[src/trunk]: src/sys/arch/usermode/usermode Make signals work for NetBSD/user...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7bb5ecb38140
branches:  trunk
changeset: 772210:7bb5ecb38140
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Sat Dec 24 12:26:58 2011 +0000

description:
Make signals work for NetBSD/usermode[i386] !

diffstat:

 sys/arch/usermode/usermode/machdep.c |  131 +++++++++++++++++++++++++++++-----
 1 files changed, 112 insertions(+), 19 deletions(-)

diffs (170 lines):

diff -r 20d3545d8090 -r 7bb5ecb38140 sys/arch/usermode/usermode/machdep.c
--- a/sys/arch/usermode/usermode/machdep.c      Sat Dec 24 12:23:24 2011 +0000
+++ b/sys/arch/usermode/usermode/machdep.c      Sat Dec 24 12:26:58 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: machdep.c,v 1.41 2011/12/20 22:48:59 jmcneill Exp $ */
+/* $NetBSD: machdep.c,v 1.42 2011/12/24 12:26:58 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%netbsd.org@localhost>
@@ -27,11 +27,18 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+/*
+ * Note that this machdep.c uses the `dummy' mcontext_t defined for usermode.
+ * This is basicly a blob of PAGE_SIZE big. We might want to switch over to
+ * non-generic mcontext_t's one day, but will this break non-NetBSD hosts?
+ */
+
+
 #include "opt_memsize.h"
 #include "opt_sdl.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.41 2011/12/20 22:48:59 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.42 2011/12/24 12:26:58 reinoud Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -141,22 +148,6 @@
        printf("NetBSD/usermode startup\n");
 }
 
-void
-sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
-{
-#if 1
-       printf("%s: ", __func__);
-       printf("flags %d, ", (int) ksi->ksi_flags);
-       printf("to lwp %d, signo %d, code %d, errno %d\n",
-               (int) ksi->ksi_lid,
-               ksi->ksi_signo,
-               ksi->ksi_code,
-               ksi->ksi_errno);
-#endif
-
-       panic("%s not implemented", __func__);
-}
-
 int
 mm_md_physacc(paddr_t pa, vm_prot_t prog)
 {
@@ -184,6 +175,108 @@
 }
 #endif
 
+
+/* from sys/arch/i386/include/frame.h : KEEP IN SYNC */
+
+/*
+ * New-style signal frame
+ */
+struct sigframe_siginfo {
+       int             sf_ra;          /* return address for handler */
+       int             sf_signum;      /* "signum" argument for handler */
+       siginfo_t       *sf_sip;        /* "sip" argument for handler */
+       ucontext_t      *sf_ucp;        /* "ucp" argument for handler */
+       siginfo_t       sf_si;          /* actual saved siginfo */
+       ucontext_t      sf_uc;          /* actual saved ucontext */
+};
+
+
+/*
+ * mcontext extensions to handle signal delivery.
+ */
+#define _UC_SETSTACK   0x00010000
+#define _UC_CLRSTACK   0x00020000
+#define _UC_VM         0x00040000
+#define        _UC_TLSBASE     0x00080000
+
+
+void
+sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
+{
+       struct lwp *l = curlwp;
+       struct proc *p = l->l_proc;
+       struct pcb *pcb = lwp_getpcb(l);
+       struct sigacts *ps = p->p_sigacts;
+       struct sigframe_siginfo *fp, frame;
+       int sig = ksi->ksi_signo;
+       sig_t catcher = SIGACTION(p, sig).sa_handler;
+       ucontext_t *ucp = &pcb->pcb_userret_ucp;
+       register_t *reg = (register_t *) &ucp->uc_mcontext;
+       int onstack, error;
+
+       KASSERT(mutex_owned(p->p_lock));
+
+#if 0
+       printf("%s: ", __func__);
+       printf("flags %d, ", (int) ksi->ksi_flags);
+       printf("to lwp %d, signo %d, code %d, errno %d\n",
+               (int) ksi->ksi_lid,
+               ksi->ksi_signo,
+               ksi->ksi_code,
+               ksi->ksi_errno);
+#endif
+
+       /* do we need to jump onto the signal stack? */
+       onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0
+           && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
+
+       fp = (void *) reg[17];  /* ESP */
+       if (onstack)
+               fp = (void *)
+                       ((char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
+
+       fp--;
+
+       /* set up stack frame */
+       frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp;
+       frame.sf_signum = sig;
+       frame.sf_sip = &fp->sf_si;
+       frame.sf_ucp = &fp->sf_uc;
+       frame.sf_si._info = ksi->ksi_info;
+
+       /* copy our userret context into sf_uc */
+       memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t));
+       frame.sf_uc.uc_sigmask = *mask;
+       frame.sf_uc.uc_link = l->l_ctxlink; /* XXX ??? */
+       frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK)
+           ? _UC_SETSTACK : _UC_CLRSTACK;
+       memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack));
+
+       sendsig_reset(l, sig);
+
+       /* copyout our frame to the stackframe */
+       mutex_exit(p->p_lock);
+       error = copyout(&frame, fp, sizeof(frame));
+       mutex_enter(p->p_lock);
+
+       if (error != 0) {
+               /*
+                * Process has trashed its stack; give it an illegal
+                * instruction to halt it in its tracks.
+                */
+               sigexit(l, SIGILL);
+               /* NOTREACHED */
+       }
+
+       /* set catcher and the new stack pointer */
+       reg[17] = (register_t) fp;      /* ESP */
+       reg[14] = (register_t) catcher; /* EIP */
+
+       /* Remember that we're now on the signal stack. */
+       if (onstack)
+               l->l_sigstk.ss_flags |= SS_ONSTACK;
+}
+
 void
 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack)
 {
@@ -298,7 +391,7 @@
 {
        register_t *reg = (register_t *) &ucp->uc_mcontext;
 //     uint8_t  *p8  = (uint8_t *) (reg[14]);
-       uint16_t *p16 = (uint16_t*) (reg[14]);
+       uint16_t *p16 = (uint16_t*) (reg[14]);  /* EIP */
 
        switch (*p16) {
        case 0xff0f:    /* UD1      */