From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- Documentation/gpu/panfrost.rst | 49 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/gpu/panfrost.rst (limited to 'Documentation/gpu/panfrost.rst') diff --git a/Documentation/gpu/panfrost.rst b/Documentation/gpu/panfrost.rst new file mode 100644 index 000000000..51ba375fd --- /dev/null +++ b/Documentation/gpu/panfrost.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +========================= + drm/Panfrost Mali Driver +========================= + +.. _panfrost-usage-stats: + +Panfrost DRM client usage stats implementation +============================================== + +The drm/Panfrost driver implements the DRM client usage stats specification as +documented in :ref:`drm-client-usage-stats`. + +Example of the output showing the implemented key value pairs and entirety of +the currently possible format options: + +:: + pos: 0 + flags: 02400002 + mnt_id: 27 + ino: 531 + drm-driver: panfrost + drm-client-id: 14 + drm-engine-fragment: 1846584880 ns + drm-cycles-fragment: 1424359409 + drm-maxfreq-fragment: 799999987 Hz + drm-curfreq-fragment: 799999987 Hz + drm-engine-vertex-tiler: 71932239 ns + drm-cycles-vertex-tiler: 52617357 + drm-maxfreq-vertex-tiler: 799999987 Hz + drm-curfreq-vertex-tiler: 799999987 Hz + drm-total-memory: 290 MiB + drm-shared-memory: 0 MiB + drm-active-memory: 226 MiB + drm-resident-memory: 36496 KiB + drm-purgeable-memory: 128 KiB + +Possible `drm-engine-` key names are: `fragment`, and `vertex-tiler`. +`drm-curfreq-` values convey the current operating frequency for that engine. + +Users must bear in mind that engine and cycle sampling are disabled by default, +because of power saving concerns. `fdinfo` users and benchmark applications which +query the fdinfo file must make sure to toggle the job profiling status of the +driver by writing into the appropriate sysfs node:: + + echo > /sys/bus/platform/drivers/panfrost/[a-f0-9]*.gpu/profiling + +Where `N` is either `0` or `1`, depending on the desired enablement status. -- cgit v1.3.1