[Fault-injection-developer] [PATCH 1/4] all-in-one kprobes patch against 2.5.47 in FITH
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[Fault-injection-developer] [PATCH 1/4] all-in-one kprobes patch against 2.5.47 in FITH
|
From: Zhuang, L. <lou...@in...> - 2002-11-25 10:08:37
|
In fact, it is not a part of FITH. FITH needs kprobes as its infrastructure.
Here is our all-in-one kprobes-2 porting against 2.5.47 kernel.
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/Kconfig
linux-2.5-kp/linux-2.5.47/arch/i386/Kconfig
--- linux-2.5/linux-2.5.47/arch/i386/Kconfig Mon Nov 25 15:10:39 2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/Kconfig Mon Nov 25 15:12:19 2002
@@ -1551,6 +1551,23 @@
Say Y here if you are developing drivers or trying to debug and
identify kernel problems.
+config KPROBES
+ bool "Kprobes"
+ depends on DEBUG_KERNEL
+ help
+ Kprobes allows you to trap at almost any kernel address, using
+ register_kprobe(), and providing a callback function. This is
useful
+ for kernel debugging, non-intrusive instrumentation and testing.
If
+ in doubt, say "N".
+
+config DEBUGREG
+ bool "Global Debug Registers"
+ depend on DEBUG_KERNEL
+
+config KWATCH
+ bool "Kwatch points"
+ depend on DEBUGREG
+
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/Makefile
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/Makefile
--- linux-2.5/linux-2.5.47/arch/i386/kernel/Makefile Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/Makefile Mon Nov 25 15:12:19
2002
@@ -4,7 +4,7 @@
EXTRA_TARGETS := head.o init_task.o
-export-objs := mca.o i386_ksyms.o time.o
+export-objs := mca.o i386_ksyms.o time.o debugreg.o kwatch.o
obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
ptrace.o i8259.o ioport.o ldt.o setup.o time.o sys_i386.o \
@@ -28,6 +28,9 @@
obj-$(CONFIG_X86_NUMAQ) += numaq.o
obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_EDD) += edd.o
+obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_DEBUGREG) += debugreg.o
+obj-$(CONFIG_KWATCH) += kwatch.o
EXTRA_AFLAGS := -traditional
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/debugreg.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/debugreg.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/debugreg.c Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/debugreg.c Mon Nov 25
15:12:19 2002
@@ -0,0 +1,178 @@
+/*
+ * This provides a debug register allocation mechanism, to be
+ * used by all debuggers, which need debug registers.
+ *
+ * Author: vam...@in...
+ * bh...@in...
+ */
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <asm/debugreg.h>
+
+struct debugreg dr_list[DR_MAX];
+unsigned long dr7_global_mask = 0;
+static spinlock_t dr_lock = SPIN_LOCK_UNLOCKED;
+
+static inline void set_dr7_global_mask(int regnum)
+{
+ switch (regnum) {
+ case 0: dr7_global_mask |= DR7_DR0_BITS; break;
+ case 1: dr7_global_mask |= DR7_DR1_BITS; break;
+ case 2: dr7_global_mask |= DR7_DR2_BITS; break;
+ case 3: dr7_global_mask |= DR7_DR3_BITS; break;
+ }
+ return;
+}
+
+static inline void clear_dr7_global_mask(int regnum)
+{
+ switch (regnum) {
+ case 0: dr7_global_mask &= ~DR7_DR0_BITS; break;
+ case 1: dr7_global_mask &= ~DR7_DR1_BITS; break;
+ case 2: dr7_global_mask &= ~DR7_DR2_BITS; break;
+ case 3: dr7_global_mask &= ~DR7_DR3_BITS; break;
+ }
+ return;
+}
+
+static int get_dr(int regnum, int flag)
+{
+ if ((flag == DR_ALLOC_GLOBAL) && (dr_list[regnum].flag ==
DR_UNUSED)) {
+ dr_list[regnum].flag = DR_GLOBAL;
+ set_dr7_global_mask(regnum);
+ return regnum;
+ }
+ else if ((dr_list[regnum].flag == DR_UNUSED) ||
(dr_list[regnum].flag == DR_LOCAL)) {
+ dr_list[regnum].use_count++;
+ dr_list[regnum].flag = DR_LOCAL;
+ return regnum;
+ }
+ return -1;
+}
+
+static int get_any_dr(int flag)
+{
+ int i;
+ if (flag == DR_ALLOC_LOCAL) {
+ for (i = 0; i < DR_MAX; i++) {
+ if (dr_list[i].flag == DR_LOCAL) {
+ dr_list[i].use_count++;
+ return i;
+ } else if (dr_list[i].flag == DR_UNUSED) {
+ dr_list[i].flag = DR_LOCAL;
+ dr_list[i].use_count = 1;
+ return i;
+ }
+ }
+ } else {
+ for (i = DR_MAX-1; i >= 0; i--) {
+ if (dr_list[i].flag == DR_UNUSED) {
+ dr_list[i].flag = DR_GLOBAL;
+ set_dr7_global_mask(i);
+ return i;
+ }
+ }
+ }
+ return -1;
+}
+
+static inline void dr_free_local(int regnum)
+{
+ if (! (--dr_list[regnum].use_count))
+ dr_list[regnum].flag = DR_UNUSED;
+ return;
+}
+
+static inline void dr_free_global(int regnum)
+{
+ dr_list[regnum].flag = DR_UNUSED;
+ dr_list[regnum].use_count = 0;
+ clear_dr7_global_mask(regnum);
+ return;
+}
+
+int dr_alloc(int regnum, int flag)
+{
+ int ret;
+
+ spin_lock(&dr_lock);
+ if (regnum == DR_ANY)
+ ret = get_any_dr(flag);
+ else if (regnum >= DR_MAX)
+ ret = -1;
+ else
+ ret = get_dr(regnum, flag);
+ spin_unlock(&dr_lock);
+ return ret;
+}
+
+int dr_free(int regnum)
+{
+ spin_lock(&dr_lock);
+ if (regnum >= DR_MAX || dr_list[regnum].flag == DR_UNUSED) {
+ spin_unlock(&dr_lock);
+ return -1;
+ }
+ if (dr_list[regnum].flag == DR_LOCAL)
+ dr_free_local(regnum);
+ else
+ dr_free_global(regnum);
+ spin_unlock(&dr_lock);
+ return 0;
+}
+
+void dr_inc_use_count(unsigned long mask)
+{
+ int i;
+
+ spin_lock(&dr_lock);
+ for (i =0; i < DR_MAX; i++) {
+ if (DR_IS_LOCAL(mask, i))
+ dr_list[i].use_count++;
+ }
+ spin_unlock(&dr_lock);
+}
+
+void dr_dec_use_count(unsigned long mask)
+{
+ int i;
+
+ spin_lock(&dr_lock);
+ for (i =0; i < DR_MAX; i++) {
+ if (DR_IS_LOCAL(mask, i))
+ dr_free_local(i);
+ }
+ spin_unlock(&dr_lock);
+}
+
+/*
+ * This routine decides if the ptrace request is for enabling or disabling
+ * a debug reg, and accordingly calls dr_alloc() or dr_free().
