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authorPeter Lieven <pl@kamp.de>2016-09-27 11:58:45 +0200
committerKevin Wolf <kwolf@redhat.com>2016-09-29 14:13:39 +0200
commit7d992e4d5a95d0b21c6c33bd32cef8671805e39b (patch)
tree3d99c261cb5f7056970c9a7c158c08b2fc7a8d06 /util
parent2f4aa2329945c741e10fd5b6631e99a4be25ea60 (diff)
downloadqemu-arm-7d992e4d5a95d0b21c6c33bd32cef8671805e39b.tar.gz
oslib-posix: add a configure switch to debug stack usage
this adds a knob to track the maximum stack usage of stacks created by qemu_alloc_stack. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'util')
-rw-r--r--util/oslib-posix.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index d950c347e2..aaec1891f5 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -50,6 +50,10 @@
#include "qemu/mmap-alloc.h"
+#ifdef CONFIG_DEBUG_STACK_USAGE
+#include "qemu/error-report.h"
+#endif
+
int qemu_get_thread_id(void)
{
#if defined(__linux__)
@@ -503,6 +507,9 @@ pid_t qemu_fork(Error **errp)
void *qemu_alloc_stack(size_t *sz)
{
void *ptr, *guardpage;
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ void *ptr2;
+#endif
size_t pagesz = getpagesize();
#ifdef _SC_THREAD_STACK_MIN
/* avoid stacks smaller than _SC_THREAD_STACK_MIN */
@@ -534,10 +541,38 @@ void *qemu_alloc_stack(size_t *sz)
abort();
}
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) {
+ *(uint32_t *)ptr2 = 0xdeadbeaf;
+ }
+#endif
+
return ptr;
}
+#ifdef CONFIG_DEBUG_STACK_USAGE
+static __thread unsigned int max_stack_usage;
+#endif
+
void qemu_free_stack(void *stack, size_t sz)
{
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ unsigned int usage;
+ void *ptr;
+
+ for (ptr = stack + getpagesize(); ptr < stack + sz;
+ ptr += sizeof(uint32_t)) {
+ if (*(uint32_t *)ptr != 0xdeadbeaf) {
+ break;
+ }
+ }
+ usage = sz - (uintptr_t) (ptr - stack);
+ if (usage > max_stack_usage) {
+ error_report("thread %d max stack usage increased from %u to %u",
+ qemu_get_thread_id(), max_stack_usage, usage);
+ max_stack_usage = usage;
+ }
+#endif
+
munmap(stack, sz);
}