| Message ID | 20220509123116.3169267-1-trix@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/shmem: initialize folio to NULL | expand |
On Mon, May 09, 2022 at 08:31:16AM -0400, Tom Rix wrote: > The clang build fails with > mm/shmem.c:1704:7: error: variable 'folio' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] > if (!page) { > ^~~~~ > The error handler for !page jumps to an if-check for an unset folio. > So initialize folio to NULL. I appreciate you're trying to help, but the fourth report of a problem adds more noise than utility. https://lore.kernel.org/linux-mm/?q=shmem+folio shows emails about this from the cgelbot, Dan Carpenter, SeongJae Park, Colin King, Nathan Chancellor and Sebastian Siewior. So actually you were seventh, not fourth.
On 5/9/22 6:59 AM, Matthew Wilcox wrote: > On Mon, May 09, 2022 at 08:31:16AM -0400, Tom Rix wrote: >> The clang build fails with >> mm/shmem.c:1704:7: error: variable 'folio' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] >> if (!page) { >> ^~~~~ >> The error handler for !page jumps to an if-check for an unset folio. >> So initialize folio to NULL. > I appreciate you're trying to help, but the fourth report of a problem > adds more noise than utility. > > https://lore.kernel.org/linux-mm/?q=shmem+folio > > shows emails about this from the cgelbot, Dan Carpenter, SeongJae Park, > Colin King, Nathan Chancellor and Sebastian Siewior. So actually you > were seventh, not fourth. From my point of view, the build has been broken for a week. It would be good if this and the other folio issue was fixed in linux-next soon. Tom >
On Mon, May 09, 2022 at 07:51:25AM -0700, Tom Rix wrote: > > On 5/9/22 6:59 AM, Matthew Wilcox wrote: > > On Mon, May 09, 2022 at 08:31:16AM -0400, Tom Rix wrote: > > > The clang build fails with > > > mm/shmem.c:1704:7: error: variable 'folio' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] > > > if (!page) { > > > ^~~~~ > > > The error handler for !page jumps to an if-check for an unset folio. > > > So initialize folio to NULL. > > I appreciate you're trying to help, but the fourth report of a problem > > adds more noise than utility. > > > > https://lore.kernel.org/linux-mm/?q=shmem+folio > > > > shows emails about this from the cgelbot, Dan Carpenter, SeongJae Park, > > Colin King, Nathan Chancellor and Sebastian Siewior. So actually you > > were seventh, not fourth. > > From my point of view, the build has been broken for a week. Yeah, shit happens when you're trying to fix patches and attend a conference at the same time. > It would be good if this and the other folio issue was fixed in linux-next > soon. As you can see, I sent a replacement patch series on the 4th which fixes far more than the two problems you noticed. https://lore.kernel.org/linux-mm/20220504182857.4013401-1-willy@infradead.org/ I can do no more than this.
diff --git a/mm/shmem.c b/mm/shmem.c index 107f1e4dd0aa..7faaa61ff7fa 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1682,7 +1682,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, struct shmem_inode_info *info = SHMEM_I(inode); struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; struct page *page; - struct folio *folio; + struct folio *folio = NULL; swp_entry_t swap; int error;
The clang build fails with mm/shmem.c:1704:7: error: variable 'folio' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!page) { ^~~~~ The error handler for !page jumps to an if-check for an unset folio. So initialize folio to NULL. Fixes: 2b58b3f33ba2 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()") Signed-off-by: Tom Rix <trix@redhat.com> --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)