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Author SHA1 Message Date
Peter Xu
9c67a20704 mm/hugetlb: introduce hugetlb_walk()
huge_pte_offset() is the main walker function for hugetlb pgtables.  The
name is not really representing what it does, though.

Instead of renaming it, introduce a wrapper function called hugetlb_walk()
which will use huge_pte_offset() inside.  Assert on the locks when walking
the pgtable.

Note, the vma lock assertion will be a no-op for private mappings.

Document the last special case in the page_vma_mapped_walk() path where we
don't need any more lock to call hugetlb_walk().

Taking vma lock there is not needed because either: (1) potential callers
of hugetlb pvmw holds i_mmap_rwsem already (from one rmap_walk()), or (2)
the caller will not walk a hugetlb vma at all so the hugetlb code path not
reachable (e.g.  in ksm or uprobe paths).

It's slightly implicit for future page_vma_mapped_walk() callers on that
lock requirement.  But anyway, when one day this rule breaks, one will get
a straightforward warning in hugetlb_walk() with lockdep, then there'll be
a way out.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20221216155229.2043750-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:39 -08:00
Peter Xu
dd361e5033 mm/hugetlb: make walk_hugetlb_range() safe to pmd unshare
Since walk_hugetlb_range() walks the pgtable, it needs the vma lock to
make sure the pgtable page will not be freed concurrently.

Link: https://lkml.kernel.org/r/20221216155226.2043738-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:39 -08:00
Peter Xu
eefc7fa536 mm/hugetlb: make follow_hugetlb_page() safe to pmd unshare
Since follow_hugetlb_page() walks the pgtable, it needs the vma lock to
make sure the pgtable page will not be freed concurrently.

Link: https://lkml.kernel.org/r/20221216155223.2043727-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:39 -08:00
Peter Xu
7d049f3a03 mm/hugetlb: make hugetlb_follow_page_mask() safe to pmd unshare
Since hugetlb_follow_page_mask() walks the pgtable, it needs the vma lock
to make sure the pgtable page will not be freed concurrently.

Link: https://lkml.kernel.org/r/20221216155219.2043714-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:39 -08:00
Peter Xu
b8da2e4660 mm/hugetlb: make userfaultfd_huge_must_wait() safe to pmd unshare
We can take the hugetlb walker lock, here taking vma lock directly.

Link: https://lkml.kernel.org/r/20221216155217.2043700-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Peter Xu
fcd48540d1 mm/hugetlb: move swap entry handling into vma lock when faulted
In hugetlb_fault(), there used to have a special path to handle swap entry
at the entrance using huge_pte_offset().  That's unsafe because
huge_pte_offset() for a pmd sharable range can access freed pgtables if
without any lock to protect the pgtable from being freed after pmd
unshare.

Here the simplest solution to make it safe is to move the swap handling to
be after the vma lock being held.  We may need to take the fault mutex on
either migration or hwpoison entries now (also the vma lock, but that's
really needed), however neither of them is hot path.

Note that the vma lock cannot be released in hugetlb_fault() when the
migration entry is detected, because in migration_entry_wait_huge() the
pgtable page will be used again (by taking the pgtable lock), so that also
need to be protected by the vma lock.  Modify migration_entry_wait_huge()
so that it must be called with vma read lock held, and properly release
the lock in __migration_entry_wait_huge().

Link: https://lkml.kernel.org/r/20221216155100.2043537-5-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Peter Xu
fe7d4c6d5a mm/hugetlb: document huge_pte_offset usage
huge_pte_offset() is potentially a pgtable walker, looking up pte_t* for a
hugetlb address.

Normally, it's always safe to walk a generic pgtable as long as we're with
the mmap lock held for either read or write, because that guarantees the
pgtable pages will always be valid during the process.

But it's not true for hugetlbfs, especially shared: hugetlbfs can have its
pgtable freed by pmd unsharing, it means that even with mmap lock held for
current mm, the PMD pgtable page can still go away from under us if pmd
unsharing is possible during the walk.

So we have two ways to make it safe even for a shared mapping:

  (1) If we're with the hugetlb vma lock held for either read/write, it's
      okay because pmd unshare cannot happen at all.

  (2) If we're with the i_mmap_rwsem lock held for either read/write, it's
      okay because even if pmd unshare can happen, the pgtable page cannot
      be freed from under us.

Document it.

Link: https://lkml.kernel.org/r/20221216155100.2043537-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Peter Xu
bb373dce2c mm/hugetlb: don't wait for migration entry during follow page
That's what the code does with !hugetlb pages, so we should logically do
the same for hugetlb, so migration entry will also be treated as no page.

This is probably also the last piece in follow_page code that may sleep,
the last one should be removed in cf994dd8af27 ("mm/gup: remove
FOLL_MIGRATION", 2022-11-16).

Link: https://lkml.kernel.org/r/20221216155100.2043537-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Peter Xu
243b1f2d3b mm/hugetlb: let vma_offset_start() to return start
Patch series "mm/hugetlb: Make huge_pte_offset() thread-safe for pmd
unshare", v4.

Problem
=======

huge_pte_offset() is a major helper used by hugetlb code paths to walk a
hugetlb pgtable.  It's used mostly everywhere since that's needed even
before taking the pgtable lock.

huge_pte_offset() is always called with mmap lock held with either read or
write.  It was assumed to be safe but it's actually not.  One race
condition can easily trigger by: (1) firstly trigger pmd share on a memory
range, (2) do huge_pte_offset() on the range, then at the meantime, (3)
another thread unshare the pmd range, and the pgtable page is prone to lost
if the other shared process wants to free it completely (by either munmap
or exit mm).

The recent work from Mike on vma lock can resolve most of this already.
It's achieved by forbidden pmd unsharing during the lock being taken, so no
further risk of the pgtable page being freed.  It means if we can take the
vma lock around all huge_pte_offset() callers it'll be safe.

There're already a bunch of them that we did as per the latest mm-unstable,
but also quite a few others that we didn't for various reasons especially
on huge_pte_offset() usage.

One more thing to mention is that besides the vma lock, i_mmap_rwsem can
also be used to protect the pgtable page (along with its pgtable lock) from
being freed from under us.  IOW, huge_pte_offset() callers need to either
hold the vma lock or i_mmap_rwsem to safely walk the pgtables.

