aboutsummaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorJeff Garzik <jgarzik@pobox.com>2005-08-11 00:07:03 -0400
committerJeff Garzik <jgarzik@pobox.com>2005-08-11 00:07:03 -0400
commitcd04b947bc674f8fc9cac38ec30497bae5d664ad (patch)
tree988b0b7ea08063e5499672346eb2f619f0629717 /Documentation
parentb3df9f813bc7b9db62ae0c90b8990b1cebf97345 (diff)
parentbc68552faad0e134eb22281343d5ae5a4873fa80 (diff)
Merge /spare/repo/linux-2.6/
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/SubmittingPatches5
-rw-r--r--Documentation/arm/Samsung-S3C24XX/USB-Host.txt93
-rw-r--r--Documentation/dontdiff1
-rw-r--r--Documentation/fb/vesafb.txt16
-rw-r--r--Documentation/kprobes.txt588
-rw-r--r--Documentation/networking/bonding.txt978
-rw-r--r--Documentation/usb/usbmon.txt2
-rw-r--r--Documentation/video4linux/CARDLIST.cx881
-rw-r--r--Documentation/video4linux/CARDLIST.tuner2
-rw-r--r--Documentation/video4linux/bttv/Insmod-options3
-rw-r--r--Documentation/x86_64/boot-options.txt5
11 files changed, 1391 insertions, 303 deletions
diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index 6761a7b241a..7f43b040311 100644
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -149,6 +149,11 @@ USB, framebuffer devices, the VFS, the SCSI subsystem, etc. See the
MAINTAINERS file for a mailing list that relates specifically to
your change.
+If changes affect userland-kernel interfaces, please send
+the MAN-PAGES maintainer (as listed in the MAINTAINERS file)
+a man-pages patch, or at least a notification of the change,
+so that some information makes its way into the manual pages.
+
Even if the maintainer did not respond in step #4, make sure to ALWAYS
copy the maintainer when you change their code.
diff --git a/Documentation/arm/Samsung-S3C24XX/USB-Host.txt b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt
new file mode 100644
index 00000000000..b93b68e2b14
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt
@@ -0,0 +1,93 @@
+ S3C24XX USB Host support
+ ========================
+
+
+
+Introduction
+------------
+
+ This document details the S3C2410/S3C2440 in-built OHCI USB host support.
+
+Configuration
+-------------
+
+ Enable at least the following kernel options:
+
+ menuconfig:
+
+ Device Drivers --->
+ USB support --->
+ <*> Support for Host-side USB
+ <*> OHCI HCD support
+
+
+ .config:
+ CONFIG_USB
+ CONFIG_USB_OHCI_HCD
+
+
+ Once these options are configured, the standard set of USB device
+ drivers can be configured and used.
+
+
+Board Support
+-------------
+
+ The driver attaches to a platform device, which will need to be
+ added by the board specific support file in linux/arch/arm/mach-s3c2410,
+ such as mach-bast.c or mach-smdk2410.c
+
+ The platform device's platform_data field is only needed if the
+ board implements extra power control or over-current monitoring.
+
+ The OHCI driver does not ensure the state of the S3C2410's MISCCTRL
+ register, so if both ports are to be used for the host, then it is
+ the board support file's responsibility to ensure that the second
+ port is configured to be connected to the OHCI core.
+
+
+Platform Data
+-------------
+
+ See linux/include/asm-arm/arch-s3c2410/usb-control.h for the
+ descriptions of the platform device data. An implementation
+ can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c .
+
+ The `struct s3c2410_hcd_info` contains a pair of functions
+ that get called to enable over-current detection, and to
+ control the port power status.
+
+ The ports are numbered 0 and 1.
+
+ power_control:
+
+ Called to enable or disable the power on the port.
+
+ enable_oc:
+
+ Called to enable or disable the over-current monitoring.
+ This should claim or release the resources being used to
+ check the power condition on the port, such as an IRQ.
