[PATCH 4/6] sysctl: remove all extern declaration from sysctl.c

Christoph Hellwig
2020-04-17T06:42:07Z

Extern declarations in .c files are a bad style and can lead to
mismatches. Use existing definitions in headers where they exist,
and otherwise move the external declarations to suitable header
files.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/coredump.h | 6 ++++++
include/linux/file.h | 2 ++
include/linux/mm.h | 2 ++
include/linux/mmzone.h | 2 ++
include/linux/sysctl.h | 8 +++++++
kernel/sysctl.c | 45 +++-------------------------------------
6 files changed, 23 insertions(+), 42 deletions(-)

diff --git a/include/linux/coredump.h b/include/linux/coredump.h
index abf4b4e65dbb..0fe8f3131e97 100644
--- a/include/linux/coredump.h
+++ b/include/linux/coredump.h
@@ -22,4 +22,10 @@ extern void do_coredump(const kernel_siginfo_t *siginfo);
static inline void do_coredump(const kernel_siginfo_t *siginfo) {}
#endif

+extern int core_uses_pid;
+extern char core_pattern[];
+extern unsigned int core_pipe_limit;
+extern int pid_max;
+extern int pid_max_min, pid_max_max;
+
#endif /* _LINUX_COREDUMP_H */
diff --git a/include/linux/file.h b/include/linux/file.h
index 142d102f285e..122f80084a3e 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -94,4 +94,6 @@ extern void fd_install(unsigned int fd, struct file *file);
extern void flush_delayed_fput(void);
extern void __fput_sync(struct file *);

+extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
+
#endif /* __LINUX_FILE_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5a323422d783..9c4e7e76dedd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3140,5 +3140,7 @@ unsigned long wp_shared_mapping_range(struct address_space *mapping,
pgoff_t first_index, pgoff_t nr);
#endif

+extern int sysctl_nr_trim_pages;
+
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index f37bb8f187fc..b2af594ef0f7 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -909,6 +909,7 @@ static inline int is_highmem(struct zone *zone)

/* These two functions are used to setup the per zone pages min values */
struct ctl_table;
+
int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
@@ -925,6 +926,7 @@ int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,

extern int numa_zonelist_order_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
+extern int percpu_pagelist_fraction;
extern char numa_zonelist_order[];
#define NUMA_ZONELIST_ORDER_LEN 16

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 02fa84493f23..36143ca40b56 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -207,7 +207,15 @@ void unregister_sysctl_table(struct ctl_table_header * table);

extern int sysctl_init(void);

+extern int pwrsw_enabled;
+extern int unaligned_enabled;
+extern int unaligned_dump_stack;
+extern int no_unaligned_warning;
+
extern struct ctl_table sysctl_mount_point[];
+extern struct ctl_table random_table[];
+extern struct ctl_table firmware_config_table[];
+extern struct ctl_table epoll_table[];

#else /* CONFIG_SYSCTL */
static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 99d27acf4646..31b934865ebc 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -68,6 +68,9 @@
#include <linux/bpf.h>
#include <linux/mount.h>
#include <linux/userfaultfd_k.h>
+#include <linux/coredump.h>
+#include <linux/latencytop.h>
+#include <linux/pid.h>

#include "../lib/kstrtox.h"

@@ -103,22 +106,6 @@

#if defined(CONFIG_SYSCTL)

-/* External variables not in a header file. */
-extern int suid_dumpable;
-#ifdef CONFIG_COREDUMP
-extern int core_uses_pid;
-extern char core_pattern[];
-extern unsigned int core_pipe_limit;
-#endif
-extern int pid_max;
-extern int pid_max_min, pid_max_max;
-extern int percpu_pagelist_fraction;
-extern int latencytop_enabled;
-extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
-#ifndef CONFIG_MMU
-extern int sysctl_nr_trim_pages;
-#endif
-
/* Constants used for minimum and maximum */
#ifdef CONFIG_LOCKUP_DETECTOR
static int sixty = 60;
@@ -160,24 +147,6 @@ static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
#ifdef CONFIG_INOTIFY_USER
#include <linux/inotify.h>
#endif
-#ifdef CONFIG_SPARC
-#endif
-
-#ifdef CONFIG_PARISC
-extern int pwrsw_enabled;
-#endif
-
-#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
-extern int unaligned_enabled;
-#endif
-
-#ifdef CONFIG_IA64
-extern int unaligned_dump_stack;
-#endif
-
-#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
-extern int no_unaligned_warning;
-#endif

#ifdef CONFIG_PROC_SYSCTL

@@ -243,14 +212,6 @@ static struct ctl_table vm_table[];
static struct ctl_table fs_table[];
static struct ctl_table debug_table[];
static struct ctl_table dev_table[];
-extern struct ctl_table random_table[];
-#ifdef CONFIG_EPOLL
-extern struct ctl_table epoll_table[];
-#endif
-
-#ifdef CONFIG_FW_LOADER_USER_HELPER
-extern struct ctl_table firmware_config_table[];
-#endif

#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
--
2.25.1