+ *
+ * gdb uses ptrace to write to debug registers. It assumes that writing to
+ * debug register always succeds and it doesn't check the return value of
+ * ptrace. Now with this new global debug register allocation/freeing,
+ * ptrace request for a local debug register can fail, if the required
debug
+ * register is already globally allocated. Since gdb fails to notice this
+ * failure, it sometimes tries to free a debug register, which is not
+ * allocated for it.
+ */
+int enable_debugreg(unsigned long old_dr7, unsigned long new_dr7)
+{
+ int i, dr_shift = 1UL;
+ for (i = 0; i < DR_MAX; i++, dr_shift <<= 2) {
+ if ((old_dr7 ^ new_dr7) & dr_shift) {
+ if (new_dr7 & dr_shift)
+ dr_alloc(i, DR_ALLOC_LOCAL);
+ else
+ dr_free(i);
+ return 0;
+ }
+ }
+ return -1;
+}
+
+EXPORT_SYMBOL(dr_alloc);
+EXPORT_SYMBOL(dr_free);
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/entry.S
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/entry.S
--- linux-2.5/linux-2.5.47/arch/i386/kernel/entry.S Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/entry.S Mon Nov 25 15:12:19
2002
@@ -404,9 +404,16 @@
jmp ret_from_exception
ENTRY(debug)
+ pushl $-1 # mark this as an int
+ SAVE_ALL
+ movl %esp,%edx
pushl $0
- pushl $do_debug
- jmp error_code
+ pushl %edx
+ call do_debug
+ addl $8,%esp
+ testl %eax,%eax
+ jnz restore_all
+ jmp ret_from_exception
ENTRY(nmi)
pushl %eax
@@ -419,9 +426,16 @@
RESTORE_ALL
ENTRY(int3)
+ pushl $-1 # mark this as an int
+ SAVE_ALL
+ movl %esp,%edx
pushl $0
- pushl $do_int3
- jmp error_code
+ pushl %edx
+ call do_int3
+ addl $8,%esp
+ testl %eax,%eax
+ jnz restore_all
+ jmp ret_from_exception
ENTRY(overflow)
pushl $0
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/kprobes.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/kprobes.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/kprobes.c Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/kprobes.c Mon Nov 25
15:12:19 2002
@@ -0,0 +1,170 @@
+/*
+ * Support for kernel probes.
+ * (C) 2002 Vamsi Krishna S <vam...@in...>.
+ */
+
+#include <linux/config.h>
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/spinlock.h>
+#include <linux/preempt.h>
+
+/* kprobe_status settings */
+#define KPROBE_HIT_ACTIVE 0x00000001
+#define KPROBE_HIT_SS 0x00000002
+
+static struct kprobe *current_kprobe;
+static unsigned long kprobe_status, kprobe_old_eflags, kprobe_saved_eflags;
+
+/*
+ * returns non-zero if opcode modifies the interrupt flag.
+ */
+static inline int is_IF_modifier(u8 opcode)
+{
+ switch(opcode) {
+ case 0xfa: /* cli */
+ case 0xfb: /* sti */
+ case 0xcf: /* iret/iretd */
+ case 0x9d: /* popf/popfd */
+ return 1;
+ }
+ return 0;
+}
+
+static inline void disarm_kprobe(struct kprobe *p, struct pt_regs *regs)
+{
+ if (!p->at.inode) {
+ /* remember the address to be used when rearming the probe.
*/
+ p->at.addr = (void *)(regs->eip - 1);
+ }
+ *p->at.addr = p->opcode;
+ regs->eip = (unsigned long)p->at.addr;
+}
+
+/*
+ * Interrupts are disabled on entry as trap3 is an interrupt gate and they
+ * remain disabled thorough out this function.
+ */
+int kprobe_handler(struct pt_regs *regs)
+{
+ struct kprobe *p;
+ int ret = 0;
+ u8 *addr = (u8 *)(regs->eip-1);
+
+ /* We're in an interrupt, but this is clear and BUG()-safe. */
+ preempt_disable();
+
+ /* Check we're not actually recursing */
+ if (kprobe_running()) {
+ /* We *are* holding lock here, so this is safe.
+ Disarm the probe we just hit, and ignore it. */
+ p = get_kprobe(addr);
+ if (p) {
+ disarm_kprobe(p, regs);
+ ret = 1;
+ }
+ /* If it's not ours, can't be delete race, (we hold lock).
