um: Rewrite show_stack()

Currently on UML stack traces are not very reliable and both
x86 and x86_64 have their on implementations.
This patch unifies both and adds support to outline unreliable
functions calls.

Signed-off-by: Richard Weinberger <richard@nod.at>

4 files changed, 11 insertions, 73 deletions

diff --git a/arch/x86/um/asm/processor_32.h b/arch/x86/um/asm/processor_32.h
index 6c6689e..c112de8 100644
--- a/arch/x86/um/asm/processor_32.h
+++ b/arch/x86/um/asm/processor_32.h
@@ -33,6 +33,8 @@ struct arch_thread {
 	.faultinfo		= { 0, 0, 0 } \
 }
 
+#define STACKSLOTS_PER_LINE 8
+
 static inline void arch_flush_thread(struct arch_thread *thread)
 {
 	/* Clear any TLS still hanging */
@@ -53,4 +55,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
 #define current_text_addr() \
 	({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
 
+#define current_sp() ({ void *sp; __asm__("movl %%esp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movl %%ebp, %0" : "=r" (bp) : ); bp; })
+
 #endif
diff --git a/arch/x86/um/asm/processor_64.h b/arch/x86/um/asm/processor_64.h
index 4b02a84..c3be852 100644
--- a/arch/x86/um/asm/processor_64.h
+++ b/arch/x86/um/asm/processor_64.h
@@ -19,6 +19,8 @@ struct arch_thread {
 			   .fs			= 0, \
 			   .faultinfo		= { 0, 0, 0 } }
 
+#define STACKSLOTS_PER_LINE 4
+
 static inline void arch_flush_thread(struct arch_thread *thread)
 {
 }
@@ -32,4 +34,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
 #define current_text_addr() \
 	({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })
 
+#define current_sp() ({ void *sp; __asm__("movq %%rsp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movq %%rbp, %0" : "=r" (bp) : ); bp; })
+
 #endif
diff --git a/arch/x86/um/sysrq_32.c b/arch/x86/um/sysrq_32.c
index c9bee5b..16ee0e4 100644
--- a/arch/x86/um/sysrq_32.c
+++ b/arch/x86/um/sysrq_32.c
@@ -30,70 +30,4 @@ void show_regs(struct pt_regs *regs)
         printk(" DS: %04lx ES: %04lx\n",
 	       0xffff & PT_REGS_DS(regs), 
 	       0xffff & PT_REGS_ES(regs));
-
-        show_trace(NULL, (unsigned long *) &regs);
 }
-
-/* Copied from i386. */
-static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
-{
-	return	p > (void *)tinfo &&
-		p < (void *)tinfo + THREAD_SIZE - 3;
-}
-
-/* Adapted from i386 (we also print the address we read from). */
-static inline unsigned long print_context_stack(struct thread_info *tinfo,
-				unsigned long *stack, unsigned long ebp)
-{
-	unsigned long addr;
-
-#ifdef CONFIG_FRAME_POINTER
-	while (valid_stack_ptr(tinfo, (void *)ebp)) {
-		addr = *(unsigned long *)(ebp + 4);
-		printk("%08lx:  [<%08lx>]", ebp + 4, addr);
-		print_symbol(" %s", addr);
-		printk("\n");
-		ebp = *(unsigned long *)ebp;
-	}
-#else
-	while (valid_stack_ptr(tinfo, stack)) {
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			printk("%08lx:  [<%08lx>]", (unsigned long) stack, addr);
-			print_symbol(" %s", addr);
-			printk("\n");
-		}
-		stack++;
-	}
-#endif
-	return ebp;
-}
-
-void show_trace(struct task_struct* task, unsigned long * stack)
-{
-	unsigned long ebp;
-	struct thread_info *context;
-
-	/* Turn this into BUG_ON if possible. */
-	if (!stack) {
-		stack = (unsigned long*) &stack;
-		printk("show_trace: got NULL stack, implicit assumption task == current");
-		WARN_ON(1);
-	}
-
-	if (!task)
-		task = current;
-
-	if (task != current) {
-		ebp = (unsigned long) KSTK_EBP(task);
-	} else {
-		asm ("movl %%ebp, %0" : "=r" (ebp) : );
-	}
-
-	context = (struct thread_info *)
-		((unsigned long)stack & (~(THREAD_SIZE - 1)));
-	print_context_stack(context, stack, ebp);
-
-	printk("\n");
-}
-
diff --git a/arch/x86/um/sysrq_64.c b/arch/x86/um/sysrq_64.c
index a0e7fb1..38b4e4a 100644
--- a/arch/x86/um/sysrq_64.c
+++ b/arch/x86/um/sysrq_64.c
@@ -12,7 +12,7 @@
 #include <asm/ptrace.h>
 #include <asm/sysrq.h>
 
-void __show_regs(struct pt_regs *regs)
+void show_regs(struct pt_regs *regs)
 {
 	printk("\n");
 	print_modules();
@@ -33,9 +33,3 @@ void __show_regs(struct pt_regs *regs)
 	printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
 	       PT_REGS_R13(regs), PT_REGS_R14(regs), PT_REGS_R15(regs));
 }
-
-void show_regs(struct pt_regs *regs)
-{
-	__show_regs(regs);
-	show_trace(current, (unsigned long *) &regs);
-}