5.4-stable patches

added patches:
	mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps.patch

diff --git a/queue-5.4/mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps.patch b/queue-5.4/mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps.patch
new file mode 100644 (file)
index 0000000..86a9794
--- /dev/null
+++ b/queue-5.4/mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps.patch
@@ -0,0 +1,95 @@
+From 3489dbb696d25602aea8c3e669a6d43b76bd5358 Mon Sep 17 00:00:00 2001
+From: Mike Kravetz <mike.kravetz@oracle.com>
+Date: Thu, 26 Jan 2023 14:27:20 -0800
+Subject: mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps
+
+From: Mike Kravetz <mike.kravetz@oracle.com>
+
+commit 3489dbb696d25602aea8c3e669a6d43b76bd5358 upstream.
+
+Patch series "Fixes for hugetlb mapcount at most 1 for shared PMDs".
+
+This issue of mapcount in hugetlb pages referenced by shared PMDs was
+discussed in [1].  The following two patches address user visible behavior
+caused by this issue.
+
+[1] https://lore.kernel.org/linux-mm/Y9BF+OCdWnCSilEu@monkey/
+
+
+This patch (of 2):
+
+A hugetlb page will have a mapcount of 1 if mapped by multiple processes
+via a shared PMD.  This is because only the first process increases the
+map count, and subsequent processes just add the shared PMD page to their
+page table.
+
+page_mapcount is being used to decide if a hugetlb page is shared or
+private in /proc/PID/smaps.  Pages referenced via a shared PMD were
+incorrectly being counted as private.
+
+To fix, check for a shared PMD if mapcount is 1.  If a shared PMD is found
+count the hugetlb page as shared.  A new helper to check for a shared PMD
+is added.
+
+[akpm@linux-foundation.org: simplification, per David]
+[akpm@linux-foundation.org: hugetlb.h: include page_ref.h for page_count()]
+Link: https://lkml.kernel.org/r/20230126222721.222195-2-mike.kravetz@oracle.com
+Fixes: 25ee01a2fca0 ("mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps")
+Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
+Acked-by: Peter Xu <peterx@redhat.com>
+Cc: David Hildenbrand <david@redhat.com>
+Cc: James Houghton <jthoughton@google.com>
+Cc: Matthew Wilcox <willy@infradead.org>
+Cc: Michal Hocko <mhocko@suse.com>
+Cc: Muchun Song <songmuchun@bytedance.com>
+Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
+Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
+Cc: Yang Shi <shy828301@gmail.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/proc/task_mmu.c      |    4 +---
+ include/linux/hugetlb.h |   13 +++++++++++++
+ 2 files changed, 14 insertions(+), 3 deletions(-)
+
+--- a/fs/proc/task_mmu.c
++++ b/fs/proc/task_mmu.c
+@@ -723,9 +723,7 @@ static int smaps_hugetlb_range(pte_t *pt
+                       page = device_private_entry_to_page(swpent);
+       }
+       if (page) {
+-              int mapcount = page_mapcount(page);
+-
+-              if (mapcount >= 2)
++              if (page_mapcount(page) >= 2 || hugetlb_pmd_shared(pte))
+                       mss->shared_hugetlb += huge_page_size(hstate_vma(vma));
+               else
+                       mss->private_hugetlb += huge_page_size(hstate_vma(vma));
+--- a/include/linux/hugetlb.h
++++ b/include/linux/hugetlb.h
+@@ -7,6 +7,7 @@
+ #include <linux/fs.h>
+ #include <linux/hugetlb_inline.h>
+ #include <linux/cgroup.h>
++#include <linux/page_ref.h>
+ #include <linux/list.h>
+ #include <linux/kref.h>
+ #include <asm/pgtable.h>
+@@ -744,4 +745,16 @@ static inline spinlock_t *huge_pte_lock(
+       return ptl;
+ }
+ 
++#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
++static inline bool hugetlb_pmd_shared(pte_t *pte)
++{
++      return page_count(virt_to_page(pte)) > 1;
++}
++#else
++static inline bool hugetlb_pmd_shared(pte_t *pte)
++{
++      return false;
++}
++#endif
++
+ #endif /* _LINUX_HUGETLB_H */

diff --git a/queue-5.4/series b/queue-5.4/series
index 6a2911cebc6397807c82bfacee9fd43800c8165e..5b028bd7209ec1ad4d23bbee5ed29f09da198a12 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -43,3 +43,4 @@ iio-adc-twl6030-enable-measurements-of-vusb-vbat-and-others.patch
 parisc-fix-return-code-of-pdc_iodc_print.patch
 parisc-wire-up-ptrace_getregs-ptrace_setregs-for-compat-case.patch
 riscv-disable-generation-of-unwind-tables.patch
+mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps.patch