On Fri, Apr 24, 2020 at 08:43:36AM +0200, Christoph Hellwig wrote: > 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@xxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -Kees > --- > include/linux/coredump.h | 4 ++++ > include/linux/file.h | 2 ++ > include/linux/mm.h | 2 ++ > include/linux/mmzone.h | 2 ++ > include/linux/pid.h | 3 +++ > include/linux/sysctl.h | 8 +++++++ > kernel/sysctl.c | 45 +++------------------------------------- > 7 files changed, 24 insertions(+), 42 deletions(-) > > diff --git a/include/linux/coredump.h b/include/linux/coredump.h > index abf4b4e65dbb9..7a899e83835d5 100644 > --- a/include/linux/coredump.h > +++ b/include/linux/coredump.h > @@ -22,4 +22,8 @@ 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; > + > #endif /* _LINUX_COREDUMP_H */ > diff --git a/include/linux/file.h b/include/linux/file.h > index 142d102f285e5..122f80084a3ef 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 5a323422d783d..9c4e7e76deddc 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 f37bb8f187fc7..b2af594ef0f7c 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/pid.h b/include/linux/pid.h > index cc896f0fc4e34..93543cbc0e6b3 100644 > --- a/include/linux/pid.h > +++ b/include/linux/pid.h > @@ -108,6 +108,9 @@ extern void transfer_pid(struct task_struct *old, struct task_struct *new, > struct pid_namespace; > extern struct pid_namespace init_pid_ns; > > +extern int pid_max; > +extern int pid_max_min, pid_max_max; > + > /* > * look up a PID in the hash table. Must be called with the tasklist_lock > * or rcu_read_lock() held. > diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h > index 02fa84493f237..36143ca40b56b 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 99d27acf46465..31b934865ebc3 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) > -- > 2.26.1 > -- Kees Cook