+
+ report_oc:
+
+ The OHCI driver fills this field in for the over-current code
+ to call when there is a change to the over-current state on
+ an port. The ports argument is a bitmask of 1 bit per port,
+ with bit X being 1 for an over-current on port X.
+
+ The function s3c2410_usb_report_oc() has been provided to
+ ensure this is called correctly.
+
+ port[x]:
+
+ This is struct describes each port, 0 or 1. The platform driver
+ should set the flags field of each port to S3C_HCDFLG_USED if
+ the port is enabled.
+
+
+
+Document Author
+---------------
+
+Ben Dooks, (c) 2005 Simtec Electronics
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index b974cf595d0..96bea278bbf 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -104,6 +104,7 @@ logo_*.c
logo_*_clut224.c
logo_*_mono.c
lxdialog
+mach-types
mach-types.h
make_times_h
map
diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt
index 814e2f56a6a..62db6758d1c 100644
--- a/Documentation/fb/vesafb.txt
+++ b/Documentation/fb/vesafb.txt
@@ -144,7 +144,21 @@ vgapal Use the standard vga registers for palette changes.
This is the default.
pmipal Use the protected mode interface for palette changes.
-mtrr setup memory type range registers for the vesafb framebuffer.
+mtrr:n setup memory type range registers for the vesafb framebuffer
+ where n:
+ 0 - disabled (equivalent to nomtrr)
+ 1 - uncachable
+ 2 - write-back
+ 3 - write-combining (default)
+ 4 - write-through
+
+ If you see the following in dmesg, choose the type that matches the
+ old one. In this example, use "mtrr:2".
+...
+mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining
+...
+
+nomtrr disable mtrr
vremap:n
remap 'n' MiB of video RAM. If 0 or not specified, remap memory
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
new file mode 100644
index 00000000000..0541fe1de70
--- /dev/null
+++ b/Documentation/kprobes.txt
@@ -0,0 +1,588 @@
+Title : Kernel Probes (Kprobes)
+Authors : Jim Keniston <jkenisto@us.ibm.com>
+ : Prasanna S Panchamukhi <prasanna@in.ibm.com>
+
+CONTENTS
+
+1. Concepts: Kprobes, Jprobes, Return Probes
+2. Architectures Supported
+3. Configuring Kprobes
+4. API Reference
+5. Kprobes Features and Limitations
+6. Probe Overhead
+7. TODO
+8. Kprobes Example
+9. Jprobes Example
+10. Kretprobes Example
+
+1. Concepts: Kprobes, Jprobes, Return Probes
+
+Kprobes enables you to dynamically break into any kernel routine and
+collect debugging and performance information non-disruptively. You
+can trap at almost any kernel code address, specifying a handler
+routine to be invoked when the breakpoint is hit.
+
+There are currently three types of probes: kprobes, jprobes, and
+kretprobes (also called return probes). A kprobe can be inserted
+on virtually any instruction in the kernel. A jprobe is inserted at
+the entry to a kernel function, and provides convenient access to the
+function's arguments. A return probe fires when a specified function
+returns.
+
+In the typical case, Kprobes-based instrumentation is packaged as
+a kernel module. The module's init function installs ("registers")
+one or more probes, and the exit function unregisters them. A
+registration function such as register_kprobe() specifies where
+the probe is to be inserted and what handler is to be called when
+the probe is hit.
+
+The next three subsections explain how the different types of
+probes work. They explain certain things that you'll need to
+know in order to make the best use of Kprobes -- e.g., the
+difference between a pre_handler and a post_handler, and how
+to use the maxactive and nmissed fields of a kretprobe. But
+if you're in a hurry to start using Kprobes, you can skip ahead
+to section 2.
+
+1.1 How Does a Kprobe Work?
+
+When a kprobe is registered, Kprobes makes a copy of the probed
+instruction and replaces the first byte(s) of the probed instruction
+with a breakpoint instruction (e.g., int3 on i386 and x86_64).
