linux.git/fs/binfmt_elf.c, branch v6.6 Linux kernel source tree Merge branch 'expand-stack' 2023-06-29T03:35:21+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-29T03:35:21+00:00 9471f1f2f50282b9e8f59198ec6bb738b4ccc009 This modifies our user mode stack expansion code to always take the mmap_lock for writing before modifying the VM layout. It's actually something we always technically should have done, but because we didn't strictly need it, we were being lazy ("opportunistic" sounds so much better, doesn't it?) about things, and had this hack in place where we would extend the stack vma in-place without doing the proper locking. And it worked fine. We just needed to change vm_start (or, in the case of grow-up stacks, vm_end) and together with some special ad-hoc locking using the anon_vma lock and the mm->page_table_lock, it all was fairly straightforward. That is, it was all fine until Ruihan Li pointed out that now that the vma layout uses the maple tree code, we *really* don't just change vm_start and vm_end any more, and the locking really is broken. Oops. It's not actually all _that_ horrible to fix this once and for all, and do proper locking, but it's a bit painful. We have basically three different cases of stack expansion, and they all work just a bit differently: - the common and obvious case is the page fault handling. It's actually fairly simple and straightforward, except for the fact that we have something like 24 different versions of it, and you end up in a maze of twisty little passages, all alike. - the simplest case is the execve() code that creates a new stack. There are no real locking concerns because it's all in a private new VM that hasn't been exposed to anybody, but lockdep still can end up unhappy if you get it wrong. - and finally, we have GUP and page pinning, which shouldn't really be expanding the stack in the first place, but in addition to execve() we also use it for ptrace(). And debuggers do want to possibly access memory under the stack pointer and thus need to be able to expand the stack as a special case. None of these cases are exactly complicated, but the page fault case in particular is just repeated slightly differently many many times. And ia64 in particular has a fairly complicated situation where you can have both a regular grow-down stack _and_ a special grow-up stack for the register backing store. So to make this slightly more manageable, the bulk of this series is to first create a helper function for the most common page fault case, and convert all the straightforward architectures to it. Thus the new 'lock_mm_and_find_vma()' helper function, which ends up being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa. So we not only convert more than half the architectures, we now have more shared code and avoid some of those twisty little passages. And largely due to this common helper function, the full diffstat of this series ends up deleting more lines than it adds. That still leaves eight architectures (ia64, m68k, microblaze, openrisc, parisc, s390, sparc64 and um) that end up doing 'expand_stack()' manually because they are doing something slightly different from the normal pattern. Along with the couple of special cases in execve() and GUP. So there's a couple of patches that first create 'locked' helper versions of the stack expansion functions, so that there's a obvious path forward in the conversion. The execve() case is then actually pretty simple, and is a nice cleanup from our old "grow-up stackls are special, because at execve time even they grow down". The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because it's just more straightforward to write out the stack expansion there manually, instead od having get_user_pages_remote() do it for us in some situations but not others and have to worry about locking rules for GUP. And the final step is then to just convert the remaining odd cases to a new world order where 'expand_stack()' is called with the mmap_lock held for reading, but where it might drop it and upgrade it to a write, only to return with it held for reading (in the success case) or with it completely dropped (in the failure case). In the process, we remove all the stack expansion from GUP (where dropping the lock wouldn't be ok without special rules anyway), and add it in manually to __access_remote_vm() for ptrace(). Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases. Everything else here felt pretty straightforward, but the ia64 rules for stack expansion are really quite odd and very different from everything else. Also thanks to Vegard Nossum who caught me getting one of those odd conditions entirely the wrong way around. Anyway, I think I want to actually move all the stack expansion code to a whole new file of its own, rather than have it split up between mm/mmap.c and mm/memory.c, but since this will have to be backported to the initial maple tree vma introduction anyway, I tried to keep the patches _fairly_ minimal. Also, while I don't think it's valid to expand the stack from GUP, the final patch in here is a "warn if some crazy GUP user wants to try to expand the stack" patch. That one will be reverted before the final release, but it's left to catch any odd cases during the merge window and release candidates. Reported-by: Ruihan Li <lrh2000@pku.edu.cn> * branch 'expand-stack': gup: add warning if some caller would seem to want stack expansion mm: always expand the stack with the mmap write lock held execve: expand new process stack manually ahead of time mm: make find_extend_vma() fail if write lock not held powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma() mm/fault: convert remaining simple cases to lock_mm_and_find_vma() arm/mm: Convert to using lock_mm_and_find_vma() riscv/mm: Convert to using lock_mm_and_find_vma() mips/mm: Convert to using lock_mm_and_find_vma() powerpc/mm: Convert to using lock_mm_and_find_vma() arm64/mm: Convert to using lock_mm_and_find_vma() mm: make the page fault mmap locking killable mm: introduce new 'lock_mm_and_find_vma()' page fault helper 
This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.

