[src/trunk]: src/sys/arch/usermode/usermode Replace the dynamically allocated...

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

details:   https://anonhg.NetBSD.org/src/rev/712e77bedbf3
branches:  trunk
changeset: 322802:712e77bedbf3
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Fri May 18 20:24:16 2018 +0000

description:
Replace the dynamically allocated signal stack to a static claimed one and add
diagnostic messages that can be enabled.

diffstat:

 sys/arch/usermode/usermode/trap.c |  34 +++++++++++++++++++++-------------
 1 files changed, 21 insertions(+), 13 deletions(-)

diffs (100 lines):

diff -r 2aa7028406a2 -r 712e77bedbf3 sys/arch/usermode/usermode/trap.c
--- a/sys/arch/usermode/usermode/trap.c Fri May 18 20:21:14 2018 +0000
+++ b/sys/arch/usermode/usermode/trap.c Fri May 18 20:24:16 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.66 2012/08/04 14:53:32 reinoud Exp $ */
+/* $NetBSD: trap.c,v 1.67 2018/05/18 20:24:16 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%netbsd.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.66 2012/08/04 14:53:32 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.67 2018/05/18 20:24:16 reinoud Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -62,6 +62,7 @@
 static sigfunc_t pass_on;
 
 /* raw signal handlers */
+static char    sig_stack[SIGSTKSZ];
 static stack_t sigstk;
 ucontext_t jump_ucp;
 
@@ -108,8 +109,7 @@
         * effects. Especially ld.so and friends have such tiny stacks that
         * its not feasable.
         */
-       if ((sigstk.ss_sp = thunk_malloc(SIGSTKSZ)) == NULL)
-               panic("can't allocate signal stack space\n");
+       sigstk.ss_sp    = sig_stack;
        sigstk.ss_size  = SIGSTKSZ;
        sigstk.ss_flags = 0;
        if (thunk_sigaltstack(&sigstk, 0) < 0)
@@ -293,8 +293,8 @@
 #endif
 }
 #else /* DEBUG */
-#define print_mem_access_siginfo(s, i, c, p, v, sp)
-#define print_illegal_instruction_siginfo(s, i, c, p, v, sp)
+#define print_mem_access_siginfo(s, i, c, p, v, sp) {}
+#define print_illegal_instruction_siginfo(s, i, c, p, v, sp) {}
 #endif /* DEBUG */
 
 
@@ -349,7 +349,7 @@
                sp = fp - sizeof(register_t);   /* slack */
 
                /* sanity check before copying */
-               if (fp - 2*PAGE_SIZE < (vaddr_t) pcb->sys_stack)
+               if (fp - 4*PAGE_SIZE < (vaddr_t) pcb->sys_stack)
                        panic("%s: out of system stack", __func__);
        }
 
@@ -431,6 +431,11 @@
        }
 
        /* ask UVM */
+#if 0
+thunk_printf("%s: l %p, pcb %p, ", __func__, l, pcb);
+thunk_printf("pc %p, va %p ", (void *) pc, (void *) va);
+thunk_printf("derived atype %d\n", atype);
+#endif
        thunk_printf_debug("pmap fault couldn't handle it! : "
                "derived atype %d\n", atype);
 
@@ -452,10 +457,6 @@
                goto out;
        }
 
-       /* something got wrong */
-       thunk_printf("%s: uvm fault %d, pc %p, va %p, from_kernel %d\n",
-               __func__, error, (void *) pc, (void *) va, from_kernel);
-
        /* check if its from copyin/copyout */
        if (onfault) {
                panic("%s: can't call onfault yet\n", __func__);
@@ -468,11 +469,18 @@
                goto out;
        }
 
-       if (from_kernel)
+       if (from_kernel) {
+               thunk_printf("%s: uvm fault %d, pc %p, va %p, from_kernel %d\n",
+                       __func__, error, (void *) pc, (void *) va, from_kernel);
                panic("Unhandled page fault in kernel mode");
+       }
 
        /* send signal */
-       thunk_printf("giving signal to userland\n");
+       /* something got wrong */
+       thunk_printf_debug("%s: uvm fault %d, pc %p, va %p, from_kernel %d\n",
+               __func__, error, (void *) pc, (void *) va, from_kernel);
+
+       thunk_printf_debug("giving signal to userland\n");
 
        KASSERT(from_userland);
        KSI_INIT_TRAP(&ksi);