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/* SPDX-License-Identifier: copyleft-next-0.3.1 */
/* Copyright 2023 Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
#include <kmi/uapi.h>
#include <kmi/caps.h>
#include <kmi/tcb.h>
/**
* @file cap.c
* Sycalls handlers for thread capabilities.
*/
/**
* Check that values are legal for thread ID and offset.
*
* @param tid Thread ID of thread whose caps should be fetched.
* @param off Offset of capabilities.
* @return Pointer to capabilities of \p tid, \c 0 otherwise.
*/
static capflags_t *__get_tcb_caps(id_t tid, size_t off)
{
if (!cap_off_ok(off))
return NULL;
struct tcb *t = get_tcb(tid);
if (!t)
return NULL;
return &t->caps;
}
/**
* Set capabilities.
*
* @param t Current tcb.
* @param tid Thread ID whose capabilities to set.
* @param off Offset of capability, multiple of \c bits(cap).
* @param caps Mask of capabilities to set.
* @return \ref OK on success, \ref ERR_INVAL on invalid input.
*/
SYSCALL_DEFINE3(set_cap)(struct tcb *t, sys_arg_t tid, sys_arg_t off,
sys_arg_t caps)
{
if (!is_set(t->caps, CAP_CAPS))
return_args1(t, ERR_PERM);
capflags_t *c;
if (!(c = __get_tcb_caps(tid, off)))
return_args1(t, ERR_INVAL);
set_caps(*c, off, caps);
return_args1(t, OK);
}
/**
* Get capabilities.
*
* @param t Current tcb.
* @param tid Thread ID whose capabilities to get.
* @param off Offset of capability, multiple of \c bits(cap).
* @return \ref OK, capabilities.
*/
SYSCALL_DEFINE2(get_cap)(struct tcb *t, sys_arg_t tid, sys_arg_t off)
{
capflags_t *c;
if (!(c = __get_tcb_caps(tid, off)))
return_args1(t, ERR_INVAL);
return_args2(t, OK, get_caps(*c, off));
}
/**
* Clear capabilities.
*
* @param t Current tcb.
* @param tid Thread ID whose capabilities to clear.
* @param off Offset of capability, multiple of \c bits(cap).
* @param caps Mask of capabilities to clear.
* @return ERR_LERM if invalid permissions, ERR_INVAL if \p tid doesn't exist,
* otherwise OK.
*/
SYSCALL_DEFINE3(clear_cap)(struct tcb *t, sys_arg_t tid, sys_arg_t off,
sys_arg_t caps)
{
if (!is_set(t->caps, CAP_CAPS))
return_args1(t, ERR_PERM);
capflags_t *c;
if (!(c = __get_tcb_caps(tid, off)))
return_args1(t, ERR_INVAL);
clear_caps(*c, off, caps);
return_args1(t, OK);
}
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