A reproducer of such problem, based on hugetlb GUP (NOTE: since the race is
very hard to trigger, one needs to apply another kernel delay patch too,
see below):

======8<=======
  #define _GNU_SOURCE
  #include <stdio.h>
  #include <stdlib.h>
  #include <errno.h>
  #include <unistd.h>
  #include <sys/mman.h>
  #include <fcntl.h>
  #include <linux/memfd.h>
  #include <assert.h>
  #include <pthread.h>

  #define  MSIZE  (1UL << 30)     /* 1GB */
  #define  PSIZE  (2UL << 20)     /* 2MB */

  #define  HOLD_SEC  (1)

  int pipefd[2];
  void *buf;

  void *do_map(int fd)
  {
      unsigned char *tmpbuf, *p;
      int ret;

      ret = posix_memalign((void **)&tmpbuf, MSIZE, MSIZE);
      if (ret) {
          perror("posix_memalign() failed");
          return NULL;
      }

      tmpbuf = mmap(tmpbuf, MSIZE, PROT_READ | PROT_WRITE,
                    MAP_SHARED | MAP_FIXED, fd, 0);
      if (tmpbuf == MAP_FAILED) {
          perror("mmap() failed");
          return NULL;
      }
      printf("mmap() -> %p\n", tmpbuf);

      for (p = tmpbuf; p < tmpbuf + MSIZE; p += PSIZE) {
          *p = 1;
      }

      return tmpbuf;
  }

  void do_unmap(void *buf)
  {
      munmap(buf, MSIZE);
  }

  void proc2(int fd)
  {
      unsigned char c;

      buf = do_map(fd);
      if (!buf)
          return;

      read(pipefd[0], &c, 1);
      /*
       * This frees the shared pgtable page, causing use-after-free in
       * proc1_thread1 when soft walking hugetlb pgtable.
       */
      do_unmap(buf);

      printf("Proc2 quitting\n");
  }

  void *proc1_thread1(void *data)
  {
      /*
       * Trigger follow-page on 1st 2m page.  Kernel hack patch needed to
       * withhold this procedure for easier reproduce.
       */
      madvise(buf, PSIZE, MADV_POPULATE_WRITE);
      printf("Proc1-thread1 quitting\n");
      return NULL;
  }

  void *proc1_thread2(void *data)
  {
      unsigned char c;

      /* Wait a while until proc1_thread1() start to wait */
      sleep(0.5);
      /* Trigger pmd unshare */
      madvise(buf, PSIZE, MADV_DONTNEED);
      /* Kick off proc2 to release the pgtable */
      write(pipefd[1], &c, 1);

      printf("Proc1-thread2 quitting\n");
      return NULL;
  }

  void proc1(int fd)
  {
      pthread_t tid1, tid2;
      int ret;

      buf = do_map(fd);
      if (!buf)
          return;

      ret = pthread_create(&tid1, NULL, proc1_thread1, NULL);
      assert(ret == 0);
      ret = pthread_create(&tid2, NULL, proc1_thread2, NULL);
      assert(ret == 0);

      /* Kick the child to share the PUD entry */
      pthread_join(tid1, NULL);
      pthread_join(tid2, NULL);

      do_unmap(buf);
  }

  int main(void)
  {
      int fd, ret;

      fd = memfd_create("test-huge", MFD_HUGETLB | MFD_HUGE_2MB);
      if (fd < 0) {
          perror("open failed");
          return -1;
      }

      ret = ftruncate(fd, MSIZE);
      if (ret) {
          perror("ftruncate() failed");
          return -1;
      }

      ret = pipe(pipefd);
      if (ret) {
          perror("pipe() failed");
          return -1;
      }

      if (fork()) {
          proc1(fd);
      } else {
          proc2(fd);
      }

      close(pipefd[0]);
      close(pipefd[1]);
      close(fd);

      return 0;
  }
======8<=======

The kernel patch needed to present such a race so it'll trigger 100%:

======8<=======
: diff --git a/mm/hugetlb.c b/mm/hugetlb.c
: index 9d97c9a2a15d..f8d99dad5004 100644
: --- a/mm/hugetlb.c
: +++ b/mm/hugetlb.c
: @@ -38,6 +38,7 @@
:  #include <asm/page.h>
:  #include <asm/pgalloc.h>
:  #include <asm/tlb.h>
: +#include <asm/delay.h>
: 
:  #include <linux/io.h>
:  #include <linux/hugetlb.h>
: @@ -6290,6 +6291,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
:                 bool unshare = false;
:                 int absent;
:                 struct page *page;
: +               unsigned long c = 0;
: 
:                 /*
:                  * If we have a pending SIGKILL, don't keep faulting pages and
: @@ -6309,6 +6311,13 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
:                  */
:                 pte = huge_pte_offset(mm, vaddr & huge_page_mask(h),
:                                       huge_page_size(h));
: +
: +               pr_info("%s: withhold 1 sec...\n", __func__);
: +               for (c = 0; c < 100; c++) {
: +                       udelay(10000);
: +               }
: +               pr_info("%s: withhold 1 sec...done\n", __func__);
: +
:                 if (pte)
:                         ptl = huge_pte_lock(h, mm, pte);
:                 absent = !pte || huge_pte_none(huge_ptep_get(pte));
: ======8<=======

It'll trigger use-after-free of the pgtable spinlock:

