X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fx86_64%2Fkernel%2Fptrace.c;h=57bf883a7d8e5a77d3d27cd63f3acb7bc89ea07e;hb=refs%2Fheads%2Fvserver;hp=280bc88f2c9b973a12abed8c89b428a032ed4b54;hpb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;p=linux-2.6.git

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index 280bc88f2..57bf883a7 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -119,17 +119,17 @@ unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *r
 	return addr;
 }
 
-static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
+static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
 {
 	int i, copied;
-	unsigned char opcode[16];
+	unsigned char opcode[15];
 	unsigned long addr = convert_rip_to_linear(child, regs);
 
 	copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
 	for (i = 0; i < copied; i++) {
 		switch (opcode[i]) {
-		/* popf */
-		case 0x9d:
+		/* popf and iret */
+		case 0x9d: case 0xcf:
 			return 1;
 
 			/* CHECKME: 64 65 */
@@ -141,14 +141,17 @@ static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
 		case 0x26: case 0x2e:
 		case 0x36: case 0x3e:
 		case 0x64: case 0x65:
-		case 0xf0: case 0xf2: case 0xf3:
+		case 0xf2: case 0xf3:
 			continue;
 
-		/* REX prefixes */
 		case 0x40 ... 0x4f:
+			if (regs->cs != __USER_CS)
+				/* 32-bit mode: register increment */
+				return 0;
+			/* 64-bit mode: REX prefix */
 			continue;
 
-			/* CHECKME: f0, f2, f3 */
+			/* CHECKME: f2, f3 */
 
 		/*
 		 * pushf: NOTE! We should probably not let
@@ -189,10 +192,8 @@ void tracehook_enable_single_step(struct task_struct *child)
 	 * ..but if TF is changed by the instruction we will trace,
 	 * don't mark it as being "us" that set it, so that we
 	 * won't clear it by hand later.
-	 *
-	 * AK: this is not enough, LAHF and IRET can change TF in user space too.
 	 */
-	if (is_at_popf(child, regs))
+	if (is_setting_trap_flag(child, regs))
 		return;
 
 	set_tsk_thread_flag(child, TIF_FORCED_TF);
@@ -424,6 +425,7 @@ dbregs_set(struct task_struct *target,
 	   unsigned int pos, unsigned int count,
 	   const void *kbuf, const void __user *ubuf)
 {
+
 	unsigned long maxaddr = TASK_SIZE_OF(target);
 	maxaddr -= test_tsk_thread_flag(target, TIF_IA32) ? 3 : 7;
 
@@ -487,6 +489,10 @@ dbregs_set(struct task_struct *target,
 				if ((0x5554 >> ((val >> (16 + 4*i)) & 0xf))
 				    & 1)
 					return -EIO;
+			if (val)
+			  	set_tsk_thread_flag(target, TIF_DEBUG);
+			else
+			  	clear_tsk_thread_flag(target, TIF_DEBUG);
 			SET_DBREG(7);
 			break;
 #undef	SET_DBREG
@@ -512,7 +518,7 @@ fpregs_get(struct task_struct *target,
 	if (tsk_used_math(target)) {
 		if (target == current)
 			unlazy_fpu(target);
-	}
+	} 
 	else
 		init_fpu(target);
 
@@ -669,8 +675,7 @@ static const struct utrace_regset native_regsets[] = {
 
 const struct utrace_regset_view utrace_x86_64_native = {
 	.name = "x86-64", .e_machine = EM_X86_64,
-	.regsets = native_regsets,
-	.n = sizeof native_regsets / sizeof native_regsets[0],
+	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 };
 EXPORT_SYMBOL_GPL(utrace_x86_64_native);
 
@@ -678,16 +683,16 @@ EXPORT_SYMBOL_GPL(utrace_x86_64_native);
 #ifdef CONFIG_PTRACE
 static const struct ptrace_layout_segment x86_64_uarea[] = {
 	{0, sizeof(struct user_regs_struct), 0, 0},
+	{sizeof(struct user_regs_struct),
+	 offsetof(struct user, u_debugreg[0]), -1, 0},
 	{offsetof(struct user, u_debugreg[0]),
-	 offsetof(struct user, u_debugreg[4]), 3, 0},
-	{offsetof(struct user, u_debugreg[6]),
-	 offsetof(struct user, u_debugreg[8]), 3, 6 * sizeof(long)},
+	 offsetof(struct user, u_debugreg[8]), 3, 0},
 	{0, 0, -1, 0}
 };
 
-fastcall int arch_ptrace(long *req, struct task_struct *child,
-			 struct utrace_attached_engine *engine,
-			 unsigned long addr, unsigned long data, long *val)
+int arch_ptrace(long *req, struct task_struct *child,
+		struct utrace_attached_engine *engine,
+		unsigned long addr, unsigned long data, long *val)
 {
 	switch (*req) {
 	case PTRACE_PEEKUSR: