[PATCH RFC v2 8/8] drm/i915: check if current->mm is not NULL
From: Mauro Carvalho Chehab
Date: Thu Nov 03 2022 - 10:52:12 EST
The mmap tests require mm in order to work. Failing to do that
will cause a crash:
[ 316.820722] BUG: kernel NULL pointer dereference, address: 00000000000000e8
[ 316.822517] #PF: supervisor write access in kernel mode
[ 316.823430] #PF: error_code(0x0002) - not-present page
[ 316.824390] PGD 0 P4D 0
[ 316.825357] Oops: 0002 [#1] PREEMPT SMP NOPTI
[ 316.826350] CPU: 0 PID: 1517 Comm: kunit_try_catch Tainted: G U N 6.1.0-rc2-drm-266703e6f163+ #14
[ 316.827503] Hardware name: Intel Corporation Tiger Lake Client Platform/TigerLake Y LPDDR4x T4 Crb, BIOS TGLSFWI1.R00.3243.A01.2006102133 06/10/2020
[ 316.828633] RIP: 0010:down_write_killable+0x50/0x110
[ 316.829756] Code: 24 10 45 31 c9 31 c9 41 b8 01 00 00 00 31 d2 31 f6 48 89 ef e8 e1 74 4a ff bf 01 00 00 00 e8 87 d6 46 ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 13 0f 94 c0 5a 84 c0 74 62 8b 05 49 12 e4 00 85 c0 74
[ 316.830896] RSP: 0018:ffffc90001eabc58 EFLAGS: 00010246
[ 316.832008] RAX: 0000000000000000 RBX: 00000000000000e8 RCX: 0000000000000000
[ 316.833141] RDX: 0000000000000001 RSI: ffffffff81c94fc9 RDI: ffffffff81c94fc9
[ 316.834195] RBP: 0000000000000158 R08: 0000000000000001 R09: 0000000000000000
[ 316.835231] R10: 0000000000000000 R11: ffff8883a13350b8 R12: 0000000000000002
[ 316.836259] R13: 0000000000000001 R14: 0000000000100000 R15: 00000000000000e8
[ 316.837237] FS: 0000000000000000(0000) GS:ffff8883a3800000(0000) knlGS:0000000000000000
[ 316.838214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 316.839190] CR2: 00000000000000e8 CR3: 0000000002812003 CR4: 0000000000770ef0
[ 316.840147] PKRU: 55555554
[ 316.841099] Call Trace:
[ 316.842047] <TASK>
[ 316.842990] ? vm_mmap_pgoff+0x78/0x150
[ 316.843936] vm_mmap_pgoff+0x78/0x150
[ 316.844884] igt_mmap_offset+0x178/0x1b9 [i915]
[ 316.846119] __igt_mmap+0xfe/0x680 [i915]
Unfortunately, when KUnit module runs, it doesn't create an
user context, causing mmap tests to fail.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---
To avoid mailbombing on a large number of people, only mailing lists were C/C on the cover.
See [PATCH RFC v2 0/8] at: https://lore.kernel.org/all/cover.1667486144.git.mchehab@xxxxxxxxxx/
drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
index add5ae56cd89..2c5f93e946b5 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
@@ -1845,6 +1845,11 @@ int i915_gem_mman_live_selftests(struct drm_i915_private *i915)
SUBTEST(igt_mmap_gpu),
};
+ if (!current->mm) {
+ pr_err("Test called without an user context!\n");
+ return -EINVAL;
+ }
+
return i915_live_subtests(tests, i915);
}
EXPORT_SYMBOL_NS_GPL(i915_gem_mman_live_selftests, I915_SELFTEST);
--
2.38.1