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 6c6689e574ce..c112de81c9e1 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 4b02a8455bd1..c3be85205a65 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 c9bee5b8c0d3..16ee0e450e3e 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 a0e7fb1134a0..38b4e4abd0f8 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);
-}