It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.

And it worked fine.  We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.

That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken.  Oops.

It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful.  We have basically three
different cases of stack expansion, and they all work just a bit
differently:

 - the common and obvious case is the page fault handling. It's actually
   fairly simple and straightforward, except for the fact that we have
   something like 24 different versions of it, and you end up in a maze
   of twisty little passages, all alike.

 - the simplest case is the execve() code that creates a new stack.
   There are no real locking concerns because it's all in a private new
   VM that hasn't been exposed to anybody, but lockdep still can end up
   unhappy if you get it wrong.

 - and finally, we have GUP and page pinning, which shouldn't really be
   expanding the stack in the first place, but in addition to execve()
   we also use it for ptrace(). And debuggers do want to possibly access
   memory under the stack pointer and thus need to be able to expand the
   stack as a special case.

None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times.  And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.

So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.

Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa.  So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.

And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.

That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern.  Along with the couple of special cases in execve() and
GUP.

So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion.  The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".

The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.

And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).

In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().

Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else.  Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.

Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.

Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch.  That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.

Reported-by: Ruihan Li <lrh2000@pku.edu.cn>

* branch 'expand-stack':
  gup: add warning if some caller would seem to want stack expansion
  mm: always expand the stack with the mmap write lock held
  execve: expand new process stack manually ahead of time
  mm: make find_extend_vma() fail if write lock not held
  powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
  mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
  arm/mm: Convert to using lock_mm_and_find_vma()
  riscv/mm: Convert to using lock_mm_and_find_vma()
  mips/mm: Convert to using lock_mm_and_find_vma()
  powerpc/mm: Convert to using lock_mm_and_find_vma()
  arm64/mm: Convert to using lock_mm_and_find_vma()
  mm: make the page fault mmap locking killable
  mm: introduce new 'lock_mm_and_find_vma()' page fault helper
mm: always expand the stack with the mmap write lock held 2023-06-27T16:41:30+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-24T20:45:51+00:00 8d7071af890768438c14db6172cc8f9f4d04e184 This finishes the job of always holding the mmap write lock when extending the user stack vma, and removes the 'write_locked' argument from the vm helper functions again. For some cases, we just avoid expanding the stack at all: drivers and page pinning really shouldn't be extending any stacks. Let's see if any strange users really wanted that. It's worth noting that architectures that weren't converted to the new lock_mm_and_find_vma() helper function are left using the legacy "expand_stack()" function, but it has been changed to drop the mmap_lock and take it for writing while expanding the vma. This makes it fairly straightforward to convert the remaining architectures. As a result of dropping and re-taking the lock, the calling conventions for this function have also changed, since the old vma may no longer be valid. So it will now return the new vma if successful, and NULL - and the lock dropped - if the area could not be extended. Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # ia64 Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This finishes the job of always holding the mmap write lock when
extending the user stack vma, and removes the 'write_locked' argument
from the vm helper functions again.

For some cases, we just avoid expanding the stack at all: drivers and
page pinning really shouldn't be extending any stacks.  Let's see if any
strange users really wanted that.

It's worth noting that architectures that weren't converted to the new
lock_mm_and_find_vma() helper function are left using the legacy
"expand_stack()" function, but it has been changed to drop the mmap_lock
and take it for writing while expanding the vma.  This makes it fairly
straightforward to convert the remaining architectures.

