PERFORCE change 228886 for review

[Philip Withnall]

http://p4web.freebsd.org/@@228886?ac=10

Change 228886 by prw35 at pwithnall_zenith on 2013/05/20 23:18:42

	Add copyincap() and copyoutcap() system support functions
	
	These function like the copyin() and copyout() functions, except copy
	capabilities. Their implementation is simple at the moment, performing
	few security checks, and only copying a single capability (i.e. the
	length argument is ignored).
	
	Some supporting register/instruction macros have been added to asm.h.

Affected files ...

.. //depot/projects/ctsrd/cheribsd/src/sys/mips/include/asm.h#4 edit
.. //depot/projects/ctsrd/cheribsd/src/sys/mips/mips/support.S#5 edit
.. //depot/projects/ctsrd/cheribsd/src/sys/sys/systm.h#6 edit

Differences ...

==== //depot/projects/ctsrd/cheribsd/src/sys/mips/include/asm.h#4 (text+ko) ====

@@ -370,37 +370,61 @@
  */
 #if _BYTE_ORDER == _LITTLE_ENDIAN
 # define LWHI lwr
+# define CLWHI clwr
 # define LWLO lwl
+# define CLWLO clwl
 # define SWHI swr
+# define CSWHI cswr
 # define SWLO swl
+# define CSWLO cswl
 # if SZREG == 4
 #  define REG_LHI   lwr
+#  define REG_CLHI  clwr
 #  define REG_LLO   lwl
+#  define REG_CLLO  clwl
 #  define REG_SHI   swr
+#  define REG_CSHI  cswr
 #  define REG_SLO   swl
+#  define REG_CSLO  cswl
 # else
 #  define REG_LHI   ldr
+#  define REG_CLHI  cldr
 #  define REG_LLO   ldl
+#  define REG_CLLO  cldl
 #  define REG_SHI   sdr
+#  define REG_CSHI  csdr
 #  define REG_SLO   sdl
+#  define REG_CSLO  csdl
 # endif
 #endif
 
 #if _BYTE_ORDER == _BIG_ENDIAN
 # define LWHI lwl
+# define CLWHI clwl
 # define LWLO lwr
+# define CLWLO clwr
 # define SWHI swl
+# define CSWHI cswl
 # define SWLO swr
+# define CSWLO cswr
 # if SZREG == 4
 #  define REG_LHI   lwl
+#  define REG_CLHI  clwl
 #  define REG_LLO   lwr
+#  define REG_CLLO  clwr
 #  define REG_SHI   swl
+#  define REG_CSHI  cswl
 #  define REG_SLO   swr
+#  define REG_CSLO  cswr
 # else
 #  define REG_LHI   ldl
+#  define REG_CLHI  cldl
 #  define REG_LLO   ldr
+#  define REG_CLLO  cldr
 #  define REG_SHI   sdl
+#  define REG_CSHI  csdl
 #  define REG_SLO   sdr
+#  define REG_CSLO  csdr
 # endif
 #endif
 

==== //depot/projects/ctsrd/cheribsd/src/sys/mips/mips/support.S#5 (text+ko) ====

@@ -93,9 +93,13 @@
 #include <machine/regnum.h>
 #include <machine/cpuregs.h>
 #include <machine/pcb.h>
+#include <machine/cherireg.h>
 
 #include "assym.s"
 
+/* Build the kernel data capability (KDC) register identifier. */
+#define KDC $c30
+
 	.set	noreorder		# Noreorder is default style!
 