+
+When a CPU hits the breakpoint instruction, a trap occurs, the CPU's
+registers are saved, and control passes to Kprobes via the
+notifier_call_chain mechanism. Kprobes executes the "pre_handler"
+associated with the kprobe, passing the handler the addresses of the
+kprobe struct and the saved registers.
+
+Next, Kprobes single-steps its copy of the probed instruction.
+(It would be simpler to single-step the actual instruction in place,
+but then Kprobes would have to temporarily remove the breakpoint
+instruction. This would open a small time window when another CPU
+could sail right past the probepoint.)
+
+After the instruction is single-stepped, Kprobes executes the
+"post_handler," if any, that is associated with the kprobe.
+Execution then continues with the instruction following the probepoint.
+
+1.2 How Does a Jprobe Work?
+
+A jprobe is implemented using a kprobe that is placed on a function's
+entry point. It employs a simple mirroring principle to allow
+seamless access to the probed function's arguments. The jprobe
+handler routine should have the same signature (arg list and return
+type) as the function being probed, and must always end by calling
+the Kprobes function jprobe_return().
+
+Here's how it works. When the probe is hit, Kprobes makes a copy of
+the saved registers and a generous portion of the stack (see below).
+Kprobes then points the saved instruction pointer at the jprobe's
+handler routine, and returns from the trap. As a result, control
+passes to the handler, which is presented with the same register and
+stack contents as the probed function. When it is done, the handler
+calls jprobe_return(), which traps again to restore the original stack
+contents and processor state and switch to the probed function.
+
+By convention, the callee owns its arguments, so gcc may produce code
+that unexpectedly modifies that portion of the stack. This is why
+Kprobes saves a copy of the stack and restores it after the jprobe
+handler has run. Up to MAX_STACK_SIZE bytes are copied -- e.g.,
+64 bytes on i386.
+
+Note that the probed function's args may be passed on the stack
+or in registers (e.g., for x86_64 or for an i386 fastcall function).
+The jprobe will work in either case, so long as the handler's
+prototype matches that of the probed function.
+
+1.3 How Does a Return Probe Work?
+
+When you call register_kretprobe(), Kprobes establishes a kprobe at
+the entry to the function. When the probed function is called and this
+probe is hit, Kprobes saves a copy of the return address, and replaces
+the return address with the address of a "trampoline." The trampoline
+is an arbitrary piece of code -- typically just a nop instruction.
+At boot time, Kprobes registers a kprobe at the trampoline.
+
+When the probed function executes its return instruction, control
+passes to the trampoline and that probe is hit. Kprobes' trampoline
+handler calls the user-specified handler associated with the kretprobe,
+then sets the saved instruction pointer to the saved return address,
+and that's where execution resumes upon return from the trap.
+
+While the probed function is executing, its return address is
+stored in an object of type kretprobe_instance. Before calling
+register_kretprobe(), the user sets the maxactive field of the
+kretprobe struct to specify how many instances of the specified
+function can be probed simultaneously. register_kretprobe()
+pre-allocates the indicated number of kretprobe_instance objects.
+
+For example, if the function is non-recursive and is called with a
+spinlock 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. If maxactive <= 0, it is
+set to a default value. If CONFIG_PREEMPT is enabled, the default
+is max(10, 2*NR_CPUS). Otherwise, the default is NR_CPUS.
+
+It's not a disaster if you set maxactive too low; you'll just miss
+some probes. In the kretprobe struct, the nmissed field is set to
+zero when the return probe is registered, and is incremented every
+time the probed function is entered but there is no kretprobe_instance
+object available for establishing the return probe.
+
+2. Architectures Supported
+
+Kprobes, jprobes, and return probes are implemented on the following
+architectures:
+
+- i386
+- x86_64 (AMD-64, E64MT)
+- ppc64
+- ia64 (Support for probes on certain instruction types is still in progress.)
+- sparc64 (Return probes not yet implemented.)
