Merge branch 'do_once_lite'

Tanner Love says:

====================
net: update netdev_rx_csum_fault() print dump only once

First patch implements DO_ONCE_LITE to abstract uses of the ".data.once"
trick. It is defined in its own, new header file  -- rather than
alongside the existing DO_ONCE in include/linux/once.h -- because
include/linux/once.h includes include/linux/jump_label.h, and this
causes the build to break for some architectures if
include/linux/once.h is included in include/linux/printk.h or
include/asm-generic/bug.h.

Second patch uses DO_ONCE_LITE in netdev_rx_csum_fault to print dump
only once.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/fs/xfs/xfs_message.h b/fs/xfs/xfs_message.h
index 7ec1a92..bb9860e 100644 (file)
--- a/fs/xfs/xfs_message.h
+++ b/fs/xfs/xfs_message.h
@@ -2,6 +2,8 @@
 #ifndef __XFS_MESSAGE_H
 #define __XFS_MESSAGE_H 1
 
+#include <linux/once_lite.h>
+
 struct xfs_mount;
 
 extern __printf(2, 3)
@@ -41,16 +43,7 @@ do {                                                                 \
 } while (0)
 
 #define xfs_printk_once(func, dev, fmt, ...)                   \
-({                                                             \
-       static bool __section(".data.once") __print_once;       \
-       bool __ret_print_once = !__print_once;                  \
-                                                               \
-       if (!__print_once) {                                    \
-               __print_once = true;                            \
-               func(dev, fmt, ##__VA_ARGS__);                  \
-       }                                                       \
-       unlikely(__ret_print_once);                             \
-})
+       DO_ONCE_LITE(func, dev, fmt, ##__VA_ARGS__)
 
 #define xfs_emerg_ratelimited(dev, fmt, ...)                           \
        xfs_printk_ratelimited(xfs_emerg, dev, fmt, ##__VA_ARGS__)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index b402494..bafc51f 100644 (file)
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -4,6 +4,7 @@
 
 #include <linux/compiler.h>
 #include <linux/instrumentation.h>
+#include <linux/once_lite.h>
 
 #define CUT_HERE               "------------[ cut here ]------------\n"
 
@@ -140,39 +141,15 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 })
 
 #ifndef WARN_ON_ONCE
-#define WARN_ON_ONCE(condition)        ({                              \
-       static bool __section(".data.once") __warned;           \
-       int __ret_warn_once = !!(condition);                    \
-                                                               \
-       if (unlikely(__ret_warn_once && !__warned)) {           \
-               __warned = true;                                \
-               WARN_ON(1);                                     \
-       }                                                       \
-       unlikely(__ret_warn_once);                              \
-})
+#define WARN_ON_ONCE(condition)                                        \
+       DO_ONCE_LITE_IF(condition, WARN_ON, 1)
 #endif
 
-#define WARN_ONCE(condition, format...)        ({                      \
-       static bool __section(".data.once") __warned;           \
-       int __ret_warn_once = !!(condition);                    \
-                                                               \
-       if (unlikely(__ret_warn_once && !__warned)) {           \
-               __warned = true;                                \
-               WARN(1, format);                                \
-       }                                                       \
-       unlikely(__ret_warn_once);                              \
-})
+#define WARN_ONCE(condition, format...)                                \
+       DO_ONCE_LITE_IF(condition, WARN, 1, format)
 
-#define WARN_TAINT_ONCE(condition, taint, format...)   ({      \
-       static bool __section(".data.once") __warned;           \
-       int __ret_warn_once = !!(condition);                    \
-                                                               \
-       if (unlikely(__ret_warn_once && !__warned)) {           \
-               __warned = true;                                \
-               WARN_TAINT(1, taint, format);                   \
-       }                                                       \
-       unlikely(__ret_warn_once);                              \
-})
+#define WARN_TAINT_ONCE(condition, taint, format...)           \
+       DO_ONCE_LITE_IF(condition, WARN_TAINT, 1, taint, format)
 