 /*
@@ -248,6 +252,35 @@
 END(copyin)
 
 /*
+ * Copy specified amount of data from user space into the kernel, preserving
+ * capability tags
+ *	copyincap(from, to, len)
+ *	          caddr_t *from;	(user source address)
+ *	          caddr_t *to;		(kernel destination address)
+ *	          unsigned len;
+ */
+NON_LEAF(copyincap, CALLFRAME_SIZ, ra)
+	PTR_SUBU	sp, sp, CALLFRAME_SIZ
+	.mask	0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ)
+	PTR_LA	v0, copyerr
+	blt	a0, zero, _C_LABEL(copyerr)  # make sure address is in user space
+	REG_S	ra, CALLFRAME_RA(sp)
+	GET_CPU_PCPU(v1)
+	PTR_L	v1, PC_CURPCB(v1)
+	# TODO: Implement a loop, perform more checking, etc.
+	clc	$c1, a0, 0(KDC)			# load the source
+	csc	$c1, a1, 0(KDC)			# store to the destination
+	PTR_S	v0, U_PCB_ONFAULT(v1)
+	REG_L	ra, CALLFRAME_RA(sp)
+	GET_CPU_PCPU(v1)
+	PTR_L	v1, PC_CURPCB(v1)	 	# bcopycap modified v1, so reload
+	PTR_S	zero, U_PCB_ONFAULT(v1)
+	PTR_ADDU	sp, sp, CALLFRAME_SIZ
+	j	ra
+	move	v0, zero
+END(copyincap)
+
+/*
  * Copy specified amount of data from kernel to the user space
  *	copyout(from, to, len)
  *		caddr_t *from;	(kernel source address)
@@ -273,6 +306,35 @@
 	move	v0, zero
 END(copyout)
 
+/*
+ * Copy specified amount of data from kernel to the user space, preserving
+ * capability tags
+ *	copyoutcap(from, to, len)
+ *		   caddr_t *from;	(kernel source address)
+ *		   caddr_t *to;		(user destination address)
+ *		   unsigned len;
+ */
+NON_LEAF(copyoutcap, CALLFRAME_SIZ, ra)
+	PTR_SUBU	sp, sp, CALLFRAME_SIZ
+	.mask	0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ)
+	PTR_LA	v0, copyerr
+	blt	a1, zero, _C_LABEL(copyerr) # make sure address is in user space
+	REG_S	ra, CALLFRAME_RA(sp)
+	GET_CPU_PCPU(v1)
+	PTR_L	v1, PC_CURPCB(v1)
+	# TODO: Implement a loop, perform more checking, etc.
+	clc	$c1, a0, 0(KDC)			# load the source
+	csc	$c1, a1, 0(KDC)			# store to the destination
+	PTR_S	v0, U_PCB_ONFAULT(v1)
+	REG_L	ra, CALLFRAME_RA(sp)
+	GET_CPU_PCPU(v1)
+	PTR_L	v1, PC_CURPCB(v1)	 	# bcopycap modified v1, so reload
+	PTR_S	zero, U_PCB_ONFAULT(v1)
+	PTR_ADDU	sp, sp, CALLFRAME_SIZ
+	j	ra
+	move	v0, zero
+END(copyoutcap)
+
 LEAF(copyerr)
 	REG_L	ra, CALLFRAME_RA(sp)
 	PTR_ADDU	sp, sp, CALLFRAME_SIZ

==== //depot/projects/ctsrd/cheribsd/src/sys/sys/systm.h#6 (text+ko) ====

@@ -234,10 +234,14 @@
 	    __nonnull(1) __nonnull(2);
 int	copyin(const void * __restrict udaddr, void * __restrict kaddr,
 	    size_t len) __nonnull(1) __nonnull(2);
+int	copyincap(const void * __restrict udaddr, void * __restrict kaddr,
+	    size_t len) __nonnull(1) __nonnull(2);
 int	copyin_nofault(const void * __restrict udaddr, void * __restrict kaddr,
 	    size_t len) __nonnull(1) __nonnull(2);
 int	copyout(const void * __restrict kaddr, void * __restrict udaddr,
 	    size_t len) __nonnull(1) __nonnull(2);
+int	copyoutcap(const void * __restrict kaddr, void * __restrict udaddr,
+	    size_t len) __nonnull(1) __nonnull(2);
 int	copyout_nofault(const void * __restrict kaddr, void * __restrict udaddr,
 	    size_t len) __nonnull(1) __nonnull(2);