* Scheduling discipline */ + + __u8 ac_pad[3]; + __u32 ac_uid; /* User ID */ + __u32 ac_gid; /* Group ID */ + __u32 ac_pid; /* Process ID */ + __u32 ac_ppid; /* Parent process ID */ + + /* The time when a task begins, in [secs] since 1970. */ + __u32 ac_btime; /* Begin time [sec since 1970] */ + + /* The elapsed time of a task, in [usec]. */ + __u64 ac_etime; /* Elapsed time [usec] */ + + /* The user CPU time of a task, in [usec]. */ + __u64 ac_utime; /* User CPU time [usec] */ + + /* The system CPU time of a task, in [usec]. */ + __u64 ac_stime; /* System CPU time [usec] */ + + /* The minor page fault count of a task, as set in task->min_flt. */ + __u64 ac_minflt; /* Minor Page Fault Count */ + + /* The major page fault count of a task, as set in task->maj_flt. */ + __u64 ac_majflt; /* Major Page Fault Count */ + + +2) Delay accounting fields: + /* Delay accounting fields start + * + * All values, until the comment "Delay accounting fields end" are + * available only if delay accounting is enabled, even though the last + * few fields are not delays + * + * xxx_count is the number of delay values recorded + * xxx_delay_total is the corresponding cumulative delay in nanoseconds + * + * xxx_delay_total wraps around to zero on overflow + * xxx_count incremented regardless of overflow + */ + + /* Delay waiting for cpu, while runnable + * count, delay_total NOT updated atomically + */ + __u64 cpu_count; + __u64 cpu_delay_total; + + /* Following four fields atomically updated using task->delays->lock */ + + /* Delay waiting for synchronous block I/O to complete + * does not account for delays in I/O submission + */ + __u64 blkio_count; + __u64 blkio_delay_total; + + /* Delay waiting for page fault I/O (swap in only) */ + __u64 swapin_count; + __u64 swapin_delay_total; + + /* cpu "wall-clock" running time + * On some architectures, value will adjust for cpu time stolen + * from the kernel in involuntary waits due to virtualization. + * Value is cumulative, in nanoseconds, without a corresponding count + * and wraps around to zero silently on overflow + */ + __u64 cpu_run_real_total; + + /* cpu "virtual" running time + * Uses time intervals seen by the kernel i.e. no adjustment + * for kernel's involuntary waits due to virtualization. + * Value is cumulative, in nanoseconds, without a corresponding count + * and wraps around to zero silently on overflow + */ + __u64 cpu_run_virtual_total; + /* Delay accounting fields end */ + /* version 1 ends here */ + + +3) Extended accounting fields + /* Extended accounting fields start */ + + /* Accumulated RSS usage in duration of a task, in MBytes-usecs. + * The current rss usage is added to this counter every time + * a tick is charged to a task's system time. So, at the end we + * will have memory usage multiplied by system time. Thus an + * average usage per system time unit can be calculated. + */ + __u64 coremem; /* accumulated RSS usage in MB-usec */ + + /* Accumulated virtual memory usage in duration of a task. + * Same as acct_rss_mem1 above except that we keep track of VM usage. + */ + __u64 virtmem; /* accumulated VM usage in MB-usec */ + + /* High watermark of RSS usage in duration of a task, in KBytes. */ + __u64 hiwater_rss; /* High-watermark of RSS usage */ + + /* High watermark of VM usage in duration of a task, in KBytes. */ + __u64 hiwater_vm; /* High-water virtual memory usage */ + + /* The following four fields are I/O statistics of a task. */ + __u64 read_char; /* bytes read */ + __u64 write_char; /* bytes written */ + __u64 read_syscalls; /* read syscalls */ + __u64 write_syscalls; /* write syscalls */ + + /* Extended accounting fields end */ + +} diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 247d7f619aa..eb1a6cad21e 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -356,10 +356,9 @@ The last two are called only from check_disk_change(). prototypes: loff_t (*llseek) (struct file *, loff_t, int); ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); - ssize_t (*aio_read) (struct kiocb *, char __user *, size_t, loff_t); ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); - ssize_t (*aio_write) (struct kiocb *, const char __user *, size_t, - loff_t); + ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); + ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); int (*readdir) (struct file *, void *, filldir_t); unsigned int (*poll) (struct file *, struct poll_table_struct *); int (*ioctl) (struct inode *, struct file *, unsigned int, diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 1cb7e8be927..cd07c21b840 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -699,9 +699,9 @@ This describes how the VFS can manipulate an