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parisc: add strict copy size checks (v2) 

Add CONFIG_DEBUG_STRICT_USER_COPY_CHECKS, copied from the x86
implementation. Tested with 32 and 64bit kernel.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
This commit is contained in:
Helge Deller 2010-02-01 19:56:33 +00:00 committed by Kyle McMartin
parent a3bee03e71
commit 888c31fc83
3 changed files with 41 additions and 3 deletions
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14
arch/parisc/Kconfig.debug
View File

@ -12,4 +12,18 @@ config DEBUG_RODATA
portion of the kernel code won't be covered by a TLB anymore.
If in doubt, say "N".
config DEBUG_STRICT_USER_COPY_CHECKS
bool "Strict copy size checks"
depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
---help---
Enabling this option turns a certain set of sanity checks for user
copy operations into compile time failures.
The copy_from_user() etc checks are there to help test if there
are sufficient security checks on the length argument of
the copy operation, by having gcc prove that the argument is
within bounds.
If unsure, or if you run an older (pre 4.4) gcc, say N.
endmenu

27
arch/parisc/include/asm/uaccess.h
View File

@ -7,6 +7,7 @@
#include <asm/page.h>
#include <asm/system.h>
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm-generic/uaccess-unaligned.h>
#define VERIFY_READ 0
@ -234,13 +235,35 @@ extern long lstrnlen_user(const char __user *,long);
unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
#define __copy_to_user copy_to_user
unsigned long copy_from_user(void *dst, const void __user *src, unsigned long len);
#define __copy_from_user copy_from_user
unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
#define __copy_in_user copy_in_user
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
extern void copy_from_user_overflow(void)
#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
__compiletime_error("copy_from_user() buffer size is not provably correct")
#else
__compiletime_warning("copy_from_user() buffer size is not provably correct")
#endif
;
static inline unsigned long __must_check copy_from_user(void *to,
const void __user *from,
unsigned long n)
{
int sz = __compiletime_object_size(to);
int ret = -EFAULT;
if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
ret = __copy_from_user(to, from, n);
else
copy_from_user_overflow();
return ret;
}
struct pt_regs;
int fixup_exception(struct pt_regs *regs);

3
arch/parisc/lib/memcpy.c
View File

@ -475,7 +475,8 @@ unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len)
return pa_memcpy((void __force *)dst, src, len);
}
unsigned long copy_from_user(void *dst, const void __user *src, unsigned long len)
EXPORT_SYMBOL(__copy_from_user);
unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len)
{
mtsp(get_user_space(), 1);
mtsp(get_kernel_space(), 2);