+
+3. Configuring Kprobes
+
+When configuring the kernel using make menuconfig/xconfig/oldconfig,
+ensure that CONFIG_KPROBES is set to "y". Under "Kernel hacking",
+look for "Kprobes". You may have to enable "Kernel debugging"
+(CONFIG_DEBUG_KERNEL) before you can enable Kprobes.
+
+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.
+
+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),
+so you can use "objdump -d -l vmlinux" to see the source-to-object
+code mapping.
+
+4. API Reference
+
+The Kprobes API includes a "register" function and an "unregister"
+function for each type of probe. Here are terse, mini-man-page
+specifications for these functions and the associated probe handlers
+that you'll write. See the latter half of this document for examples.
+
+4.1 register_kprobe
+
+#include <linux/kprobes.h>
+int register_kprobe(struct kprobe *kp);
+
+Sets a breakpoint at the address kp->addr. When the breakpoint is
+hit, Kprobes calls kp->pre_handler. After the probed instruction
+is single-stepped, Kprobe calls kp->post_handler. If a fault
+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.
+
+register_kprobe() returns 0 on success, or a negative errno otherwise.
+
+User's pre-handler (kp->pre_handler):
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+int pre_handler(struct kprobe *p, struct pt_regs *regs);
+
+Called with p pointing to the kprobe associated with the breakpoint,
+and regs pointing to the struct containing the registers saved when
+the breakpoint was hit. Return 0 here unless you're a Kprobes geek.
+
+User's post-handler (kp->post_handler):
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+void post_handler(struct kprobe *p, struct pt_regs *regs,
+ unsigned long flags);
+
+p and regs are as described for the pre_handler. flags always seems
+to be zero.
+
+User's fault-handler (kp->fault_handler):
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+int fault_handler(struct kprobe *p, struct pt_regs *regs, int trapnr);
+
+p and regs are as described for the pre_handler. trapnr is the
+architecture-specific trap number associated with the fault (e.g.,
+on i386, 13 for a general protection fault or 14 for a page fault).
+Returns 1 if it successfully handled the exception.
+
+4.2 register_jprobe
+
+#include <linux/kprobes.h>
+int register_jprobe(struct jprobe *jp)
+
+Sets a breakpoint at the address jp->kp.addr, which must be the address
+of the first instruction of a function. When the breakpoint is hit,
+Kprobes runs the handler whose address is jp->entry.
+
+The handler should have the same arg list and return type as the probed
+function; and just before it returns, it must call jprobe_return().
+(The handler never actually returns, since jprobe_return() returns
+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.
+
+register_jprobe() returns 0 on success, or a negative errno otherwise.
+
+4.3 register_kretprobe
+
+#include <linux/kprobes.h>
+int register_kretprobe(struct kretprobe *rp);
+
+Establishes a return probe for the function whose address is
+rp->kp.addr. When that function returns, Kprobes calls rp->handler.
+You must set rp->maxactive appropriately before you call
+register_kretprobe(); see "How Does a Return Probe Work?" for details.
+
+register_kretprobe() returns 0 on success, or a negative errno
+otherwise.
+
+User's return-probe handler (rp->handler):
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+int kretprobe_handler(struct kretprobe_instance *ri, struct pt_regs *regs);
+
+regs is as described for kprobe.pre_handler. ri points to the
+kretprobe_instance object, of which the following fields may be
+of interest:
+- ret_addr: the return address
+- rp: points to the corresponding kretprobe object
+- task: points to the corresponding task struct
+The handler's return value is currently ignored.
+
+4.4 unregister_*probe
+
+#include <linux/kprobes.h>
+void unregister_kprobe(struct kprobe *kp);
+void unregister_jprobe(struct jprobe *jp);
+void unregister_kretprobe(struct kretprobe *rp);
+
+Removes the specified probe. The unregister function can be called
+at any time after the probe has been registered.
+
+5. Kprobes Features and Limitations
+
+As of Linux v2.6.12, Kprobes allows multiple probes at the same
+address. Currently, however, there cannot be multiple jprobes on
+the same function at the same time.
