/*
 *	Wrapper functions for 16bit uid back compatibility. All nicely tied
 *	together in the faint hope we can take the out in five years time.
 */

#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.h>
#include <linux/capability.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/security.h>
#include <linux/syscalls.h>

#include <linux/uaccess.h>

SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
	return sys_chown(filename, low2highuid(user), low2highgid(group));
}

SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
{
	return sys_lchown(filename, low2highuid(user), low2highgid(group));
}

SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
{
	return sys_fchown(fd, low2highuid(user), low2highgid(group));
}

SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
{
	return sys_setregid(low2highgid(rgid), low2highgid(egid));
}

SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
{
	return sys_setgid(low2highgid(gid));
}

SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
{
	return sys_setreuid(low2highuid(ruid), low2highuid(euid));
}

SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
{
	return sys_setuid(low2highuid(uid));
}

SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
{
	return sys_setresuid(low2highuid(ruid), low2highuid(euid),
				 low2highuid(suid));
}

SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp)
{
	const struct cred *cred = current_cred();
	int retval;
	old_uid_t ruid, euid, suid;

	ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
	euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
	suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));

	if (!(retval   = put_user(ruid, ruidp)) &&
	    !(retval   = put_user(euid, euidp)))
		retval = put_user(suid, suidp);

	return retval;
}

SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid)
{
	return sys_setresgid(low2highgid(rgid), low2highgid(egid),
				 low2highgid(sgid));
}


SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egidp, old_gid_t __user *, sgidp)
{
	const struct cred *cred = current_cred();
	int retval;
	old_gid_t rgid, egid, sgid;

	rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
	egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
	sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));

	if (!(retval   = put_user(rgid, rgidp)) &&
	    !(retval   = put_user(egid, egidp)))
		retval = put_user(sgid, sgidp);

	return retval;
}

SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
{
	return sys_setfsuid(low2highuid(uid));
}

SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
{
	return sys_setfsgid(low2highgid(gid));
}

static int groups16_to_user(old_gid_t __user *grouplist,
    struct group_info *group_info)
{
	struct user_namespace *user_ns = current_user_ns();
	int i;
	old_gid_t group;
	kgid_t kgid;

	for (i = 0; i < group_info->ngroups; i++) {
		kgid = group_info->gid[i];
		group = high2lowgid(from_kgid_munged(user_ns, kgid));
		if (put_user(group, grouplist+i))
			return -EFAULT;
	}

	return 0;
}

static int groups16_from_user(struct group_info *group_info,
    old_gid_t __user *grouplist)
{
	struct user_namespace *user_ns = current_user_ns();
	int i;
	old_gid_t group;
	kgid_t kgid;

	for (i = 0; i < group_info->ngroups; i++) {
		if (get_user(group, grouplist+i))
			return  -EFAULT;

		kgid = make_kgid(user_ns, low2highgid(group));
		if (!gid_valid(kgid))
			return -EINVAL;

		group_info->gid[i] = kgid;
	}

	return 0;
}

SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
{
	const struct cred *cred = current_cred();
	int i;

	if (gidsetsize < 0)
		return -EINVAL;

	i = cred->group_info->ngroups;
	if (gidsetsize) {
		if (i > gidsetsize) {
			i = -EINVAL;
			goto out;
		}
		if (groups16_to_user(grouplist, cred->group_info)) {
			i = -EFAULT;
			goto out;
		}
	}
out:
	return i;
}

SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
{
	struct group_info *group_info;
	int retval;

	if (!may_setgroups())
		return -EPERM;
	if ((unsigned)gidsetsize > NGROUPS_MAX)
		return -EINVAL;

	group_info = groups_alloc(gidsetsize);
	if (!group_info)
		return -ENOMEM;
	retval = groups16_from_user(group_info, grouplist);
	if (retval) {
		put_group_info(group_info);
		return retval;
	}

	retval = set_current_groups(group_info);
	put_group_info(group_info);

	return retval;
}

SYSCALL_DEFINE0(getuid16)
{
	return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
}

SYSCALL_DEFINE0(geteuid16)
{
	return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
}

SYSCALL_DEFINE0(getgid16)
{
	return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
}

SYSCALL_DEFINE0(getegid16)
{
	return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
}
t/patch/include/dt-bindings/spmi?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>d53fbdac9d0781e39a13b2ac6b2bd258cf3b4140</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings/spmi?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>include/dt-bindings/spmi</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/spmi?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/spmi?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'include/dt-bindings/spmi')</div><table summary='diffstat' class='diffstat'>