As a result of dropping and re-taking the lock, the calling conventions
for this function have also changed, since the old vma may no longer be
valid.  So it will now return the new vma if successful, and NULL - and
the lock dropped - if the area could not be extended.

Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # ia64
Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: make find_extend_vma() fail if write lock not held 2023-06-24T21:13:54+00:00 Liam R. Howlett Liam.Howlett@oracle.com 2023-06-16T22:58:54+00:00 f440fa1ac955e2898893f9301568435eb5cdfc4b Make calls to extend_vma() and find_extend_vma() fail if the write lock is required. To avoid making this a flag-day event, this still allows the old read-locking case for the trivial situations, and passes in a flag to say "is it write-locked". That way write-lockers can say "yes, I'm being careful", and legacy users will continue to work in all the common cases until they have been fully converted to the new world order. Co-Developed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Make calls to extend_vma() and find_extend_vma() fail if the write lock
is required.

To avoid making this a flag-day event, this still allows the old
read-locking case for the trivial situations, and passes in a flag to
say "is it write-locked".  That way write-lockers can say "yes, I'm
being careful", and legacy users will continue to work in all the common
cases until they have been fully converted to the new world order.

Co-Developed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
binfmt_elf: fix comment typo s/reset/regset/ 2023-06-23T16:36:30+00:00 Baruch Siach baruch@tkos.co.il 2023-06-23T05:56:44+00:00 aa88054b70905069d1cf706aa5e9a3418d1d341d Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/0b2967c4a4141875c493e835d5a6f8f2d19ae2d6.1687499804.git.baruch@tkos.co.il 
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/0b2967c4a4141875c493e835d5a6f8f2d19ae2d6.1687499804.git.baruch@tkos.co.il
coredump, vmcore: Set p_align to 4 for PT_NOTE 2023-05-16T21:32:00+00:00 Fangrui Song maskray@google.com 2023-05-12T02:25:28+00:00 60592fb6b67c653beaa2e7acad9a9d7aa0b71dff Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program header as an array of 4-byte entries or 8-byte entries. Currently, there are workarounds[1] in place for Linux to treat p_align==0 as 4. However, it would be more appropriate to set the correct alignment so that tools do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as well. [1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6 [2]: https://reviews.llvm.org/D150022 Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com 
Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
Merge tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2023-04-28T02:57:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-04-28T02:57:00+00:00 33afd4b76393627477e878b3b195d606e585d816 Pull non-MM updates from Andrew Morton: "Mainly singleton patches all over the place. Series of note are: - updates to scripts/gdb from Glenn Washburn - kexec cleanups from Bjorn Helgaas" * tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits) mailmap: add entries for Paul Mackerras libgcc: add forward declarations for generic library routines mailmap: add entry for Oleksandr ocfs2: reduce ioctl stack usage fs/proc: add Kthread flag to /proc/$pid/status ia64: fix an addr to taddr in huge_pte_offset() checkpatch: introduce proper bindings license check epoll: rename global epmutex scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry() scripts/gdb: create linux/vfs.py for VFS related GDB helpers uapi/linux/const.h: prefer ISO-friendly __typeof__ delayacct: track delays from IRQ/SOFTIRQ scripts/gdb: timerlist: convert int chunks to str scripts/gdb: print interrupts scripts/gdb: raise error with reduced debugging information scripts/gdb: add a Radix Tree Parser lib/rbtree: use '+' instead of '|' for setting color. proc/stat: remove arch_idle_time() checkpatch: check for misuse of the link tags checkpatch: allow Closes tags with links ... 
Pull non-MM updates from Andrew Morton:
 "Mainly singleton patches all over the place.

