Re: [Lse-tech] Re: 2.5.69-mjb1

[William Lee Irwin III]

On Mon, May 12, 2003 at 08:05:15AM -0700, Dave Hansen wrote:
> Wow, that's intuitive :)
> They're trying to access the variables that have been pushed onto the
> top of the stack.  The thread_info field points to the bottom of the
> kernel's stack (no matter how big it is).  I don't know where the -5 and
> -2 come from.  It needs a big, fat stinking comment.

I'm not 100% convinced it DTRT on modern kernels. I vaguely wonder if
the following would be more appropriate. Shame the typedef isn't there
yet; the _struct suffix is an eyesore.

-- wli

diff -prauN linux-2.5.69/include/asm-i386/processor.h kstk-2.5.69-1/include/asm-i386/processor.h
--- linux-2.5.69/include/asm-i386/processor.h	2003-05-04 16:53:00.000000000 -0700
+++ kstk-2.5.69-1/include/asm-i386/processor.h	2003-05-12 14:02:13.000000000 -0700
@@ -96,9 +96,9 @@ extern struct cpuinfo_x86 cpu_data[];
 
 extern char ignore_fpu_irq;
 
-extern void identify_cpu(struct cpuinfo_x86 *);
-extern void print_cpu_info(struct cpuinfo_x86 *);
-extern void dodgy_tsc(void);
+void identify_cpu(struct cpuinfo_x86 *);
+void print_cpu_info(struct cpuinfo_x86 *);
+void dodgy_tsc(void);
 
 /*
  * EFLAGS bits
@@ -457,21 +457,21 @@ struct task_struct;
 struct mm_struct;
 
 /* Free all resources held by a thread. */
-extern void release_thread(struct task_struct *);
+void release_thread(struct task_struct *);
 
 /* Prepare to copy thread state - unlazy all lazy status */
-extern void prepare_to_copy(struct task_struct *tsk);
+void prepare_to_copy(struct task_struct *);
 
 /*
  * create a kernel thread without removing it from tasklists
  */
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 
-extern unsigned long thread_saved_pc(struct task_struct *tsk);
+unsigned long thread_saved_pc(struct task_struct *);
 
-unsigned long get_wchan(struct task_struct *p);
-#define KSTK_EIP(tsk)	(((unsigned long *)(4096+(unsigned long)(tsk)->thread_info))[1019])
-#define KSTK_ESP(tsk)	(((unsigned long *)(4096+(unsigned long)(tsk)->thread_info))[1022])
+unsigned long get_wchan(struct task_struct *);
+#define KSTK_EIP(task)	((task)->thread.eip)
+#define KSTK_ESP(task)	((task)->thread.esp)
 
 struct microcode {
 	unsigned int hdrver;