I think this is fine, but I was wondering if it would be simpler and
easier to just remove the sched cleanup from v3d_job_init and instead
always rely on callers to eventually call v3d_job_cleanup for fail
paths, where we are already calling v3d_job_cleanup.
Iago
El mar, 09-01-2024 a las 11:28 -0300, Maíra Canal escribió:
> Currently, if `v3d_job_init()` fails (e.g. in the IGT test "bad-in-
> sync",
> where we submit an invalid in-sync to the IOCTL), then we end up with
> the following NULL pointer dereference:
>
> [ 34.146279] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000078
> [ 34.146301] Mem abort info:
> [ 34.146306] ESR = 0x0000000096000005
> [ 34.146315] EC = 0x25: DABT (current EL), IL = 32 bits
> [ 34.146322] SET = 0, FnV = 0
> [ 34.146328] EA = 0, S1PTW = 0
> [ 34.146334] FSC = 0x05: level 1 translation fault
> [ 34.146340] Data abort info:
> [ 34.146345] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
> [ 34.146351] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [ 34.146357] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [ 34.146366] user pgtable: 4k pages, 39-bit VAs,
> pgdp=00000001232e6000
> [ 34.146375] [0000000000000078] pgd=0000000000000000,
> p4d=0000000000000000, pud=0000000000000000
> [ 34.146399] Internal error: Oops: 0000000096000005 [#1] PREEMPT
> SMP
> [ 34.146406] Modules linked in: rfcomm snd_seq_dummy snd_hrtimer
> snd_seq snd_seq_device algif_hash aes_neon_bs aes_neon_blk
> algif_skcipher af_alg bnep hid_logitech_hidpp brcmfmac_wcc brcmfmac
> brcmutil hci_uart vc4 btbcm cfg80211 bluetooth bcm2835_v4l2(C)
> snd_soc_hdmi_codec binfmt_misc cec drm_display_helper hid_logitech_dj
> bcm2835_mmal_vchiq(C) drm_dma_helper drm_kms_helper videobuf2_v4l2
> raspberrypi_hwmon ecdh_generic videobuf2_vmalloc videobuf2_memops ecc
> videobuf2_common rfkill videodev libaes snd_soc_core dwc2 i2c_brcmstb
> snd_pcm_dmaengine snd_bcm2835(C) i2c_bcm2835 pwm_bcm2835 snd_pcm mc
> v3d snd_timer snd gpu_sched drm_shmem_helper nvmem_rmem
> uio_pdrv_genirq uio i2c_dev drm fuse dm_mod
> drm_panel_orientation_quirks backlight configfs ip_tables x_tables
> ipv6
> [ 34.146556] CPU: 1 PID: 1890 Comm: v3d_submit_csd Tainted:
> G C 6.7.0-rc3-g49ddab089611 #68
> [ 34.146563] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
> [ 34.146569] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [ 34.146575] pc : drm_sched_job_cleanup+0x3c/0x190 [gpu_sched]
> [ 34.146611] lr : v3d_submit_csd_ioctl+0x1b4/0x460 [v3d]
> [ 34.146653] sp : ffffffc083cbbb80
> [ 34.146658] x29: ffffffc083cbbb90 x28: ffffff81035afc00 x27:
> ffffffe77a641168
> [ 34.146668] x26: ffffff81056a8000 x25: 0000000000000058 x24:
> 0000000000000000
> [ 34.146677] x23: ffffff81065e2000 x22: ffffff81035afe00 x21:
> ffffffc083cbbcf0
> [ 34.146686] x20: ffffff81035afe00 x19: 00000000ffffffea x18:
> 0000000000000000
> [ 34.146694] x17: 0000000000000000 x16: ffffffe7989e34b0 x15:
> 0000000000000000
> [ 34.146703] x14: 0000000004000004 x13: ffffff81035afe80 x12:
> ffffffc083cb8000
> [ 34.146711] x11: cc57e05dfbe5ef00 x10: cc57e05dfbe5ef00 x9 :
> ffffffe77a64131c
> [ 34.146719] x8 : 0000000000000000 x7 : 0000000000000000 x6 :
> 000000000000003f
> [ 34.146727] x5 : 0000000000000040 x4 : ffffff81fefb03f0 x3 :
> ffffffc083cbba40
> [ 34.146736] x2 : ffffff81056a8000 x1 : ffffffe7989e35e8 x0 :
> 0000000000000000
> [ 34.146745] Call trace:
> [ 34.146748] drm_sched_job_cleanup+0x3c/0x190 [gpu_sched]
> [ 34.146768] v3d_submit_csd_ioctl+0x1b4/0x460 [v3d]
> [ 34.146791] drm_ioctl_kernel+0xe0/0x120 [drm]
> [ 34.147029] drm_ioctl+0x264/0x408 [drm]
> [ 34.147135] __arm64_sys_ioctl+0x9c/0xe0
> [ 34.147152] invoke_syscall+0x4c/0x118
> [ 34.147162] el0_svc_common+0xb8/0xf0
> [ 34.147168] do_el0_svc+0x28/0x40
> [ 34.147174] el0_svc+0x38/0x88
> [ 34.147184] el0t_64_sync_handler+0x84/0x100
> [ 34.147191] el0t_64_sync+0x190/0x198
> [ 34.147201] Code: aa0003f4 f90007e8 f9401008 aa0803e0 (b8478c09)
> [ 34.147210] ---[ end trace 0000000000000000 ]---
>
> This happens because we are calling `drm_sched_job_cleanup()` twice:
> once at `v3d_job_init()` and again when we call `v3d_job_cleanup()`.