+
+In general, you can install a probe anywhere in the kernel.
+In particular, you can probe interrupt handlers. Known exceptions
+are discussed in this section.
+
+For obvious reasons, it's a bad idea to install a probe in
+the code that implements Kprobes (mostly kernel/kprobes.c and
+arch/*/kernel/kprobes.c). A patch in the v2.6.13 timeframe instructs
+Kprobes to reject such requests.
+
+If you install a probe in an inline-able function, Kprobes makes
+no attempt to chase down all inline instances of the function and
+install probes there. gcc may inline a function without being asked,
+so keep this in mind if you're not seeing the probe hits you expect.
+
+A probe handler can modify the environment of the probed function
+-- e.g., by modifying kernel data structures, or by modifying the
+contents of the pt_regs struct (which are restored to the registers
+upon return from the breakpoint). So Kprobes can be used, for example,
+to install a bug fix or to inject faults for testing. Kprobes, of
+course, has no way to distinguish the deliberately injected faults
+from the accidental ones. Don't drink and probe.
+
+Kprobes makes no attempt to prevent probe handlers from stepping on
+each other -- e.g., probing printk() and then calling printk() from a
+probe handler. As of Linux v2.6.12, if a probe handler hits a probe,
+that second probe's handlers won't be run in that instance.
+
+In Linux v2.6.12 and previous versions, Kprobes' data structures are
+protected by a single lock that is held during probe registration and
+unregistration and while handlers are run. Thus, no two handlers
+can run simultaneously. To improve scalability on SMP systems,
+this restriction will probably be removed soon, in which case
+multiple handlers (or multiple instances of the same handler) may
+run concurrently on different CPUs. Code your handlers accordingly.
+
+Kprobes does not use semaphores or allocate memory except during
+registration and unregistration.
+
+Probe handlers are run with preemption disabled. Depending on the
+architecture, handlers may also run with interrupts disabled. In any
+case, your handler should not yield the CPU (e.g., by attempting to
+acquire a semaphore).
+
+Since a return probe is implemented by replacing the return
+address with the trampoline's address, stack backtraces and calls
+to __builtin_return_address() will typically yield the trampoline's
+address instead of the real return address for kretprobed functions.
+(As far as we can tell, __builtin_return_address() is used only
+for instrumentation and error reporting.)
+
+If the number of times a function is called does not match the
+number of times it returns, registering a return probe on that
+function may produce undesirable results. We have the do_exit()
+and do_execve() cases covered. do_fork() is not an issue. We're
+unaware of other specific cases where this could be a problem.
+
+6. Probe Overhead
+
+On a typical CPU in use in 2005, a kprobe hit takes 0.5 to 1.0
+microseconds to process. Specifically, a benchmark that hits the same
+probepoint repeatedly, firing a simple handler each time, reports 1-2
+million hits per second, depending on the architecture. A jprobe or
+return-probe hit typically takes 50-75% longer than a kprobe hit.
+When you have a return probe set on a function, adding a kprobe at
+the entry to that function adds essentially no overhead.
+
+Here are sample overhead figures (in usec) for different architectures.
+k = kprobe; j = jprobe; r = return probe; kr = kprobe + return probe
+on same function; jr = jprobe + return probe on same function
+
+i386: Intel Pentium M, 1495 MHz, 2957.31 bogomips
+k = 0.57 usec; j = 1.00; r = 0.92; kr = 0.99; jr = 1.40
+
+x86_64: AMD Opteron 246, 1994 MHz, 3971.48 bogomips
+k = 0.49 usec; j = 0.76; r = 0.80; kr = 0.82; jr = 1.07
+
+ppc64: POWER5 (gr), 1656 MHz (SMT disabled, 1 virtual CPU per physical CPU)
+k = 0.77 usec; j = 1.31; r = 1.26; kr = 1.45; jr = 1.99
+
+7. TODO
+
+a. SystemTap (http://sourceware.org/systemtap): Work in progress
+to provide a simplified programming interface for probe-based
+instrumentation.
