Commit graph

4 commits

Author SHA1 Message Date
Alex Deucher
d7c4563aa3 drm/amdkfd: don't allow mapping the MMIO HDP page with large pages
commit be4a2a81b6b90d1a47eaeaace4cc8e2cb57b96c7 upstream.

We don't get the right offset in that case.  The GPU has
an unused 4K area of the register BAR space into which you can
remap registers.  We remap the HDP flush registers into this
space to allow userspace (CPU or GPU) to flush the HDP when it
updates VRAM.  However, on systems with >4K pages, we end up
exposing PAGE_SIZE of MMIO space.

Fixes: d8e408a82704 ("drm/amdkfd: Expose HDP registers to user space")
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:20:53 +01:00
Lancelot SIX
64c2a79382 drm/amdkfd: Flush the process wq before creating a kfd_process
[ Upstream commit f5b9053398e70a0c10aa9cb4dd5910ab6bc457c5 ]

There is a race condition when re-creating a kfd_process for a process.
This has been observed when a process under the debugger executes
exec(3).  In this scenario:
- The process executes exec.
 - This will eventually release the process's mm, which will cause the
   kfd_process object associated with the process to be freed
   (kfd_process_free_notifier decrements the reference count to the
   kfd_process to 0).  This causes kfd_process_ref_release to enqueue
   kfd_process_wq_release to the kfd_process_wq.
- The debugger receives the PTRACE_EVENT_EXEC notification, and tries to
  re-enable AMDGPU traps (KFD_IOC_DBG_TRAP_ENABLE).
 - When handling this request, KFD tries to re-create a kfd_process.
   This eventually calls kfd_create_process and kobject_init_and_add.

At this point the call to kobject_init_and_add can fail because the
old kfd_process.kobj has not been freed yet by kfd_process_wq_release.

This patch proposes to avoid this race by making sure to drain
kfd_process_wq before creating a new kfd_process object.  This way, we
know that any cleanup task is done executing when we reach
kobject_init_and_add.

Signed-off-by: Lancelot SIX <lancelot.six@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:26:52 +01:00
Dave Airlie
ddb3855894 amdkfd: use calloc instead of kzalloc to avoid integer overflow
commit 3b0daecfeac0103aba8b293df07a0cbaf8b43f29 upstream.

This uses calloc instead of doing the multiplication which might
overflow.

Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 09:22:13 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00