>
> To mitigate this issue, we can return to the same approach that we
> used
> to use before 464c61e76de8: deallocate the job after `v3d_job_init()`
> fails and assign it to NULL. Then, when we call `v3d_job_cleanup()`,
> job
> is NULL and the function returns.
>
> Fixes: 464c61e76de8 ("drm/v3d: Decouple job allocation from job
> initiation")
> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
> ---
> drivers/gpu/drm/v3d/v3d_submit.c | 35 +++++++++++++++++++++++++-----
> --
> 1 file changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_submit.c
> b/drivers/gpu/drm/v3d/v3d_submit.c
> index fcff41dd2315..88f63d526b22 100644
> --- a/drivers/gpu/drm/v3d/v3d_submit.c
> +++ b/drivers/gpu/drm/v3d/v3d_submit.c
> @@ -147,6 +147,13 @@ v3d_job_allocate(void **container, size_t size)
> return 0;
> }
>
> +static void
> +v3d_job_deallocate(void **container)
> +{
> + kfree(*container);
> + *container = NULL;
> +}
> +
> static int
> v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
> struct v3d_job *job, void (*free)(struct kref *ref),
> @@ -273,8 +280,10 @@ v3d_setup_csd_jobs_and_bos(struct drm_file
> *file_priv,
>
> ret = v3d_job_init(v3d, file_priv, &(*job)->base,
> v3d_job_free, args->in_sync, se,
> V3D_CSD);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)job);
> return ret;
> + }
>
> ret = v3d_job_allocate((void *)clean_job,
> sizeof(**clean_job));
> if (ret)
> @@ -282,8 +291,10 @@ v3d_setup_csd_jobs_and_bos(struct drm_file
> *file_priv,
>
> ret = v3d_job_init(v3d, file_priv, *clean_job,
> v3d_job_free, 0, NULL, V3D_CACHE_CLEAN);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)clean_job);
> return ret;
> + }
>
> (*job)->args = *args;
>
> @@ -860,8 +871,10 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void
> *data,
>
> ret = v3d_job_init(v3d, file_priv, &render->base,
> v3d_render_job_free, args->in_sync_rcl,
> &se, V3D_RENDER);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)&render);
> goto fail;
> + }
>
> render->start = args->rcl_start;
> render->end = args->rcl_end;
> @@ -874,8 +887,10 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void
> *data,
>
> ret = v3d_job_init(v3d, file_priv, &bin->base,
> v3d_job_free, args->in_sync_bcl,
> &se, V3D_BIN);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)&bin);
> goto fail;
> + }
>
> bin->start = args->bcl_start;
> bin->end = args->bcl_end;
> @@ -892,8 +907,10 @@ v3d_submit_cl_ioctl(struct drm_device *dev, void
> *data,
>
> ret = v3d_job_init(v3d, file_priv, clean_job,
> v3d_job_free, 0, NULL,
> V3D_CACHE_CLEAN);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)&clean_job);
> goto fail;
> + }
>
> last_job = clean_job;
> } else {
> @@ -1015,8 +1032,10 @@ v3d_submit_tfu_ioctl(struct drm_device *dev,
> void *data,
>
> ret = v3d_job_init(v3d, file_priv, &job->base,
> v3d_job_free, args->in_sync, &se,
> V3D_TFU);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)&job);
> goto fail;
> + }
>
> job->base.bo = kcalloc(ARRAY_SIZE(args->bo_handles),
> sizeof(*job->base.bo), GFP_KERNEL);
> @@ -1233,8 +1252,10 @@ v3d_submit_cpu_ioctl(struct drm_device *dev,
> void *data,
>
> ret = v3d_job_init(v3d, file_priv, &cpu_job->base,
> v3d_job_free, 0, &se, V3D_CPU);
> - if (ret)
> + if (ret) {
> + v3d_job_deallocate((void *)&cpu_job);
> goto fail;
> + }
>
> clean_job = cpu_job->indirect_csd.clean_job;
> csd_job = cpu_job->indirect_csd.job;
> --
> 2.43.0
>
>
