---

yaml
---
r: 37877
b: refs/heads/master
c: 12dce62
h: refs/heads/master
i:
  37875: 43c71c7
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 04b314b2c3732bb5aa752fdbb3076de16decdab6
+refs/heads/master: 12dce6263d43daeb4e16fa4eb964c1c99fa4fa2e

trunk/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)

trunk/arch/alpha/kernel/alpha_ksyms.c

@@ -36,7 +36,6 @@
 #include <asm/cacheflush.h>
 #include <asm/vga.h>
 
-#define __KERNEL_SYSCALLS__
 #include <asm/unistd.h>
 
 extern struct hwrpb_struct *hwrpb;
@@ -116,7 +115,7 @@ EXPORT_SYMBOL(sys_dup);
 EXPORT_SYMBOL(sys_exit);
 EXPORT_SYMBOL(sys_write);
 EXPORT_SYMBOL(sys_lseek);
-EXPORT_SYMBOL(execve);
+EXPORT_SYMBOL(kernel_execve);
 EXPORT_SYMBOL(sys_setsid);
 EXPORT_SYMBOL(sys_wait4);
 

trunk/arch/alpha/kernel/entry.S

@@ -655,12 +655,12 @@ kernel_thread:
 .end kernel_thread
 
 /*
- * execve(path, argv, envp)
+ * kernel_execve(path, argv, envp)
  */
 	.align	4
-	.globl	execve
-	.ent	execve
-execve:
+	.globl	kernel_execve
+	.ent	kernel_execve
+kernel_execve:
 	/* We can be called from a module.  */
 	ldgp	$gp, 0($27)
 	lda	$sp, -(32+SIZEOF_PT_REGS+8)($sp)
@@ -704,7 +704,7 @@ execve:
 
 1:	lda	$sp, 32+SIZEOF_PT_REGS+8($sp)
 	ret
-.end execve
+.end kernel_execve
 
 
 /*

trunk/arch/alpha/kernel/osf_sys.c

@@ -402,15 +402,15 @@ osf_utsname(char __user *name)
 
 	down_read(&uts_sem);
 	error = -EFAULT;
-	if (copy_to_user(name + 0, system_utsname.sysname, 32))
+	if (copy_to_user(name + 0, utsname()->sysname, 32))
 		goto out;
-	if (copy_to_user(name + 32, system_utsname.nodename, 32))
+	if (copy_to_user(name + 32, utsname()->nodename, 32))
 		goto out;
-	if (copy_to_user(name + 64, system_utsname.release, 32))
+	if (copy_to_user(name + 64, utsname()->release, 32))
 		goto out;
-	if (copy_to_user(name + 96, system_utsname.version, 32))
+	if (copy_to_user(name + 96, utsname()->version, 32))
 		goto out;
-	if (copy_to_user(name + 128, system_utsname.machine, 32))
+	if (copy_to_user(name + 128, utsname()->machine, 32))
 		goto out;
 
 	error = 0;
@@ -449,8 +449,8 @@ osf_getdomainname(char __user *name, int namelen)
 
 	down_read(&uts_sem);
 	for (i = 0; i < len; ++i) {
-		__put_user(system_utsname.domainname[i], name + i);
-		if (system_utsname.domainname[i] == '\0')
+		__put_user(utsname()->domainname[i], name + i);
+		if (utsname()->domainname[i] == '\0')
 			break;
 	}
 	up_read(&uts_sem);
@@ -607,12 +607,12 @@ osf_sigstack(struct sigstack __user *uss, struct sigstack __user *uoss)
 asmlinkage long
 osf_sysinfo(int command, char __user *buf, long count)
 {
-	static char * sysinfo_table[] = {
-		system_utsname.sysname,
-		system_utsname.nodename,
-		system_utsname.release,
-		system_utsname.version,
-		system_utsname.machine,
+	char *sysinfo_table[] = {
+		utsname()->sysname,
+		utsname()->nodename,
+		utsname()->release,
+		utsname()->version,
+		utsname()->machine,
 		"alpha",	/* instruction set architecture */
 		"dummy",	/* hardware serial number */
 		"dummy",	/* hardware manufacturer */

trunk/arch/alpha/kernel/srmcons.c

@@ -229,7 +229,7 @@ srmcons_close(struct tty_struct *tty, struct file *filp)
 
 static struct tty_driver *srmcons_driver;
 
-static struct tty_operations srmcons_ops = {
+static const struct tty_operations srmcons_ops = {
 	.open		= srmcons_open,
 	.close		= srmcons_close,
 	.write		= srmcons_write,

trunk/arch/arm/kernel/setup.c

@@ -348,7 +348,7 @@ static void __init setup_processor(void)
 	       cpu_name, processor_id, (int)processor_id & 15,
 	       proc_arch[cpu_architecture()], cr_alignment);
 
-	sprintf(system_utsname.machine, "%s%c", list->arch_name, ENDIANNESS);
+	sprintf(init_utsname()->machine, "%s%c", list->arch_name, ENDIANNESS);
 	sprintf(elf_platform, "%s%c", list->elf_name, ENDIANNESS);
 	elf_hwcap = list->elf_hwcap;
 #ifndef CONFIG_ARM_THUMB

trunk/arch/arm/kernel/smp.c

@@ -36,7 +36,9 @@
  * The online bitmask indicates that the CPU is up and running.
  */
 cpumask_t cpu_possible_map;
+EXPORT_SYMBOL(cpu_possible_map);
 cpumask_t cpu_online_map;
+EXPORT_SYMBOL(cpu_online_map);
 
 /*
  * as from 2.5, kernels no longer have an init_tasks structure

trunk/arch/arm/kernel/sys_arm.c

@@ -279,7 +279,7 @@ asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
 	return error;
 }
 
-long execve(const char *filename, char **argv, char **envp)
+int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 {
 	struct pt_regs regs;
 	int ret;
@@ -317,7 +317,7 @@ long execve(const char *filename, char **argv, char **envp)
  out:
 	return ret;
 }
-EXPORT_SYMBOL(execve);
+EXPORT_SYMBOL(kernel_execve);
 
 /*
  * Since loff_t is a 64 bit type we avoid a lot of ABI hastle

trunk/arch/arm26/kernel/setup.c

@@ -143,7 +143,7 @@ static void __init setup_processor(void)
 
 	dump_cpu_info();
 
-	sprintf(system_utsname.machine, "%s", list->arch_name);
+	sprintf(init_utsname()->machine, "%s", list->arch_name);
 	sprintf(elf_platform, "%s", list->elf_name);
 	elf_hwcap = list->elf_hwcap;
 

trunk/arch/arm26/kernel/sys_arm.c

@@ -283,7 +283,7 @@ asmlinkage int sys_execve(char *filenamei, char **argv, char **envp, struct pt_r
 }
 
 /* FIXME - see if this is correct for arm26 */
-long execve(const char *filename, char **argv, char **envp)
+int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 {
 	struct pt_regs regs;
         int ret;
@@ -320,4 +320,4 @@ long execve(const char *filename, char **argv, char **envp)
         return ret;
 }
 
-EXPORT_SYMBOL(execve);
+EXPORT_SYMBOL(kernel_execve);