[PATCH] drm/i915: Add VM_DONTEXPAND to exported buffers

[Jacek Lawrynowicz]

drm_gem_mmap_obj() expects VM_DONTEXPAND flag to be set after mmap
callback is executed. Set this flag at the end of i915_gem_dmabuf_mmap()
to prevent WARN on mmap in buffers imported from i915 e.g.,

[  283.623215] WARNING: CPU: 1 PID: 12693 at drivers/gpu/drm/drm_gem.c:1087 drm_gem_mmap_obj+0x196/0x1c0
[  283.623221] Modules linked in: intel_vpu(OE) cmac nls_utf8 cifs cifs_arc4 nls_ucs2_utils cifs_md4 netfs overlay nls_iso8859_1 binfmt_misc intel_uncore_frequency intel_uncore_frequency_common x86_pkg_temp_thermal intel_powerclamp intel_rapl_msr coretemp rapl intel_cstate kvm_intel wmi_bmof input_leds kvm processor_thermal_device_pci processor_thermal_device processor_thermal_wt_hint processor_thermal_rfim processor_thermal_rapl intel_rapl_common processor_thermal_wt_req intel_vsec processor_thermal_stc processor_thermal_power_floor igen6_edac processor_thermal_mbox pac1934 industrialio int3403_thermal int340x_thermal_zone intel_pmc_core int3400_thermal pmt_telemetry intel_hid pmt_class acpi_thermal_rel sparse_keymap acpi_tad acpi_pad efi_pstore autofs4 btrfs blake2b_generic raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 xe drm_ttm_helper drm_suballoc_helper drm_gpuvm drm_exec hid_sensor_custom hid_sensor_hub intel_ishtp_hid hid_generic usbhid hid i915
[  283.623254]  crct10dif_pclmul i2c_algo_bit crc32_pclmul drm_buddy ghash_clmulni_intel ttm sha512_ssse3 sha256_ssse3 e1000e drm_display_helper nvme sha1_ssse3 intel_lpss_pci thunderbolt intel_ish_ipc intel_lpss vmd intel_ishtp idma64 nvme_core drm_kms_helper video wmi pinctrl_meteorlake backlight pinctrl_intel aesni_intel crypto_simd cryptd [last unloaded: intel_vpu(OE)]
[  283.623267] CPU: 1 UID: 0 PID: 12693 Comm: npu-kmd-test Tainted: G     U     OE      6.12.0-performance-20241122-11972534541 #1 f86ee8132c283cf158e9fd89cc84f4adeb3b79b7
[  283.623269] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  283.623270] Hardware name: Intel Corporation Meteor Lake Client Platform/MTL-P DDR5 SODIMM SBS RVP, BIOS MTLPFWI1.R00.4122.D21.2408281317 08/28/2024
[  283.623271] RIP: 0010:drm_gem_mmap_obj+0x196/0x1c0
[  283.623273] Code: 49 8b 94 24 40 01 00 00 48 8b 12 48 85 d2 74 31 89 45 ec 4c 89 e7 ff d2 0f 1f 00 8b 45 ec e9 f8 fe ff ff 0f 0b e9 54 ff ff ff <0f> 0b e9 ea fe ff ff b8 ea ff ff ff 31 d2 31 f6 31 ff c3 cc cc cc
[  283.623274] RSP: 0018:ffffc90004103b20 EFLAGS: 00010246
[  283.623275] RAX: 0000000000000000 RBX: ffff888313ebafd0 RCX: 0000000000000000
[  283.623276] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  283.623276] RBP: ffffc90004103b38 R08: 0000000000000000 R09: ffffc90004103bd8
[  283.623277] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888108b95400
[  283.623277] R13: ffff888108b95400 R14: ffff88815ee50000 R15: ffff88830133b000
[  283.623278] FS:  00007fcbf9063740(0000) GS:ffff88846fe40000(0000) knlGS:0000000000000000
[  283.623279] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  283.623280] CR2: 00007fcbeb15d460 CR3: 00000001076a2002 CR4: 0000000000f72ef0
[  283.623280] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  283.623281] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
[  283.623281] PKRU: 55555554
[  283.623282] Call Trace:
[  283.623283]  <TASK>
[  283.623285]  ? show_regs+0x75/0x90
[  283.623289]  ? __warn+0x91/0x150
[  283.623291]  ? drm_gem_mmap_obj+0x196/0x1c0
[  283.623292]  ? report_bug+0x1af/0x1c0
[  283.623295]  ? handle_bug+0x6e/0xb0
[  283.623297]  ? exc_invalid_op+0x1d/0x90
[  283.623298]  ? asm_exc_invalid_op+0x1f/0x30
[  283.623302]  ? drm_gem_mmap_obj+0x196/0x1c0
[  283.623304]  drm_gem_mmap+0x125/0x200
[  283.623305]  __mmap_region+0x7bc/0xc30
[  283.623310]  mmap_region+0x96/0xd0
[  283.623311]  do_mmap+0x526/0x650
[  283.623313]  vm_mmap_pgoff+0xec/0x1c0
[  283.623315]  ? __count_memcg_events+0x89/0x160
[  283.623317]  ksys_mmap_pgoff+0x175/0x230
[  283.623318]  __x64_sys_mmap+0x37/0x70
[  283.623320]  x64_sys_call+0x1c1d/0x2790
[  283.623322]  do_syscall_64+0x62/0x180
[  283.623324]  entry_SYSCALL_64_after_hwframe+0x71/0x79
[  283.623325] RIP: 0033:0x7fcbf8b1ea27
[  283.623327] Code: 00 00 00 89 ef e8 59 ae ff ff eb e4 e8 42 7b 01 00 66 90 f3 0f 1e fa 41 89 ca 41 f7 c1 ff 0f 00 00 75 10 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 21 c3 48 8b 05 d9 b3 0f 00 64 c7 00 16 00 00
[  283.623328] RSP: 002b:00007fff157ded78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[  283.623329] RAX: ffffffffffffffda RBX: 00007fff157dedf0 RCX: 00007fcbf8b1ea27
[  283.623330] RDX: 0000000000000003 RSI: 0000000000002000 RDI: 0000000000000000
[  283.623330] RBP: 00007fff157def80 R08: 0000000000000004 R09: 000000010418a000
[  283.623331] R10: 0000000000000001 R11: 0000000000000246 R12: 00007fff157dee70
[  283.623331] R13: 0000644e2fb203f8 R14: 00007fff157deef0 R15: 00007fff157deeb0
[  283.623333]  </TASK>
[  283.623333] ---[ end trace 0000000000000000 ]---

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 9473050ac8425..809018265e36f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -110,6 +110,7 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *
 	if (ret)
 		return ret;
 
+	vm_flags_set(vma, VM_DONTEXPAND);
 	vma_set_file(vma, obj->base.filp);
 
 	return 0;
-- 
2.45.1