+b. Improved SMP scalability: Currently, work is in progress to handle
+multiple kprobes in parallel.
+c. Kernel return probes for sparc64.
+d. Support for other architectures.
+e. User-space probes.
+
+8. Kprobes Example
+
+Here's a sample kernel module showing the use of kprobes to dump a
+stack trace and selected i386 registers when do_fork() is called.
+----- cut here -----
+/*kprobe_example.c*/
+#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*/
+static struct kprobe kp;
+
+/*kprobe pre_handler: called just before the probed instruction is executed*/
+int handler_pre(struct kprobe *p, struct pt_regs *regs)
+{
+ printk("pre_handler: p->addr=0x%p, eip=%lx, eflags=0x%lx\n",
+ p->addr, regs->eip, regs->eflags);
+ dump_stack();
+ return 0;
+}
+
+/*kprobe post_handler: called after the probed instruction is executed*/
+void handler_post(struct kprobe *p, struct pt_regs *regs, unsigned long flags)
+{
+ printk("post_handler: p->addr=0x%p, eflags=0x%lx\n",
+ p->addr, regs->eflags);
+}
+
+/* fault_handler: this is called if an exception is generated for any
+ * instruction within the pre- or post-handler, or when Kprobes
+ * single-steps the probed instruction.
+ */
+int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr)
+{
+ printk("fault_handler: p->addr=0x%p, trap #%dn",
+ p->addr, trapnr);
+ /* Return 0 because we don't handle the fault. */
+ return 0;
+}
+
+int init_module(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;
+ }
+ if ((ret = register_kprobe(&kp) < 0)) {
+ printk("register_kprobe failed, returned %d\n", ret);
+ return -1;
+ }
+ printk("kprobe registered\n");
+ return 0;
+}
+
+void cleanup_module(void)
+{
+ unregister_kprobe(&kp);
+ printk("kprobe unregistered\n");
+}
+
+MODULE_LICENSE("GPL");
+----- cut here -----
+
+You can build the kernel module, kprobe-example.ko, using the following
+Makefile:
+----- cut here -----
+obj-m := kprobe-example.o
+KDIR := /lib/modules/$(shell uname -r)/build
+PWD := $(shell pwd)
+default:
+ $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
+clean:
+ rm -f *.mod.c *.ko *.o
+----- cut here -----
+
+$ make
+$ su -
+...
+# insmod kprobe-example.ko
+
+You will see the trace data in /var/log/messages and on the console
+whenever do_fork() is invoked to create a new process.
+
+9. Jprobes Example
+
+Here's a sample kernel module showing the use of jprobes to dump
+the arguments of do_fork().
+----- cut here -----
+/*jprobe-example.c */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uio.h>
+#include <linux/kprobes.h>
+#include <linux/kallsyms.h>
+
+/*
+ * Jumper probe for do_fork.
+ * Mirror principle enables access to arguments of the probed routine
+ * from the probe handler.
+ */
+
+/* Proxy routine having the same arguments as actual do_fork() routine */
+long jdo_fork(unsigned long clone_flags, unsigned long stack_start,
+ struct pt_regs *regs, unsigned long stack_size,
+ int __user * parent_tidptr, int __user * child_tidptr)
+{
+ printk("jprobe: clone_flags=0x%lx, stack_size=0x%lx, regs=0x%p\n",
+ clone_flags, stack_size, regs);
+ /* Always end with a call to jprobe_return(). */
+ jprobe_return();
+ /*NOTREACHED*/
+ return 0;
+}
+
+static struct jprobe my_jprobe = {
+ .entry = (kprobe_opcode_t *) jdo_fork
+};
+
+int init_module(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;
+ }
+
+ if ((ret = register_jprobe(&my_jprobe)) <0) {
+ printk("register_jprobe failed, returned %d\n", ret);
+ return -1;
+ }
+ printk("Planted jprobe at %p, handler addr %p\n",
+ my_jprobe.kp.addr, my_jprobe.entry);
+ return 0;
+}
+
+void cleanup_module(void)
+{
+ unregister_jprobe(&my_jprobe);
+ printk("jprobe unregistered\n");
+}
+
+MODULE_LICENSE("GPL");
+----- cut here -----
+
+Build and insert the kernel module as shown in the above kprobe
+example. You will see the trace data in /var/log/messages and on
+the console whenever do_fork() is invoked to create a new process.
