From 9f50c91b1195dfffd183d5d8505e45af86623532 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2019 11:45:17 +0200 Subject: [PATCH] tracing: Remove the last struct stack_trace usage Simplify the stack retrieval code by using the storage array based interface. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Cc: linux-arch@vger.kernel.org Link: https://lkml.kernel.org/r/20190425094803.340000461@linutronix.de --- kernel/trace/trace_stack.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4efda5f7..5d16f73 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -23,11 +23,7 @@ static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; -struct stack_trace stack_trace_max = { - .max_entries = STACK_TRACE_ENTRIES, - .entries = &stack_dump_trace[0], -}; - +static unsigned int stack_trace_nr_entries; static unsigned long stack_trace_max_size; static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; @@ -44,10 +40,10 @@ static void print_max_stack(void) pr_emerg(" Depth Size Location (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); - for (i = 0; i < stack_trace_max.nr_entries; i++) { - if (i + 1 == stack_trace_max.nr_entries) + for (i = 0; i < stack_trace_nr_entries; i++) { + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; @@ -93,13 +89,12 @@ static void check_stack(unsigned long ip, unsigned long *stack) stack_trace_max_size = this_size; - stack_trace_max.nr_entries = 0; - stack_trace_max.skip = 0; - - save_stack_trace(&stack_trace_max); + stack_trace_nr_entries = stack_trace_save(stack_dump_trace, + ARRAY_SIZE(stack_dump_trace) - 1, + 0); /* Skip over the overhead of the stack tracer itself */ - for (i = 0; i < stack_trace_max.nr_entries; i++) { + for (i = 0; i < stack_trace_nr_entries; i++) { if (stack_dump_trace[i] == ip) break; } @@ -108,7 +103,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) * Some archs may not have the passed in ip in the dump. * If that happens, we need to show everything. */ - if (i == stack_trace_max.nr_entries) + if (i == stack_trace_nr_entries) i = 0; /* @@ -126,13 +121,13 @@ static void check_stack(unsigned long ip, unsigned long *stack) * loop will only happen once. This code only takes place * on a new max, so it is far from a fast path. */ - while (i < stack_trace_max.nr_entries) { + while (i < stack_trace_nr_entries) { int found = 0; stack_trace_index[x] = this_size; p = start; - for (; p < top && i < stack_trace_max.nr_entries; p++) { + for (; p < top && i < stack_trace_nr_entries; p++) { /* * The READ_ONCE_NOCHECK is used to let KASAN know that * this is not a stack-out-of-bounds error. @@ -163,7 +158,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) i++; } - stack_trace_max.nr_entries = x; + stack_trace_nr_entries = x; if (task_stack_end_corrupted(current)) { print_max_stack(); @@ -265,7 +260,7 @@ __next(struct seq_file *m, loff_t *pos) { long n = *pos - 1; - if (n >= stack_trace_max.nr_entries) + if (n >= stack_trace_nr_entries) return NULL; m->private = (void *)n; @@ -329,7 +324,7 @@ static int t_show(struct seq_file *m, void *v) seq_printf(m, " Depth Size Location" " (%d entries)\n" " ----- ---- --------\n", - stack_trace_max.nr_entries); + stack_trace_nr_entries); if (!stack_tracer_enabled && !stack_trace_max_size) print_disabled(m); @@ -339,10 +334,10 @@ static int t_show(struct seq_file *m, void *v) i = *(long *)v; - if (i >= stack_trace_max.nr_entries) + if (i >= stack_trace_nr_entries) return 0; - if (i + 1 == stack_trace_max.nr_entries) + if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; -- 2.7.4