*/
+ goto no_kprobe;
+ }
+
+ lock_kprobes();
+ p = get_kprobe(addr);
+ if (!p) {
+ unlock_kprobes();
+ /* Unregistered (on another cpu) after this hit? Ignore */
+ if (*addr != BREAKPOINT_INSTRUCTION)
+ ret = 1;
+ /* Not one of ours: let kernel handle it */
+ goto no_kprobe;
+ }
+
+ kprobe_status = KPROBE_HIT_ACTIVE;
+ current_kprobe = p;
+ kprobe_saved_eflags = kprobe_old_eflags
+ = (regs->eflags & (TF_MASK|IF_MASK));
+ if (is_IF_modifier(p->opcode))
+ kprobe_saved_eflags &= ~IF_MASK;
+
+ p->pre_handler(p, regs);
+
+ regs->eflags |= TF_MASK;
+ regs->eflags &= ~IF_MASK;
+
+ /* We hold lock, now we remove breakpoint and single step. */
+ disarm_kprobe(p, regs);
+ kprobe_status = KPROBE_HIT_SS;
+ return 1;
+
+no_kprobe:
+ preempt_enable_no_resched();
+ return ret;
+}
+
+static void rearm_kprobe(struct kprobe *p, struct pt_regs *regs)
+{
+ regs->eflags &= ~TF_MASK;
+ *p->at.addr = BREAKPOINT_INSTRUCTION;
+}
+
+/*
+ * Interrupts are disabled on entry as trap1 is an interrupt gate and they
+ * remain disabled thorough out this function. And we hold kprobe lock.
+ */
+int post_kprobe_handler(struct pt_regs *regs)
+{
+ if (!kprobe_running())
+ return 0;
+
+ if (current_kprobe->post_handler)
+ current_kprobe->post_handler(current_kprobe, regs, 0);
+
+ /*
+ * We singlestepped with interrupts disabled. So, the result on
+ * the stack would be incorrect for "pushfl" instruction.
+ * Note that regs->esp is actually the top of the stack when the
+ * trap occurs in kernel space.
+ */
+ if (current_kprobe->opcode == 0x9c) { /* pushfl */
+ unsigned long *tos;
+
+ if (regs->eip > PAGE_OFFSET)
+ tos = ®s->esp;
+ else
+ tos = (unsigned long *)regs->esp;
+ *tos &= ~(TF_MASK | IF_MASK);
+ *tos |= kprobe_old_eflags;
+ }
+
+ rearm_kprobe(current_kprobe, regs);
+ regs->eflags |= kprobe_saved_eflags;
+
+ unlock_kprobes();
+ preempt_enable_no_resched();
+
+ /*
+ * if somebody else is singlestepping across a probe point, eflags
+ * will have TF set, in which case, continue the remaining
processing
+ * of do_debug, as if this is not a probe hit.
+ */
+ if (regs->eflags & TF_MASK)
+ return 0;
+
+ return 1;
+}
+
+/* Interrupts disabled, kprobe_lock held. */
+int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+ if (current_kprobe->fault_handler
+ && current_kprobe->fault_handler(current_kprobe, regs, trapnr))
+ return 1;
+
+ if (kprobe_status & KPROBE_HIT_SS) {
+ rearm_kprobe(current_kprobe, regs);
+ regs->eflags |= kprobe_old_eflags;
+
+ unlock_kprobes();
+ preempt_enable_no_resched();
+ }
+ return 0;
+}
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/kwatch.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/kwatch.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/kwatch.c Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/kwatch.c Mon Nov 25 15:12:19
2002
@@ -0,0 +1,135 @@
+/*
+ * Support for kernel watchpoints.
+ * (C) 2002 Vamsi Krishna S <vam...@in...>.
+ */
+#include <linux/config.h>
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <asm/kwatch.h>
+#include <asm/debugreg.h>
+#include <asm/bitops.h>
+
+static struct kwatch kwatch_list[DR_MAX];
+static spinlock_t kwatch_lock = SPIN_LOCK_UNLOCKED;
+static unsigned long kwatch_in_progress; /* currently being handled */
+
+struct dr_info {
+ int debugreg;
+ unsigned long addr;
+ int type;
+};
+
+static inline void write_smp_dr(void *info)
+{
+ struct dr_info *dr = (struct dr_info *)info;
+
+ if (cpu_has_de && dr->type == DR_TYPE_IO)
+ set_in_cr4(X86_CR4_DE);
+ write_dr(dr->debugreg, dr->addr);
+}
+
+/* Update the debug register on all CPUs */
+static void sync_dr(int debugreg, unsigned long addr, int type)
+{
+ struct dr_info dr;
+ dr.debugreg = debugreg;
+ dr.addr = addr;
+ dr.type = type;
+ smp_call_function(write_smp_dr, &dr, 0, 0);
+}
+
+/*
+ * Interrupts are disabled on entry as trap1 is an interrupt gate and they
+ * remain disabled thorough out this function.
