x86/stacktrace: Use common infrastructure

Replace the stack_trace_save*() functions with the new arch_stack_walk()
interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-arch@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20190425094803.816485461@linutronix.de

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5ad9241..b5978e3 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -74,6 +74,7 @@ config X86
        select ARCH_MIGHT_HAVE_ACPI_PDC         if ACPI
        select ARCH_MIGHT_HAVE_PC_PARPORT
        select ARCH_MIGHT_HAVE_PC_SERIO
+       select ARCH_STACKWALK
        select ARCH_SUPPORTS_ACPI
        select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_SUPPORTS_NUMA_BALANCING     if X86_64

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index b2f706f..2abf27d 100644 (file)
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -12,75 +12,31 @@
 #include <asm/stacktrace.h>
 #include <asm/unwind.h>
 
-static int save_stack_address(struct stack_trace *trace, unsigned long addr,
-                             bool nosched)
-{
-       if (nosched && in_sched_functions(addr))
-               return 0;
-
-       if (trace->skip > 0) {
-               trace->skip--;
-               return 0;
-       }
-
-       if (trace->nr_entries >= trace->max_entries)
-               return -1;
-
-       trace->entries[trace->nr_entries++] = addr;
-       return 0;
-}
-
-static void noinline __save_stack_trace(struct stack_trace *trace,
-                              struct task_struct *task, struct pt_regs *regs,
-                              bool nosched)
+void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
+                    struct task_struct *task, struct pt_regs *regs)
 {
        struct unwind_state state;
        unsigned long addr;
 
-       if (regs)
-               save_stack_address(trace, regs->ip, nosched);
+       if (regs && !consume_entry(cookie, regs->ip, false))
+               return;
 
        for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
             unwind_next_frame(&state)) {
                addr = unwind_get_return_address(&state);
-               if (!addr || save_stack_address(trace, addr, nosched))
+               if (!addr || !consume_entry(cookie, addr, false))
                        break;
        }
 }
 
 /*
- * Save stack-backtrace addresses into a stack_trace buffer.
+ * 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.
  */
-void save_stack_trace(struct stack_trace *trace)
-{
-       trace->skip++;
-       __save_stack_trace(trace, current, NULL, false);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace);
-
-void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
-{
-       __save_stack_trace(trace, current, regs, false);
-}
-
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
-{
-       if (!try_get_task_stack(tsk))
-               return;
-
-       if (tsk == current)
-               trace->skip++;
-       __save_stack_trace(trace, tsk, NULL, true);
-
-       put_task_stack(tsk);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
-
-#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
-
-static int __always_inline
-__save_stack_trace_reliable(struct stack_trace *trace,
-                           struct task_struct *task)
+int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
+                            void *cookie, struct task_struct *task)
 {
        struct unwind_state state;
        struct pt_regs *regs;
@@ -117,7 +73,7 @@ __save_stack_trace_reliable(struct stack_trace *trace,
                if (!addr)
                        return -EINVAL;
 
-               if (save_stack_address(trace, addr, false))
+               if (!consume_entry(cookie, addr, false))
                        return -EINVAL;
        }
 
@@ -132,32 +88,6 @@ __save_stack_trace_reliable(struct stack_trace *trace,
        return 0;
 }
 
-/*
- * 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.
- */
-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_reliable(trace, tsk);
-
-       put_task_stack(tsk);
-
-       return ret;
-}
-#endif /* CONFIG_HAVE_RELIABLE_STACKTRACE */
-
 /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
 
 struct stack_frame_user {
@@ -182,15 +112,15 @@ copy_stack_frame(const void __user *fp, struct stack_frame_user *frame)
        return ret;
 }
 
-static inline void __save_stack_trace_user(struct stack_trace *trace)
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+                         const struct pt_regs *regs)
 {
-       const struct pt_regs *regs = task_pt_regs(current);
        const void __user *fp = (const void __user *)regs->bp;
 
-       if (trace->nr_entries < trace->max_entries)
-               trace->entries[trace->nr_entries++] = regs->ip;
+       if (!consume_entry(cookie, regs->ip, false))
+               return;
 
-       while (trace->nr_entries < trace->max_entries) {
+       while (1) {
                struct stack_frame_user frame;
 
                frame.next_fp = NULL;
@@ -200,8 +130,8 @@ static inline void __save_stack_trace_user(struct stack_trace *trace)
                if ((unsigned long)fp < regs->sp)
                        break;
                if (frame.ret_addr) {
-                       trace->entries[trace->nr_entries++] =
-                               frame.ret_addr;
+                       if (!consume_entry(cookie, frame.ret_addr, false))
+                               return;
                }
                if (fp == frame.next_fp)
                        break;
@@ -209,11 +139,3 @@ static inline void __save_stack_trace_user(struct stack_trace *trace)
        }
 }
 
-void save_stack_trace_user(struct stack_trace *trace)
-{
-       /*
-        * Trace user stack if we are not a kernel thread
-        */
-       if (current->mm)
-               __save_stack_trace_user(trace);
-}