powerpc: Convert stacktrace to generic ARCH_STACKWALK

This patch converts powerpc stacktrace to the generic ARCH_STACKWALK
implemented by commit 214d8ca6ee85 ("stacktrace: Provide common
infrastructure")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/73b36bbb101299760b95ecd2cd3a46554bea8bf9.1615881400.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e446d68bebe4aecd370bf1bac002250320b48987..08e594a4ffb877c3030d281d5120854c632114af 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -145,6 +145,7 @@ config PPC
        select ARCH_MIGHT_HAVE_PC_PARPORT
        select ARCH_MIGHT_HAVE_PC_SERIO
        select ARCH_OPTIONAL_KERNEL_RWX         if ARCH_HAS_STRICT_KERNEL_RWX
+       select ARCH_STACKWALK
        select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_SUPPORTS_DEBUG_PAGEALLOC    if PPC32 || PPC_BOOK3S_64
        select ARCH_USE_BUILTIN_BSWAP

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 5b93650bc16c8c11ff1de1bf2cb58d83fa5055df..80f92f5b539390c311149666b2172272cb5949a1 100644 (file)
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -23,12 +23,18 @@
 
 #include <asm/paca.h>
 
-/*
- * Save stack-backtrace addresses into a stack_trace buffer.
- */
-static void save_context_stack(struct stack_trace *trace, unsigned long sp,
-                       struct task_struct *task, int savesched)
+void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
+                    struct task_struct *task, struct pt_regs *regs)
 {
+       unsigned long sp;
+
+       if (regs)
+               sp = regs->gpr[1];
+       else if (task == current)
+               sp = current_stack_frame();
+       else
+               sp = task->thread.ksp;
+
        for (;;) {
                unsigned long *stack = (unsigned long *) sp;
                unsigned long newsp, ip;
@@ -39,63 +45,21 @@ static void save_context_stack(struct stack_trace *trace, unsigned long sp,
                newsp = stack[0];
                ip = stack[STACK_FRAME_LR_SAVE];
 
-               if (savesched || !in_sched_functions(ip)) {
-                       if (!trace->skip)
-                               trace->entries[trace->nr_entries++] = ip;
-                       else
-                               trace->skip--;
-               }
-
-               if (trace->nr_entries >= trace->max_entries)
+               if (!consume_entry(cookie, ip))
                        return;
 
                sp = newsp;
        }
 }
 
-void save_stack_trace(struct stack_trace *trace)
-{
-       unsigned long sp;
-
-       sp = current_stack_frame();
-
-       save_context_stack(trace, sp, current, 1);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace);
-
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
-{
-       unsigned long sp;
-
-       if (!try_get_task_stack(tsk))
-               return;
-
-       if (tsk == current)
-               sp = current_stack_frame();
-       else
-               sp = tsk->thread.ksp;
-
-       save_context_stack(trace, sp, tsk, 0);
-
-       put_task_stack(tsk);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
-
-void
-save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
-{
-       save_context_stack(trace, regs->gpr[1], current, 0);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace_regs);
-
 /*
  * This function returns an error if it detects any unreliable features of the
  * stack.  Otherwise it guarantees that the stack trace is reliable.
  *
  * If the task is not 'current', the caller *must* ensure the task is inactive.
  */
-static int __save_stack_trace_tsk_reliable(struct task_struct *task,
-                                          struct stack_trace *trace)
+int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
+                            void *cookie, struct task_struct *task)
 {
        unsigned long sp;
        unsigned long newsp;
@@ -191,35 +155,12 @@ static int __save_stack_trace_tsk_reliable(struct task_struct *task,
                        return -EINVAL;
 #endif
 
-               if (trace->nr_entries >= trace->max_entries)
-                       return -E2BIG;
-               if (!trace->skip)
-                       trace->entries[trace->nr_entries++] = ip;
-               else
-                       trace->skip--;
+               if (!consume_entry(cookie, ip))
+                       return -EINVAL;
        }
        return 0;
 }
 
-int save_stack_trace_tsk_reliable(struct task_struct *tsk,
-                                 struct stack_trace *trace)
-{
-       int ret;
-
-       /*
-        * If the task doesn't have a stack (e.g., a zombie), the stack is
-        * "reliably" empty.
-        */
-       if (!try_get_task_stack(tsk))
-               return 0;
-
-       ret = __save_stack_trace_tsk_reliable(tsk, trace);
-
-       put_task_stack(tsk);
-
-       return ret;
-}
-
 #if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
 static void handle_backtrace_ipi(struct pt_regs *regs)
 {