| 1 | /* The kernel call that is implemented in this file:
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| 2 | * m_type: SYS_SIGRETURN
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| 3 | *
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| 4 | * The parameters for this kernel call are:
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| 5 | * m2_i1: SIG_PROC # process returning from handler
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| 6 | * m2_p1: SIG_CTXT_PTR # pointer to sigcontext structure
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| 7 | *
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| 8 | */
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| 9 |
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| 10 | #include "../system.h"
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| 11 | #include <string.h>
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| 12 | #include <signal.h>
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| 13 | #include <sys/sigcontext.h>
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| 14 |
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| 15 | #if USE_SIGRETURN
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| 16 |
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| 17 | /*===========================================================================*
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| 18 | * do_sigreturn *
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| 19 | *===========================================================================*/
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| 20 | PUBLIC int do_sigreturn(m_ptr)
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| 21 | message *m_ptr; /* pointer to request message */
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| 22 | {
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| 23 | /* POSIX style signals require sys_sigreturn to put things in order before
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| 24 | * the signalled process can resume execution
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| 25 | */
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| 26 | struct sigcontext sc;
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| 27 | register struct proc *rp;
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| 28 | phys_bytes src_phys;
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| 29 |
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| 30 | if (! isokprocn(m_ptr->SIG_PROC)) return(EINVAL);
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| 31 | if (iskerneln(m_ptr->SIG_PROC)) return(EPERM);
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| 32 | rp = proc_addr(m_ptr->SIG_PROC);
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| 33 |
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| 34 | /* Copy in the sigcontext structure. */
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| 35 | src_phys = umap_local(rp, D, (vir_bytes) m_ptr->SIG_CTXT_PTR,
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| 36 | (vir_bytes) sizeof(struct sigcontext));
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| 37 | if (src_phys == 0) return(EFAULT);
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| 38 | phys_copy(src_phys, vir2phys(&sc), (phys_bytes) sizeof(struct sigcontext));
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| 39 |
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| 40 | /* Make sure that this is not just a jump buffer. */
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| 41 | if ((sc.sc_flags & SC_SIGCONTEXT) == 0) return(EINVAL);
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| 42 |
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| 43 | /* Fix up only certain key registers if the compiler doesn't use
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| 44 | * register variables within functions containing setjmp.
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| 45 | */
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| 46 | if (sc.sc_flags & SC_NOREGLOCALS) {
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| 47 | rp->p_reg.retreg = sc.sc_retreg;
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| 48 | rp->p_reg.fp = sc.sc_fp;
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| 49 | rp->p_reg.pc = sc.sc_pc;
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| 50 | rp->p_reg.sp = sc.sc_sp;
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| 51 | return(OK);
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| 52 | }
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| 53 | sc.sc_psw = rp->p_reg.psw;
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| 54 |
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| 55 | #if (CHIP == INTEL)
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| 56 | /* Don't panic kernel if user gave bad selectors. */
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| 57 | sc.sc_cs = rp->p_reg.cs;
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| 58 | sc.sc_ds = rp->p_reg.ds;
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| 59 | sc.sc_es = rp->p_reg.es;
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| 60 | #if _WORD_SIZE == 4
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| 61 | sc.sc_fs = rp->p_reg.fs;
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| 62 | sc.sc_gs = rp->p_reg.gs;
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| 63 | #endif
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| 64 | #endif
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| 65 |
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| 66 | /* Restore the registers. */
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| 67 | memcpy(&rp->p_reg, &sc.sc_regs, sizeof(struct sigregs));
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| 68 | return(OK);
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| 69 | }
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| 70 | #endif /* USE_SIGRETURN */
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| 71 |
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