 #else /* !CONFIG_BUG */
 #ifndef HAVE_ARCH_BUG

diff --git a/include/linux/once_lite.h b/include/linux/once_lite.h
new file mode 100644 (file)
index 0000000..861e606
--- /dev/null
+++ b/include/linux/once_lite.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ONCE_LITE_H
+#define _LINUX_ONCE_LITE_H
+
+#include <linux/types.h>
+
+/* Call a function once. Similar to DO_ONCE(), but does not use jump label
+ * patching via static keys.
+ */
+#define DO_ONCE_LITE(func, ...)                                                \
+       DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__)
+#define DO_ONCE_LITE_IF(condition, func, ...)                          \
+       ({                                                              \
+               static bool __section(".data.once") __already_done;     \
+               bool __ret_do_once = !!(condition);                     \
+                                                                       \
+               if (unlikely(__ret_do_once && !__already_done)) {       \
+                       __already_done = true;                          \
+                       func(__VA_ARGS__);                              \
+               }                                                       \
+               unlikely(__ret_do_once);                                \
+       })
+
+#endif /* _LINUX_ONCE_LITE_H */

diff --git a/include/linux/printk.h b/include/linux/printk.h
index fe7eb23..885379a 100644 (file)
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -8,6 +8,7 @@
 #include <linux/linkage.h>
 #include <linux/cache.h>
 #include <linux/ratelimit_types.h>
+#include <linux/once_lite.h>
 
 extern const char linux_banner[];
 extern const char linux_proc_banner[];
@@ -436,27 +437,9 @@ extern int kptr_restrict;
 
 #ifdef CONFIG_PRINTK
 #define printk_once(fmt, ...)                                  \
-({                                                             \
-       static bool __section(".data.once") __print_once;       \
-       bool __ret_print_once = !__print_once;                  \
-                                                               \
-       if (!__print_once) {                                    \
-               __print_once = true;                            \
-               printk(fmt, ##__VA_ARGS__);                     \
-       }                                                       \
-       unlikely(__ret_print_once);                             \
-})
+       DO_ONCE_LITE(printk, fmt, ##__VA_ARGS__)
 #define printk_deferred_once(fmt, ...)                         \
-({                                                             \
-       static bool __section(".data.once") __print_once;       \
-       bool __ret_print_once = !__print_once;                  \
-                                                               \
-       if (!__print_once) {                                    \
-               __print_once = true;                            \
-               printk_deferred(fmt, ##__VA_ARGS__);            \
-       }                                                       \
-       unlikely(__ret_print_once);                             \
-})
+       DO_ONCE_LITE(printk_deferred, fmt, ##__VA_ARGS__)
 #else
 #define printk_once(fmt, ...)                                  \
        no_printk(fmt, ##__VA_ARGS__)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cd80d04..d5d8c08 100644 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -20,6 +20,7 @@
 #include <linux/irq_work.h>
 #include <linux/workqueue.h>
 #include <linux/ctype.h>
+#include <linux/once_lite.h>
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 #include <asm/unistd.h>                /* For NR_SYSCALLS           */
@@ -99,16 +100,8 @@ enum trace_type {
 #include "trace_entries.h"
 
 /* Use this for memory failure errors */
-#define MEM_FAIL(condition, fmt, ...) ({                       \
-       static bool __section(".data.once") __warned;           \
-       int __ret_warn_once = !!(condition);                    \
-                                                               \
-       if (unlikely(__ret_warn_once && !__warned)) {           \
-               __warned = true;                                \
-               pr_err("ERROR: " fmt, ##__VA_ARGS__);           \
-       }                                                       \
-       unlikely(__ret_warn_once);                              \
-})
+#define MEM_FAIL(condition, fmt, ...)                                  \
+       DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
 
 /*
  * syscalls are special, and need special handling, this is why

diff --git a/net/core/dev.c b/net/core/dev.c
index 991d09b..d609366 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -148,6 +148,7 @@
 #include <net/devlink.h>
 #include <linux/pm_runtime.h>
 #include <linux/prandom.h>
+#include <linux/once_lite.h>
 
 #include "net-sysfs.h"
 
@@ -3487,13 +3488,16 @@ EXPORT_SYMBOL(__skb_gso_segment);
 
 /* Take action when hardware reception checksum errors are detected. */
 #ifdef CONFIG_BUG
+static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
+{
+       pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
+       skb_dump(KERN_ERR, skb, true);
+       dump_stack();
+}
+
 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
 {
-       if (net_ratelimit()) {
-               pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
-               skb_dump(KERN_ERR, skb, true);
-               dump_stack();
-       }
+       DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
 }
 EXPORT_SYMBOL(netdev_rx_csum_fault);
 #endif