diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/exec_domain.c | |
| download | olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip  | |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'kernel/exec_domain.c')
| -rw-r--r-- | kernel/exec_domain.c | 209 | 
1 files changed, 209 insertions, 0 deletions
diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c new file mode 100644 index 00000000000..867d6dbeb57 --- /dev/null +++ b/kernel/exec_domain.c @@ -0,0 +1,209 @@ +/* + * Handling of different ABIs (personalities). + * + * We group personalities into execution domains which have their + * own handlers for kernel entry points, signal mapping, etc... + * + * 2001-05-06	Complete rewrite,  Christoph Hellwig (hch@infradead.org) + */ + +#include <linux/config.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/module.h> +#include <linux/personality.h> +#include <linux/sched.h> +#include <linux/syscalls.h> +#include <linux/sysctl.h> +#include <linux/types.h> + + +static void default_handler(int, struct pt_regs *); + +static struct exec_domain *exec_domains = &default_exec_domain; +static DEFINE_RWLOCK(exec_domains_lock); + + +static u_long ident_map[32] = { +	0,	1,	2,	3,	4,	5,	6,	7, +	8,	9,	10,	11,	12,	13,	14,	15, +	16,	17,	18,	19,	20,	21,	22,	23, +	24,	25,	26,	27,	28,	29,	30,	31 +}; + +struct exec_domain default_exec_domain = { +	.name		= "Linux",		/* name */ +	.handler	= default_handler,	/* lcall7 causes a seg fault. */ +	.pers_low	= 0, 			/* PER_LINUX personality. */ +	.pers_high	= 0,			/* PER_LINUX personality. */ +	.signal_map	= ident_map,		/* Identity map signals. */ +	.signal_invmap	= ident_map,		/*  - both ways. */ +}; + + +static void +default_handler(int segment, struct pt_regs *regp) +{ +	set_personality(0); + +	if (current_thread_info()->exec_domain->handler != default_handler) +		current_thread_info()->exec_domain->handler(segment, regp); +	else +		send_sig(SIGSEGV, current, 1); +} + +static struct exec_domain * +lookup_exec_domain(u_long personality) +{ +	struct exec_domain *	ep; +	u_long			pers = personality(personality); +		 +	read_lock(&exec_domains_lock); +	for (ep = exec_domains; ep; ep = ep->next) { +		if (pers >= ep->pers_low && pers <= ep->pers_high) +			if (try_module_get(ep->module)) +				goto out; +	} + +#ifdef CONFIG_KMOD +	read_unlock(&exec_domains_lock); +	request_module("personality-%ld", pers); +	read_lock(&exec_domains_lock); + +	for (ep = exec_domains; ep; ep = ep->next) { +		if (pers >= ep->pers_low && pers <= ep->pers_high) +			if (try_module_get(ep->module)) +				goto out; +	} +#endif + +	ep = &default_exec_domain; +out: +	read_unlock(&exec_domains_lock); +	return (ep); +} + +int +register_exec_domain(struct exec_domain *ep) +{ +	struct exec_domain	*tmp; +	int			err = -EBUSY; + +	if (ep == NULL) +		return -EINVAL; + +	if (ep->next != NULL) +		return -EBUSY; + +	write_lock(&exec_domains_lock); +	for (tmp = exec_domains; tmp; tmp = tmp->next) { +		if (tmp == ep) +			goto out; +	} + +	ep->next = exec_domains; +	exec_domains = ep; +	err = 0; + +out: +	write_unlock(&exec_domains_lock); +	return (err); +} + +int +unregister_exec_domain(struct exec_domain *ep) +{ +	struct exec_domain	**epp; + +	epp = &exec_domains; +	write_lock(&exec_domains_lock); +	for (epp = &exec_domains; *epp; epp = &(*epp)->next) { +		if (ep == *epp) +			goto unregister; +	} +	write_unlock(&exec_domains_lock); +	return -EINVAL; + +unregister: +	*epp = ep->next; +	ep->next = NULL; +	write_unlock(&exec_domains_lock); +	return 0; +} + +int +__set_personality(u_long personality) +{ +	struct exec_domain	*ep, *oep; + +	ep = lookup_exec_domain(personality); +	if (ep == current_thread_info()->exec_domain) { +		current->personality = personality; +		return 0; +	} + +	if (atomic_read(¤t->fs->count) != 1) { +		struct fs_struct *fsp, *ofsp; + +		fsp = copy_fs_struct(current->fs); +		if (fsp == NULL) { +			module_put(ep->module); +			return -ENOMEM; +		} + +		task_lock(current); +		ofsp = current->fs; +		current->fs = fsp; +		task_unlock(current); + +		put_fs_struct(ofsp); +	} + +	/* +	 * At that point we are guaranteed to be the sole owner of +	 * current->fs. +	 */ + +	current->personality = personality; +	oep = current_thread_info()->exec_domain; +	current_thread_info()->exec_domain = ep; +	set_fs_altroot(); + +	module_put(oep->module); +	return 0; +} + +int +get_exec_domain_list(char *page) +{ +	struct exec_domain	*ep; +	int			len = 0; + +	read_lock(&exec_domains_lock); +	for (ep = exec_domains; ep && len < PAGE_SIZE - 80; ep = ep->next) +		len += sprintf(page + len, "%d-%d\t%-16s\t[%s]\n", +			       ep->pers_low, ep->pers_high, ep->name, +			       module_name(ep->module)); +	read_unlock(&exec_domains_lock); +	return (len); +} + +asmlinkage long +sys_personality(u_long personality) +{ +	u_long old = current->personality; + +	if (personality != 0xffffffff) { +		set_personality(personality); +		if (current->personality != personality) +			return -EINVAL; +	} + +	return (long)old; +} + + +EXPORT_SYMBOL(register_exec_domain); +EXPORT_SYMBOL(unregister_exec_domain); +EXPORT_SYMBOL(__set_personality);  |