+(Some messages may be suppressed if syslogd is configured to
+eliminate duplicate messages.)
+
+10. Kretprobes Example
+
+Here's a sample kernel module showing the use of return probes to
+report failed calls to sys_open().
+----- cut here -----
+/*kretprobe-example.c*/
+#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;
+ if (retval < 0) {
+ printk("%s returns %d\n", probed_func, retval);
+ }
+ return 0;
+}
+
+static struct kretprobe my_kretprobe = {
+ .handler = ret_handler,
+ /* Probe up to 20 instances concurrently. */
+ .maxactive = 20
+};
+
+int init_module(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;
+ }
+ if ((ret = register_kretprobe(&my_kretprobe)) < 0) {
+ printk("register_kretprobe failed, returned %d\n", ret);
+ return -1;
+ }
+ printk("Planted return probe at %p\n", my_kretprobe.kp.addr);
+ return 0;
+}
+
+void cleanup_module(void)
+{
+ unregister_kretprobe(&my_kretprobe);
+ printk("kretprobe unregistered\n");
+ /* nmissed > 0 suggests that maxactive was set too low. */
+ printk("Missed probing %d instances of %s\n",
+ my_kretprobe.nmissed, probed_func);
+}
+
+MODULE_LICENSE("GPL");
+----- cut here -----
+
+Build and insert the kernel module as shown in the above kprobe
+example. You will see the trace data in /var/log/messages and on the
+console whenever sys_open() returns a negative value. (Some messages
+may be suppressed if syslogd is configured to eliminate duplicate
+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/
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 0bc2ed136a3..24d029455ba 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -1,5 +1,7 @@
- Linux Ethernet Bonding Driver HOWTO
+ Linux Ethernet Bonding Driver HOWTO
+
+ Latest update: 21 June 2005
Initial release : Thomas Davis <tadavis at lbl.gov>
Corrections, HA extensions : 2000/10/03-15 :
@@ -11,15 +13,22 @@ Corrections, HA extensions : 2000/10/03-15 :
Reorganized and updated Feb 2005 by Jay Vosburgh
-Note :
-------
+Introduction
+============
+
+ The Linux bonding driver provides a method for aggregating
+multiple network interfaces into a single logical "bonded" interface.
+The behavior of the bonded interfaces depends upon the mode; generally
+speaking, modes provide either hot standby or load balancing services.
+Additionally, link integrity monitoring may be performed.
-The bonding driver originally came from Donald Becker's beowulf patches for
-kernel 2.0. It has changed quite a bit since, and the original tools from
-extreme-linux and beowulf sites will not work with this version of the driver.
+ The bonding driver originally came from Donald Becker's
+beowulf patches for kernel 2.0. It has changed quite a bit since, and
+the original tools from extreme-linux and beowulf sites will not work
+with this version of the driver.
-For new versions of the driver, patches for older kernels and the updated
-userspace tools, please follow the links at the end of this file.
+ For new versions of the driver, updated userspace tools, and
+who to ask for help, please follow the links at the end of this file.
