Differential D44702 Diff 136833 sys/kern/uipc_shm.c

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sys/kern/uipc_shm.c

Show First 20 Lines • Show All 1,167 Lines • ▼ Show 20 Lines	kern_shm_open2(struct thread td, const char userpath, int flags, mode_t mode,
if ((shmflags & ~(SHM_ALLOW_SEALING \| SHM_GROW_ON_WRITE \|		if ((shmflags & ~(SHM_ALLOW_SEALING \| SHM_GROW_ON_WRITE \|
SHM_LARGEPAGE)) != 0)		SHM_LARGEPAGE)) != 0)
return (EINVAL);		return (EINVAL);

initial_seals = F_SEAL_SEAL;		initial_seals = F_SEAL_SEAL;
if ((shmflags & SHM_ALLOW_SEALING) != 0)		if ((shmflags & SHM_ALLOW_SEALING) != 0)
initial_seals &= ~F_SEAL_SEAL;		initial_seals &= ~F_SEAL_SEAL;

#ifdef CAPABILITY_MODE
/*
* shm_open(2) is only allowed for anonymous objects.
*/
if (userpath != SHM_ANON) {
if (CAP_TRACING(td))
ktrcapfail(CAPFAIL_NAMEI, userpath);
if (IN_CAPABILITY_MODE(td))
return (ECAPMODE);
}
#endif

AUDIT_ARG_FFLAGS(flags);		AUDIT_ARG_FFLAGS(flags);
AUDIT_ARG_MODE(mode);		AUDIT_ARG_MODE(mode);

if ((flags & O_ACCMODE) != O_RDONLY && (flags & O_ACCMODE) != O_RDWR)		if ((flags & O_ACCMODE) != O_RDONLY && (flags & O_ACCMODE) != O_RDWR)
return (EINVAL);		return (EINVAL);

if ((flags & ~(O_ACCMODE \| O_CREAT \| O_EXCL \| O_TRUNC \| O_CLOEXEC)) != 0)		if ((flags & ~(O_ACCMODE \| O_CREAT \| O_EXCL \| O_TRUNC \| O_CLOEXEC)) != 0)
return (EINVAL);		return (EINVAL);

largepage = (shmflags & SHM_LARGEPAGE) != 0;		largepage = (shmflags & SHM_LARGEPAGE) != 0;
if (largepage && !PMAP_HAS_LARGEPAGES)		if (largepage && !PMAP_HAS_LARGEPAGES)
return (ENOTTY);		return (ENOTTY);

/*		/*
* Currently only F_SEAL_SEAL may be set when creating or opening shmfd.		* Currently only F_SEAL_SEAL may be set when creating or opening shmfd.
* If the decision is made later to allow additional seals, care must be		* If the decision is made later to allow additional seals, care must be
* taken below to ensure that the seals are properly set if the shmfd		* taken below to ensure that the seals are properly set if the shmfd
* already existed -- this currently assumes that only F_SEAL_SEAL can		* already existed -- this currently assumes that only F_SEAL_SEAL can
* be set and doesn't take further precautions to ensure the validity of		* be set and doesn't take further precautions to ensure the validity of
* the seals being added with respect to current mappings.		* the seals being added with respect to current mappings.
*/		*/
if ((initial_seals & ~F_SEAL_SEAL) != 0)		if ((initial_seals & ~F_SEAL_SEAL) != 0)
return (EINVAL);		return (EINVAL);

		if (userpath != SHM_ANON) {
		error = shm_copyin_path(td, userpath, &path);
		if (error != 0)
		return (error);

		#ifdef CAPABILITY_MODE
		/*
		* shm_open(2) is only allowed for anonymous objects.
		*/
		if (CAP_TRACING(td))
		ktrcapfail(CAPFAIL_NAMEI, path);
		if (IN_CAPABILITY_MODE(td)) {
		free(path, M_SHMFD);
		return (ECAPMODE);
		}
		#endif

		AUDIT_ARG_UPATH1_CANON(path);
		}

pdp = td->td_proc->p_pd;		pdp = td->td_proc->p_pd;
cmode = (mode & ~pdp->pd_cmask) & ACCESSPERMS;		cmode = (mode & ~pdp->pd_cmask) & ACCESSPERMS;

/*		/*
* shm_open(2) created shm should always have O_CLOEXEC set, as mandated		* shm_open(2) created shm should always have O_CLOEXEC set, as mandated
* by POSIX. We allow it to be unset here so that an in-kernel		* by POSIX. We allow it to be unset here so that an in-kernel
* interface may be written as a thin layer around shm, optionally not		* interface may be written as a thin layer around shm, optionally not
* setting CLOEXEC. For shm_open(2), O_CLOEXEC is set unconditionally		* setting CLOEXEC. For shm_open(2), O_CLOEXEC is set unconditionally
* in sys_shm_open() to keep this implementation compliant.		* in sys_shm_open() to keep this implementation compliant.
*/		*/
error = falloc_caps(td, &fp, &fd, flags & O_CLOEXEC, fcaps);		error = falloc_caps(td, &fp, &fd, flags & O_CLOEXEC, fcaps);
if (error)		if (error) {
		free(path, M_SHMFD);
return (error);		return (error);
		}

/* A SHM_ANON path pointer creates an anonymous object. */		/* A SHM_ANON path pointer creates an anonymous object. */
if (userpath == SHM_ANON) {		if (userpath == SHM_ANON) {
/* A read-only anonymous object is pointless. */		/* A read-only anonymous object is pointless. */
if ((flags & O_ACCMODE) == O_RDONLY) {		if ((flags & O_ACCMODE) == O_RDONLY) {
fdclose(td, fp, fd);		fdclose(td, fp, fd);
fdrop(fp, td);		fdrop(fp, td);
return (EINVAL);		return (EINVAL);
}		}
shmfd = shm_alloc(td->td_ucred, cmode, largepage);		shmfd = shm_alloc(td->td_ucred, cmode, largepage);
shmfd->shm_seals = initial_seals;		shmfd->shm_seals = initial_seals;
shmfd->shm_flags = shmflags;		shmfd->shm_flags = shmflags;
} else {		} else {
error = shm_copyin_path(td, userpath, &path);
if (error != 0) {
fdclose(td, fp, fd);
fdrop(fp, td);
return (error);
}

AUDIT_ARG_UPATH1_CANON(path);
fnv = fnv_32_str(path, FNV1_32_INIT);		fnv = fnv_32_str(path, FNV1_32_INIT);
sx_xlock(&shm_dict_lock);		sx_xlock(&shm_dict_lock);
shmfd = shm_lookup(path, fnv);		shmfd = shm_lookup(path, fnv);
if (shmfd == NULL) {		if (shmfd == NULL) {
/* Object does not yet exist, create it if requested. */		/* Object does not yet exist, create it if requested. */
if (flags & O_CREAT) {		if (flags & O_CREAT) {
#ifdef MAC		#ifdef MAC
error = mac_posixshm_check_create(td->td_ucred,		error = mac_posixshm_check_create(td->td_ucred,
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