PATCH Kernel watchpoint interface-2.6.9-rc4-mm1

178 lines not on this page · raw message

diff -puN arch/i386/kernel/process.c~kprobes-debug-regs-2.6.9-rc4-mm1 arch/i386/kernel/process.c
@@ -50,6 +50,7 @@
 #ifdef CONFIG_MATH_EMULATION
 #include <asm/math_emu.h>
 #endif
+#include <asm/debugreg.h>
 
 #include <linux/irq.h>
 #include <linux/err.h>

@@ -317,6 +318,8 @@ void exit_thread(void)
 		tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
 		put_cpu();
 	}
+	if (tsk->thread.debugreg[7])
+		dr_dec_use_count(tsk->thread.debugreg[7]);
 	perfctr_exit_thread(&tsk->thread);
 }
 

@@ -324,6 +327,8 @@ 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));	
 	/*

@@ -416,6 +421,9 @@ int copy_thread(int nr, unsigned long cl
 		desc->b = LDT_entry_b(&info);
 	}
 
+	if (tsk->thread.debugreg[7])
+		dr_inc_use_count(tsk->thread.debugreg[7]);
+
 	err = 0;
  out:
 	if (err && p->thread.io_bitmap_ptr) {

@@ -593,6 +601,24 @@ struct task_struct fastcall * __switch_t
 	/*
 	 * 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);

@@ -602,7 +628,7 @@ struct task_struct fastcall * __switch_t
 		loaddebug(next, 6);
 		loaddebug(next, 7);
 	}
-
+#endif
 	if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr))
 		handle_io_bitmap(next, tss);
 

diff -puN arch/i386/kernel/ptrace.c~kprobes-debug-regs-2.6.9-rc4-mm1 arch/i386/kernel/ptrace.c
@@ -353,6 +353,11 @@ asmlinkage int sys_ptrace(long request, 
 
 			  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 -puN arch/i386/kernel/signal.c~kprobes-debug-regs-2.6.9-rc4-mm1 arch/i386/kernel/signal.c
@@ -25,6 +25,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/debugreg.h>
 #include "sigframe.h"
 
 #define DEBUG_SIG 0

@@ -600,7 +601,7 @@ int fastcall do_signal(struct pt_regs *r
 		 * 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, &ka, oldset, regs);

diff -puN arch/i386/kernel/traps.c~kprobes-debug-regs-2.6.9-rc4-mm1 arch/i386/kernel/traps.c
@@ -812,9 +812,7 @@ asmlinkage void do_debug(struct pt_regs 
 	 * the signal is delivered.
 	 */
 clear_dr7:
-	__asm__("movl %0,%%db7"
-		: /* no output */
-		: "r" (0));
+	load_process_dr7(0);
 	CHK_REMOTE_DEBUG(1,SIGTRAP,error_code,regs,)
 	return;
 

166 lines not on this page · raw message

171 lines not on this page · raw message

diff -puN arch/i386/kernel/traps.c~kprobes-kernel-watchpoint-2.6.9-rc4-mm1 arch/i386/kernel/traps.c
@@ -43,6 +43,7 @@
 #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>

diff -puN /dev/null include/asm-i386/kwatch.h
@@ -0,0 +1,31 @@
+#ifndef _ASM_KWATCH_H
+#define _ASM_KWATCH_H
+/*
+ * Dynamic Probes (kwatch points) support
+ *  	Vamsi Krishna S <[email protected]>, 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 */

190 lines not on this page · raw message

50 lines not on this page · raw message

288 lines not on this page · raw message

diff -puN arch/i386/kernel/process.c~kprobes-debug-regs-2.6.9-final arch/i386/kernel/process.c
@@ -49,6 +49,7 @@
 #ifdef CONFIG_MATH_EMULATION
 #include <asm/math_emu.h>
 #endif
+#include <asm/debugreg.h>
 
 #include <linux/irq.h>
 #include <linux/err.h>

@@ -316,12 +317,16 @@ void exit_thread(void)
 		tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
 		put_cpu();
 	}
+	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));	
 	/*

@@ -413,6 +418,9 @@ int copy_thread(int nr, unsigned long cl
 		desc->b = LDT_entry_b(&info);
 	}
 
+	if (tsk->thread.debugreg[7])
+		dr_inc_use_count(tsk->thread.debugreg[7]);
+
 	err = 0;
  out:
 	if (err && p->thread.io_bitmap_ptr) {

@@ -588,14 +596,19 @@ struct task_struct fastcall * __switch_t
 	/*
 	 * Now maybe reload the debug registers
 	 */
-	if (unlikely(next->debugreg[7])) {
-		loaddebug(next, 0);
-		loaddebug(next, 1);
-		loaddebug(next, 2);
-		loaddebug(next, 3);
+	/*
+	 * 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 (prev->debugreg[0] != next->debugreg[0]) loaddebug(next, 0);
+		if (prev->debugreg[1] != next->debugreg[1]) loaddebug(next, 1);
+		if (prev->debugreg[2] != next->debugreg[2]) loaddebug(next, 2);
+		if (prev->debugreg[3] != next->debugreg[3]) loaddebug(next, 3);
 		/* no 4 and 5 */
 		loaddebug(next, 6);
-		loaddebug(next, 7);
+		load_process_dr7(next_dr7);
 	}
 
 	if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr))

diff -puN arch/i386/kernel/ptrace.c~kprobes-debug-regs-2.6.9-final arch/i386/kernel/ptrace.c
@@ -353,6 +353,11 @@ asmlinkage int sys_ptrace(long request, 
 
 			  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 -puN arch/i386/kernel/signal.c~kprobes-debug-regs-2.6.9-final arch/i386/kernel/signal.c
@@ -25,6 +25,7 @@
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
+#include <asm/debugreg.h>
 #include "sigframe.h"
 
 #define DEBUG_SIG 0

@@ -600,7 +601,7 @@ int fastcall do_signal(struct pt_regs *r
 		 * 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, &ka, oldset, regs);

diff -puN arch/i386/kernel/traps.c~kprobes-debug-regs-2.6.9-final arch/i386/kernel/traps.c
@@ -760,9 +760,7 @@ asmlinkage void do_debug(struct pt_regs 
 	 * the signal is delivered.
 	 */
 clear_dr7:
-	__asm__("movl %0,%%db7"
-		: /* no output */
-		: "r" (0));
+	load_process_dr7(0);
 	return;
 
 debug_vm86:

166 lines not on this page · raw message