+ */
+int kwatch_handler(unsigned long condition, struct pt_regs *regs)
+{
+ int debugreg = dr_trap(condition);
+ unsigned long addr = dr_trap_addr(condition);
+ int retval = 0;
+
+ if (!(condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3))) {
+ return 0;
+ }
+
+ /* We're in an interrupt, but this is clear and BUG()-safe. */
+ preempt_disable();
+
+ /* If we are recursing, we already hold the lock. */
+ if (kwatch_in_progress) {
+ goto recursed;
+ }
+ set_bit(debugreg, &kwatch_in_progress);
+
+ spin_lock(&kwatch_lock);
+ if (kwatch_list[debugreg].addr != addr)
+ goto out;
+
+ if (kwatch_list[debugreg].handler) {
+ kwatch_list[debugreg].handler(&kwatch_list[debugreg], regs);
+ }
+
+ if (kwatch_list[debugreg].type == DR_TYPE_EXECUTE)
+ regs->eflags |= RF_MASK;
+out:
+ clear_bit(debugreg, &kwatch_in_progress);
+ spin_unlock(&kwatch_lock);
+ preempt_enable_no_resched();
+ return retval;
+
+recursed:
+ if (kwatch_list[debugreg].type == DR_TYPE_EXECUTE)
+ regs->eflags |= RF_MASK;
+ preempt_enable_no_resched();
+ return 1;
+}
+
+int register_kwatch(unsigned long addr, u8 length, u8 type,
+ kwatch_handler_t handler)
+{
+ int debugreg;
+ unsigned long dr7, flags;
+
+ debugreg = dr_alloc(DR_ANY, DR_ALLOC_GLOBAL);
+ if (debugreg < 0) {
+ return -1;
+ }
+
+ spin_lock_irqsave(&kwatch_lock, flags);
+ kwatch_list[debugreg].addr = addr;
+ kwatch_list[debugreg].length = length;
+ kwatch_list[debugreg].type = type;
+ kwatch_list[debugreg].handler = handler;
+ spin_unlock_irqrestore(&kwatch_lock, flags);
+
+ write_dr(debugreg, (unsigned long)addr);
+ sync_dr(debugreg, (unsigned long)addr, type);
+ if (cpu_has_de && type == DR_TYPE_IO)
+ set_in_cr4(X86_CR4_DE);
+
+ dr7 = read_dr(7);
+ SET_DR7(dr7, debugreg, type, length);
+ write_dr(7, dr7);
+ sync_dr(7, dr7, 0);
+ return debugreg;
+}
+
+void unregister_kwatch(int debugreg)
+{
+ unsigned long flags;
+ unsigned long dr7 = read_dr(7);
+
+ RESET_DR7(dr7, debugreg);
+ write_dr(7, dr7);
+ sync_dr(7, dr7, 0);
+ dr_free(debugreg);
+
+ spin_lock_irqsave(&kwatch_lock, flags);
+ kwatch_list[debugreg].addr = 0;
+ kwatch_list[debugreg].handler = NULL;
+ spin_unlock_irqrestore(&kwatch_lock, flags);
+}
+EXPORT_SYMBOL_GPL(register_kwatch);
+EXPORT_SYMBOL_GPL(unregister_kwatch);
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/process.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/process.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/process.c Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/process.c Mon Nov 25
15:12:19 2002
@@ -47,6 +47,7 @@
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
+#include <asm/debugreg.h>
#include <linux/irq.h>
#include <linux/err.h>
@@ -241,12 +242,16 @@
kfree(tsk->thread.ts_io_bitmap);
tsk->thread.ts_io_bitmap = NULL;
}
+ if (tsk->thread.debugreg[7])
+ dr_dec_use_count(tsk->thread.debugreg[7]);
}
void flush_thread(void)
{
struct task_struct *tsk = current;
+ if (tsk->thread.debugreg[7])
+ dr_dec_use_count(tsk->thread.debugreg[7]);
memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
memset(tsk->thread.tls_array, 0,
sizeof(tsk->thread.tls_array));
/*
@@ -330,6 +335,9 @@
desc->a = LDT_entry_a(&info);
desc->b = LDT_entry_b(&info);
}
+
+ if (current->thread.debugreg[7])
+ dr_inc_use_count(current->thread.debugreg[7]);
return 0;
}
@@ -464,6 +472,24 @@
/*
* Now maybe reload the debug registers
*/
+#ifdef CONFIG_DEBUGREG
+{
+ /*
+ * Don't reload global debug registers. Don't touch the global debug
+ * register settings in dr7.
+ */
+ unsigned long next_dr7 = next->debugreg[7];
+ if (unlikely(next_dr7)) {
+ if (DR7_L0(next_dr7)) loaddebug(next, 0);
+ if (DR7_L1(next_dr7)) loaddebug(next, 1);
+ if (DR7_L2(next_dr7)) loaddebug(next, 2);
+ if (DR7_L3(next_dr7)) loaddebug(next, 3);
+ /* no 4 and 5 */
+ loaddebug(next, 6);
+ load_process_dr7(next_dr7);
+ }
+}
+#else
if (unlikely(next->debugreg[7])) {
loaddebug(next, 0);
loaddebug(next, 1);
@@ -473,7 +499,7 @@
loaddebug(next, 6);
loaddebug(next, 7);
}
-
+#endif
if (unlikely(prev->ts_io_bitmap || next->ts_io_bitmap)) {
if (next->ts_io_bitmap) {
/*
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/ptrace.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/ptrace.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/ptrace.c Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/ptrace.c Mon Nov 25 15:12:19
2002
@@ -269,6 +269,11 @@
addr -= (long) &dummy->u_debugreg;
addr = addr >> 2;
+
+ if (addr == 7 &&
(enable_debugreg(child->thread.debugreg[addr], data)) < 0) {
+ ret = -EBUSY;
+ break;
+ }
child->thread.debugreg[addr] = data;
ret = 0;
}
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/signal.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/signal.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/signal.c Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/signal.c Mon Nov 25 15:12:19
2002
@@ -22,6 +22,7 @@
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
+#include <asm/debugreg.h>
#define DEBUG_SIG 0
@@ -574,7 +575,7 @@
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
- __asm__("movl %0,%%db7" : : "r"
(current->thread.debugreg[7]));
+ load_process_dr7(current->thread.debugreg[7]);
/* Whee! Actually deliver the signal. */
handle_signal(signr, &info, oldset, regs);
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/kernel/traps.c
linux-2.5-kp/linux-2.5.47/arch/i386/kernel/traps.c
--- linux-2.5/linux-2.5.47/arch/i386/kernel/traps.c Mon Nov 25 15:10:39
2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/kernel/traps.c Mon Nov 25 15:12:19
2002
@@ -23,6 +23,7 @@
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
+#include <linux/kprobes.h>
#ifdef CONFIG_EISA
#include <linux/ioport.h>
@@ -38,6 +39,7 @@
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/debugreg.h>
+#include <asm/kwatch.h>
#include <asm/desc.h>
#include <asm/i387.h>
#include <asm/nmi.h>
@@ -402,7 +404,6 @@
}
DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV,
regs->eip)
-DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN,
regs->eip)
@@ -418,6 +419,9 @@
{
if (regs->eflags & VM_MASK)
goto gp_in_vm86;
+
+ if (kprobe_running() && kprobe_fault_handler(regs, 13))
+ return;
if (!(regs->xcs & 3))
goto gp_in_kernel;
@@ -549,6 +553,17 @@
nmi_callback = dummy_nmi_callback;
}
+asmlinkage int do_int3(struct pt_regs *regs, long error_code)
+{
+ if (kprobe_handler(regs))
+ return 1;
+ /* This is an interrupt gate, because kprobes wants interrupts
+ disabled. Normal trap handlers don't. */
+ restore_interrupts(regs);
+ do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
+ return 0;
+}
+
/*
* Our handling of the processor debug registers is non-trivial.