open file. As of kernel struct file_operations { loff_t (*llseek) (struct file *, loff_t, int); ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); - ssize_t (*aio_read) (struct kiocb *, char __user *, size_t, loff_t); ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); - ssize_t (*aio_write) (struct kiocb *, const char __user *, size_t, loff_t); + ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); + ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); int (*readdir) (struct file *, void *, filldir_t); unsigned int (*poll) (struct file *, struct poll_table_struct *); int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long); diff --git a/Documentation/input/ff.txt b/Documentation/input/ff.txt index c7e10eaff20..c53b1c11aa4 100644 --- a/Documentation/input/ff.txt +++ b/Documentation/input/ff.txt @@ -1,67 +1,37 @@ Force feedback for Linux. By Johann Deneux <deneux@ifrance.com> on 2001/04/22. +Updated by Anssi Hannula <anssi.hannula@gmail.com> on 2006/04/09. You may redistribute this file. Please remember to include shape.fig and interactive.fig as well. ---------------------------------------------------------------------------- -0. Introduction +1. Introduction ~~~~~~~~~~~~~~~ This document describes how to use force feedback devices under Linux. The goal is not to support these devices as if they were simple input-only devices (as it is already the case), but to really enable the rendering of force effects. -At the moment, only I-Force devices are supported, and not officially. That -means I had to find out how the protocol works on my own. Of course, the -information I managed to grasp is far from being complete, and I can not -guarranty that this driver will work for you. -This document only describes the force feedback part of the driver for I-Force -devices. Please read joystick.txt before reading further this document. +This document only describes the force feedback part of the Linux input +interface. Please read joystick.txt and input.txt before reading further this +document. 2. Instructions to the user ~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Here are instructions on how to compile and use the driver. In fact, this -driver is the normal iforce, input and evdev drivers written by Vojtech -Pavlik, plus additions to support force feedback. +To enable force feedback, you have to: + +1. have your kernel configured with evdev and a driver that supports your + device. +2. make sure evdev module is loaded and /dev/input/event* device files are + created. Before you start, let me WARN you that some devices shake violently during the initialisation phase. This happens for example with my "AVB Top Shot Pegasus". To stop this annoying behaviour, move you joystick to its limits. Anyway, you -should keep a hand on your device, in order to avoid it to brake down if +should keep a hand on your device, in order to avoid it to break down if something goes wrong. -At the kernel's compilation: - - Enable IForce/Serial - - Enable Event interface - -Compile the modules, install them. - -You also need inputattach. - -You then need to insert the modules into the following order: -% modprobe joydev -% modprobe serport # Only for serial -% modprobe iforce -% modprobe evdev -% ./inputattach -ifor $2 & # Only for serial -If you are using USB, you don't need the inputattach step. - -Please check that you have all the /dev/input entries needed: -cd /dev -rm js* -mkdir input -mknod input/js0 c 13 0 -mknod input/js1 c 13 1 -mknod input/js2 c 13 2 -mknod input/js3 c 13 3 -ln -s input/js0 js0 -ln -s input/js1 js1 -ln -s input/js2 js2 -ln -s input/js3 js3 - -mknod input/event0 c 13 64 -mknod input/event1 c 13 65 -mknod input/event2 c 13 66 -mknod input/event3 c 13 67 +If you have a serial iforce device, you need to start inputattach. See +joystick.txt for details. 2.1 Does it work ? ~~~~~~~~~~~~~~~~~~ @@ -70,9 +40,9 @@ There is an utility called fftest that will allow you to test the driver. 3. Instructions to the developper ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - All interactions are done using the event API. That is, you can use ioctl() +All interactions are done using the event API. That is, you can use ioctl() and write() on /dev/input/eventXX. - This information is subject to change. +This information is subject to change. 