From 23f919d4ad0eb325595f10f55be4301b2965d6d6 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 12 Dec 2016 16:42:28 -0800 Subject: [PATCH] shmem: avoid maybe-uninitialized warning After enabling -Wmaybe-uninitialized warnings, we get a false-postive warning for shmem: mm/shmem.c: In function `shmem_getpage_gfp': include/linux/spinlock.h:332:21: error: `info' may be used uninitialized in this function [-Werror=maybe-uninitialized] This can be easily avoided, since the correct 'info' pointer is known at the time we first enter the function, so we can simply move the initialization up. Moving it before the first label avoids the warning and lets us remove two later initializations. Note that the function is so hard to read that it not only confuses the compiler, but also most readers and without this patch it could\ easily break if one of the 'goto's changed. Link: https://www.spinics.net/lists/kernel/msg2368133.html Link: http://lkml.kernel.org/r/20161024205725.786455-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Acked-by: Michal Hocko Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Cc: Hugh Dickins Cc: Andreas Gruenbacher Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 9d32e1cb9f38..ba0d7644ee20 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1539,7 +1539,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, struct mm_struct *fault_mm, int *fault_type) { struct address_space *mapping = inode->i_mapping; - struct shmem_inode_info *info; + struct shmem_inode_info *info = SHMEM_I(inode); struct shmem_sb_info *sbinfo; struct mm_struct *charge_mm; struct mem_cgroup *memcg; @@ -1589,7 +1589,6 @@ repeat: * Fast cache lookup did not find it: * bring it back from swap or allocate. */ - info = SHMEM_I(inode); sbinfo = SHMEM_SB(inode->i_sb); charge_mm = fault_mm ? : current->mm; @@ -1837,7 +1836,6 @@ unlock: put_page(page); } if (error == -ENOSPC && !once++) { - info = SHMEM_I(inode); spin_lock_irq(&info->lock); shmem_recalc_inode(inode); spin_unlock_irq(&info->lock); -- 2.20.1