1
0
Fork 0
mirror of https://github.com/hermitcore/libhermit.git synced 2025-03-09 00:00:03 +01:00
libhermit/arch/x86_64/kernel/syscall.c

100 lines
3.3 KiB
C
Raw Permalink Normal View History

/*
* Copyright (c) 2016, Stefan Lankes, RWTH Aachen University
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <hermit/stddef.h>
#include <hermit/stdio.h>
#include <hermit/tasks.h>
#include <hermit/errno.h>
#include <hermit/syscall.h>
#include <hermit/logging.h>
void __startcontext(void);
void makecontext(ucontext_t *ucp, void (*func)(), int argc, ...)
{
va_list ap;
if (BUILTIN_EXPECT(!ucp, 0))
return;
LOG_DEBUG("sys_makecontext %p, func %p, stack 0x%zx, task %d\n", ucp, func, ucp->uc_stack.ss_sp, per_core(current_task)->id);
size_t* stack = (size_t*) ((size_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
stack -= (argc > 6 ? argc - 6 : 0) + 1;
uint32_t idx = (argc > 6 ? argc - 6 : 0) + 1;
/* Align stack and reserve space for trampoline address. */
stack = (size_t*) ((((size_t) stack) & ~0xFULL) - 0x8);
/* Setup context */
ucp->uc_mregs.rip = (size_t) func;
ucp->uc_mregs.rbx = (size_t) &stack[idx];
ucp->uc_mregs.rsp = (size_t) stack;
stack[0] = (size_t) &__startcontext;
stack[idx] = (size_t) ucp->uc_link; // link to the next context
va_start(ap, argc);
for (int i = 0; i < argc; i++)
{
switch (i)
{
case 0:
ucp->uc_mregs.rdi = va_arg(ap, size_t);
break;
case 1:
ucp->uc_mregs.rsi = va_arg(ap, size_t);
break;
case 2:
ucp->uc_mregs.rdx = va_arg(ap, size_t);
break;
case 3:
ucp->uc_mregs.rcx = va_arg(ap, size_t);
break;
case 4:
ucp->uc_mregs.r8 = va_arg(ap, size_t);
break;
case 5:
ucp->uc_mregs.r9 = va_arg(ap, size_t);
break;
default:
/* copy value on stack */
stack[i - 5] = va_arg(ap, size_t);
break;
}
}
va_end(ap);
}
int swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
{
//TODO: implementation is missing
LOG_WARNING("sys_swapcontext is currently not implemented: %p <=> %p\n", oucp, ucp);
return -ENOSYS;
}