AMD64 - Fix bogus signal interruption

* The TF_XFLAGS field in the trap frame was not getting cleared on trap and
  syscall entry.  This field can cause a mailbox signal to be flagged in
  the signal frame which in turn can cause the next blockable system call
  to return EINTR.

  This fixes the last issue with mount_mfs.

* Cast the signal function to intptr_t rather then int.

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index c8030e7..d5fc263 100644 (file)
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1677,8 +1677,8 @@ issignal(struct lwp *lp, int maytrace)
                 * Return the signal's number, or fall through
                 * to clear it from the pending mask.
                 */
-               switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
-               case (int)SIG_DFL:
+               switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
+               case (intptr_t)SIG_DFL:
                        /*
                         * Don't take default actions on system processes.
                         */
@@ -1731,7 +1731,7 @@ issignal(struct lwp *lp, int maytrace)
 
                        /*NOTREACHED*/
 
-               case (int)SIG_IGN:
+               case (intptr_t)SIG_IGN:
                        /*
                         * Masking above should prevent us ever trying
                         * to take action on an ignored signal other

diff --git a/sys/platform/pc64/amd64/exception.S b/sys/platform/pc64/amd64/exception.S
index a925abe..a0c8c93 100644 (file)
--- a/sys/platform/pc64/amd64/exception.S
+++ b/sys/platform/pc64/amd64/exception.S
@@ -128,6 +128,7 @@ IDTVEC(xmm)
        subq $TF_ERR,%rsp; \
        movq $(a),TF_TRAPNO(%rsp) ; \
        movq $0,TF_ADDR(%rsp) ; \
+       movq $0,TF_XFLAGS(%rsp) ; \
        jmp alltraps
 IDTVEC(tss)
        TRAP_ERR(T_TSSFLT)
@@ -200,6 +201,7 @@ IDTVEC(dblfault)
        movq    $T_DOUBLEFLT,TF_TRAPNO(%rsp)
        movq    $0,TF_ADDR(%rsp)
        movq    $0,TF_ERR(%rsp)
+       movq    $0,TF_XFLAGS(%rsp)
        movq    %rdi,TF_RDI(%rsp)
        movq    %rsi,TF_RSI(%rsp)
        movq    %rdx,TF_RDX(%rsp)
@@ -233,6 +235,7 @@ IDTVEC(page)
        movq    %rdi,TF_RDI(%rsp)       /* free up a GP register */
        movq    %cr2,%rdi               /* preserve %cr2 before ..  */
        movq    %rdi,TF_ADDR(%rsp)      /* enabling interrupts. */
+       movq    $0,TF_XFLAGS(%rsp)
        testq   $PSL_I,TF_RFLAGS(%rsp)
        jz      alltraps_pushregs_no_rdi
        sti
@@ -248,6 +251,7 @@ IDTVEC(prot)
        subq    $TF_ERR,%rsp
        movq    $T_PROTFLT,TF_TRAPNO(%rsp)
        movq    $0,TF_ADDR(%rsp)
+       movq    $0,TF_XFLAGS(%rsp)
        movq    %rdi,TF_RDI(%rsp)       /* free up a GP register */
        leaq    doreti_iret(%rip),%rdi
        cmpq    %rdi,TF_RIP(%rsp)
@@ -283,6 +287,7 @@ IDTVEC(fast_syscall)
        movq    $KUDSEL,TF_SS(%rsp)
        movq    $KUCSEL,TF_CS(%rsp)
        movq    $2,TF_ERR(%rsp)
+       movq    $0,TF_XFLAGS(%rsp)      /* note: used in signal frame */
        movq    %rdi,TF_RDI(%rsp)       /* arg 1 */
        movq    %rsi,TF_RSI(%rsp)       /* arg 2 */
        movq    %rdx,TF_RDX(%rsp)       /* arg 3 */
@@ -337,6 +342,7 @@ IDTVEC(nmi)
        movq    $(T_NMI),TF_TRAPNO(%rsp)
        movq    $0,TF_ADDR(%rsp)
        movq    $0,TF_ERR(%rsp)
+       movq    $0,TF_XFLAGS(%rsp)
        movq    %rdi,TF_RDI(%rsp)
        movq    %rsi,TF_RSI(%rsp)
        movq    %rdx,TF_RDX(%rsp)