ipc/shm: some shmat cleanups
Clean up early flag and address some minutia.
Link: http://lkml.kernel.org/r/1486673582-6979-3-git-send-email-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/shm.c b/ipc/shm.c
index 481d2a9..34c4344 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1095,11 +1095,11 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
ulong *raddr, unsigned long shmlba)
{
struct shmid_kernel *shp;
- unsigned long addr;
+ unsigned long addr = (unsigned long)shmaddr;
unsigned long size;
struct file *file;
int err;
- unsigned long flags;
+ unsigned long flags = MAP_SHARED;
unsigned long prot;
int acc_mode;
struct ipc_namespace *ns;
@@ -1111,7 +1111,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
err = -EINVAL;
if (shmid < 0)
goto out;
- else if ((addr = (ulong)shmaddr)) {
+
+ if (addr) {
if (addr & (shmlba - 1)) {
/*
* Round down to the nearest multiple of shmlba.
@@ -1126,13 +1127,10 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
#endif
goto out;
}
- flags = MAP_SHARED | MAP_FIXED;
- } else {
- if ((shmflg & SHM_REMAP))
- goto out;
- flags = MAP_SHARED;
- }
+ flags |= MAP_FIXED;
+ } else if ((shmflg & SHM_REMAP))
+ goto out;
if (shmflg & SHM_RDONLY) {
prot = PROT_READ;