======8<=======
[   16.959907] follow_hugetlb_page: withhold 1 sec...
[   17.960315] follow_hugetlb_page: withhold 1 sec...done
[   17.960550] ------------[ cut here ]------------
[   17.960742] DEBUG_LOCKS_WARN_ON(1)
[   17.960756] WARNING: CPU: 3 PID: 542 at kernel/locking/lockdep.c:231 __lock_acquire+0x955/0x1fa0
[   17.961264] Modules linked in:
[   17.961394] CPU: 3 PID: 542 Comm: hugetlb-pmd-sha Not tainted 6.1.0-rc4-peterx+ #46
[   17.961704] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   17.962266] RIP: 0010:__lock_acquire+0x955/0x1fa0
[   17.962516] Code: c0 0f 84 5f fe ff ff 44 8b 1d 0f 9a 29 02 45 85 db 0f 85 4f fe ff ff 48 c7 c6 75 50 83 82 48 c7 c7 1b 4b 7d 82 e8 d3 22 d8 00 <0f> 0b 31 c0 4c 8b 54 24 08 4c 8b 04 24 e9
[   17.963494] RSP: 0018:ffffc90000e4fba8 EFLAGS: 00010096
[   17.963704] RAX: 0000000000000016 RBX: fffffffffd3925a8 RCX: 0000000000000000
[   17.963989] RDX: 0000000000000002 RSI: ffffffff82863ccf RDI: 00000000ffffffff
[   17.964276] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000e4fa58
[   17.964557] R10: 0000000000000003 R11: ffffffff83162688 R12: 0000000000000000
[   17.964839] R13: 0000000000000001 R14: ffff888105eac748 R15: 0000000000000001
[   17.965123] FS:  00007f17c0a00640(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000
[   17.965443] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   17.965672] CR2: 00007f17c09ffef8 CR3: 000000010c87a005 CR4: 0000000000770ee0
[   17.965956] PKRU: 55555554
[   17.966068] Call Trace:
[   17.966172]  <TASK>
[   17.966268]  ? tick_nohz_tick_stopped+0x12/0x30
[   17.966455]  lock_acquire+0xbf/0x2b0
[   17.966603]  ? follow_hugetlb_page.cold+0x75/0x5c4
[   17.966799]  ? _printk+0x48/0x4e
[   17.966934]  _raw_spin_lock+0x2f/0x40
[   17.967087]  ? follow_hugetlb_page.cold+0x75/0x5c4
[   17.967285]  follow_hugetlb_page.cold+0x75/0x5c4
[   17.967473]  __get_user_pages+0xbb/0x620
[   17.967635]  faultin_vma_page_range+0x9a/0x100
[   17.967817]  madvise_vma_behavior+0x3c0/0xbd0
[   17.967998]  ? mas_prev+0x11/0x290
[   17.968141]  ? find_vma_prev+0x5e/0xa0
[   17.968304]  ? madvise_vma_anon_name+0x70/0x70
[   17.968486]  madvise_walk_vmas+0xa9/0x120
[   17.968650]  do_madvise.part.0+0xfa/0x270
[   17.968813]  __x64_sys_madvise+0x5a/0x70
[   17.968974]  do_syscall_64+0x37/0x90
[   17.969123]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   17.969329] RIP: 0033:0x7f1840f0efdb
[   17.969477] Code: c3 66 0f 1f 44 00 00 48 8b 15 39 6e 0e 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 1c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d 68
[   17.970205] RSP: 002b:00007f17c09ffe38 EFLAGS: 00000202 ORIG_RAX: 000000000000001c
[   17.970504] RAX: ffffffffffffffda RBX: 00007f17c0a00640 RCX: 00007f1840f0efdb
[   17.970786] RDX: 0000000000000017 RSI: 0000000000200000 RDI: 00007f1800000000
[   17.971068] RBP: 00007f17c09ffe50 R08: 0000000000000000 R09: 00007ffd3954164f
[   17.971353] R10: 00007f1840e10348 R11: 0000000000000202 R12: ffffffffffffff80
[   17.971709] R13: 0000000000000000 R14: 00007ffd39541550 R15: 00007f17c0200000
[   17.972083]  </TASK>
[   17.972199] irq event stamp: 2353
[   17.972372] hardirqs last  enabled at (2353): [<ffffffff8117fe4e>] __up_console_sem+0x5e/0x70
[   17.972869] hardirqs last disabled at (2352): [<ffffffff8117fe33>] __up_console_sem+0x43/0x70
[   17.973365] softirqs last  enabled at (2330): [<ffffffff810f763d>] __irq_exit_rcu+0xed/0x160
[   17.973857] softirqs last disabled at (2323): [<ffffffff810f763d>] __irq_exit_rcu+0xed/0x160
[   17.974341] ---[ end trace 0000000000000000 ]---
[   17.974614] BUG: kernel NULL pointer dereference, address: 00000000000000b8
[   17.975012] #PF: supervisor read access in kernel mode
[   17.975314] #PF: error_code(0x0000) - not-present page
[   17.975615] PGD 103f7b067 P4D 103f7b067 PUD 106cd7067 PMD 0
[   17.975943] Oops: 0000 [#1] PREEMPT SMP NOPTI
[   17.976197] CPU: 3 PID: 542 Comm: hugetlb-pmd-sha Tainted: G        W          6.1.0-rc4-peterx+ #46
[   17.976712] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   17.977370] RIP: 0010:__lock_acquire+0x190/0x1fa0
[   17.977655] Code: 98 00 00 00 41 89 46 24 81 e2 ff 1f 00 00 48 0f a3 15 e4 ba dd 02 0f 83 ff 05 00 00 48 8d 04 52 48 c1 e0 06 48 05 c0 d2 f4 83 <44> 0f b6 a0 b8 00 00 00 41 0f b7 46 20 6f
[   17.979170] RSP: 0018:ffffc90000e4fba8 EFLAGS: 00010046
[   17.979787] RAX: 0000000000000000 RBX: fffffffffd3925a8 RCX: 0000000000000000
[   17.980838] RDX: 0000000000000002 RSI: ffffffff82863ccf RDI: 00000000ffffffff
[   17.982048] RBP: 0000000000000000 R08: ffff888105eac720 R09: ffffc90000e4fa58
[   17.982892] R10: ffff888105eab900 R11: ffffffff83162688 R12: 0000000000000000
[   17.983771] R13: 0000000000000001 R14: ffff888105eac748 R15: 0000000000000001
[   17.984815] FS:  00007f17c0a00640(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000
[   17.985924] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   17.986265] CR2: 00000000000000b8 CR3: 000000010c87a005 CR4: 0000000000770ee0
[   17.986674] PKRU: 55555554
[   17.986832] Call Trace:
[   17.987012]  <TASK>
[   17.987266]  ? tick_nohz_tick_stopped+0x12/0x30
[   17.987770]  lock_acquire+0xbf/0x2b0
[   17.988118]  ? follow_hugetlb_page.cold+0x75/0x5c4
[   17.988575]  ? _printk+0x48/0x4e
[   17.988889]  _raw_spin_lock+0x2f/0x40
[   17.989243]  ? follow_hugetlb_page.cold+0x75/0x5c4
[   17.989687]  follow_hugetlb_page.cold+0x75/0x5c4
[   17.990119]  __get_user_pages+0xbb/0x620
[   17.990500]  faultin_vma_page_range+0x9a/0x100
[   17.990928]  madvise_vma_behavior+0x3c0/0xbd0
[   17.991354]  ? mas_prev+0x11/0x290
[   17.991678]  ? find_vma_prev+0x5e/0xa0
[   17.992024]  ? madvise_vma_anon_name+0x70/0x70
[   17.992421]  madvise_walk_vmas+0xa9/0x120
[   17.992793]  do_madvise.part.0+0xfa/0x270
[   17.993166]  __x64_sys_madvise+0x5a/0x70
[   17.993539]  do_syscall_64+0x37/0x90
[   17.993879]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
======8<=======

Resolution
==========

This patchset protects all the huge_pte_offset() callers to also take the
vma lock properly.

