minix/kernel/system/do_sigreturn.c
Jorrit Herder 42ab148155 Reorganized system call library; uses separate file per call now.
New configuration header file to include/ exclude functionality.
Extracted privileged features from struct proc and create new struct priv.
Renamed various system calls for readability.
2005-07-14 15:12:12 +00:00

80 lines
2.5 KiB
C

/* The system call that is implemented in this file:
* SYS_SIGCTL # signal handling functionality
*
* The parameters and types for this system call are:
* SIG_REQUEST # request to perform (long)
* SIG_PROC # process to signal/ pending (int)
* SIG_CTXT_PTR # pointer to sigcontext structure (pointer)
* SIG_FLAGS # flags for S_SIGRETURN call (int)
* SIG_MAP # bit map with pending signals (long)
* SIG_NUMBER # signal number to send to process (int)
*
* Supported request types are in the parameter SIG_REQUEST:
* S_GETSIG # get a pending kernel signal
* S_ENDSIG # signal has been processed
* S_SENDSIG # deliver a POSIX-style signal
* S_SIGRETURN # return from a POSIX-style signal
* S_KILL # send a signal to a process
*/
#include "../system.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;
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. */
kmemcpy(&rp->p_reg, (char *)&sc.sc_regs, sizeof(struct sigregs));
return(OK);
}
#endif /* USE_SIGRETURN */