1 /* The kernel call that is implemented in this file: 2 * m_type: SYS_SIGRETURN 3 * 4 * The parameters for this kernel call are: 5 * m_sigcalls.endp # process returning from handler 6 * m_sigcalls.sigctx # pointer to sigcontext structure 7 * 8 */ 9 10 #include "kernel/system.h" 11 #include <string.h> 12 #include <machine/cpu.h> 13 14 #if USE_SIGRETURN 15 16 /*===========================================================================* 17 * do_sigreturn * 18 *===========================================================================*/ 19 int do_sigreturn(struct proc * caller, message * m_ptr) 20 { 21 /* POSIX style signals require sys_sigreturn to put things in order before 22 * the signalled process can resume execution 23 */ 24 struct sigcontext sc; 25 register struct proc *rp; 26 int proc_nr, r; 27 28 if (!isokendpt(m_ptr->m_sigcalls.endpt, &proc_nr)) return EINVAL; 29 if (iskerneln(proc_nr)) return EPERM; 30 rp = proc_addr(proc_nr); 31 32 /* Copy in the sigcontext structure. */ 33 if ((r = data_copy(m_ptr->m_sigcalls.endpt, 34 (vir_bytes)m_ptr->m_sigcalls.sigctx, KERNEL, 35 (vir_bytes)&sc, sizeof(struct sigcontext))) != OK) 36 return r; 37 38 #if defined(__i386__) 39 /* Restore user bits of psw from sc, maintain system bits from proc. */ 40 sc.sc_eflags = (sc.sc_eflags & X86_FLAGS_USER) | 41 (rp->p_reg.psw & ~X86_FLAGS_USER); 42 #endif 43 44 #if defined(__i386__) 45 /* Write back registers we allow to be restored, i.e. 46 * not the segment ones. 47 */ 48 rp->p_reg.di = sc.sc_edi; 49 rp->p_reg.si = sc.sc_esi; 50 rp->p_reg.fp = sc.sc_ebp; 51 rp->p_reg.bx = sc.sc_ebx; 52 rp->p_reg.dx = sc.sc_edx; 53 rp->p_reg.cx = sc.sc_ecx; 54 rp->p_reg.retreg = sc.sc_eax; 55 rp->p_reg.pc = sc.sc_eip; 56 rp->p_reg.psw = sc.sc_eflags; 57 rp->p_reg.sp = sc.sc_esp; 58 #endif 59 60 #if defined(__arm__) 61 rp->p_reg.psr = sc.sc_spsr; 62 rp->p_reg.retreg = sc.sc_r0; 63 rp->p_reg.r1 = sc.sc_r1; 64 rp->p_reg.r2 = sc.sc_r2; 65 rp->p_reg.r3 = sc.sc_r3; 66 rp->p_reg.r4 = sc.sc_r4; 67 rp->p_reg.r5 = sc.sc_r5; 68 rp->p_reg.r6 = sc.sc_r6; 69 rp->p_reg.r7 = sc.sc_r7; 70 rp->p_reg.r8 = sc.sc_r8; 71 rp->p_reg.r9 = sc.sc_r9; 72 rp->p_reg.r10 = sc.sc_r10; 73 rp->p_reg.fp = sc.sc_r11; 74 rp->p_reg.r12 = sc.sc_r12; 75 rp->p_reg.sp = sc.sc_usr_sp; 76 rp->p_reg.lr = sc.sc_usr_lr; 77 rp->p_reg.pc = sc.sc_pc; 78 #endif 79 80 /* Restore the registers. */ 81 arch_proc_setcontext(rp, &rp->p_reg, 1, sc.trap_style); 82 83 if(sc.sc_magic != SC_MAGIC) { printf("kernel sigreturn: corrupt signal context\n"); } 84 85 #if defined(__i386__) 86 if (sc.sc_flags & MF_FPU_INITIALIZED) 87 { 88 memcpy(rp->p_seg.fpu_state, &sc.sc_fpu_state, FPU_XFP_SIZE); 89 rp->p_misc_flags |= MF_FPU_INITIALIZED; /* Restore math usage flag. */ 90 /* force reloading FPU */ 91 release_fpu(rp); 92 } 93 #endif 94 95 return OK; 96 } 97 #endif /* USE_SIGRETURN */ 98 99