X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fptrace.c;h=4a8f8a2597233d06316afa6463d9e1eabdd9592e;hp=d3db03f4085d75ef607acda75e020cf0c0f10ffe;hb=9cdd79c9b99873d600d397fda012fc3f57cc2776;hpb=b3cf257623fabd8f1ee6700a6d328cc1c5da5a1d

diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index d3db03f4085d..4a8f8a259723 100644
--- a/arch/i386/kernel/ptrace.c
+++ b/arch/i386/kernel/ptrace.c
@@ -45,7 +45,7 @@
 /*
  * Offset of eflags on child stack..
  */
-#define EFL_OFFSET ((EFL-2)*4-sizeof(struct pt_regs))
+#define EFL_OFFSET offsetof(struct pt_regs, eflags)
 
 static inline struct pt_regs *get_child_regs(struct task_struct *task)
 {
@@ -54,24 +54,24 @@ static inline struct pt_regs *get_child_regs(struct task_struct *task)
 }
 
 /*
- * this routine will get a word off of the processes privileged stack. 
- * the offset is how far from the base addr as stored in the TSS.  
- * this routine assumes that all the privileged stacks are in our
+ * This routine will get a word off of the processes privileged stack.
+ * the offset is bytes into the pt_regs structure on the stack.
+ * This routine assumes that all the privileged stacks are in our
  * data space.
  */   
 static inline int get_stack_long(struct task_struct *task, int offset)
 {
 	unsigned char *stack;
 
-	stack = (unsigned char *)task->thread.esp0;
+	stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
 	stack += offset;
 	return (*((int *)stack));
 }
 
 /*
- * this routine will put a word on the processes privileged stack. 
- * the offset is how far from the base addr as stored in the TSS.  
- * this routine assumes that all the privileged stacks are in our
+ * This routine will put a word on the processes privileged stack.
+ * the offset is bytes into the pt_regs structure on the stack.
+ * This routine assumes that all the privileged stacks are in our
  * data space.
  */
 static inline int put_stack_long(struct task_struct *task, int offset,
@@ -79,7 +79,7 @@ static inline int put_stack_long(struct task_struct *task, int offset,
 {
 	unsigned char * stack;
 
-	stack = (unsigned char *) task->thread.esp0;
+	stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
 	stack += offset;
 	*(unsigned long *) stack = data;
 	return 0;
@@ -89,11 +89,6 @@ static int putreg(struct task_struct *child,
 	unsigned long regno, unsigned long value)
 {
 	switch (regno >> 2) {
-		case FS:
-			if (value && (value & 3) != 3)
-				return -EIO;
-			child->thread.fs = value;
-			return 0;
 		case GS:
 			if (value && (value & 3) != 3)
 				return -EIO;
@@ -101,6 +96,7 @@ static int putreg(struct task_struct *child,
 			return 0;
 		case DS:
 		case ES:
+		case FS:
 			if (value && (value & 3) != 3)
 				return -EIO;
 			value &= 0xffff;
@@ -116,9 +112,9 @@ static int putreg(struct task_struct *child,
 			value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
 			break;
 	}
-	if (regno > GS*4)
-		regno -= 2*4;
-	put_stack_long(child, regno - sizeof(struct pt_regs), value);
+	if (regno > FS*4)
+		regno -= 1*4;
+	put_stack_long(child, regno, value);
 	return 0;
 }
 
@@ -128,22 +124,19 @@ static unsigned long getreg(struct task_struct *child,
 	unsigned long retval = ~0UL;
 
 	switch (regno >> 2) {
-		case FS:
-			retval = child->thread.fs;
-			break;
 		case GS:
 			retval = child->thread.gs;
 			break;
 		case DS:
 		case ES:
+		case FS:
 		case SS:
 		case CS:
 			retval = 0xffff;
 			/* fall through */
 		default:
-			if (regno > GS*4)
-				regno -= 2*4;
-			regno = regno - sizeof(struct pt_regs);
+			if (regno > FS*4)
+				regno -= 1*4;
 			retval &= get_stack_long(child, regno);
 	}
 	return retval;
@@ -185,17 +178,17 @@ static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_
 	return addr;
 }
 
-static inline int is_at_popf(struct task_struct *child, struct pt_regs *regs)
+static inline 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_eip_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;
 		/* opcode and address size prefixes */
 		case 0x66: case 0x67:
@@ -247,7 +240,7 @@ static void set_singlestep(struct task_struct *child)
 	 * don't mark it as being "us" that set it, so that we
 	 * won't clear it by hand later.
 	 */
-	if (is_at_popf(child, regs))
+	if (is_setting_trap_flag(child, regs))
 		return;
 	
 	child->ptrace |= PT_DTRACE;