minix/kernel/system/do_sigsend.c
Jorrit Herder 0946d128cd - Kernel call handlers cleaned up. More strict checking of input parameters.
- Moved generic_handler() from system.c to system/do_irqctl.c.
- Set privileges of system processes somewhat stricter.
2005-07-29 15:26:23 +00:00

83 lines
2.7 KiB
C

/* The system call that is implemented in this file:
* m_type: SYS_SIGSEND
*
* The parameters for this system call are:
* m2_i1: SIG_PROC # process to call signal handler
* m2_p1: SIG_CTXT_PTR # pointer to sigcontext structure
* m2_i3: SIG_FLAGS # flags for S_SIGRETURN call
*
*/
#include "../system.h"
#include <signal.h>
#include <string.h>
#include <sys/sigcontext.h>
#if USE_SIGSEND
/*===========================================================================*
* do_sigsend *
*===========================================================================*/
PUBLIC int do_sigsend(m_ptr)
message *m_ptr; /* pointer to request message */
{
/* Handle sys_sigsend, POSIX-style signal handling. */
struct sigmsg smsg;
register struct proc *rp;
phys_bytes src_phys, dst_phys;
struct sigcontext sc, *scp;
struct sigframe fr, *frp;
if (! isokprocn(m_ptr->SIG_PROC)) return(EINVAL);
if (iskerneln(m_ptr->SIG_PROC)) return(EPERM);
rp = proc_addr(m_ptr->SIG_PROC);
/* Get the sigmsg structure into our address space. */
src_phys = umap_local(proc_addr(PM_PROC_NR), D, (vir_bytes)
m_ptr->SIG_CTXT_PTR, (vir_bytes) sizeof(struct sigmsg));
if (src_phys == 0) return(EFAULT);
phys_copy(src_phys,vir2phys(&smsg),(phys_bytes) sizeof(struct sigmsg));
/* Compute the user stack pointer where sigcontext will be stored. */
scp = (struct sigcontext *) smsg.sm_stkptr - 1;
/* Copy the registers to the sigcontext structure. */
memcpy(&sc.sc_regs, (char *) &rp->p_reg, sizeof(struct sigregs));
/* Finish the sigcontext initialization. */
sc.sc_flags = SC_SIGCONTEXT;
sc.sc_mask = smsg.sm_mask;
/* Copy the sigcontext structure to the user's stack. */
dst_phys = umap_local(rp, D, (vir_bytes) scp,
(vir_bytes) sizeof(struct sigcontext));
if (dst_phys == 0) return(EFAULT);
phys_copy(vir2phys(&sc), dst_phys, (phys_bytes) sizeof(struct sigcontext));
/* Initialize the sigframe structure. */
frp = (struct sigframe *) scp - 1;
fr.sf_scpcopy = scp;
fr.sf_retadr2= (void (*)()) rp->p_reg.pc;
fr.sf_fp = rp->p_reg.fp;
rp->p_reg.fp = (reg_t) &frp->sf_fp;
fr.sf_scp = scp;
fr.sf_code = 0; /* XXX - should be used for type of FP exception */
fr.sf_signo = smsg.sm_signo;
fr.sf_retadr = (void (*)()) smsg.sm_sigreturn;
/* Copy the sigframe structure to the user's stack. */
dst_phys = umap_local(rp, D, (vir_bytes) frp,
(vir_bytes) sizeof(struct sigframe));
if (dst_phys == 0) return(EFAULT);
phys_copy(vir2phys(&fr), dst_phys, (phys_bytes) sizeof(struct sigframe));
/* Reset user registers to execute the signal handler. */
rp->p_reg.sp = (reg_t) frp;
rp->p_reg.pc = (reg_t) smsg.sm_sighandler;
return(OK);
}
#endif /* USE_SIGSEND */