3.1 Querying device capabilities ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -86,18 +56,29 @@ int ioctl(int file_descriptor, int request, unsigned long *features); Returns the features supported by the device. features is a bitfield with the following bits: -- FF_X has an X axis (usually joysticks) -- FF_Y has an Y axis (usually joysticks) -- FF_WHEEL has a wheel (usually sterring wheels) - FF_CONSTANT can render constant force effects -- FF_PERIODIC can render periodic effects (sine, triangle, square...) +- FF_PERIODIC can render periodic effects with the following waveforms: + - FF_SQUARE square waveform + - FF_TRIANGLE triangle waveform + - FF_SINE sine waveform + - FF_SAW_UP sawtooth up waveform + - FF_SAW_DOWN sawtooth down waveform + - FF_CUSTOM custom waveform - FF_RAMP can render ramp effects - FF_SPRING can simulate the presence of a spring -- FF_FRICTION can simulate friction +- FF_FRICTION can simulate friction - FF_DAMPER can simulate damper effects -- FF_RUMBLE rumble effects (normally the only effect supported by rumble - pads) +- FF_RUMBLE rumble effects - FF_INERTIA can simulate inertia +- FF_GAIN gain is adjustable +- FF_AUTOCENTER autocenter is adjustable + +Note: In most cases you should use FF_PERIODIC instead of FF_RUMBLE. All + devices that support FF_RUMBLE support FF_PERIODIC (square, triangle, + sine) and the other way around. + +Note: The exact syntax FF_CUSTOM is undefined for the time being as no driver + supports it yet. int ioctl(int fd, EVIOCGEFFECTS, int *n); @@ -108,7 +89,7 @@ Returns the number of effects the device can keep in its memory. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <linux/input.h> #include <sys/ioctl.h> - + int ioctl(int file_descriptor, int request, struct ff_effect *effect); "request" must be EVIOCSFF. @@ -120,6 +101,9 @@ to the unique id assigned by the driver. This data is required for performing some operations (removing an effect, controlling the playback). This if field must be set to -1 by the user in order to tell the driver to allocate a new effect. + +Effects are file descriptor specific. + See <linux/input.h> for a description of the ff_effect struct. You should also find help in a few sketches, contained in files shape.fig and interactive.fig. You need xfig to visualize these files. @@ -128,8 +112,8 @@ You need xfig to visualize these files. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ int ioctl(int fd, EVIOCRMFF, effect.id); -This makes room for new effects in the device's memory. Please note this won't -stop the effect if it was playing. +This makes room for new effects in the device's memory. Note that this also +stops the effect if it was playing. 3.4 Controlling the playback of effects ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -149,22 +133,21 @@ Control of playing is done with write(). Below is an example: play.type = EV_FF; play.code = effect.id; play.value = 3; - + write(fd, (const void*) &play, sizeof(play)); ... /* Stop an effect */ stop.type = EV_FF; stop.code = effect.id; stop.value = 0; - + write(fd, (const void*) &play, sizeof(stop)); 3.5 Setting the gain ~~~~~~~~~~~~~~~~~~~~ Not all devices have the same strength. Therefore, users should set a gain factor depending on how strong they want effects to be. This setting is -persistent across access to the driver, so you should not care about it if -you are writing games, as another utility probably already set this for you. +persistent across access to the driver. /* Set the gain of the device int gain; /* between 0 and 100 */ @@ -204,11 +187,14 @@ type of device, not all parameters can be dynamically updated. For example, the direction of an effect cannot be updated with iforce devices. In this case, the driver stops the effect, up-load it, and restart it. +Therefore it is recommended to dynamically change direction while the effect +is playing only when it is ok to restart the effect with a replay count of 1. 3.8 Information about the status of effects ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Every time the status of an effect is changed, an event is sent. The values and meanings of the fields of the event are as follows: + struct input_event { /* When the status of the effect changed */ struct timeval time; @@ -225,3 +211,9 @@ struct input_event { FF_STATUS_STOPPED The effect stopped playing FF_STATUS_PLAYING The effect started to play + +NOTE: Status feedback is only supported by iforce driver. If you have + a really good reason to use this, please contact + linux-joystick@atrey.karlin.mff.cuni.cz or anssi.hannula@gmail.com + so that support for it can be added to the rest of the drivers. + diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index 2c3b1eae428..ba26201d502 100644 --- a/Documentation/kprobes.txt +++ b/Documentation/kprobes.txt @@ -151,9 +151,9 @@ So that you can load and unload Kprobes-based instrumentation modules, make sure "Loadable module support" (CONFIG_MODULES) and "Module unloading" (CONFIG_MODULE_UNLOAD) are set to "y". -You may also want to ensure