@@ -21,6 +21,7 @@
#include <linux/ptrace.h>
#include <linux/ratelimit.h>
#include <linux/syscalls.h>
+#include <linux/pagemap.h>
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
@@ -632,7 +633,6 @@ static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
struct ucontext __user *, new_ctx, long, ctx_size)
{
- unsigned char tmp;
sigset_t set;
unsigned long new_msr = 0;
int ctx_has_vsx_region = 0;
@@ -667,9 +667,8 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
}
if (new_ctx == NULL)
return 0;
- if (!access_ok(new_ctx, ctx_size)
- || __get_user(tmp, (u8 __user *) new_ctx)
- || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
+ if (!access_ok(new_ctx, ctx_size) ||
+ fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
return -EFAULT;
/*
Instead of doing a __get_user() from the first and last location into a tmp var which won't be used, use fault_in_pages_readable() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/signal_64.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)