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authorRusty Russell <rusty@rustcorp.com.au>2007-10-22 11:24:24 +1000
committerRusty Russell <rusty@rustcorp.com.au>2007-10-23 15:49:56 +1000
commit2d37f94a28170ca656438758fca577acb49a7932 (patch)
tree21049219a98d314a2c442293e512b74d879e6270 /drivers/lguest/lg.h
parent56ae43dfe233323683248a5c553bad7160db2fa5 (diff)
downloadop-kernel-dev-2d37f94a28170ca656438758fca577acb49a7932.zip
op-kernel-dev-2d37f94a28170ca656438758fca577acb49a7932.tar.gz
generalize lgread_u32/lgwrite_u32.
Jes complains that page table code still uses lgread_u32 even though it now uses general kernel pte types. The best thing to do is to generalize lgread_u32 and lgwrite_u32. This means we lose the efficiency of getuser(). We could potentially regain it if we used __copy_from_user instead of copy_from_user, but I'm not certain that our range check is equivalent to access_ok() on all platforms. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Jes Sorensen <jes@sgi.com>
Diffstat (limited to 'drivers/lguest/lg.h')
-rw-r--r--drivers/lguest/lg.h23
1 files changed, 19 insertions, 4 deletions
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 4d45b70..d9144be 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -98,12 +98,27 @@ struct lguest
extern struct mutex lguest_lock;
/* core.c: */
-u32 lgread_u32(struct lguest *lg, unsigned long addr);
-void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
-void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
-void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
int lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len);
+void __lgread(struct lguest *, void *, unsigned long, unsigned);
+void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
+
+/*L:306 Using memory-copy operations like that is usually inconvient, so we
+ * have the following helper macros which read and write a specific type (often
+ * an unsigned long).
+ *
+ * This reads into a variable of the given type then returns that. */
+#define lgread(lg, addr, type) \
+ ({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
+
+/* This checks that the variable is of the given type, then writes it out. */
+#define lgwrite(lg, addr, type, val) \
+ do { \
+ typecheck(type, val); \
+ __lgwrite((lg), (addr), &(val), sizeof(val)); \
+ } while(0)
+/* (end of memory access helper routines) :*/
+
int run_guest(struct lguest *lg, unsigned long __user *user);
/* Helper macros to obtain the first 12 or the last 20 bits, this is only the
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