that CONFIG_KALLSYMS and perhaps even -CONFIG_KALLSYMS_ALL are set to "y", since kallsyms_lookup_name() -is a handy, version-independent way to find a function's address. +Also make sure that CONFIG_KALLSYMS and perhaps even CONFIG_KALLSYMS_ALL +are set to "y", since kallsyms_lookup_name() is used by the in-kernel +kprobe address resolution code. If you need to insert a probe in the middle of a function, you may find it useful to "Compile the kernel with debug info" (CONFIG_DEBUG_INFO), @@ -179,6 +179,27 @@ occurs during execution of kp->pre_handler or kp->post_handler, or during single-stepping of the probed instruction, Kprobes calls kp->fault_handler. Any or all handlers can be NULL. +NOTE: +1. With the introduction of the "symbol_name" field to struct kprobe, +the probepoint address resolution will now be taken care of by the kernel. +The following will now work: + + kp.symbol_name = "symbol_name"; + +(64-bit powerpc intricacies such as function descriptors are handled +transparently) + +2. Use the "offset" field of struct kprobe if the offset into the symbol +to install a probepoint is known. This field is used to calculate the +probepoint. + +3. Specify either the kprobe "symbol_name" OR the "addr". If both are +specified, kprobe registration will fail with -EINVAL. + +4. With CISC architectures (such as i386 and x86_64), the kprobes code +does not validate if the kprobe.addr is at an instruction boundary. +Use "offset" with caution. + register_kprobe() returns 0 on success, or a negative errno otherwise. User's pre-handler (kp->pre_handler): @@ -225,6 +246,12 @@ control to Kprobes.) If the probed function is declared asmlinkage, fastcall, or anything else that affects how args are passed, the handler's declaration must match. +NOTE: A macro JPROBE_ENTRY is provided to handle architecture-specific +aliasing of jp->entry. In the interest of portability, it is advised +to use: + + jp->entry = JPROBE_ENTRY(handler); + register_jprobe() returns 0 on success, or a negative errno otherwise. 4.3 register_kretprobe @@ -251,6 +278,11 @@ of interest: - ret_addr: the return address - rp: points to the corresponding kretprobe object - task: points to the corresponding task struct + +The regs_return_value(regs) macro provides a simple abstraction to +extract the return value from the appropriate register as defined by +the architecture's ABI. + The handler's return value is currently ignored. 4.4 unregister_*probe @@ -369,7 +401,6 @@ stack trace and selected i386 registers when do_fork() is called. #include <linux/kernel.h> #include <linux/module.h> #include <linux/kprobes.h> -#include <linux/kallsyms.h> #include <linux/sched.h> /*For each probe you need to allocate a kprobe structure*/ @@ -403,18 +434,14 @@ int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr) return 0; } -int init_module(void) +static int __init kprobe_init(void) { int ret; kp.pre_handler = handler_pre; kp.post_handler = handler_post; kp.fault_handler = handler_fault; - kp.addr = (kprobe_opcode_t*) kallsyms_lookup_name("do_fork"); - /* register the kprobe now */ - if (!kp.addr) { - printk("Couldn't find %s to plant kprobe\n", "do_fork"); - return -1; - } + kp.symbol_name = "do_fork"; + if ((ret = register_kprobe(&kp) < 0)) { printk("register_kprobe failed, returned %d\n", ret); return -1; @@ -423,12 +450,14 @@ int init_module(void) return 0; } -void cleanup_module(void) +static void __exit kprobe_exit(void) { unregister_kprobe(&kp); printk("kprobe unregistered\n"); } +module_init(kprobe_init) +module_exit(kprobe_exit) MODULE_LICENSE("GPL"); ----- cut here ----- @@ -463,7 +492,6 @@ the arguments of do_fork(). #include <linux/fs.h> #include <linux/uio.h> #include <linux/kprobes.h> -#include <linux/kallsyms.h> /* * Jumper probe for do_fork. @@ -485,17 +513,13 @@ long jdo_fork(unsigned long clone_flags, unsigned long stack_start, } static struct jprobe my_jprobe = { - .entry = (kprobe_opcode_t *) jdo_fork + .entry = JPROBE_ENTRY(jdo_fork) }; -int init_module(void) +static int __init jprobe_init(void) { int ret; - my_jprobe.kp.addr = (kprobe_opcode_t *) kallsyms_lookup_name("do_fork"); - if (!my_jprobe.kp.addr) { - printk("Couldn't find %s to plant jprobe\n", "do_fork"); - return -1; - } + my_jprobe.kp.symbol_name = "do_fork"; if ((ret = register_jprobe(&my_jprobe)) <0) { printk("register_jprobe failed, returned %d\n", ret); @@ -506,12 +530,14 @@ int init_module(void) return 0; } -void cleanup_module(void) +static void __exit jprobe_exit(void) { unregister_jprobe(&my_jprobe); printk("jprobe unregistered\n"); } +module_init(jprobe_init) +module_exit(jprobe_exit) MODULE_LICENSE("GPL"); ----- cut here ----- @@ -530,16 +556,13 @@ report failed