Pull the tier-2 card one last time and break the get/setcontext and

sigreturn() ABI and the signal context on the stack.

Make the trapframe (and its shadows in the ucontext and sigframe etc)
8 bytes larger in order to preserve 16 byte stack alignment for the
following C code calls.  I could have done some padding after the
trapframe was saved, but some of the C code still expects an argument of
'struct trapframe'.  Anyway, this gives me a spare field that can be used
to store things like 'partial trapframe' status or something else in
the future.

The runtime impact is fairly small, *except* for threaded apps and things
that decode contexts and the signal stack (eg: cvsup binary).  Signal
delivery isn't too badly affected because the kernel generates the
sigframe that sigreturn uses after the handler has been called.

The size of mcontext_t and struct sigframe hasn't changed.  Only
the last few fields (sc_eip etc) got moved a little and I eliminated
a spare field.  mc_len/sc_len did change location though so the
sanity checks there will still trap it.

5 files changed, 17 insertions, 5 deletions

diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
index 0a8cac2..03afd4e 100644
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -228,7 +228,7 @@ IDTVEC(fast_syscall)
 	movq	%rsp,PCPU(SCRATCH_RSP)
 	movq	common_tss+COMMON_TSS_RSP0,%rsp
 	/* Now emulate a trapframe. Make the 8 byte alignment odd for call. */
-	subq	$TF_SIZE+8,%rsp
+	subq	$TF_SIZE,%rsp
 	/* defer TF_RSP till we have a spare register */
 	movq	%r11,TF_RFLAGS(%rsp)
 	movq	%rcx,TF_RIP(%rsp)	/* %rcx original value is in %r10 */
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 024a9d5..612a692 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -258,6 +258,9 @@ trap(frame)
 		default:
 			ucode = code + BUS_SEGM_FAULT ;
 			i = SIGBUS;
+printf("trap %d: pid %d err %p eva %p, rip %p, rax %p, rbx %p, rcx %p, rdx %p, rsp %p, rbp %p, rsi %p, rdi %p\n", type, p->p_pid, (void *)frame.tf_err,
+(void *)frame.tf_addr, (void *)frame.tf_rip, (void *)frame.tf_rax, (void *)frame.tf_rbx, (void *)frame.tf_rcx, (void *)frame.tf_rdx, (void *)frame.tf_rsp, (void *)frame.tf_rbp, (void *)frame.tf_rsi, (void *)frame.tf_rdi);
+
 			break;
 
 		case T_PAGEFLT:		/* page fault */
@@ -542,6 +545,12 @@ nogo:
 		return (-1);
 	}
 
+printf("trap_pfault: pid %d %s %s %s eva %p, rip %p, rax %p, rbx %p, rcx %p, rdx %p, rsp %p, rbp %p, rsi %p, rdi %p\n", p->p_pid,
+			frame->tf_err & PGEX_U ? "user" : "supervisor",
+			frame->tf_err & PGEX_W ? "write" : "read",
+			frame->tf_err & PGEX_P ? "protection violation" : "page not present",
+(void *)eva, (void *)frame->tf_rip, (void *)frame->tf_rax, (void *)frame->tf_rbx, (void *)frame->tf_rcx, (void *)frame->tf_rdx, (void *)frame->tf_rsp, (void *)frame->tf_rbp, (void *)frame->tf_rsi, (void *)frame->tf_rdi);
+
 	return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
 }
 
diff --git a/sys/amd64/include/frame.h b/sys/amd64/include/frame.h
index 09321e7..e6cbe85 100644
--- a/sys/amd64/include/frame.h
+++ b/sys/amd64/include/frame.h
@@ -69,6 +69,7 @@ struct trapframe {
 	register_t	tf_r15;
 	register_t	tf_trapno;
 	register_t	tf_addr;
+	register_t	tf_flags;
 	/* below portion defined in hardware */
 	register_t	tf_err;
 	register_t	tf_rip;
@@ -98,6 +99,7 @@ struct intrframe {
 	register_t	if_r15;
 	register_t	:64;		/* compat with trap frame - trapno */
 	register_t	:64;		/* compat with trap frame - addr */
+	register_t	:64;		/* compat with trap frame - flags */
 	register_t	:64;		/* compat with trap frame - err */
 	/* below portion defined in hardware */
 	register_t	if_rip;
@@ -127,6 +129,7 @@ struct clockframe {
 	register_t	cf_r15;
 	register_t	:64;		/* compat with trap frame - trapno */
 	register_t	:64;		/* compat with trap frame - addr */
+	register_t	:64;		/* compat with trap frame - flags */
 	register_t	:64;		/* compat with trap frame - err */
 	/* below portion defined in hardware */
 	register_t	cf_rip;
diff --git a/sys/amd64/include/signal.h b/sys/amd64/include/signal.h
index 46b35ab..9aad84a 100644
--- a/sys/amd64/include/signal.h
+++ b/sys/amd64/include/signal.h
@@ -91,6 +91,7 @@ struct sigcontext {
 	long	sc_r15;
 	long	sc_trapno;
 	long	sc_addr;
+	long	sc_flags;
 	long	sc_err;
 	long	sc_rip;
 	long	sc_cs;
@@ -104,9 +105,8 @@ struct sigcontext {
 	 */
 	long	sc_fpformat;
 	long	sc_ownedfp;
-	long	sc_spare1[1];
 	long	sc_fpstate[64] __aligned(16);
-	long	sc_spare2[8];
+	long	sc_spare[8];
 };
 #endif /* __BSD_VISIBLE */
 
diff --git a/sys/amd64/include/ucontext.h b/sys/amd64/include/ucontext.h
index 7e68dc1..ca2044c 100644
--- a/sys/amd64/include/ucontext.h
+++ b/sys/amd64/include/ucontext.h
@@ -55,6 +55,7 @@ typedef struct __mcontext {
 	__register_t	mc_r15;
 	__register_t	mc_trapno;
 	__register_t	mc_addr;
+	__register_t	mc_flags;
 	__register_t	mc_err;
 	__register_t	mc_rip;
 	__register_t	mc_cs;
@@ -70,12 +71,11 @@ typedef struct __mcontext {
 #define	_MC_FPOWNED_FPU		0x20001	/* FP state came from FPU */
 #define	_MC_FPOWNED_PCB		0x20002	/* FP state came from PCB */
 	long	mc_ownedfp;
-	long	mc_spare1[1];		/* align mc_fpstate to 16 bytes */
 	/*
 	 * See <machine/npx.h> for the internals of mc_fpstate[].
 	 */
 	long	mc_fpstate[64] __aligned(16);
-	long	mc_spare2[8];
+	long	mc_spare[8];
 } mcontext_t;
 
 #endif /* !_MACHINE_UCONTEXT_H_ */