Table of Contents
=================
@@ -30,9 +39,13 @@ Table of Contents
3. Configuring Bonding Devices
3.1 Configuration with sysconfig support
+3.1.1 Using DHCP with sysconfig
+3.1.2 Configuring Multiple Bonds with sysconfig
3.2 Configuration with initscripts support
+3.2.1 Using DHCP with initscripts
+3.2.2 Configuring Multiple Bonds with initscripts
3.3 Configuring Bonding Manually
-3.4 Configuring Multiple Bonds
+3.3.1 Configuring Multiple Bonds Manually
5. Querying Bonding Configuration
5.1 Bonding Configuration
@@ -56,21 +69,30 @@ Table of Contents
11. Promiscuous mode
-12. High Availability Information
+12. Configuring Bonding for High Availability
12.1 High Availability in a Single Switch Topology
-12.1.1 Bonding Mode Selection for Single Switch Topology
-12.1.2 Link Monitoring for Single Switch Topology
12.2 High Availability in a Multiple Switch Topology
-12.2.1 Bonding Mode Selection for Multiple Switch Topology
-12.2.2 Link Monitoring for Multiple Switch Topology
-12.3 Switch Behavior Issues for High Availability
+12.2.1 HA Bonding Mode Selection for Multiple Switch Topology
+12.2.2 HA Link Monitoring for Multiple Switch Topology
+
+13. Configuring Bonding for Maximum Throughput
+13.1 Maximum Throughput in a Single Switch Topology
+13.1.1 MT Bonding Mode Selection for Single Switch Topology
+13.1.2 MT Link Monitoring for Single Switch Topology
+13.2 Maximum Throughput in a Multiple Switch Topology
+13.2.1 MT Bonding Mode Selection for Multiple Switch Topology
+13.2.2 MT Link Monitoring for Multiple Switch Topology
-13. Hardware Specific Considerations
-13.1 IBM BladeCenter
+14. Switch Behavior Issues
+14.1 Link Establishment and Failover Delays
+14.2 Duplicated Incoming Packets
-14. Frequently Asked Questions
+15. Hardware Specific Considerations
+15.1 IBM BladeCenter
-15. Resources and Links
+16. Frequently Asked Questions
+
+17. Resources and Links
1. Bonding Driver Installation
@@ -86,16 +108,10 @@ the following steps:
1.1 Configure and build the kernel with bonding
-----------------------------------------------
- The latest version of the bonding driver is available in the
+ The current version of the bonding driver is available in the
drivers/net/bonding subdirectory of the most recent kernel source
-(which is available on http://kernel.org).
-
- Prior to the 2.4.11 kernel, the bonding driver was maintained
-largely outside the kernel tree; patches for some earlier kernels are
-available on the bonding sourceforge site, although those patches are
-still several years out of date. Most users will want to use either
-the most recent kernel from kernel.org or whatever kernel came with
-their distro.
+(which is available on http://kernel.org). Most users "rolling their
+own" will want to use the most recent kernel from kernel.org.
Configure kernel with "make menuconfig" (or "make xconfig" or
"make config"), then select "Bonding driver support" in the "Network
@@ -103,8 +119,8 @@ device support" section. It is recommended that you configure the
driver as module since it is currently the only way to pass parameters
to the driver or configure more than one bonding device.
- Build and install the new kernel and modules, then proceed to
-step 2.
+ Build and install the new kernel and modules, then continue
+below to install ifenslave.
1.2 Install ifenslave Control Utility
-------------------------------------
@@ -147,9 +163,9 @@ default kernel source include directory.
Options for the bonding driver are supplied as parameters to
the bonding module at load time. They may be given as command line
arguments to the insmod or modprobe command, but are usually specified
-in either the /etc/modprobe.conf configuration file, or in a
-distro-specific configuration file (some of which are detailed in the
-next section).
+in either the /etc/modules.conf or /etc/modprobe.conf configuration
+file, or in a distro-specific configuration file (some of which are
+detailed in the next section).
The available bonding driver parameters are listed below. If a
parameter is not specified the default value is used. When initially
@@ -162,34 +178,34 @@ degradation will occur during link failures. Very few devices do not
support at least miimon, so there is really no reason not to use it.
Options with textual values will accept either the text name
- or, for backwards compatibility, the option value. E.g.,
- "mode=802.3ad" and "mode=4" set the same mode.
+or, for backwards compatibility, the option value. E.g.,
+"mode=802.3ad" and "mode=4" set the same mode.
The parameters are as foll