Files
linux/drivers/gpu/drm/i915/i915_selftest.h
Krzysztof Karas e8c3344765 drm/i915/selftests: Prevent userspace mapping invalidation
Migration testing in i915 assumes current task's address space
to allocate new userspace mapping and uses it without
registering real user for that address space in mm_struct.
On single NUMA node setups PCI probe executes in the same
context as userspace process calling the test (i915_selftest
from IGT), but when multiple nodes are available, the PCI code
puts probe into a kernel workqueue. This switches execution to
a kworker, which does not have its own address space in
userspace and must borrow such memory from another process, so
"current->active_mm" is unknown at the start of the test.

It was observed that mm->mm_users would occasionally be 0
or drop to 0 during the test due to short delay between
scheduling and executing work in forked process, which reaped
userspace mappings, further leading to failures upon reading
from userland memory.

Prevent this by adding a PID parameter to a trusted task, so its
mm_struct may be used if needed.

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14204
Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20260508080214.1979686-2-krzysztof.karas@intel.com
2026-05-19 13:28:49 +02:00

146 lines
4.6 KiB
C

/*
* Copyright © 2016 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef __I915_SELFTEST_H__
#define __I915_SELFTEST_H__
#include <linux/types.h>
#define STACK_MAGIC 0xdeadbeef
struct pci_dev;
struct drm_i915_private;
struct i915_selftest {
unsigned long timeout_jiffies;
unsigned int timeout_ms;
unsigned int random_seed;
unsigned int userspace_pid;
char *filter;
int mock;
int live;
int perf;
};
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include <linux/fault-inject.h>
extern struct i915_selftest i915_selftest;
int i915_mock_selftests(void);
int i915_live_selftests(struct pci_dev *pdev);
int i915_perf_selftests(struct pci_dev *pdev);
/* We extract the function declarations from i915_mock_selftests.h and
* i915_live_selftests.h Add your unit test declarations there!
*
* Mock unit tests are run very early upon module load, before the driver
* is probed. All hardware interactions, as well as other subsystems, must
* be "mocked".
*
* Live unit tests are run after the driver is loaded - all hardware
* interactions are real.
*/
#define selftest(name, func) int func(void);
#include "selftests/i915_mock_selftests.h"
#undef selftest
#define selftest(name, func) int func(struct drm_i915_private *i915);
#include "selftests/i915_live_selftests.h"
#include "selftests/i915_perf_selftests.h"
#undef selftest
struct i915_subtest {
int (*func)(void *data);
const char *name;
};
int __i915_nop_setup(void *data);
int __i915_nop_teardown(int err, void *data);
int __i915_live_setup(void *data);
int __i915_live_teardown(int err, void *data);
int __intel_gt_live_setup(void *data);
int __intel_gt_live_teardown(int err, void *data);
int __i915_subtests(const char *caller,
int (*setup)(void *data),
int (*teardown)(int err, void *data),
const struct i915_subtest *st,
unsigned int count,
void *data);
#define i915_subtests(T, data) \
__i915_subtests(__func__, \
__i915_nop_setup, __i915_nop_teardown, \
T, ARRAY_SIZE(T), data)
#define i915_live_subtests(T, data) ({ \
typecheck(struct drm_i915_private *, data); \
(data)->gt[0]->uc.guc.submission_state.sched_disable_delay_ms = 0; \
__i915_subtests(__func__, \
__i915_live_setup, __i915_live_teardown, \
T, ARRAY_SIZE(T), data); \
})
#define intel_gt_live_subtests(T, data) ({ \
typecheck(struct intel_gt *, data); \
(data)->uc.guc.submission_state.sched_disable_delay_ms = 0; \
__i915_subtests(__func__, \
__intel_gt_live_setup, __intel_gt_live_teardown, \
T, ARRAY_SIZE(T), data); \
})
#define SUBTEST(x) { x, #x }
#define I915_SELFTEST_DECLARE(x) x
#define I915_SELFTEST_ONLY(x) unlikely(x)
#define I915_SELFTEST_EXPORT
#else /* !IS_ENABLED(CONFIG_DRM_I915_SELFTEST) */
static inline int i915_mock_selftests(void) { return 0; }
static inline int i915_live_selftests(struct pci_dev *pdev) { return 0; }
static inline int i915_perf_selftests(struct pci_dev *pdev) { return 0; }
#define I915_SELFTEST_DECLARE(x)
#define I915_SELFTEST_ONLY(x) 0
#define I915_SELFTEST_EXPORT static
#endif
/* Using the i915_selftest_ prefix becomes a little unwieldy with the helpers.
* Instead we use the igt_ shorthand, in reference to the intel-gpu-tools
* suite of uabi test cases (which includes a test runner for our selftests).
*/
#define IGT_TIMEOUT(name__) \
unsigned long name__ = jiffies + i915_selftest.timeout_jiffies
__printf(2, 3)
bool __igt_timeout(unsigned long timeout, const char *fmt, ...);
#define igt_timeout(t, fmt, ...) \
__igt_timeout((t), KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
void igt_hexdump(const void *buf, size_t len);
#endif /* !__I915_SELFTEST_H__ */