72 lines
2.1 KiB
C
72 lines
2.1 KiB
C
/* The system call that is implemented in this file:
|
|
* m_type: SYS_SIGRETURN
|
|
*
|
|
* The parameters for this system call are:
|
|
* m2_i1: SIG_PROC # process returning from handler
|
|
* m2_p1: SIG_CTXT_PTR # pointer to sigcontext structure
|
|
*
|
|
*/
|
|
|
|
#include "../system.h"
|
|
#include <string.h>
|
|
#include <signal.h>
|
|
#include <sys/sigcontext.h>
|
|
|
|
#if USE_SIGRETURN
|
|
|
|
/*===========================================================================*
|
|
* do_sigreturn *
|
|
*===========================================================================*/
|
|
PUBLIC int do_sigreturn(m_ptr)
|
|
message *m_ptr; /* pointer to request message */
|
|
{
|
|
/* POSIX style signals require sys_sigreturn to put things in order before
|
|
* the signalled process can resume execution
|
|
*/
|
|
struct sigcontext sc;
|
|
register struct proc *rp;
|
|
phys_bytes src_phys;
|
|
|
|
if (! isokprocn(m_ptr->SIG_PROC)) return(EINVAL);
|
|
if (iskerneln(m_ptr->SIG_PROC)) return(EPERM);
|
|
rp = proc_addr(m_ptr->SIG_PROC);
|
|
|
|
/* Copy in the sigcontext structure. */
|
|
src_phys = umap_local(rp, D, (vir_bytes) m_ptr->SIG_CTXT_PTR,
|
|
(vir_bytes) sizeof(struct sigcontext));
|
|
if (src_phys == 0) return(EFAULT);
|
|
phys_copy(src_phys, vir2phys(&sc), (phys_bytes) sizeof(struct sigcontext));
|
|
|
|
/* Make sure that this is not just a jump buffer. */
|
|
if ((sc.sc_flags & SC_SIGCONTEXT) == 0) return(EINVAL);
|
|
|
|
/* Fix up only certain key registers if the compiler doesn't use
|
|
* register variables within functions containing setjmp.
|
|
*/
|
|
if (sc.sc_flags & SC_NOREGLOCALS) {
|
|
rp->p_reg.retreg = sc.sc_retreg;
|
|
rp->p_reg.fp = sc.sc_fp;
|
|
rp->p_reg.pc = sc.sc_pc;
|
|
rp->p_reg.sp = sc.sc_sp;
|
|
return(OK);
|
|
}
|
|
sc.sc_psw = rp->p_reg.psw;
|
|
|
|
#if (CHIP == INTEL)
|
|
/* Don't panic kernel if user gave bad selectors. */
|
|
sc.sc_cs = rp->p_reg.cs;
|
|
sc.sc_ds = rp->p_reg.ds;
|
|
sc.sc_es = rp->p_reg.es;
|
|
#if _WORD_SIZE == 4
|
|
sc.sc_fs = rp->p_reg.fs;
|
|
sc.sc_gs = rp->p_reg.gs;
|
|
#endif
|
|
#endif
|
|
|
|
/* Restore the registers. */
|
|
memcpy(&rp->p_reg, &sc.sc_regs, sizeof(struct sigregs));
|
|
return(OK);
|
|
}
|
|
#endif /* USE_SIGRETURN */
|
|
|