From f0cb88026f51a0d8c952cf5e09e1933ef10b50b4 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Mon, 8 May 2017 15:57:03 -0700 Subject: [PATCH] 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 Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/shm.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/ipc/shm.c b/ipc/shm.c index 481d2a9c298a..34c4344e8d4b 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;