* We do not clear them on entry and exit from the kernel. Therefore
@@ -571,7 +586,7 @@
* find every occurrence of the TF bit that could be saved away even
* by user code)
*/
-asmlinkage void do_debug(struct pt_regs * regs, long error_code)
+asmlinkage int do_debug(struct pt_regs * regs, long error_code)
{
unsigned int condition;
struct task_struct *tsk = current;
@@ -579,6 +594,15 @@
__asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
+ if (post_kprobe_handler(regs))
+ return 1;
+
+ if (kwatch_handler(condition, regs))
+ return 1;
+
+ /* Interrupts not disabled for normal trap handling. */
+ restore_interrupts(regs);
+
/* Mask out spurious debug traps due to lazy DR7 setting */
if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
if (!tsk->thread.debugreg[7])
@@ -626,18 +650,16 @@
* the signal is delivered.
*/
clear_dr7:
- __asm__("movl %0,%%db7"
- : /* no output */
- : "r" (0));
- return;
+ load_process_dr7(0);
+ return 0;
debug_vm86:
handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
- return;
+ return 0;
clear_TF:
regs->eflags &= ~TF_MASK;
- return;
+ return 0;
}
/*
@@ -801,6 +823,8 @@
struct task_struct *tsk = current;
clts(); /* Allow maths ops (or we recurse) */
+ if (kprobe_running() && kprobe_fault_handler(®s, 7))
+ return;
if (!tsk->used_math)
init_fpu(tsk);
restore_fpu(tsk);
@@ -894,9 +918,9 @@
#endif
set_trap_gate(0,÷_error);
- set_trap_gate(1,&debug);
+ _set_gate(idt_table+1,14,3,&debug); /* debug trap for kprobes */
set_intr_gate(2,&nmi);
- set_system_gate(3,&int3); /* int3-5 can be called from all */
+ _set_gate(idt_table+3,14,3,&int3); /* int3-5 can be called from all
*/
set_system_gate(4,&overflow);
set_system_gate(5,&bounds);
set_trap_gate(6,&invalid_op);
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/arch/i386/mm/fault.c
linux-2.5-kp/linux-2.5.47/arch/i386/mm/fault.c
--- linux-2.5/linux-2.5.47/arch/i386/mm/fault.c Mon Nov 25 15:10:40 2002
+++ linux-2.5-kp/linux-2.5.47/arch/i386/mm/fault.c Mon Nov 25 15:12:20
2002
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/vt_kern.h> /* For unblank_screen() */
+#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -163,6 +164,9 @@
/* get the address */
__asm__("movl %%cr2,%0":"=r" (address));
+ if (kprobe_running() && kprobe_fault_handler(regs, 14))
+ return;
+
/* It's safe to allow irq's after cr2 has been saved */
if (regs->eflags & X86_EFLAGS_IF)
local_irq_enable();
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/include/asm-i386/debugreg.h
linux-2.5-kp/linux-2.5.47/include/asm-i386/debugreg.h
--- linux-2.5/linux-2.5.47/include/asm-i386/debugreg.h Mon Nov 25 15:11:24
2002
+++ linux-2.5-kp/linux-2.5.47/include/asm-i386/debugreg.h Mon Nov 25
15:12:55 2002
@@ -61,4 +61,166 @@
#define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */
#define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */
+struct debugreg {
+ unsigned long flag;
+ unsigned long use_count;
+};
+
+/* debugreg flags */
+#define DR_UNUSED 0
+#define DR_LOCAL 1
+#define DR_GLOBAL 2
+
+#define DR_MAX 4
+#define DR_ANY DR_MAX + 1
+
+/* global or local allocation requests */
+#define DR_ALLOC_GLOBAL 0
+#define DR_ALLOC_LOCAL 1
+
+#define DR7_RW_SET(dr, regnum, rw) do { \
+ (dr) &= ~(0x3 << (16 + (4 * (regnum)))); \
+ (dr) |= (((rw) & 0x3) << (16 + (4 * (regnum)))); \
+ } while (0)
+
+#define DR7_RW_VAL(dr, regnum) \
+ (((dr) >> (16 + (4 * (regnum)))) & 0x3)
+
+#define DR7_LEN_SET(dr, regnum, len) do { \
+ (dr) &= ~(0x3 << (18 + (4 * (regnum)))); \
+ (dr) |= (((len-1) & 0x3) << (18 + (4 * (regnum)))); \
+ } while (0)
+
+#define DR7_LEN_VAL(dr, regnum) \
+ (((dr) >> (18 + (4 * (regnum)))) & 0x3)
+
+#define DR7_L0(dr) (((dr))&0x1)
+#define DR7_L1(dr) (((dr)>>2)&0x1)
+#define DR7_L2(dr) (((dr)>>4)&0x1)
+#define DR7_L3(dr) (((dr)>>6)&0x1)
+
+#define DR_IS_LOCAL(dr, num) ((dr) & (1UL << (num <<1)))
+
+/* Set the rw, len and global flag in dr7 for a debug register */
