Pull sony into release branch

[pandora-kernel.git] / arch / i386 / kernel / ptrace.c

diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index d3db03f..4a8f8a2 100644 (file)
--- 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;