| Message ID | 894b351b82da6013cde7f36ff4b5493cd0ec30d0.1600285923.git.joe@perches.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at | expand |
On 9/16/20 1:40 PM, 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 <joe@perches.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
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 <joe@perches.com> > --- > 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
On Sat, 2020-09-19 at 08:22 +0200, Greg Kroah-Hartman wrote:
> I'll take a look at it on Monday...
It's decidedly not urgent/critical.
There are several logical defects all over the kernel
for these unbounded sprintfs, but I don't know of an
actual instance where the PAGE_SIZE buf is overfilled.
On Sat, 2020-09-19 at 08:22 +0200, Greg Kroah-Hartman wrote:
> I'll take a look at it on Monday...
Thoughts?
On Sat, 2020-09-19 at 08:22 +0200, Greg Kroah-Hartman wrote: > 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. [] > I'll take a look at it on Monday... (noting that you didn't say _which_ Monday...) Greg are you going to take this or should I ask someone else? The first sysfs_emit addition patch was first posted about a month ago without much change. I think it'd be useful to get it into -next before 5.9 is released.
On Mon, Sep 28, 2020 at 05:53:07PM -0700, Joe Perches wrote: > On Sat, 2020-09-19 at 08:22 +0200, Greg Kroah-Hartman wrote: > > 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. > [] > > I'll take a look at it on Monday... > > (noting that you didn't say _which_ Monday...) True :) > Greg are you going to take this or should I ask someone else? > > The first sysfs_emit addition patch was first posted about a month > ago without much change. > > I think it'd be useful to get it into -next before 5.9 is released. I'll dig into this today...
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]); } void hugetlb_show_meminfo(void)
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 <joe@perches.com> --- drivers/base/node.c | 2 +- include/linux/hugetlb.h | 4 ++-- mm/hugetlb.c | 18 ++++++++++-------- 3 files changed, 13 insertions(+), 11 deletions(-)