From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45658) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bN0Sz-0007a8-M6 for qemu-devel@nongnu.org; Tue, 12 Jul 2016 12:23:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bN0Sw-0003c0-GT for qemu-devel@nongnu.org; Tue, 12 Jul 2016 12:23:24 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:60458 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bN0Sw-0003bn-7i for qemu-devel@nongnu.org; Tue, 12 Jul 2016 12:23:22 -0400 From: Peter Lieven Date: Tue, 12 Jul 2016 18:23:05 +0200 Message-Id: <1468340586-19304-6-git-send-email-pl@kamp.de> In-Reply-To: <1468340586-19304-1-git-send-email-pl@kamp.de> References: <1468340586-19304-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCH V5 5/6] oslib-posix: add a configure switch to debug stack usage List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, pbonzini@redhat.com, mst@redhat.com, dgilbert@redhat.com, peter.maydell@linaro.org, eblake@redhat.com, rth@twiddle.net, armbru@redhat.com, Peter Lieven this adds a knob to track the maximum stack usage of stacks created by qemu_alloc_stack. Signed-off-by: Peter Lieven --- configure | 19 +++++++++++++++++++ util/oslib-posix.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/configure b/configure index 5ada56d..a7ee2f3 100755 --- a/configure +++ b/configure @@ -296,6 +296,7 @@ libiscsi="" libnfs="" coroutine="" coroutine_pool="" +debug_stack_usage="no" seccomp="" glusterfs="" glusterfs_xlator_opt="no" @@ -1005,6 +1006,8 @@ for opt do ;; --enable-coroutine-pool) coroutine_pool="yes" ;; + --enable-debug-stack-usage) debug_stack_usage="yes" + ;; --disable-docs) docs="no" ;; --enable-docs) docs="yes" @@ -4302,6 +4305,17 @@ if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)" fi +if test "$debug_stack_usage" = "yes"; then + if test "$cpu" = "ia64" -o "$cpu" = "hppa"; then + error_exit "stack usage debugging is not supported for $cpu" + fi + if test "$coroutine_pool" = "yes"; then + echo "WARN: disabling coroutine pool for stack usage debugging" + coroutine_pool=no + fi +fi + + ########################################## # check if we have open_by_handle_at @@ -4879,6 +4893,7 @@ echo "QGA MSI support $guest_agent_msi" echo "seccomp support $seccomp" echo "coroutine backend $coroutine" echo "coroutine pool $coroutine_pool" +echo "debug stack usage $debug_stack_usage" echo "GlusterFS support $glusterfs" echo "Archipelago support $archipelago" echo "gcov $gcov_tool" @@ -5347,6 +5362,10 @@ else echo "CONFIG_COROUTINE_POOL=0" >> $config_host_mak fi +if test "$debug_stack_usage" = "yes" ; then + echo "CONFIG_DEBUG_STACK_USAGE=y" >> $config_host_mak +fi + if test "$open_by_handle_at" = "yes" ; then echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak fi diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 2303ca6..e818d38 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -50,6 +50,10 @@ #include +#ifdef CONFIG_DEBUG_STACK_USAGE +#include "qemu/error-report.h" +#endif + int qemu_get_thread_id(void) { #if defined(__linux__) @@ -512,6 +516,9 @@ static size_t adjust_stack_size(size_t sz) void *qemu_alloc_stack(size_t sz) { void *ptr, *guardpage; +#ifdef CONFIG_DEBUG_STACK_USAGE + void *ptr2; +#endif size_t pagesz = getpagesize(); sz = adjust_stack_size(sz); @@ -535,11 +542,41 @@ 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; +#endif sz = adjust_stack_size(sz); + +#ifdef CONFIG_DEBUG_STACK_USAGE + 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); } -- 1.9.1