--- /dev/null
+From be4a2a81b6b90d1a47eaeaace4cc8e2cb57b96c7 Mon Sep 17 00:00:00 2001
+From: Alex Deucher <alexander.deucher@amd.com>
+Date: Sun, 14 Apr 2024 13:06:39 -0400
+Subject: drm/amdkfd: don't allow mapping the MMIO HDP page with large pages
+
+From: Alex Deucher <alexander.deucher@amd.com>
+
+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>
+---
+ drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
++++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+@@ -1311,7 +1311,7 @@ static int kfd_ioctl_alloc_memory_of_gpu
+ goto err_unlock;
+ }
+ offset = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd);
+- if (!offset) {
++ if (!offset || (PAGE_SIZE > 4096)) {
+ err = -ENOMEM;
+ goto err_unlock;
+ }
+@@ -1969,6 +1969,9 @@ static int kfd_mmio_mmap(struct kfd_dev
+ if (vma->vm_end - vma->vm_start != PAGE_SIZE)
+ return -EINVAL;
+
++ if (PAGE_SIZE > 4096)
++ return -EINVAL;
++
+ address = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd);
+
+ vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
--- /dev/null
+From 20401d1058f3f841f35a594ac2fc1293710e55b9 Mon Sep 17 00:00:00 2001
+From: Rafael Aquini <aquini@redhat.com>
+Date: Tue, 7 Sep 2021 20:00:53 -0700
+Subject: ipc: replace costly bailout check in sysvipc_find_ipc()
+
+From: Rafael Aquini <aquini@redhat.com>
+
+commit 20401d1058f3f841f35a594ac2fc1293710e55b9 upstream.
+
+sysvipc_find_ipc() was left with a costly way to check if the offset
+position fed to it is bigger than the total number of IPC IDs in use. So
+much so that the time it takes to iterate over /proc/sysvipc/* files grows
+exponentially for a custom benchmark that creates "N" SYSV shm segments
+and then times the read of /proc/sysvipc/shm (milliseconds):
+
+ 12 msecs to read 1024 segs from /proc/sysvipc/shm
+ 18 msecs to read 2048 segs from /proc/sysvipc/shm
+ 65 msecs to read 4096 segs from /proc/sysvipc/shm
+ 325 msecs to read 8192 segs from /proc/sysvipc/shm
+ 1303 msecs to read 16384 segs from /proc/sysvipc/shm
+ 5182 msecs to read 32768 segs from /proc/sysvipc/shm
+
+The root problem lies with the loop that computes the total amount of ids
+in use to check if the "pos" feeded to sysvipc_find_ipc() grew bigger than
+"ids->in_use". That is a quite inneficient way to get to the maximum
+index in the id lookup table, specially when that value is already
+provided by struct ipc_ids.max_idx.
+
+This patch follows up on the optimization introduced via commit
+15df03c879836 ("sysvipc: make get_maxid O(1) again") and gets rid of the
+aforementioned costly loop replacing it by a simpler checkpoint based on
+ipc_get_maxidx() returned value, which allows for a smooth linear increase
+in time complexity for the same custom benchmark:
+
+ 2 msecs to read 1024 segs from /proc/sysvipc/shm
+ 2 msecs to read 2048 segs from /proc/sysvipc/shm
+ 4 msecs to read 4096 segs from /proc/sysvipc/shm
+ 9 msecs to read 8192 segs from /proc/sysvipc/shm
+ 19 msecs to read 16384 segs from /proc/sysvipc/shm
+ 39 msecs to read 32768 segs from /proc/sysvipc/shm
+
+Link: https://lkml.kernel.org/r/20210809203554.1562989-1-aquini@redhat.com
+Signed-off-by: Rafael Aquini <aquini@redhat.com>
+Acked-by: Davidlohr Bueso <dbueso@suse.de>
+Acked-by: Manfred Spraul <manfred@colorfullife.com>
+Cc: Waiman Long <llong@redhat.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ ipc/util.c | 16 ++++------------
+ 1 file changed, 4 insertions(+), 12 deletions(-)
+
+--- a/ipc/util.c
++++ b/ipc/util.c
+@@ -754,21 +754,13 @@ struct pid_namespace *ipc_seq_pid_ns(str
+ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
+ loff_t *new_pos)
+ {
+- struct kern_ipc_perm *ipc;
+- int total, id;
++ struct kern_ipc_perm *ipc = NULL;
++ int max_idx = ipc_get_maxidx(ids);
+
+- total = 0;
+- for (id = 0; id < pos && total < ids->in_use; id++) {
+- ipc = idr_find(&ids->ipcs_idr, id);
+- if (ipc != NULL)
+- total++;
+- }
+-
+- ipc = NULL;
+- if (total >= ids->in_use)
++ if (max_idx == -1 || pos > max_idx)
+ goto out;
+
+- for (; pos < ipc_mni; pos++) {
++ for (; pos <= max_idx; pos++) {
+ ipc = idr_find(&ids->ipcs_idr, pos);
+ if (ipc != NULL) {
+ rcu_read_lock();
projects / thirdparty / kernel / stable-queue.git / commitdiff
