From 6c427ab926fd79e05ff650884babee962cdeaeb9 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 17 Dec 2021 14:46:04 +0100 Subject: [PATCH] util/oslib-posix: Let touch_all_pages() return an error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Let's prepare touch_all_pages() for returning differing errors. Return an error from the thread and report the last processed error. Translate SIGBUS to -EFAULT, as a SIGBUS can mean all different kind of things (memory error, read error, out of memory). When allocating memory fails via the current SIGBUS-based mechanism, we'll get: os_mem_prealloc: preallocating memory failed: Bad address Reviewed-by: Daniel P. Berrangé Reviewed-by: Michal Privoznik Signed-off-by: David Hildenbrand Message-Id: <20211217134611.31172-2-david@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- util/oslib-posix.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/util/oslib-posix.c b/util/oslib-posix.c index e8bdb02e1d..b146beef78 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -84,7 +84,6 @@ typedef struct MemsetThread MemsetThread; static MemsetThread *memset_thread; static int memset_num_threads; -static bool memset_thread_failed; static QemuMutex page_mutex; static QemuCond page_cond; @@ -452,6 +451,7 @@ static void *do_touch_pages(void *arg) { MemsetThread *memset_args = (MemsetThread *)arg; sigset_t set, oldset; + int ret = 0; /* * On Linux, the page faults from the loop below can cause mmap_sem @@ -470,7 +470,7 @@ static void *do_touch_pages(void *arg) pthread_sigmask(SIG_UNBLOCK, &set, &oldset); if (sigsetjmp(memset_args->env, 1)) { - memset_thread_failed = true; + ret = -EFAULT; } else { char *addr = memset_args->addr; size_t numpages = memset_args->numpages; @@ -494,7 +494,7 @@ static void *do_touch_pages(void *arg) } } pthread_sigmask(SIG_SETMASK, &oldset, NULL); - return NULL; + return (void *)(uintptr_t)ret; } static inline int get_memset_num_threads(int smp_cpus) @@ -509,13 +509,13 @@ static inline int get_memset_num_threads(int smp_cpus) return ret; } -static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages, - int smp_cpus) +static int touch_all_pages(char *area, size_t hpagesize, size_t numpages, + int smp_cpus) { static gsize initialized = 0; size_t numpages_per_thread, leftover; + int ret = 0, i = 0; char *addr = area; - int i = 0; if (g_once_init_enter(&initialized)) { qemu_mutex_init(&page_mutex); @@ -523,7 +523,6 @@ static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages, g_once_init_leave(&initialized, 1); } - memset_thread_failed = false; threads_created_flag = false; memset_num_threads = get_memset_num_threads(smp_cpus); memset_thread = g_new0(MemsetThread, memset_num_threads); @@ -545,12 +544,16 @@ static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages, qemu_mutex_unlock(&page_mutex); for (i = 0; i < memset_num_threads; i++) { - qemu_thread_join(&memset_thread[i].pgthread); + int tmp = (uintptr_t)qemu_thread_join(&memset_thread[i].pgthread); + + if (tmp) { + ret = tmp; + } } g_free(memset_thread); memset_thread = NULL; - return memset_thread_failed; + return ret; } void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus, @@ -573,9 +576,10 @@ void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus, } /* touch pages simultaneously */ - if (touch_all_pages(area, hpagesize, numpages, smp_cpus)) { - error_setg(errp, "os_mem_prealloc: Insufficient free host memory " - "pages available to allocate guest RAM"); + ret = touch_all_pages(area, hpagesize, numpages, smp_cpus); + if (ret) { + error_setg_errno(errp, -ret, + "os_mem_prealloc: preallocating memory failed"); } ret = sigaction(SIGBUS, &oldact, NULL);