  Series of note are:

   - updates to scripts/gdb from Glenn Washburn

   - kexec cleanups from Bjorn Helgaas"

* tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits)
  mailmap: add entries for Paul Mackerras
  libgcc: add forward declarations for generic library routines
  mailmap: add entry for Oleksandr
  ocfs2: reduce ioctl stack usage
  fs/proc: add Kthread flag to /proc/$pid/status
  ia64: fix an addr to taddr in huge_pte_offset()
  checkpatch: introduce proper bindings license check
  epoll: rename global epmutex
  scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry()
  scripts/gdb: create linux/vfs.py for VFS related GDB helpers
  uapi/linux/const.h: prefer ISO-friendly __typeof__
  delayacct: track delays from IRQ/SOFTIRQ
  scripts/gdb: timerlist: convert int chunks to str
  scripts/gdb: print interrupts
  scripts/gdb: raise error with reduced debugging information
  scripts/gdb: add a Radix Tree Parser
  lib/rbtree: use '+' instead of '|' for setting color.
  proc/stat: remove arch_idle_time()
  checkpatch: check for misuse of the link tags
  checkpatch: allow Closes tags with links
  ...
binfmt_elf: remove MODULE_LICENSE in non-modules 2023-04-13T20:13:52+00:00 Nick Alcock nick.alcock@oracle.com 2023-03-07T18:01:35+00:00 7435721a4a7b6f51b60c41a2e58075dec3cc0ca8 Since commit 8b41fc4454e ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations are used to identify modules. As a consequence, uses of the macro in non-modules will cause modprobe to misidentify their containing object file as a module when it is not (false positives), and modprobe might succeed rather than failing with a suitable error message. So remove it in the files in this commit, none of which can be built as modules. Signed-off-by: Nick Alcock <nick.alcock@oracle.com> Suggested-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: linux-modules@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> 
Since commit 8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
ELF: fix all "Elf" typos 2023-04-08T20:45:37+00:00 Alexey Dobriyan adobriyan@gmail.com 2023-02-28T12:14:17+00:00 70e79866ab36feaaed8ef26dacfbcbac6a0631c9 ELF is acronym and therefore should be spelled in all caps. I left one exception at Documentation/arm/nwfpe/nwfpe.rst which looks like being written in the first person. Link: https://lkml.kernel.org/r/Y/3wGWQviIOkyLJW@p183 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
ELF is acronym and therefore should be spelled in all caps.

I left one exception at Documentation/arm/nwfpe/nwfpe.rst which looks like
being written in the first person.

Link: https://lkml.kernel.org/r/Y/3wGWQviIOkyLJW@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge tag 'v6.2-rc6' into sched/core, to pick up fixes 2023-01-31T14:01:20+00:00 Ingo Molnar mingo@kernel.org 2023-01-31T14:01:20+00:00 57a30218fa25c469ed507964bbf028b7a064309a Pick up fixes before merging another batch of cpuidle updates. Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Pick up fixes before merging another batch of cpuidle updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
elfcore: Add a cprm parameter to elf_core_extra_{phdrs,data_size} 2023-01-05T15:12:12+00:00 Catalin Marinas catalin.marinas@arm.com 2022-12-22T18:12:50+00:00 19e183b54528f11fafeca60fc6d0821e29ff281e A subsequent fix for arm64 will use this parameter to parse the vma information from the snapshot created by dump_vma_snapshot() rather than traversing the vma list without the mmap_lock. Fixes: 6dd8b1a0b6cb ("arm64: mte: Dump the MTE tags in the core file") Cc: <stable@vger.kernel.org> # 5.18.x Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Seth Jenkins <sethjenkins@google.com> Suggested-by: Seth Jenkins <sethjenkins@google.com> Cc: Will Deacon <will@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221222181251.1345752-3-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org> 
A subsequent fix for arm64 will use this parameter to parse the vma
information from the snapshot created by dump_vma_snapshot() rather than
traversing the vma list without the mmap_lock.

Fixes: 6dd8b1a0b6cb ("arm64: mte: Dump the MTE tags in the core file")
Cc: <stable@vger.kernel.org> # 5.18.x
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Seth Jenkins <sethjenkins@google.com>
Suggested-by: Seth Jenkins <sethjenkins@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221222181251.1345752-3-catalin.marinas@arm.com
Signed-off-by: Will Deacon <will@kernel.org>