Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 63 insertions, 18 deletions

diff --git a/kernel/module/stats.c b/kernel/module/stats.c
index ad7b6ada29f2..6ab2c94d6bc3 100644
--- a/kernel/module/stats.c
+++ b/kernel/module/stats.c
@@ -276,6 +276,7 @@ static ssize_t read_file_mod_stats(struct file *file, char __user *user_buf,
 	struct mod_fail_load *mod_fail;
 	unsigned int len, size, count_failed = 0;
 	char *buf;
+	int ret;
 	u32 live_mod_count, fkreads, fdecompress, fbecoming, floads;
 	unsigned long total_size, text_size, ikread_bytes, ibecoming_bytes,
 		idecompress_bytes, imod_bytes, total_virtual_lost;
@@ -390,8 +391,9 @@ static ssize_t read_file_mod_stats(struct file *file, char __user *user_buf,
 out_unlock:
 	mutex_unlock(&module_mutex);
 out:
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
 	kfree(buf);
-        return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	return ret;
 }
 #undef MAX_PREAMBLE
 #undef MAX_FAILED_MOD_PRINT
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 9abb3905bc8e..18d36842faf5 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -17,36 +17,30 @@
 struct fprobe_rethook_node {
 	struct rethook_node node;
 	unsigned long entry_ip;
+	unsigned long entry_parent_ip;
 	char data[];
 };
 
-static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
-			   struct ftrace_ops *ops, struct ftrace_regs *fregs)
+static inline void __fprobe_handler(unsigned long ip, unsigned long parent_ip,
+			struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
 	struct fprobe_rethook_node *fpr;
 	struct rethook_node *rh = NULL;
 	struct fprobe *fp;
 	void *entry_data = NULL;
-	int bit, ret;
+	int ret = 0;
 
 	fp = container_of(ops, struct fprobe, ops);
-	if (fprobe_disabled(fp))
-		return;
-
-	bit = ftrace_test_recursion_trylock(ip, parent_ip);
-	if (bit < 0) {
-		fp->nmissed++;
-		return;
-	}
 
 	if (fp->exit_handler) {
 		rh = rethook_try_get(fp->rethook);
 		if (!rh) {
 			fp->nmissed++;
-			goto out;
+			return;
 		}
 		fpr = container_of(rh, struct fprobe_rethook_node, node);
 		fpr->entry_ip = ip;
+		fpr->entry_parent_ip = parent_ip;
 		if (fp->entry_data_size)
 			entry_data = fpr->data;
 	}
@@ -61,23 +55,60 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
 		else
 			rethook_hook(rh, ftrace_get_regs(fregs), true);
 	}
-out:
+}
+
+static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
+		struct ftrace_ops *ops, struct ftrace_regs *fregs)
+{
+	struct fprobe *fp;
+	int bit;
+
+	fp = container_of(ops, struct fprobe, ops);
+	if (fprobe_disabled(fp))
+		return;
+
+	/* recursion detection has to go before any traceable function and
+	 * all functions before this point should be marked as notrace
+	 */
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
+	if (bit < 0) {
+		fp->nmissed++;
+		return;
+	}
+	__fprobe_handler(ip, parent_ip, ops, fregs);
 	ftrace_test_recursion_unlock(bit);
+
 }
 NOKPROBE_SYMBOL(fprobe_handler);
 
 static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip,
 				  struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
-	struct fprobe *fp = container_of(ops, struct fprobe, ops);
+	struct fprobe *fp;
+	int bit;
+
+	fp = container_of(ops, struct fprobe, ops);
+	if (fprobe_disabled(fp))
+		return;
+
+	/* recursion detection has to go before any traceable function and
+	 * all functions called before this point should be marked as notrace
+	 */
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
+	if (bit < 0) {
+		fp->nmissed++;
+		return;
+	}
 
 	if (unlikely(kprobe_running())) {
 		fp->nmissed++;
 		return;
 	}
+
 	kprobe_busy_begin();
-	fprobe_handler(ip, parent_ip, ops, fregs);
+	__fprobe_handler(ip, parent_ip, ops, fregs);
 	kprobe_busy_end();
+	ftrace_test_recursion_unlock(bit);
 }
 
 static void fprobe_exit_handler(struct rethook_node *rh, void *data,
@@ -85,14 +116,26 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data,
 {
 	struct fprobe *fp = (struct fprobe *)data;
 	struct fprobe_rethook_node *fpr;
+	int bit;
 
 	if (!fp || fprobe_disabled(fp))
 		return;
 
 	fpr = container_of(rh, struct fprobe_rethook_node, node);
 
+	/*
+	 * we need to assure no calls to traceable functions in-between the
+	 * end of fprobe_handler and the beginning of fprobe_exit_handler.
+	 */
+	bit = ftrace_test_recursion_trylock(fpr->entry_ip, fpr->entry_parent_ip);
+	if (bit < 0) {
+		fp->nmissed++;
+		return;
+	}
+
 	fp->exit_handler(fp, fpr->entry_ip, regs,
 			 fp->entry_data_size ? (void *)fpr->data : NULL);
+	ftrace_test_recursion_unlock(bit);
 }
 NOKPROBE_SYMBOL(fprobe_exit_handler);
 
diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c
index 32c3dfdb4d6a..60f6cb2b486b 100644
--- a/kernel/trace/rethook.c
+++ b/kernel/trace/rethook.c
@@ -288,7 +288,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs,
 	 * These loops must be protected from rethook_free_rcu() because those
 	 * are accessing 'rhn->rethook'.
 	 */
-	preempt_disable();
+	preempt_disable_notrace();
 
 	/*
 	 * Run the handler on the shadow stack. Do not unlink the list here because
@@ -321,7 +321,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs,
 		first = first->next;
 		rethook_recycle(rhn);
 	}
-	preempt_enable();
+	preempt_enable_notrace();
 
 	return correct_ret_addr;
 }