Patch Layout
============

Patch 1-2:         cleanup, or dependency of the follow up patches
Patch 3:           before fixing, document huge_pte_offset() on lock required
Patch 4-8:         each patch resolves one possible race condition
Patch 9:           introduce hugetlb_walk() to replace huge_pte_offset()

Tests
=====

The series is verified with the above reproducer so the race cannot
trigger anymore.  It also passes all hugetlb kselftests.


This patch (of 9):

Even though vma_offset_start() is named like that, it's not returning "the
start address of the range" but rather the offset we should use to offset
the vma->vm_start address.

Make it return the real value of the start vaddr, and it also helps for
all the callers because whenever the retval is used, it'll be ultimately
added into the vma->vm_start anyway, so it's better.

Link: https://lkml.kernel.org/r/20221216155100.2043537-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20221216155100.2043537-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Mike Kravetz
379c2e60e8 hugetlb: update vma flag check for hugetlb vma lock
The check for whether a hugetlb vma lock exists partially depends on the
vma's flags.  Currently, it checks for either VM_MAYSHARE or VM_SHARED. 
The reason both flags are used is because VM_MAYSHARE was previously
cleared in hugetlb vmas as they are tore down.  This is no longer the
case, and only the VM_MAYSHARE check is required.

Link: https://lkml.kernel.org/r/20221212235042.178355-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:38 -08:00
Jeff Xu
11f75a0144 selftests/memfd: add tests for MFD_NOEXEC_SEAL MFD_EXEC
Tests to verify MFD_NOEXEC, MFD_EXEC and vm.memfd_noexec sysctl.

Link: https://lkml.kernel.org/r/20221215001205.51969-6-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@google.com>
Co-developed-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Jeff Xu
c4f75bc8bd mm/memfd: add write seals when apply SEAL_EXEC to executable memfd
In order to avoid WX mappings, add F_SEAL_WRITE when apply F_SEAL_EXEC to
an executable memfd, so W^X from start.

This implys application need to fill the content of the memfd first, after
F_SEAL_EXEC is applied, application can no longer modify the content of
the memfd.

Typically, application seals the memfd right after writing to it.
For example:
1. memfd_create(MFD_EXEC).
2. write() code to the memfd.
3. fcntl(F_ADD_SEALS, F_SEAL_EXEC) to convert the memfd to W^X.
4. call exec() on the memfd.

Link: https://lkml.kernel.org/r/20221215001205.51969-5-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Verkamp <dverkamp@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Jeff Xu
105ff5339f mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC
The new MFD_NOEXEC_SEAL and MFD_EXEC flags allows application to set
executable bit at creation time (memfd_create).

When MFD_NOEXEC_SEAL is set, memfd is created without executable bit
(mode:0666), and sealed with F_SEAL_EXEC, so it can't be chmod to be
executable (mode: 0777) after creation.

when MFD_EXEC flag is set, memfd is created with executable bit
(mode:0777), this is the same as the old behavior of memfd_create.

The new pid namespaced sysctl vm.memfd_noexec has 3 values:
0: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like
        MFD_EXEC was set.
1: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like
        MFD_NOEXEC_SEAL was set.
2: memfd_create() without MFD_NOEXEC_SEAL will be rejected.

The sysctl allows finer control of memfd_create for old-software that
doesn't set the executable bit, for example, a container with
vm.memfd_noexec=1 means the old-software will create non-executable memfd
by default.  Also, the value of memfd_noexec is passed to child namespace
at creation time.  For example, if the init namespace has
vm.memfd_noexec=2, all its children namespaces will be created with 2.

[akpm@linux-foundation.org: add stub functions to fix build]
[akpm@linux-foundation.org: remove unneeded register_pid_ns_ctl_table_vm() stub, per Jeff]
[akpm@linux-foundation.org: s/pr_warn_ratelimited/pr_warn_once/, per review]
[akpm@linux-foundation.org: fix CONFIG_SYSCTL=n warning]
Link: https://lkml.kernel.org/r/20221215001205.51969-4-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@google.com>
Co-developed-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Daniel Verkamp
32d118ad50 selftests/memfd: add tests for F_SEAL_EXEC
Basic tests to ensure that user/group/other execute bits cannot be changed
after applying F_SEAL_EXEC to a memfd.

Link: https://lkml.kernel.org/r/20221215001205.51969-3-jeffxu@google.com
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Co-developed-by: Jeff Xu <jeffxu@google.com>
Signed-off-by: Jeff Xu <jeffxu@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Daniel Verkamp
6fd7353829 mm/memfd: add F_SEAL_EXEC
Patch series "mm/memfd: introduce MFD_NOEXEC_SEAL and MFD_EXEC", v8.

Since Linux introduced the memfd feature, memfd have always had their
execute bit set, and the memfd_create() syscall doesn't allow setting it
differently.

However, in a secure by default system, such as ChromeOS, (where all
executables should come from the rootfs, which is protected by Verified
boot), this executable nature of memfd opens a door for NoExec bypass and
enables “confused deputy attack”.  E.g, in VRP bug [1]: cros_vm
process created a memfd to share the content with an external process,
however the memfd is overwritten and used for executing arbitrary code and
root escalation.  [2] lists more VRP in this kind.

On the other hand, executable memfd has its legit use, runc uses memfd’s
seal and executable feature to copy the contents of the binary then
execute them, for such system, we need a solution to differentiate runc's
use of executable memfds and an attacker's [3].

To address those above, this set of patches add following:
1> Let memfd_create() set X bit at creation time.
2> Let memfd to be sealed for modifying X bit.
3> A new pid namespace sysctl: vm.memfd_noexec to control the behavior of
   X bit.For example, if a container has vm.memfd_noexec=2, then
   memfd_create() without MFD_NOEXEC_SEAL will be rejected.
4> A new security hook in memfd_create(). This make it possible to a new
   LSM, which rejects or allows executable memfd based on its security policy.


