X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-statedump-impl.c;h=dad51ddaa25013f1bd5453aca4352854bd1ec6eb;hb=d561ecfbc9a17ca47721cd6d7742d2b1835f8ae3;hp=c8ac2d12750d210a11a9c375d2cf0f0aed39e189;hpb=5a91f3dfb2ea8b50bfcba45c4440cf20735ea3ee;p=lttng-modules.git

diff --git a/lttng-statedump-impl.c b/lttng-statedump-impl.c
index c8ac2d12..dad51dda 100644
--- a/lttng-statedump-impl.c
+++ b/lttng-statedump-impl.c
@@ -79,7 +79,7 @@ struct lttng_fd_ctx {
 	char *page;
 	struct lttng_session *session;
 	struct task_struct *p;
-	struct fdtable *fdt;
+	struct files_struct *files;
 };
 
 /*
@@ -219,13 +219,24 @@ int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
 	const struct lttng_fd_ctx *ctx = p;
 	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
 	unsigned int flags = file->f_flags;
+	struct fdtable *fdt;
 
 	/*
 	 * We don't expose kernel internal flags, only userspace-visible
 	 * flags.
 	 */
 	flags &= ~FMODE_NONOTIFY;
-	if (test_bit(fd, ctx->fdt->close_on_exec))
+	fdt = files_fdtable(ctx->files);
+	/*
+	 * We need to check here again whether fd is within the fdt
+	 * max_fds range, because we might be seeing a different
+	 * files_fdtable() than iterate_fd(), assuming only RCU is
+	 * protecting the read. In reality, iterate_fd() holds
+	 * file_lock, which should ensure the fdt does not change while
+	 * the lock is taken, but we are not aware whether this is
+	 * guaranteed or not, so play safe.
+	 */
+	if (fd < fdt->max_fds && test_bit(fd, fdt->close_on_exec))
 		flags |= O_CLOEXEC;
 	if (IS_ERR(s)) {
 		struct dentry *dentry = file->f_path.dentry;
@@ -248,10 +259,15 @@ void lttng_enumerate_task_fd(struct lttng_session *session,
 		struct task_struct *p, char *tmp)
 {
 	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
+	struct files_struct *files;
 
 	task_lock(p);
-	ctx.fdt = files_fdtable(p->files);
-	lttng_iterate_fd(p->files, 0, lttng_dump_one_fd, &ctx);
+	files = p->files;
+	if (!files)
+		goto end;
+	ctx.files = files;
+	lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
+end:
 	task_unlock(p);
 }
 
@@ -259,7 +275,11 @@ static
 int lttng_enumerate_file_descriptors(struct lttng_session *session)
 {
 	struct task_struct *p;
-	char *tmp = (char *) __get_free_page(GFP_KERNEL);
+	char *tmp;
+
+	tmp = (char *) __get_free_page(GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
 
 	/* Enumerate active file descriptors */
 	rcu_read_lock();
@@ -325,7 +345,7 @@ int lttng_enumerate_vm_maps(struct lttng_session *session)
 #endif
 
 static
-void lttng_list_interrupts(struct lttng_session *session)
+int lttng_list_interrupts(struct lttng_session *session)
 {
 	unsigned int irq;
 	unsigned long flags = 0;
@@ -347,12 +367,14 @@ void lttng_list_interrupts(struct lttng_session *session)
 		wrapper_desc_spin_unlock(&desc->lock);
 		local_irq_restore(flags);
 	}
+	return 0;
 #undef irq_to_desc
 }
 #else
 static inline
-void lttng_list_interrupts(struct lttng_session *session)
+int lttng_list_interrupts(struct lttng_session *session)
 {
+	return 0;
 }
 #endif
 
@@ -453,15 +475,35 @@ void lttng_statedump_work_func(struct work_struct *work)
 static
 int do_lttng_statedump(struct lttng_session *session)
 {
-	int cpu;
+	int cpu, ret;
 
 	trace_lttng_statedump_start(session);
-	lttng_enumerate_process_states(session);
-	lttng_enumerate_file_descriptors(session);
-	/* FIXME lttng_enumerate_vm_maps(session); */
-	lttng_list_interrupts(session);
-	lttng_enumerate_network_ip_interface(session);
-	lttng_enumerate_block_devices(session);
+	ret = lttng_enumerate_process_states(session);
+	if (ret)
+		return ret;
+	ret = lttng_enumerate_file_descriptors(session);
+	if (ret)
+		return ret;
+	/*
+	 * FIXME
+	 * ret = lttng_enumerate_vm_maps(session);
+	 * if (ret)
+	 * 	return ret;
+	 */
+	ret = lttng_list_interrupts(session);
+	if (ret)
+		return ret;
+	ret = lttng_enumerate_network_ip_interface(session);
+	if (ret)
+		return ret;
+	ret = lttng_enumerate_block_devices(session);
+	switch (ret) {
+	case -ENOSYS:
+		printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
+		break;
+	default:
+		return ret;
+	}
 
 	/* TODO lttng_dump_idt_table(session); */
 	/* TODO lttng_dump_softirq_vec(session); */