copying complete PSW after signal handler. This fixes a psw corruption bug reported by Jens de Smit <jst260@few.vu.nl>.
		
			
				
	
	
		
			67 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* The kernel call that is implemented in this file:
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 *   m_type:	SYS_SIGRETURN
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 *
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 * The parameters for this kernel call are:
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 *     m2_i1:	SIG_ENDPT  	# process returning from handler
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 *     m2_p1:	SIG_CTXT_PTR 	# pointer to sigcontext structure
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 *
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 */
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#include "../system.h"
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#include <string.h>
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#include <signal.h>
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#include <ibm/cpu.h>
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#include <sys/sigcontext.h>
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#if USE_SIGRETURN 
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/*===========================================================================*
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 *			      do_sigreturn				     *
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 *===========================================================================*/
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PUBLIC int do_sigreturn(m_ptr)
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message *m_ptr;			/* pointer to request message */
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{
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/* POSIX style signals require sys_sigreturn to put things in order before 
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 * the signalled process can resume execution
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 */
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  struct sigcontext sc;
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  register struct proc *rp;
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  phys_bytes src_phys;
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  int proc;
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  if (! isokendpt(m_ptr->SIG_ENDPT, &proc)) return(EINVAL);
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  if (iskerneln(proc)) return(EPERM);
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  rp = proc_addr(proc);
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  /* Copy in the sigcontext structure. */
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  src_phys = umap_local(rp, D, (vir_bytes) m_ptr->SIG_CTXT_PTR,
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      (vir_bytes) sizeof(struct sigcontext));
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  if (src_phys == 0) return(EFAULT);
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  phys_copy(src_phys, vir2phys(&sc), (phys_bytes) sizeof(struct sigcontext));
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  /* Restore user bits of psw from sc, maintain system bits from proc. */
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  sc.sc_psw  =  (sc.sc_psw & X86_FLAGS_USER) |
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                (rp->p_reg.psw & ~X86_FLAGS_USER);
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#if (_MINIX_CHIP == _CHIP_INTEL)
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  /* Don't panic kernel if user gave bad selectors. */
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  sc.sc_cs = rp->p_reg.cs;
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  sc.sc_ds = rp->p_reg.ds;
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  sc.sc_es = rp->p_reg.es;
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#if _WORD_SIZE == 4
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  sc.sc_fs = rp->p_reg.fs;
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  sc.sc_gs = rp->p_reg.gs;
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#endif
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#endif
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  /* Restore the registers. */
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#if _MINIX_CHIP == _CHIP_POWERPC
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  memcpy(&rp->p_reg, &sc.sc_regs, sizeof(struct stackframe_s));
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#else
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  memcpy(&rp->p_reg, &sc.sc_regs, sizeof(struct sigregs));
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#endif
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  return(OK);
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}
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#endif /* USE_SIGRETURN */
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