From 046d662f481830e652ac34cd112249adde16452a Mon Sep 17 00:00:00 2001 From: Alex Kelly Date: Thu, 4 Oct 2012 17:15:23 -0700 Subject: coredump: make core dump functionality optional Adds an expert Kconfig option, CONFIG_COREDUMP, which allows disabling of core dump. This saves approximately 2.6k in the compiled kernel, and complements CONFIG_ELF_CORE, which now depends on it. CONFIG_COREDUMP also disables coredump-related sysctls, except for suid_dumpable and related functions, which are necessary for ptrace. [akpm@linux-foundation.org: fix binfmt_aout.c build] Signed-off-by: Alex Kelly Reviewed-by: Josh Triplett Acked-by: Serge Hallyn Acked-by: Kees Cook Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 84c76a34e41c..c2a2f8084bad 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -97,10 +97,12 @@ extern int sysctl_overcommit_memory; extern int sysctl_overcommit_ratio; extern int max_threads; -extern int core_uses_pid; 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 min_free_kbytes; extern int pid_max_min, pid_max_max; @@ -177,8 +179,10 @@ static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write, static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); +#ifdef CONFIG_COREDUMP static int proc_dostring_coredump(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); +#endif #ifdef CONFIG_MAGIC_SYSRQ /* Note: sysrq code uses it's own private copy */ @@ -404,6 +408,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#ifdef CONFIG_COREDUMP { .procname = "core_uses_pid", .data = &core_uses_pid, @@ -425,6 +430,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#endif #ifdef CONFIG_PROC_SYSCTL { .procname = "tainted", @@ -2036,12 +2042,14 @@ int proc_dointvec_minmax(struct ctl_table *table, int write, static void validate_coredump_safety(void) { +#ifdef CONFIG_COREDUMP if (suid_dumpable == SUID_DUMPABLE_SAFE && core_pattern[0] != '/' && core_pattern[0] != '|') { printk(KERN_WARNING "Unsafe core_pattern used with "\ "suid_dumpable=2. Pipe handler or fully qualified "\ "core dump path required.\n"); } +#endif } static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write, @@ -2053,6 +2061,7 @@ static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write, return error; } +#ifdef CONFIG_COREDUMP static int proc_dostring_coredump(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { @@ -2061,6 +2070,7 @@ static int proc_dostring_coredump(struct ctl_table *table, int write, validate_coredump_safety(); return error; } +#endif static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write, void __user *buffer, -- cgit v1.2.3