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authorHelge Deller <deller@gmx.de>2013-06-29 14:03:14 +0200
committerHelge Deller <deller@gmx.de>2013-11-07 22:29:14 +0100
commit63379c135331c724d40a87b98eb62d2122981341 (patch)
tree35ef859d3afae3d73c0cb92c1dbd7cb79227deb3 /arch/parisc/include/asm/uaccess.h
parentparisc: correctly display number of active CPUs (diff)
downloadlinux-dev-63379c135331c724d40a87b98eb62d2122981341.tar.xz
linux-dev-63379c135331c724d40a87b98eb62d2122981341.zip
parisc: implement full version of access_ok()
Up to now PA-RISC could live with a trivial version of access_ok(). Our fault handlers can correctly handle fault cases. But testcases showed that we need a better access check else we won't always return correct errno failure codes to userspace. Problem showed up during 32bit userspace tests in which writev() used a 32bit memory area and length which would then wrap around on 64bit kernel. Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to '')
-rw-r--r--arch/parisc/include/asm/uaccess.h46
1 files changed, 42 insertions, 4 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 4006964d8e12..63f4dd0b49c2 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -4,11 +4,14 @@
/*
* User space memory access functions
*/
+#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm-generic/uaccess-unaligned.h>
+#include <linux/sched.h>
+
#define VERIFY_READ 0
#define VERIFY_WRITE 1
@@ -33,12 +36,43 @@ extern int __get_user_bad(void);
extern int __put_kernel_bad(void);
extern int __put_user_bad(void);
-static inline long access_ok(int type, const void __user * addr,
- unsigned long size)
+
+/*
+ * Test whether a block of memory is a valid user space address.
+ * Returns 0 if the range is valid, nonzero otherwise.
+ */
+static inline int __range_not_ok(unsigned long addr, unsigned long size,
+ unsigned long limit)
{
- return 1;
+ unsigned long __newaddr = addr + size;
+ return (__newaddr < addr || __newaddr > limit || size > limit);
}
+/**
+ * access_ok: - Checks if a user space pointer is valid
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
+ * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
+ * to write to a block, it is always safe to read from it.
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only. This function may sleep.
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
+ *
+ * Note that, depending on architecture, this function probably just
+ * checks that the pointer is in the user space range - after calling
+ * this function, memory access functions may still return -EFAULT.
+ */
+#define access_ok(type, addr, size) \
+( __chk_user_ptr(addr), \
+ !__range_not_ok((unsigned long) (__force void *) (addr), \
+ size, user_addr_max()) \
+)
+
#define put_user __put_user
#define get_user __get_user
@@ -219,7 +253,11 @@ extern long lstrnlen_user(const char __user *,long);
/*
* Complex access routines -- macros
*/
-#define user_addr_max() (~0UL)
+#ifdef CONFIG_COMPAT
+#define user_addr_max() (TASK_SIZE)
+#else
+#define user_addr_max() (DEFAULT_TASK_SIZE)
+#endif
#define strnlen_user lstrnlen_user
#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)