This patch (of 5):

The new F_SEAL_EXEC flag will prevent modification of the exec bits:
written as traditional octal mask, 0111, or as named flags, S_IXUSR |
S_IXGRP | S_IXOTH.  Any chmod(2) or similar call that attempts to modify
any of these bits after the seal is applied will fail with errno EPERM.

This will preserve the execute bits as they are at the time of sealing, so
the memfd will become either permanently executable or permanently
un-executable.

Link: https://lkml.kernel.org/r/20221215001205.51969-1-jeffxu@google.com
Link: https://lkml.kernel.org/r/20221215001205.51969-2-jeffxu@google.com
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Co-developed-by: Jeff Xu <jeffxu@google.com>
Signed-off-by: Jeff Xu <jeffxu@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Peter Xu
f1eb1bacfb mm/uffd: always wr-protect pte in pte|pmd_mkuffd_wp()
This patch is a cleanup to always wr-protect pte/pmd in mkuffd_wp paths.

The reasons I still think this patch is worthwhile, are:

  (1) It is a cleanup already; diffstat tells.

  (2) It just feels natural after I thought about this, if the pte is uffd
      protected, let's remove the write bit no matter what it was.

  (2) Since x86 is the only arch that supports uffd-wp, it also redefines
      pte|pmd_mkuffd_wp() in that it should always contain removals of
      write bits.  It means any future arch that want to implement uffd-wp
      should naturally follow this rule too.  It's good to make it a
      default, even if with vm_page_prot changes on VM_UFFD_WP.

  (3) It covers more than vm_page_prot.  So no chance of any potential
      future "accident" (like pte_mkdirty() sparc64 or loongarch, even
      though it just got its pte_mkdirty fixed <1 month ago).  It'll be
      fairly clear when reading the code too that we don't worry anything
      before a pte_mkuffd_wp() on uncertainty of the write bit.

We may call pte_wrprotect() one more time in some paths (e.g.  thp split),
but that should be fully local bitop instruction so the overhead should be
negligible.

Although this patch should logically also fix all the known issues on
uffd-wp too recently on page migration (not for numa hint recovery - that
may need another explcit pte_wrprotect), but this is not the plan for that
fix.  So no fixes, and stable doesn't need this.

Link: https://lkml.kernel.org/r/20221214201533.1774616-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ives van Hoorne <ives@codesandbox.io>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:37 -08:00
Sidhartha Kumar
04a42e72d7 mm: move folio_set_compound_order() to mm/internal.h
folio_set_compound_order() is moved to an mm-internal location so external
folio users cannot misuse this function.  Change the name of the function
to folio_set_order() and use WARN_ON_ONCE() rather than BUG_ON.  Also,
handle the case if a non-large folio is passed and add clarifying comments
to the function.

Link: https://lore.kernel.org/lkml/20221207223731.32784-1-sidhartha.kumar@oracle.com/T/
Link: https://lkml.kernel.org/r/20221215061757.223440-1-sidhartha.kumar@oracle.com
Fixes: 9fd330582b ("mm: add folio dtor and order setter functions")
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Muchun Song <songmuchun@bytedance.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:36 -08:00
Andrew Morton
1301f93134 Pull mm-hotfixes-stable dependencies into mm-stable.
Merge branch 'mm-hotfixes-stable' into mm-stable
2023-01-18 17:03:20 -08:00
Peter Xu
7e3ce3f8d2 mm: fix a few rare cases of using swapin error pte marker
This patch should harden commit 15520a3f04 ("mm: use pte markers for
swap errors") on using pte markers for swapin errors on a few corner
cases.

1. Propagate swapin errors across fork()s: if there're swapin errors in
   the parent mm, after fork()s the child should sigbus too when an error
   page is accessed.

2. Fix a rare condition race in pte_marker_clear() where a uffd-wp pte
   marker can be quickly switched to a swapin error.

3. Explicitly ignore swapin error pte markers in change_protection().

I mostly don't worry on (2) or (3) at all, but we should still have them. 
Case (1) is special because it can potentially cause silent data corrupt
on child when parent has swapin error triggered with swapoff, but since
swapin error is rare itself already it's probably not easy to trigger
either.

Currently there is a priority difference between the uffd-wp bit and the
swapin error entry, in which the swapin error always has higher priority
(e.g.  we don't need to wr-protect a swapin error pte marker).

If there will be a 3rd bit introduced, we'll probably need to consider a
more involved approach so we may need to start operate on the bits.  Let's
leave that for later.

This patch is tested with case (1) explicitly where we'll get corrupted
data before in the child if there's existing swapin error pte markers, and
after patch applied the child can be rightfully killed.

We don't need to copy stable for this one since 15520a3f04 just landed
as part of v6.2-rc1, only "Fixes" applied.

Link: https://lkml.kernel.org/r/20221214200453.1772655-3-peterx@redhat.com
Fixes: 15520a3f04 ("mm: use pte markers for swap errors")
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:02:19 -08:00
Peter Xu
49d6d7fb63 mm/uffd: fix pte marker when fork() without fork event
Patch series "mm: Fixes on pte markers".

Patch 1 resolves the syzkiller report from Pengfei.

Patch 2 further harden pte markers when used with the recent swapin error
markers.  The major case is we should persist a swapin error marker after
fork(), so child shouldn't read a corrupted page.


This patch (of 2):

When fork(), dst_vma is not guaranteed to have VM_UFFD_WP even if src may
have it and has pte marker installed.  The warning is improper along with
the comment.  The right thing is to inherit the pte marker when needed, or
keep the dst pte empty.

A vague guess is this happened by an accident when there's the prior patch
to introduce src/dst vma into this helper during the uffd-wp feature got
developed and I probably messed up in the rebase, since if we replace
dst_vma with src_vma the warning & comment it all makes sense too.

Hugetlb did exactly the right here (copy_hugetlb_page_range()).  Fix the
general path.

