Commit f0bc21b2 authored by Xiaoming Ni's avatar Xiaoming Ni Committed by Linus Torvalds
Browse files

fs/coredump: move coredump sysctls into its own file 

This moves the fs/coredump.c respective sysctls to its own file.

Link: https://lkml.kernel.org/r/20211129211943.640266-6-mcgrof@kernel.org


Signed-off-by: default avatarXiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Stephen Kitt <steve@sk2.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fdcd4073

fs/coredump.c

+61 −5
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/fs.h>

#include <linux/path.h>

#include <linux/timekeeping.h>

#include <linux/sysctl.h>



#include <linux/uaccess.h>

#include <asm/mmu_context.h>
@@ -52,9 +53,9 @@ 


#include <trace/events/sched.h>



int core_uses_pid;

unsigned int core_pipe_limit;

char core_pattern[CORENAME_MAX_SIZE] = "core";

static int core_uses_pid;

static unsigned int core_pipe_limit;

static char core_pattern[CORENAME_MAX_SIZE] = "core";

static int core_name_size = CORENAME_MAX_SIZE;



struct core_name {
@@ -62,8 +63,6 @@ struct core_name { 
	int used, size;

};



/* The maximal length of core_pattern is also specified in sysctl.c */



static int expand_corename(struct core_name *cn, int size)

{

	char *corename = krealloc(cn->corename, size, GFP_KERNEL);
@@ -893,6 +892,63 @@ int dump_align(struct coredump_params *cprm, int align) 
}

EXPORT_SYMBOL(dump_align);



#ifdef CONFIG_SYSCTL



void validate_coredump_safety(void)

{

	if (suid_dumpable == SUID_DUMP_ROOT &&

	    core_pattern[0] != '/' && core_pattern[0] != '|') {

		pr_warn(

"Unsafe core_pattern used with fs.suid_dumpable=2.\n"

"Pipe handler or fully qualified core dump path required.\n"

"Set kernel.core_pattern before fs.suid_dumpable.\n"

		);

	}

}



static int proc_dostring_coredump(struct ctl_table *table, int write,

		  void *buffer, size_t *lenp, loff_t *ppos)

{

	int error = proc_dostring(table, write, buffer, lenp, ppos);



	if (!error)

		validate_coredump_safety();

	return error;

}



static struct ctl_table coredump_sysctls[] = {

	{

		.procname	= "core_uses_pid",

		.data		= &core_uses_pid,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec,

	},

	{

		.procname	= "core_pattern",

		.data		= core_pattern,

		.maxlen		= CORENAME_MAX_SIZE,

		.mode		= 0644,

		.proc_handler	= proc_dostring_coredump,

	},

	{

		.procname	= "core_pipe_limit",

		.data		= &core_pipe_limit,

		.maxlen		= sizeof(unsigned int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec,

	},

	{ }

};



static int __init init_fs_coredump_sysctls(void)

{

	register_sysctl_init("kernel", coredump_sysctls);

	return 0;

}

fs_initcall(init_fs_coredump_sysctls);

#endif /* CONFIG_SYSCTL */



/*

 * The purpose of always_dump_vma() is to make sure that special kernel mappings

 * that are useful for post-mortem analysis are included in every core dump.

fs/exec.c

+0 −55
Original line number Diff line number Diff line
@@ -2103,20 +2103,6 @@ COMPAT_SYSCALL_DEFINE5(execveat, int, fd, 


#ifdef CONFIG_SYSCTL



static void validate_coredump_safety(void)

{

#ifdef CONFIG_COREDUMP

	if (suid_dumpable == SUID_DUMP_ROOT &&

	    core_pattern[0] != '/' && core_pattern[0] != '|') {

		pr_warn(

"Unsafe core_pattern used with fs.suid_dumpable=2.\n"

"Pipe handler or fully qualified core dump path required.\n"

"Set kernel.core_pattern before fs.suid_dumpable.\n"

		);

	}

#endif

}



static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,

		void *buffer, size_t *lenp, loff_t *ppos)

{
@@ -2140,50 +2126,9 @@ static struct ctl_table fs_exec_sysctls[] = { 
	{ }

};



#ifdef CONFIG_COREDUMP



static int proc_dostring_coredump(struct ctl_table *table, int write,

		  void *buffer, size_t *lenp, loff_t *ppos)

{

	int error = proc_dostring(table, write, buffer, lenp, ppos);



	if (!error)

		validate_coredump_safety();

	return error;

}



static struct ctl_table kernel_exec_sysctls[] = {

	{

		.procname	= "core_uses_pid",

		.data		= &core_uses_pid,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec,

	},

	{

		.procname	= "core_pattern",

		.data		= core_pattern,

		.maxlen		= CORENAME_MAX_SIZE,

		.mode		= 0644,

		.proc_handler	= proc_dostring_coredump,

	},

	{

		.procname	= "core_pipe_limit",

		.data		= &core_pipe_limit,

		.maxlen		= sizeof(unsigned int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec,

	},

	{ }

};

#endif



static int __init init_fs_exec_sysctls(void)

{

	register_sysctl_init("fs", fs_exec_sysctls);

#ifdef CONFIG_COREDUMP

	register_sysctl_init("kernel", kernel_exec_sysctls);

#endif

	return 0;

}

include/linux/coredump.h

+6 −4
Original line number Diff line number Diff line
@@ -14,10 +14,6 @@ struct core_vma_metadata { 
	unsigned long dump_size;

};



extern int core_uses_pid;

extern char core_pattern[];

extern unsigned int core_pipe_limit;



/*

 * These are the only things you should do on a core-file: use only these

 * functions to write out all the necessary info.
@@ -37,4 +33,10 @@ extern void do_coredump(const kernel_siginfo_t *siginfo); 
static inline void do_coredump(const kernel_siginfo_t *siginfo) {}

#endif



#if defined(CONFIG_COREDUMP) && defined(CONFIG_SYSCTL)

extern void validate_coredump_safety(void);

#else

static inline void validate_coredump_safety(void) {}

#endif



#endif /* _LINUX_COREDUMP_H */

kernel/sysctl.c

+0 −2
Original line number Diff line number Diff line
@@ -62,12 +62,10 @@ 
#include <linux/capability.h>

#include <linux/binfmts.h>

#include <linux/sched/sysctl.h>

#include <linux/sched/coredump.h>

#include <linux/kexec.h>

#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 <linux/delayacct.h>