6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sumanth Korikkar sumanthk@linux.ibm.com
commit 1f737846aa3c45f07a06fa0d018b39e1afb8084a upstream.
In order to minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y), compiler might choose to make a regular function call (out-of-line) for shmem_is_huge() instead of inlining it. When transparent hugepages are disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation error.
mm/shmem.c: In function `shmem_getattr': ./include/linux/huge_mm.h:383:27: note: in expansion of macro `BUILD_BUG' 383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; }) | ^~~~~~~~~ mm/shmem.c:1148:33: note: in expansion of macro `HPAGE_PMD_SIZE' 1148 | stat->blksize = HPAGE_PMD_SIZE;
To prevent the possible error, always inline shmem_is_huge() when transparent hugepages are disabled.
Link: https://lkml.kernel.org/r/20240409155407.2322714-1-sumanthk@linux.ibm.com Signed-off-by: Sumanth Korikkar sumanthk@linux.ibm.com Acked-by: David Hildenbrand david@redhat.com Cc: Alexander Gordeev agordeev@linux.ibm.com Cc: Heiko Carstens hca@linux.ibm.com Cc: Hugh Dickins hughd@google.com Cc: Ilya Leoshkevich iii@linux.ibm.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/shmem_fs.h | 9 +++++++++ mm/shmem.c | 6 ------ 2 files changed, 9 insertions(+), 6 deletions(-)
--- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -110,8 +110,17 @@ extern struct page *shmem_read_mapping_p extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); int shmem_unuse(unsigned int type);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, struct mm_struct *mm, unsigned long vm_flags); +#else +static __always_inline bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, + struct mm_struct *mm, unsigned long vm_flags) +{ + return false; +} +#endif + #ifdef CONFIG_SHMEM extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); #else --- a/mm/shmem.c +++ b/mm/shmem.c @@ -742,12 +742,6 @@ static long shmem_unused_huge_count(stru
#define shmem_huge SHMEM_HUGE_DENY
-bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, - struct mm_struct *mm, unsigned long vm_flags) -{ - return false; -} - static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, struct shrink_control *sc, unsigned long nr_to_split) {