calls to sys_open(). #include <linux/kernel.h> #include <linux/module.h> #include <linux/kprobes.h> -#include <linux/kallsyms.h> static const char *probed_func = "sys_open"; /* Return-probe handler: If the probed function fails, log the return value. */ static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs) { - // Substitute the appropriate register name for your architecture -- - // e.g., regs->rax for x86_64, regs->gpr[3] for ppc64. - int retval = (int) regs->eax; + int retval = regs_return_value(regs); if (retval < 0) { printk("%s returns %d\n", probed_func, retval); } @@ -552,15 +575,11 @@ static struct kretprobe my_kretprobe = { .maxactive = 20 }; -int init_module(void) +static int __init kretprobe_init(void) { int ret; - my_kretprobe.kp.addr = - (kprobe_opcode_t *) kallsyms_lookup_name(probed_func); - if (!my_kretprobe.kp.addr) { - printk("Couldn't find %s to plant return probe\n", probed_func); - return -1; - } + my_kretprobe.kp.symbol_name = (char *)probed_func; + if ((ret = register_kretprobe(&my_kretprobe)) < 0) { printk("register_kretprobe failed, returned %d\n", ret); return -1; @@ -569,7 +588,7 @@ int init_module(void) return 0; } -void cleanup_module(void) +static void __exit kretprobe_exit(void) { unregister_kretprobe(&my_kretprobe); printk("kretprobe unregistered\n"); @@ -578,6 +597,8 @@ void cleanup_module(void) my_kretprobe.nmissed, probed_func); } +module_init(kretprobe_init) +module_exit(kretprobe_exit) MODULE_LICENSE("GPL"); ----- cut here ----- @@ -590,3 +611,5 @@ messages.) For additional information on Kprobes, refer to the following URLs: http://www-106.ibm.com/developerworks/library/l-kprobes.html?ca=dgr-lnxw42Kprobe http://www.redhat.com/magazine/005mar05/features/kprobes/ +http://www-users.cs.umn.edu/~boutcher/kprobes/ +http://www.linuxsymposium.org/2006/linuxsymposium_procv2.pdf (pages 101-115) diff --git a/Documentation/lockdep-design.txt b/Documentation/lockdep-design.txt index 00d93605bfd..55a7e4fa8cc 100644 --- a/Documentation/lockdep-design.txt +++ b/Documentation/lockdep-design.txt @@ -36,6 +36,28 @@ The validator tracks lock-class usage history into 5 separate state bits: - 'ever used' [ == !unused ] +When locking rules are violated, these 4 state bits are presented in the +locking error messages, inside curlies. A contrived example: + + modprobe/2287 is trying to acquire lock: + (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 + + but task is already holding lock: + (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 + + +The bit position indicates hardirq, softirq, hardirq-read, +softirq-read respectively, and the character displayed in each +indicates: + + '.' acquired while irqs enabled + '+' acquired in irq context + '-' acquired in process context with irqs disabled + '?' read-acquired both with irqs enabled and in irq context + +Unused mutexes cannot be part of the cause of an error. + + Single-lock state rules: ------------------------ diff --git a/Documentation/rt-mutex-design.txt b/Documentation/rt-mutex-design.txt index c472ffacc2f..4b736d24da7 100644 --- a/Documentation/rt-mutex-design.txt +++ b/Documentation/rt-mutex-design.txt @@ -333,11 +333,11 @@ cmpxchg is basically the following function performed atomically: unsigned long _cmpxchg(unsigned long *A, unsigned long *B, unsigned long *C) { - unsigned long T = *A; - if (*A == *B) { - *A = *C; - } - return T; + unsigned long T = *A; + if (*A == *B) { + *A = *C; + } + return T; } #define cmpxchg(a,b,c) _cmpxchg(&a,&b,&c) @@ -582,7 +582,7 @@ contention). try_to_take_rt_mutex is used every time the task tries to grab a mutex in the slow path. The first thing that is done here is an atomic setting of the "Has Waiters" flag of the mutex's owner field. Yes, this could really -be false, because if the the mutex has no owner, there are no waiters and +be false, because if the mutex has no owner, there are no waiters and the current task also won't have any waiters. But we don't have the lock yet, so we assume we are going to be a waiter. The reason for this is to play nice for those architectures that do have CMPXCHG. By setting this flag @@ -735,7 +735,7 @@ do have CMPXCHG, that check is done in the fast path, but it is still needed in the slow path too. If a waiter of a mutex woke up because of a signal or timeout between the time the owner failed the fast path CMPXCHG check and the grabbing of the wait_lock, the mutex may not have any waiters, thus the -owner still needs to make this check. If there are no waiters than the mutex +owner still needs to make this check. If there are no waiters then the mutex owner field is set to NULL, the wait_lock is released and nothing more is needed. |