ipc/syscall.c

Source file repositories/reference/linux-study-clean/ipc/syscall.c

File Facts

System
Linux kernel
Corpus path
ipc/syscall.c
Extension
.c
Size
5180 bytes
Lines
212
Domain
Core OS
Bucket
IPC
Inferred role
Core OS: syscall or user/kernel boundary
Status
core implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
		unsigned long, third, void __user *, ptr, long, fifth)
{
	return ksys_ipc(call, first, second, third, ptr, fifth);
}
#endif

#ifdef CONFIG_COMPAT
#include <linux/compat.h>

#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA	SHMLBA
#endif

struct compat_ipc_kludge {
	compat_uptr_t msgp;
	compat_long_t msgtyp;
};

#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
int compat_ksys_ipc(u32 call, int first, int second,
	u32 third, compat_uptr_t ptr, u32 fifth)
{
	int version;
	u32 pad;

	version = call >> 16; /* hack for backward compatibility */
	call &= 0xffff;

	switch (call) {
	case SEMOP:
		/* struct sembuf is the same on 32 and 64bit :)) */
		return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
	case SEMTIMEDOP:
		if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
			return -ENOSYS;
		return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
						compat_ptr(fifth));
	case SEMGET:
		return ksys_semget(first, second, third);
	case SEMCTL:
		if (!ptr)
			return -EINVAL;
		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
			return -EFAULT;
		return compat_ksys_old_semctl(first, second, third, pad);

	case MSGSND:
		return compat_ksys_msgsnd(first, ptr, second, third);

	case MSGRCV: {
		void __user *uptr = compat_ptr(ptr);

		if (first < 0 || second < 0)
			return -EINVAL;

		if (!version) {
			struct compat_ipc_kludge ipck;
			if (!uptr)
				return -EINVAL;
			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
				return -EFAULT;
			return compat_ksys_msgrcv(first, ipck.msgp, second,
						 ipck.msgtyp, third);
		}
		return compat_ksys_msgrcv(first, ptr, second, fifth, third);
	}
	case MSGGET:
		return ksys_msgget(first, second);
	case MSGCTL:
		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));

	case SHMAT: {
		int err;
		unsigned long raddr;

		if (version == 1)
			return -EINVAL;
		err = do_shmat(first, compat_ptr(ptr), second, &raddr,
			       COMPAT_SHMLBA);
		if (err < 0)
			return err;
		return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
	}
	case SHMDT:
		return ksys_shmdt(compat_ptr(ptr));
	case SHMGET:
		return ksys_shmget(first, (unsigned int)second, third);
	case SHMCTL:
		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));

Annotation

Implementation Notes