+#define SET_DR7(dr, regnum, access, len) do { \
+ DR7_RW_SET(dr, regnum, access); \
+ DR7_LEN_SET(dr, regnum, len); \
+ dr |= (2UL << regnum*2); \
+ } while (0)
+
+/* Disable a debug register by clearing the global/local flag in dr7 */
+#define RESET_DR7(dr, regnum) dr &= ~(3UL << regnum*2)
+
+#define DR7_DR0_BITS 0x000F0003
+#define DR7_DR1_BITS 0x00F0000C
+#define DR7_DR2_BITS 0x0F000030
+#define DR7_DR3_BITS 0xF00000C0
+
+#define DR_TRAP_MASK 0xF
+
+#define DR_TYPE_EXECUTE 0x0
+#define DR_TYPE_WRITE 0x1
+#define DR_TYPE_IO 0x2
+#define DR_TYPE_RW 0x3
+
+#define get_dr(regnum, val) \
+ __asm__("movl %%db" #regnum ", %0" \
+ :"=r" (val))
+static inline unsigned long read_dr(int regnum)
+{
+ unsigned long val = 0;
+ switch (regnum) {
+ case 0: get_dr(0, val); break;
+ case 1: get_dr(1, val); break;
+ case 2: get_dr(2, val); break;
+ case 3: get_dr(3, val); break;
+ case 6: get_dr(6, val); break;
+ case 7: get_dr(7, val); break;
+ }
+ return val;
+}
+#undef get_dr
+
+#define set_dr(regnum, val) \
+ __asm__("movl %0,%%db" #regnum \
+ : /* no output */ \
+ :"r" (val))
+static inline void write_dr(int regnum, unsigned long val)
+{
+ switch (regnum) {
+ case 0: set_dr(0, val); break;
+ case 1: set_dr(1, val); break;
+ case 2: set_dr(2, val); break;
+ case 3: set_dr(3, val); break;
+ case 7: set_dr(7, val); break;
+ }
+ return;
+}
+#undef set_dr
+
+/*
+ * Given the debug status register, returns the debug register number
+ * which caused the debug trap.
+ */
+static inline int dr_trap(unsigned int condition)
+{
+ int i, reg_shift = 1UL;
+ for (i = 0; i < DR_MAX; i++, reg_shift <<= 1)
+ if ((condition & reg_shift))
+ return i;
+ return -1;
+}
+
+/*
+ * Given the debug status register, returns the address due to which
+ * the debug trap occured.
+ */
+static inline unsigned long dr_trap_addr(unsigned int condition)
+{
+ int regnum = dr_trap(condition);
+
+ if (regnum == -1)
+ return -1;
+ return read_dr(regnum);
+}
+
+/*
+ * Given the debug status register, returns the type of debug trap:
+ * execute, read/write, write or io.
+ */
+static inline int dr_trap_type(unsigned int condition)
+{
+ int regnum = dr_trap(condition);
+
+ if (regnum == -1)
+ return -1;
+ return DR7_RW_VAL(read_dr(7), regnum);
+}
+
+/* Function declarations */
+
+#ifdef CONFIG_DEBUGREG
+extern int dr_alloc(int regnum, int flag);
+extern int dr_free(int regnum);
+extern void dr_inc_use_count(unsigned long mask);
+extern void dr_dec_use_count(unsigned long mask);
+extern struct debugreg dr_list[DR_MAX];
+extern unsigned long dr7_global_mask;
+extern int enable_debugreg(unsigned long old_dr7, unsigned long new_dr7);
+
+static inline void load_process_dr7(unsigned long curr_dr7)
+{
+ write_dr(7, (read_dr(7) & dr7_global_mask) | curr_dr7);
+}
+#else
+static inline int enable_debugreg(unsigned long old_dr7, unsigned long
new_dr7) { return 0; }
+static inline void void load_process_dr7(unsigned long curr_dr7)
+{
+ write_dr(7, curr_dr7);
+}
+
+static void dr_inc_use_count(unsigned long mask) { }
+static void dr_dec_use_count(unsigned long mask) { }
+
+#endif /* CONFIG_DEBUGREG */
#endif
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/include/asm-i386/kprobes.h
linux-2.5-kp/linux-2.5.47/include/asm-i386/kprobes.h
--- linux-2.5/linux-2.5.47/include/asm-i386/kprobes.h Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/include/asm-i386/kprobes.h Mon Nov 25
15:12:57 2002
@@ -0,0 +1,34 @@
+#ifndef _ASM_KPROBES_H
+#define _ASM_KPROBES_H
+/*
+ * Dynamic Probes (kprobes) support
+ * Vamsi Krishna S <vam...@in...>, July, 2002
+ * Mailing list: dp...@ww...
+ */
+#include <linux/types.h>
+#include <linux/ptrace.h>
+
+struct pt_regs;
+
+typedef u8 kprobe_opcode_t;
+#define BREAKPOINT_INSTRUCTION 0xcc
+
+/* trap3/1 are intr gates for kprobes. So, restore the status of IF,
+ * if necessary, before executing the original int3/1 (trap) handler.