Reproducer:

https://github.com/xupengfe/syzkaller_logs/blob/main/221208_115556_copy_page_range/repro.c

Bugzilla report: https://bugzilla.kernel.org/show_bug.cgi?id=216808

Link: https://lkml.kernel.org/r/20221214200453.1772655-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20221214200453.1772655-2-peterx@redhat.com
Fixes: c56d1b62cc ("mm/shmem: handle uffd-wp during fork()")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: <stable@vger.kernel.org> # 5.19+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:02:19 -08:00
Andrew Morton
077010cef0 Sync with v6.2-rc4
Merge branch 'master' into mm-nonmm-stable
2023-01-18 16:52:33 -08:00
Andrew Morton
bd86d2ea36 Sync with v6.2-rc4
Merge branch 'master' into mm-hotfixes-stable
2023-01-18 16:52:20 -08:00
Andrew Morton
0e18a6b49b Sync with v6.2-rc4
Merge branch 'master' into mm-stable
2023-01-18 16:51:53 -08:00
Dmitry Baryshkov
b894f2cf91 ARM: dts: qcom: apq8084: add clocks and clock-names to gcc device
Add clocks and clock-names nodes to the gcc device to bind clocks using
the DT links.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-13-dmitry.baryshkov@linaro.org
2023-01-18 18:27:45 -06:00
Dmitry Baryshkov
2069c701fc clk: qcom: mmcc-apq8084: use parent_hws/_data instead of parent_names
Convert the clock driver to specify parent data rather than parent
names, to actually bind using 'clock-names' specified in the DTS rather
than global clock names. Use parent_hws where possible to refer parent
clocks directly, skipping the lookup.

Note, the system names for xo clocks were changed from "xo" to
"xo_board" to follow the example of other platforms. This switches the
clocks to use DT-provided "xo_board" clock instead of manually
registered "xo" clock and allows us to drop qcom_cc_register_board_clk()
call from the driver at some point.

In the same way change the looked up system "sleep_clk_src" clock to
"sleep_clk", which is registered from DT.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-12-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
7b347f4b67 clk: qcom: mmcc-apq8084: remove spdm clocks
SPDM is used for debug/profiling and does not have any other
functionality. These clocks can safely be removed.

Suggested-by: Stephen Boyd <sboyd@kernel.org>
Suggested-by: Georgi Djakov <djakov@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-11-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
41d01f526b clk: qcom: mmcc-apq8084: move clock parent tables down
Move clock parent tables down, after the PLL declrataions, so that we
can use pll hw clock fields in the next commit.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-10-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
891feb0bd0 clk: qcom: mmcc-apq8084: use ARRAY_SIZE instead of specifying num_parents
Use ARRAY_SIZE() instead of manually specifying num_parents. This makes
adding/removing entries to/from parent_data easy and errorproof.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-9-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
cc0269b760 clk: qcom: gcc-apq8084: add GCC_MMSS_GPLL0_CLK_SRC
Add the GCC_MMSS_GPLL0_CLK_SRC, the branch clock gating gpll0 clock for
the multimedia subsystem.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-8-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
7179ab686d clk: qcom: gcc-apq8084: use parent_hws/_data instead of parent_names
Convert the clock driver to specify parent data rather than parent
names, to actually bind using 'clock-names' specified in the DTS rather
than global clock names. Use parent_hws where possible to refer parent
clocks directly, skipping the lookup.

Note, the system names for xo clocks were changed from "xo" to
"xo_board" to follow the example of other platforms. This switches the
clocks to use DT-provided "xo_board" clock instead of manually
registered "xo" clock and allows us to drop qcom_cc_register_board_clk()
call from the driver at some point.

In the same way change the looked up system "sleep_clk_src" clock to
"sleep_clk", which is registered from DT.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-7-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
a8121eeb4b clk: qcom: gcc-apq8084: move PLL clocks up
Move PLL clock declarations up, before clock parent tables, so that we
can use pll hw clock fields in the next commit.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-6-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
21c348768f clk: qcom: gcc-apq8084: use ARRAY_SIZE instead of specifying num_parents
Use ARRAY_SIZE() instead of manually specifying num_parents. This makes
adding/removing entries to/from parent_data easy and errorproof.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-5-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
605f073812 dt-bindings: clock: qcom,mmcc: define clocks/clock-names for APQ8084
Define clock/clock-names properties of the MMCC device node to be used
on APQ8084 platform.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-4-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
93a63522de dt-bindings: clock: qcom,gcc-apq8084: add GCC_MMSS_GPLL0_CLK_SRC
Add GCC_MMSS_GPLL0_CLK_SRC, the branch clock gating gpll0 clock for the
multimedia subsystem.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-3-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Dmitry Baryshkov
0df0a8f2d2 dt-bindings: clock: qcom,gcc-apq8084: define clocks/clock-names
Define clock/clock-names properties of the GCC device node to be used
on APQ8084 platform.

Note: the driver uses a single pcie_pipe clock, however most probably
there are two pipe clocks, one from each of PCIe QMP PHYs.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111060402.1168726-2-dmitry.baryshkov@linaro.org
2023-01-18 18:27:35 -06:00
Bart Van Assche
0bfe63d075 scsi: device_handler: alua: Remove a might_sleep() annotation
The might_sleep() annotation in alua_rtpg_queue() is not correct since the
command completion code may call this function from atomic context.
Calling alua_rtpg_queue() from atomic context in the command completion
path is fine since request submitters must hold an sdev reference until
command execution has completed. This patch fixes the following kernel
complaint:

BUG: sleeping function called from invalid context at drivers/scsi/device_handler/scsi_dh_alua.c:992
Call Trace:
 dump_stack_lvl+0xac/0x100
 __might_resched+0x284/0x2c8
 alua_rtpg_queue+0x3c/0x98 [scsi_dh_alua]
 alua_check+0x122/0x250 [scsi_dh_alua]
 alua_check_sense+0x172/0x228 [scsi_dh_alua]
 scsi_check_sense+0x8a/0x2e0
 scsi_decide_disposition+0x286/0x298
 scsi_complete+0x6a/0x108
 blk_complete_reqs+0x6e/0x88
 __do_softirq+0x13e/0x6b8
 __irq_exit_rcu+0x14a/0x170
 irq_exit_rcu+0x22/0x50
 do_ext_irq+0x10a/0x1d0

Link: https://lore.kernel.org/r/20230118180557.1212577-1-bvanassche@acm.org
Reported-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Tested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-01-18 19:16:02 -05:00
Mike Christie
f484a794e4 scsi: iscsi_tcp: Fix UAF during login when accessing the shost ipaddress
If during iscsi_sw_tcp_session_create() iscsi_tcp_r2tpool_alloc() fails,
userspace could be accessing the host's ipaddress attr. If we then free the
session via iscsi_session_teardown() while userspace is still accessing the
session we will hit a use after free bug.

