git.ipfire.org Git - thirdparty/openembedded/openembedded-core-contrib.git/blob

   1 From 939200ef160c95c8a9d71fd80c99f42a1de0a9f0 Mon Sep 17 00:00:00 2001
   2 From: Michael Jeanson <mjeanson@efficios.com>
   3 Date: Tue, 7 Mar 2023 11:41:14 -0500
   4 Subject: [PATCH 1/4] fix: mm: introduce vma->vm_flags wrapper functions (v6.3)
   5
   6 See upstream commit :
   7
   8   commit bc292ab00f6c7a661a8a605c714e8a148f629ef6
   9   Author: Suren Baghdasaryan <surenb@google.com>
  10   Date:   Thu Jan 26 11:37:47 2023 -0800
  11
  12     mm: introduce vma->vm_flags wrapper functions
  13
  14     vm_flags are among VMA attributes which affect decisions like VMA merging
  15     and splitting.  Therefore all vm_flags modifications are performed after
  16     taking exclusive mmap_lock to prevent vm_flags updates racing with such
  17     operations.  Introduce modifier functions for vm_flags to be used whenever
  18     flags are updated.  This way we can better check and control correct
  19     locking behavior during these updates.
  20
  21 Upstream-Status: Backport
  22
  23 Change-Id: I2cf662420d9d7748e5e310d3ea4bac98ba7d7f94
  24 Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
  25 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  26 ---
  27  include/wrapper/mm.h                  | 16 ++++++++++++++++
  28  src/lib/ringbuffer/ring_buffer_mmap.c |  4 +++-
  29  2 files changed, 19 insertions(+), 1 deletion(-)
  30
  31 diff --git a/include/wrapper/mm.h b/include/wrapper/mm.h
  32 index d3bdda66..61ac8127 100644
  33 --- a/include/wrapper/mm.h
  34 +++ b/include/wrapper/mm.h
  35 @@ -13,6 +13,22 @@
  36
  37  #include <lttng/kernel-version.h>
  38
  39 +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(6,3,0))
  40 +static inline
  41 +void wrapper_vm_flags_set(struct vm_area_struct *vma,
  42 +               vm_flags_t flags)
  43 +{
  44 +       vm_flags_set(vma, flags);
  45 +}
  46 +#else
  47 +static inline
  48 +void wrapper_vm_flags_set(struct vm_area_struct *vma,
  49 +               vm_flags_t flags)
  50 +{
  51 +       vma->vm_flags |= flags;
  52 +}
  53 +#endif
  54 +
  55  #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,6,0) \
  56                 || LTTNG_UBUNTU_KERNEL_RANGE(4,4,25,44, 4,5,0,0))
  57
  58 diff --git a/src/lib/ringbuffer/ring_buffer_mmap.c b/src/lib/ringbuffer/ring_buffer_mmap.c
  59 index 25e2d8d5..d24b76a3 100644
  60 --- a/src/lib/ringbuffer/ring_buffer_mmap.c
  61 +++ b/src/lib/ringbuffer/ring_buffer_mmap.c
  62 @@ -17,6 +17,8 @@
  63  #include <ringbuffer/frontend.h>
  64  #include <ringbuffer/vfs.h>
  65
  66 +#include <wrapper/mm.h>
  67 +
  68  /*
  69   * fault() vm_op implementation for ring buffer file mapping.
  70   */
  71 @@ -113,7 +115,7 @@ static int lib_ring_buffer_mmap_buf(struct lttng_kernel_ring_buffer *buf,
  72                 return -EINVAL;
  73
  74         vma->vm_ops = &lib_ring_buffer_mmap_ops;
  75 -       vma->vm_flags |= VM_DONTEXPAND;
  76 +       wrapper_vm_flags_set(vma, VM_DONTEXPAND);
  77         vma->vm_private_data = buf;
  78
  79         return 0;
  80 --
  81 2.34.1
  82