+ */
+static inline void restore_interrupts(struct pt_regs *regs)
+{
+ if (regs->eflags & IF_MASK)
+ __asm__ __volatile__ ("sti");
+}
+
+#ifdef CONFIG_KPROBES
+extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
+extern int post_kprobe_handler(struct pt_regs *regs);
+extern int kprobe_handler(struct pt_regs *regs);
+#else /* !CONFIG_KPROBES */
+static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) {
return 0; }
+static inline int post_kprobe_handler(struct pt_regs *regs) { return 0; }
+static inline int kprobe_handler(struct pt_regs *regs) { return 0; }
+#endif
+#endif /* _ASM_KPROBES_H */
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/include/asm-i386/kwatch.h
linux-2.5-kp/linux-2.5.47/include/asm-i386/kwatch.h
--- linux-2.5/linux-2.5.47/include/asm-i386/kwatch.h Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/include/asm-i386/kwatch.h Mon Nov 25 15:12:57
2002
@@ -0,0 +1,31 @@
+#ifndef _ASM_KWATCH_H
+#define _ASM_KWATCH_H
+/*
+ * Dynamic Probes (kwatch points) support
+ * Vamsi Krishna S <vam...@in...>, Oct, 2002
+ */
+#include <linux/types.h>
+#include <linux/ptrace.h>
+
+struct kwatch;
+typedef void (*kwatch_handler_t)(struct kwatch *, struct pt_regs *);
+
+struct kwatch {
+ unsigned long addr; /* location of watchpoint */
+ u8 length; /* range of address */
+ u8 type; /* type of watchpoint */
+ kwatch_handler_t handler;
+};
+
+#define RF_MASK 0x00010000
+
+#ifdef CONFIG_KWATCH
+extern int register_kwatch(unsigned long addr, u8 length, u8 type,
kwatch_handler_t handler);
+extern void unregister_kwatch(int debugreg);
+extern int kwatch_handler(unsigned long condition, struct pt_regs *regs);
+#else
+static inline int register_kwatch(unsigned long addr, u8 length, u8 type,
kwatch_handler_t handler) { return -ENOSYS; }
+static inline void unregister_kwatch(int debugreg) { }
+static inline int kwatch_handler(unsigned long condition, struct pt_regs
*regs) { return 0; }
+#endif
+#endif /* _ASM_KWATCH_H */
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/include/linux/kprobes.h
linux-2.5-kp/linux-2.5.47/include/linux/kprobes.h
--- linux-2.5/linux-2.5.47/include/linux/kprobes.h Thu Jan 1 08:00:00
1970
+++ linux-2.5-kp/linux-2.5.47/include/linux/kprobes.h Mon Nov 25 15:13:03
2002
@@ -0,0 +1,66 @@
+#ifndef _LINUX_KPROBES_H
+#define _LINUX_KPROBES_H
+#include <linux/config.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <asm/kprobes.h>
+
+struct kprobe;
+struct pt_regs;
+
+typedef void (*kprobe_pre_handler_t)(struct kprobe *, struct pt_regs *);
+typedef void (*kprobe_post_handler_t)(struct kprobe *, struct pt_regs *,
+ unsigned long flags);
+typedef int (*kprobe_fault_handler_t)(struct kprobe *, struct pt_regs *,
+ int trapnr);
+struct probe_at {
+ kprobe_opcode_t *addr;
+ struct inode *inode; /* for user space probes */
+ unsigned long offset; /* for user space probes */
+};
+
+struct kprobe {
+ struct list_head list;
+
+ /* location of the probe point */
+ struct probe_at at;
+
+ /* Called before addr is executed. */
+ kprobe_pre_handler_t pre_handler;
+
+ /* Called after addr is executed, unless... */
+ kprobe_post_handler_t post_handler;
+
+ /* ... called if executing addr causes a fault (eg. page fault).
+ * Return 1 if it handled fault, otherwise kernel will see it. */
+ kprobe_fault_handler_t fault_handler;
+
+ /* Saved opcode (which has been replaced with breakpoint) */
+ kprobe_opcode_t opcode;
+};
+
+#ifdef CONFIG_KPROBES
+/* Locks kprobe: irq must be disabled */
+void lock_kprobes(void);
+void unlock_kprobes(void);
+
+/* kprobe running now on this CPU? */
+static inline int kprobe_running(void)
+{
+ extern unsigned int kprobe_cpu;
+ return kprobe_cpu == smp_processor_id();
+}
+
+/* Get the kprobe at this addr (if any). Must have called lock_kprobes */
+struct kprobe *get_kprobe(void *addr);
+
+int register_kprobe(struct kprobe *p);
+void unregister_kprobe(struct kprobe *p);
+#else
+static inline int kprobe_running(void) { return 0; }
+static inline int register_kprobe(struct kprobe *p) { return -ENOSYS; }
+static inline void unregister_kprobe(struct kprobe *p) { }
+#endif
+#endif /* _LINUX_KPROBES_H */
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/kernel/Makefile
linux-2.5-kp/linux-2.5.47/kernel/Makefile
--- linux-2.5/linux-2.5.47/kernel/Makefile Mon Nov 25 15:11:37 2002
+++ linux-2.5-kp/linux-2.5.47/kernel/Makefile Mon Nov 25 15:13:04 2002
@@ -4,7 +4,7 @@
export-objs = signal.o sys.o kmod.o workqueue.o ksyms.o pm.o exec_domain.o
\
printk.o platform.o suspend.o dma.o module.o cpufreq.o \
- profile.o rcupdate.o
+ profile.o rcupdate.o kprobes.o
obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
module.o exit.o itimer.o time.o softirq.o resource.o \
@@ -21,6 +21,7 @@
obj-$(CONFIG_CPU_FREQ) += cpufreq.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_SOFTWARE_SUSPEND) += suspend.o
+obj-$(CONFIG_KPROBES) += kprobes.o
ifneq ($(CONFIG_IA64),y)
# According to Alan Modra <al...@li...>, the
-fno-omit-frame-pointer is
diff -Nur -X dontdiff linux-2.5/linux-2.5.47/kernel/kprobes.c
linux-2.5-kp/linux-2.5.47/kernel/kprobes.c
--- linux-2.5/linux-2.5.47/kernel/kprobes.c Thu Jan 1 08:00:00 1970
+++ linux-2.5-kp/linux-2.5.47/kernel/kprobes.c Mon Nov 25 15:13:04 2002
@@ -0,0 +1,157 @@
+/* Support for kernel probes.
