On Wed, Sep 16, 2020 at 01:40:43PM -0700, Joe Perches wrote: > Convert the unbound sprintf in hugetlb_report_node_meminfo to use > sysfs_emit_at so that no possible overrun of a PAGE_SIZE buf can occur. > > Signed-off-by: Joe Perches <[email protected]> > --- > drivers/base/node.c | 2 +- > include/linux/hugetlb.h | 4 ++-- > mm/hugetlb.c | 18 ++++++++++-------- > 3 files changed, 13 insertions(+), 11 deletions(-) > > diff --git a/drivers/base/node.c b/drivers/base/node.c > index b33526a9fcfc..dafe03e82e7c 100644 > --- a/drivers/base/node.c > +++ b/drivers/base/node.c > @@ -473,7 +473,7 @@ static ssize_t node_read_meminfo(struct device *dev, > HPAGE_PMD_NR) > #endif > ); > - len += hugetlb_report_node_meminfo(nid, buf + len); > + len += hugetlb_report_node_meminfo(buf, len, nid); > return len; > } > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index d5cc5f802dd4..ebca2ef02212 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -129,7 +129,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, > struct vm_area_struct *vma, > unsigned long start, unsigned long end, > struct page *ref_page); > void hugetlb_report_meminfo(struct seq_file *); > -int hugetlb_report_node_meminfo(int, char *); > +int hugetlb_report_node_meminfo(char *buf, int len, int nid); > void hugetlb_show_meminfo(void); > unsigned long hugetlb_total_pages(void); > vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, > @@ -245,7 +245,7 @@ static inline void hugetlb_report_meminfo(struct seq_file > *m) > { > } > > -static inline int hugetlb_report_node_meminfo(int nid, char *buf) > +static inline int hugetlb_report_node_meminfo(char *buf, int len, int nid) > { > return 0; > } > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 61469fd3ad92..fe76f8fd5a73 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -3571,18 +3571,20 @@ void hugetlb_report_meminfo(struct seq_file *m) > seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); > } > > -int hugetlb_report_node_meminfo(int nid, char *buf) > +int hugetlb_report_node_meminfo(char *buf, int len, int nid) > { > struct hstate *h = &default_hstate; > + > if (!hugepages_supported()) > return 0; > - return sprintf(buf, > - "Node %d HugePages_Total: %5u\n" > - "Node %d HugePages_Free: %5u\n" > - "Node %d HugePages_Surp: %5u\n", > - nid, h->nr_huge_pages_node[nid], > - nid, h->free_huge_pages_node[nid], > - nid, h->surplus_huge_pages_node[nid]); > + > + return sysfs_emit_at(buf, len, > + "Node %d HugePages_Total: %5u\n" > + "Node %d HugePages_Free: %5u\n" > + "Node %d HugePages_Surp: %5u\n", > + nid, h->nr_huge_pages_node[nid], > + nid, h->free_huge_pages_node[nid], > + nid, h->surplus_huge_pages_node[nid]); > }
That is NOT one-value-per-file, which is required for sysfs files. This should be 3 different sysfs files. Ugh. But that's separate from this series, thanks for redoing this. I'll take a look at it on Monday... thanks, greg k-h