Set the tcp_sw_host->session after we have completed session creation and
can no longer fail.

Link: https://lore.kernel.org/r/20230117193937.21244-3-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Acked-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-01-18 19:14:56 -05:00
Mike Christie
6f1d64b130 scsi: iscsi_tcp: Fix UAF during logout when accessing the shost ipaddress
Bug report and analysis from Ding Hui.

During iSCSI session logout, if another task accesses the shost ipaddress
attr, we can get a KASAN UAF report like this:

[  276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0
[  276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088
[  276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G            E      6.1.0-rc8+ #3
[  276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[  276.944470] Call Trace:
[  276.944943]  <TASK>
[  276.945397]  dump_stack_lvl+0x34/0x48
[  276.945887]  print_address_description.constprop.0+0x86/0x1e7
[  276.946421]  print_report+0x36/0x4f
[  276.947358]  kasan_report+0xad/0x130
[  276.948234]  kasan_check_range+0x35/0x1c0
[  276.948674]  _raw_spin_lock_bh+0x78/0xe0
[  276.949989]  iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp]
[  276.951765]  show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi]
[  276.952185]  dev_attr_show+0x3f/0x80
[  276.953005]  sysfs_kf_seq_show+0x1fb/0x3e0
[  276.953401]  seq_read_iter+0x402/0x1020
[  276.954260]  vfs_read+0x532/0x7b0
[  276.955113]  ksys_read+0xed/0x1c0
[  276.955952]  do_syscall_64+0x38/0x90
[  276.956347]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  276.956769] RIP: 0033:0x7f5d3a679222
[  276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
[  276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222
[  276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003
[  276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000
[  276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000
[  276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58
[  276.960536]  </TASK>
[  276.961357] Allocated by task 2209:
[  276.961756]  kasan_save_stack+0x1e/0x40
[  276.962170]  kasan_set_track+0x21/0x30
[  276.962557]  __kasan_kmalloc+0x7e/0x90
[  276.962923]  __kmalloc+0x5b/0x140
[  276.963308]  iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi]
[  276.963712]  iscsi_session_setup+0xda/0xba0 [libiscsi]
[  276.964078]  iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp]
[  276.964431]  iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi]
[  276.964793]  iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi]
[  276.965153]  iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi]
[  276.965546]  netlink_unicast+0x4d5/0x7b0
[  276.965905]  netlink_sendmsg+0x78d/0xc30
[  276.966236]  sock_sendmsg+0xe5/0x120
[  276.966576]  ____sys_sendmsg+0x5fe/0x860
[  276.966923]  ___sys_sendmsg+0xe0/0x170
[  276.967300]  __sys_sendmsg+0xc8/0x170
[  276.967666]  do_syscall_64+0x38/0x90
[  276.968028]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  276.968773] Freed by task 2209:
[  276.969111]  kasan_save_stack+0x1e/0x40
[  276.969449]  kasan_set_track+0x21/0x30
[  276.969789]  kasan_save_free_info+0x2a/0x50
[  276.970146]  __kasan_slab_free+0x106/0x190
[  276.970470]  __kmem_cache_free+0x133/0x270
[  276.970816]  device_release+0x98/0x210
[  276.971145]  kobject_cleanup+0x101/0x360
[  276.971462]  iscsi_session_teardown+0x3fb/0x530 [libiscsi]
[  276.971775]  iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp]
[  276.972143]  iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi]
[  276.972485]  iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi]
[  276.972808]  netlink_unicast+0x4d5/0x7b0
[  276.973201]  netlink_sendmsg+0x78d/0xc30
[  276.973544]  sock_sendmsg+0xe5/0x120
[  276.973864]  ____sys_sendmsg+0x5fe/0x860
[  276.974248]  ___sys_sendmsg+0xe0/0x170
[  276.974583]  __sys_sendmsg+0xc8/0x170
[  276.974891]  do_syscall_64+0x38/0x90
[  276.975216]  entry_SYSCALL_64_after_hwframe+0x63/0xcd

We can easily reproduce by two tasks:
1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done
2. while :; do cat \
/sys/devices/platform/host*/iscsi_host/host*/ipaddress; done

            iscsid              |        cat
--------------------------------+---------------------------------------
|- iscsi_sw_tcp_session_destroy |
  |- iscsi_session_teardown     |
    |- device_release           |
      |- iscsi_session_release  ||- dev_attr_show
        |- kfree                |  |- show_host_param_
                                |             ISCSI_HOST_PARAM_IPADDRESS
                                |    |- iscsi_sw_tcp_host_get_param
                                |      |- r/w tcp_sw_host->session (UAF)
  |- iscsi_host_remove          |
  |- iscsi_host_free            |

Fix the above bug by splitting the session removal into 2 parts:

 1. removal from iSCSI class which includes sysfs and removal from host
    tracking.

 2. freeing of session.

During iscsi_tcp host and session removal we can remove the session from
sysfs then remove the host from sysfs. At this point we know userspace is
not accessing the kernel via sysfs so we can free the session and host.

Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Acked-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-01-18 19:14:56 -05:00
Bartosz Golaszewski
1a87f7e5fa arm64: defconfig: enable the clock driver for Qualcomm SA8775P platforms
Enable the GCC clock driver on SA8775P platforms. It needs to be built-in
for console to work.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109174511.1740856-4-brgl@bgdev.pl
2023-01-18 18:14:33 -06:00
Krzysztof Kozlowski
e5988fd600 arm64: dts: qcom: sm8250: drop unused properties from tx-macro
Neither qcom,sm8250-lpass-tx-macro bindings nor the driver use
"clock-frequency" and address/size cells properties.

  sm8250-mtp.dtb: txmacro@3220000: Unevaluated properties are not allowed ('clock-frequency', '#address-cells', '#size-cells' were unexpected)

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109112221.102473-4-krzysztof.kozlowski@linaro.org
2023-01-18 18:12:09 -06:00
Krzysztof Kozlowski
a496f7decf arm64: dts: qcom: sm8250: drop unused clock-frequency from wsa-macro
Neither qcom,sm8250-lpass-wsa-macro bindings nor the driver use
"clock-frequency" property.

  sm8250-hdk.dtb: codec@3240000: Unevaluated properties are not allowed ('clock-frequency' was unexpected)

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109112221.102473-3-krzysztof.kozlowski@linaro.org
2023-01-18 18:12:09 -06:00
Krzysztof Kozlowski
8a220a62eb arm64: dts: qcom: align OPP table node name with DT schema
Bindings expect OPP tables to start with "opp-table".

