minix/kernel/system/do_exec.c
Tomas Hruby 5b8b623765 SMP - lazy FPU
- when a process is migrated to a different CPU it may have an active
  FPU context in the processor registers. We must save it and migrate
  it together with the process.
2010-09-15 14:11:25 +00:00

54 lines
1.6 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_EXEC
*
* The parameters for this kernel call are:
* m1_i1: PR_ENDPT (process that did exec call)
* m1_p1: PR_STACK_PTR (new stack pointer)
* m1_p2: PR_NAME_PTR (pointer to program name)
* m1_p3: PR_IP_PTR (new instruction pointer)
*/
#include "kernel/system.h"
#include <string.h>
#include <minix/endpoint.h>
#if USE_EXEC
/*===========================================================================*
* do_exec *
*===========================================================================*/
PUBLIC int do_exec(struct proc * caller, message * m_ptr)
{
/* Handle sys_exec(). A process has done a successful EXEC. Patch it up. */
register struct proc *rp;
int proc_nr;
if(!isokendpt(m_ptr->PR_ENDPT, &proc_nr))
return EINVAL;
rp = proc_addr(proc_nr);
if(rp->p_misc_flags & MF_DELIVERMSG) {
rp->p_misc_flags &= ~MF_DELIVERMSG;
}
/* Save command name for debugging, ps(1) output, etc. */
if(data_copy(caller->p_endpoint, (vir_bytes) m_ptr->PR_NAME_PTR,
KERNEL, (vir_bytes) rp->p_name, (phys_bytes) P_NAME_LEN - 1) != OK)
strncpy(rp->p_name, "<unset>", P_NAME_LEN);
/* Do architecture-specific exec() stuff. */
arch_pre_exec(rp, (u32_t) m_ptr->PR_IP_PTR, (u32_t) m_ptr->PR_STACK_PTR);
/* No reply to EXEC call */
RTS_UNSET(rp, RTS_RECEIVING);
/* Mark fpu_regs contents as not significant, so fpu
* will be initialized, when it's used next time. */
rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
/* force reloading FPU if the current process is the owner */
release_fpu(rp);
return(OK);
}
#endif /* USE_EXEC */