x86: avoid avoid passing around 'thread_info' in stack dumping code

None of the code actually wants a thread_info, it all wants a
task_struct, and it's just converting to a thread_info pointer much too
early.

No semantic change.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 7c247e7..0944218 100644 (file)
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -14,7 +14,7 @@ extern int kstack_depth_to_print;
 struct thread_info;
 struct stacktrace_ops;
 
-typedef unsigned long (*walk_stack_t)(struct thread_info *tinfo,
+typedef unsigned long (*walk_stack_t)(struct task_struct *task,
                                      unsigned long *stack,
                                      unsigned long bp,
                                      const struct stacktrace_ops *ops,
@@ -23,13 +23,13 @@ typedef unsigned long (*walk_stack_t)(struct thread_info *tinfo,
                                      int *graph);
 
 extern unsigned long
-print_context_stack(struct thread_info *tinfo,
+print_context_stack(struct task_struct *task,
                    unsigned long *stack, unsigned long bp,
                    const struct stacktrace_ops *ops, void *data,
                    unsigned long *end, int *graph);
 
 extern unsigned long
-print_context_stack_bp(struct thread_info *tinfo,
+print_context_stack_bp(struct task_struct *task,
                       unsigned long *stack, unsigned long bp,
                       const struct stacktrace_ops *ops, void *data,
                       unsigned long *end, int *graph);

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 2bb25c3..d6209f3 100644 (file)
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -42,16 +42,14 @@ void printk_address(unsigned long address)
 static void
 print_ftrace_graph_addr(unsigned long addr, void *data,
                        const struct stacktrace_ops *ops,
-                       struct thread_info *tinfo, int *graph)
+                       struct task_struct *task, int *graph)
 {
-       struct task_struct *task;
        unsigned long ret_addr;
        int index;
 
        if (addr != (unsigned long)return_to_handler)
                return;
 
-       task = tinfo->task;
        index = task->curr_ret_stack;
 
        if (!task->ret_stack || index < *graph)
@@ -68,7 +66,7 @@ print_ftrace_graph_addr(unsigned long addr, void *data,
 static inline void
 print_ftrace_graph_addr(unsigned long addr, void *data,
                        const struct stacktrace_ops *ops,
-                       struct thread_info *tinfo, int *graph)
+                       struct task_struct *task, int *graph)
 { }
 #endif
 
@@ -79,10 +77,10 @@ print_ftrace_graph_addr(unsigned long addr, void *data,
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  */
 
-static inline int valid_stack_ptr(struct thread_info *tinfo,
+static inline int valid_stack_ptr(struct task_struct *task,
                        void *p, unsigned int size, void *end)
 {
-       void *t = tinfo;
+       void *t = task_thread_info(task);
        if (end) {
                if (p < end && p >= (end-THREAD_SIZE))
                        return 1;
@@ -93,14 +91,14 @@ static inline int valid_stack_ptr(struct thread_info *tinfo,
 }
 
 unsigned long
-print_context_stack(struct thread_info *tinfo,
+print_context_stack(struct task_struct *task,
                unsigned long *stack, unsigned long bp,
                const struct stacktrace_ops *ops, void *data,
                unsigned long *end, int *graph)
 {
        struct stack_frame *frame = (struct stack_frame *)bp;
 
-       while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
+       while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
                unsigned long addr;
 
                addr = *stack;
@@ -112,7 +110,7 @@ print_context_stack(struct thread_info *tinfo,
                        } else {
                                ops->address(data, addr, 0);
                        }
-                       print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
+                       print_ftrace_graph_addr(addr, data, ops, task, graph);
                }
                stack++;
        }
@@ -121,7 +119,7 @@ print_context_stack(struct thread_info *tinfo,
 EXPORT_SYMBOL_GPL(print_context_stack);
 
 unsigned long
-print_context_stack_bp(struct thread_info *tinfo,
+print_context_stack_bp(struct task_struct *task,
                       unsigned long *stack, unsigned long bp,
                       const struct stacktrace_ops *ops, void *data,
                       unsigned long *end, int *graph)
@@ -129,7 +127,7 @@ print_context_stack_bp(struct thread_info *tinfo,
        struct stack_frame *frame = (struct stack_frame *)bp;
        unsigned long *ret_addr = &frame->return_address;
 
-       while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
+       while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
                unsigned long addr = *ret_addr;
 
                if (!__kernel_text_address(addr))
@@ -139,7 +137,7 @@ print_context_stack_bp(struct thread_info *tinfo,
                        break;
                frame = frame->next_frame;
                ret_addr = &frame->return_address;
-               print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
+               print_ftrace_graph_addr(addr, data, ops, task, graph);
        }
 
        return (unsigned long)frame;

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 464ffd6..fef917e 100644 (file)
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -61,15 +61,13 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
                bp = stack_frame(task, regs);
 
        for (;;) {
-               struct thread_info *context;
                void *end_stack;
 
                end_stack = is_hardirq_stack(stack, cpu);
                if (!end_stack)
                        end_stack = is_softirq_stack(stack, cpu);
 
-               context = task_thread_info(task);
-               bp = ops->walk_stack(context, stack, bp, ops, data,
+               bp = ops->walk_stack(task, stack, bp, ops, data,
                                     end_stack, &graph);
 
                /* Stop if not on irq stack */

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 5f1c626..d558a8a 100644 (file)
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -153,7 +153,6 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
                const struct stacktrace_ops *ops, void *data)
 {
        const unsigned cpu = get_cpu();
-       struct thread_info *tinfo;
        unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu);
        unsigned long dummy;
        unsigned used = 0;
@@ -179,7 +178,6 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
         * current stack address. If the stacks consist of nested
         * exceptions
         */
-       tinfo = task_thread_info(task);
        while (!done) {
                unsigned long *stack_end;
                enum stack_type stype;
@@ -202,7 +200,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
                        if (ops->stack(data, id) < 0)
                                break;
 
-                       bp = ops->walk_stack(tinfo, stack, bp, ops,
+                       bp = ops->walk_stack(task, stack, bp, ops,
                                             data, stack_end, &graph);
                        ops->stack(data, "<EOE>");
                        /*
@@ -218,7 +216,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 
                        if (ops->stack(data, "IRQ") < 0)
                                break;
-                       bp = ops->walk_stack(tinfo, stack, bp,
+                       bp = ops->walk_stack(task, stack, bp,
                                     ops, data, stack_end, &graph);
                        /*
                         * We link to the next stack (which would be
@@ -240,7 +238,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
        /*
         * This handles the process stack:
         */
-       bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph);
+       bp = ops->walk_stack(task, stack, bp, ops, data, NULL, &graph);
        put_cpu();
 }
 EXPORT_SYMBOL(dump_trace);