+ (C) 2002 Vamsi Krishna S <vam...@in...>.
+*/
+#include <linux/kprobes.h>
+#include <linux/spinlock.h>
+#include <linux/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+#include <asm/errno.h>
+
+#define KPROBE_HASH_BITS 6
+#define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)
+
+static struct list_head kprobe_table[KPROBE_TABLE_SIZE];
+
+unsigned int kprobe_cpu = NR_CPUS;
+static spinlock_t kprobe_lock = SPIN_LOCK_UNLOCKED;
+
+/* Locks kprobe: irqs must be disabled */
+void lock_kprobes(void)
+{
+ spin_lock(&kprobe_lock);
+ kprobe_cpu = smp_processor_id();
+}
+
+void unlock_kprobes(void)
+{
+ kprobe_cpu = NR_CPUS;
+ spin_unlock(&kprobe_lock);
+}
+
+/*
+ * We need to look up the inode and offset from the vma. We can't depend on
+ * the page->(mapping, index) as that would be incorrect if we ever swap
this
+ * page out (possible for pages which are dirtied by GDB breakpoints etc)
+ *
+ * We acquire page_table_lock here to ensure that:
+ * - current page doesn't go away from under us (kswapd)
+ * - mm->mmap consistancy (vma are always added under this lock)
+ *
+ * We will never deadlock on page_table_lock, we always come here due to a
+ * probe in user space, no kernel code could have executed to take the
+ * page_table_lock.
+ */
+static struct kprobe *get_uprobe_at(struct inode *inode, unsigned long
offset)
+{
+ struct list_head *head;
+ struct kprobe *p;
+
+ head = &kprobe_table[hash_long((unsigned long)inode*offset,
+ KPROBE_HASH_BITS)];
+ list_for_each_entry(p, head, list) {
+ if (p->at.inode == inode && p->at.offset == offset)
+ return p;
+ }
+ return NULL;
+}
+
+static struct kprobe *get_uprobe(void *addr)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ struct inode *inode;
+ unsigned long offset;
+
+ spin_lock(&mm->page_table_lock);
+ vma = find_vma(mm, (unsigned long)addr);
+ offset = (unsigned long)addr - vma->vm_start + (vma->vm_pgoff <<
PAGE_SHIFT);
+ if (!vma->vm_file) {
+ spin_unlock(&mm->page_table_lock);
+ return NULL;
+ }
+ inode = vma->vm_file->f_dentry->d_inode;
+ spin_unlock(&mm->page_table_lock);
+
+ return get_uprobe_at(inode, offset);
+}
+
+/* You have to be holding the kprobe_lock */
+struct kprobe *get_kprobe(void *addr)
+{
+ struct list_head *head, *tmp;
+
+ if ((unsigned long)addr < PAGE_OFFSET)
+ return get_uprobe(addr);
+
+ head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)];
+ list_for_each(tmp, head) {
+ struct kprobe *p = list_entry(tmp, struct kprobe, list);
+ if (p->at.addr == addr)
+ return p;
+ }
+ return NULL;
+}
+
+/*
+ * p->at.addr has to be writeable address for uspace probes.
+ */
+int register_kprobe(struct kprobe *p)
+{
+ int ret = 0;
+ kprobe_opcode_t *addr = p->at.addr;
+
+ spin_lock_irq(&kprobe_lock);
+ if (!p->at.inode) {
+ if (get_kprobe(addr)) {
+ ret = -EEXIST;
+ goto out;
+ }
+ list_add(&p->list, &kprobe_table[hash_ptr(addr,
+ KPROBE_HASH_BITS)]);
+ } else {
+ if (get_uprobe_at(p->at.inode, p->at.offset)) {
+ ret = -EEXIST;
+ goto out;
+ }
+ list_add(&p->list,
+ &kprobe_table[hash_long(
+ (unsigned long)p->at.inode * p->at.offset,
+ KPROBE_HASH_BITS)]);
+ }
+
+ p->opcode = *addr;
+ *addr = BREAKPOINT_INSTRUCTION;
+ flush_icache_range(addr, addr + sizeof(kprobe_opcode_t));
+ out:
+ spin_unlock_irq(&kprobe_lock);
+ return ret;
+}
+
+void unregister_kprobe(struct kprobe *p)
+{
+ kprobe_opcode_t *addr = p->at.addr;
+
+ spin_lock_irq(&kprobe_lock);
+ *addr = p->opcode;
+ list_del(&p->list);
+ flush_icache_range(addr, addr + sizeof(kprobe_opcode_t));
+ spin_unlock_irq(&kprobe_lock);
+}
+
+static int __init init_kprobes(void)
+{
+ int i;
+
+ /* FIXME allocate the probe table, currently defined statically */
+ /* initialize all list heads */
+ for (i = 0; i < KPROBE_TABLE_SIZE; i++)
+ INIT_LIST_HEAD(&kprobe_table[i]);
+
+ return 0;
+}
+__initcall(init_kprobes);
+
+EXPORT_SYMBOL_GPL(register_kprobe);
+EXPORT_SYMBOL_GPL(unregister_kprobe);
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