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109112221.102473-2-krzysztof.kozlowski@linaro.org
2023-01-18 18:12:09 -06:00
Krzysztof Kozlowski
295bc71958 ARM: dts: qcom: align OPP table node name with DT schema
Bindings expect OPP tables to start with "opp-table".

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109112221.102473-1-krzysztof.kozlowski@linaro.org
2023-01-18 18:11:23 -06:00
Dmitry Baryshkov
858b0d4b04 ARM: dts: qcom: rename mdp nodes to display-controller
Follow the schema change and rename mdp nodes to generic name
'display-controller'.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109051402.317577-7-dmitry.baryshkov@linaro.org
2023-01-18 18:10:52 -06:00
Dmitry Baryshkov
1923093028 ARM: dts: qcom-msm8974: rename mdss node to display-subsystem
Follow the schema change and rename mdss node to generic name
'display-subsystem'.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109051402.317577-5-dmitry.baryshkov@linaro.org
2023-01-18 18:10:51 -06:00
Dmitry Baryshkov
0aab1b9b75 arm64: dts: qcom: rename mdp nodes to display-controller
Follow the schema change and rename mdp nodes to generic name
'display-controller'.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109051402.317577-6-dmitry.baryshkov@linaro.org
2023-01-18 18:10:27 -06:00
Dmitry Baryshkov
ecf0f5ff15 arm64: dts: qcom: rename mdss nodes to display-subsystem
Follow the schema change and rename mdss nodes to generic name
'display-subsystem'.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109051402.317577-4-dmitry.baryshkov@linaro.org
2023-01-18 18:10:27 -06:00
Dmitry Baryshkov
11691dab82 ARM: dts: qcom-msm8974: add SoC specific compat string to mdp5 node
Add SoC-specific compat string to the MDP5 device node to ease
distinguishing between various platforms.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109050152.316606-4-dmitry.baryshkov@linaro.org
2023-01-18 18:09:53 -06:00
Dmitry Baryshkov
d46fbd4579 arm64: dts: qcom: add SoC specific compat strings to mdp5 nodes
Add SoC-specific compat string to the MDP5 device nodes to ease
distinguishing between various platforms.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109050152.316606-5-dmitry.baryshkov@linaro.org
2023-01-18 18:09:17 -06:00
Johan Hovold
ba81043753 scsi: ufs: core: Fix devfreq deadlocks
There is a lock inversion and rwsem read-lock recursion in the devfreq
target callback which can lead to deadlocks.

Specifically, ufshcd_devfreq_scale() already holds a clk_scaling_lock
read lock when toggling the write booster, which involves taking the
dev_cmd mutex before taking another clk_scaling_lock read lock.

This can lead to a deadlock if another thread:

  1) tries to acquire the dev_cmd and clk_scaling locks in the correct
     order, or

  2) takes a clk_scaling write lock before the attempt to take the
     clk_scaling read lock a second time.

Fix this by dropping the clk_scaling_lock before toggling the write booster
as was done before commit 0e9d4ca43b ("scsi: ufs: Protect some contexts
from unexpected clock scaling").

While the devfreq callbacks are already serialised, add a second
serialising mutex to handle the unlikely case where a callback triggered
through the devfreq sysfs interface is racing with a request to disable
clock scaling through the UFS controller 'clkscale_enable' sysfs
attribute. This could otherwise lead to the write booster being left
disabled after having disabled clock scaling.

Also take the new mutex in ufshcd_clk_scaling_allow() to make sure that any
pending write booster update has completed on return.

Note that this currently only affects Qualcomm platforms since commit
87bd05016a ("scsi: ufs: core: Allow host driver to disable wb toggling
during clock scaling").

The lock inversion (i.e. 1 above) was reported by lockdep as:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.1.0-next-20221216 #211 Not tainted
 ------------------------------------------------------
 kworker/u16:2/71 is trying to acquire lock:
 ffff076280ba98a0 (&hba->dev_cmd.lock){+.+.}-{3:3}, at: ufshcd_query_flag+0x50/0x1c0

 but task is already holding lock:
 ffff076280ba9cf0 (&hba->clk_scaling_lock){++++}-{3:3}, at: ufshcd_devfreq_scale+0x2b8/0x380

 which lock already depends on the new lock.
[  +0.011606]
 the existing dependency chain (in reverse order) is:

 -> #1 (&hba->clk_scaling_lock){++++}-{3:3}:
        lock_acquire+0x68/0x90
        down_read+0x58/0x80
        ufshcd_exec_dev_cmd+0x70/0x2c0
        ufshcd_verify_dev_init+0x68/0x170
        ufshcd_probe_hba+0x398/0x1180
        ufshcd_async_scan+0x30/0x320
        async_run_entry_fn+0x34/0x150
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 -> #0 (&hba->dev_cmd.lock){+.+.}-{3:3}:
        __lock_acquire+0x12a0/0x2240
        lock_acquire.part.0+0xcc/0x220
        lock_acquire+0x68/0x90
        __mutex_lock+0x98/0x430
        mutex_lock_nested+0x2c/0x40
        ufshcd_query_flag+0x50/0x1c0
        ufshcd_query_flag_retry+0x64/0x100
        ufshcd_wb_toggle+0x5c/0x120
        ufshcd_devfreq_scale+0x2c4/0x380
        ufshcd_devfreq_target+0xf4/0x230
        devfreq_set_target+0x84/0x2f0
        devfreq_update_target+0xc4/0xf0
        devfreq_monitor+0x38/0x1f0
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0                    CPU1
        ----                    ----
   lock(&hba->clk_scaling_lock);
                                lock(&hba->dev_cmd.lock);
                                lock(&hba->clk_scaling_lock);
   lock(&hba->dev_cmd.lock);

  *** DEADLOCK ***

Fixes: 0e9d4ca43b ("scsi: ufs: Protect some contexts from unexpected clock scaling")
Cc: stable@vger.kernel.org      # 5.12
Cc: Can Guo <quic_cang@quicinc.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230116161201.16923-1-johan+linaro@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-01-18 19:08:37 -05:00