Re: [PATCH 1/2] drm/imagination: Propagate map failures correctly from pvr_mmu_map_sgl()

[Alexandru Dadu]

On Wed, 2026-09-02 at 15:25 +0530, Brajesh Gupta wrote:
Hi Brajesh,
> *** NOTE: This is an internal email from Imagination Technologies ***
> 
> 
> 
> 
> Map failure from pvr_mmu_map_sgl() interface was not returned
> correctly
> to pvr_mmu_map() interface. This resulted in pvr_mmu_map() interface
> to
> continue instead of returning an error to caller.
> Fix it by returning a proper error code from pvr_mmu_map_sgl()
> interface.
> 
> Call stack for crash:
> [ 1179.286237] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000008
> [ 1179.295067] Mem abort info:
> [ 1179.297877]   ESR = 0x0000000096000004
> [ 1179.301656]   EC = 0x25: DABT (current EL), IL = 32 bits
> [ 1179.306987]   SET = 0, FnV = 0
> [ 1179.310048]   EA = 0, S1PTW = 0
> [ 1179.313198]   FSC = 0x04: level 0 translation fault
> [ 1179.318096] Data abort info:
> [ 1179.320993]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [ 1179.326483]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [ 1179.331546]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [ 1179.336895] user pgtable: 4k pages, 48-bit VAs,
> pgdp=000000009822a000
> [ 1179.343402] [0000000000000008] pgd=0000000000000000,
> p4d=0000000000000000
> [ 1179.350243] Internal error: Oops: 0000000096000004 [#2]  SMP
> [ 1179.355908] Modules linked in: powervr gpu_sched drm_shmem_helper
> drm_gpuvm drm_exec xhci_plat_hcd xhci_hcd dwc3 usbcore usb_common
> snd_soc_simple_card snd_soc_simple_card_utils dwc3_am62 at24 sa2ul
> sha512 libsha512 sha256 authenc sch_fq_codel fuse dm_mod ipv6
> [ 1179.378992] CPU: 1 UID: 1000 PID: 680 Comm: deqp-vk Tainted:
> G      D             6.17.0 #1 PREEMPT
> [ 1179.388120] Tainted: [D]=DIE
> [ 1179.390994] Hardware name: Texas Instruments AM625 SK (DT)
> [ 1179.396467] pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [ 1179.403415] pc : pvr_mmu_op_context_unmap_curr_page+0x6c/0x134
> [powervr]
> [ 1179.410140] lr : pvr_mmu_op_context_unmap_curr_page+0x58/0x134
> [powervr]
> [ 1179.416848] sp : ffff8000839ab8c0
> [ 1179.420153] x29: ffff8000839ab8c0 x28: 0000000000000001 x27:
> 000000008f386000
> [ 1179.427283] x26: ffff000016d1df98 x25: 0000000000247000 x24:
> 00000000000001e6
> [ 1179.434413] x23: 0000000000000002 x22: 000000000000ffff x21:
> 0000000000000247
> [ 1179.441540] x20: 0000000000000245 x19: ffff000016d1df60 x18:
> 0000000000000002
> [ 1179.448668] x17: 0000000000000000 x16: 0000000000000000 x15:
> 0000000000000001
> [ 1179.455793] x14: 0000000000060810 x13: ffff80007fffffff x12:
> ffff000004190480
> [ 1179.462921] x11: ffff8000853f7000 x10: ffff8000811ae000 x9 :
> ffff0000041900b8
> [ 1179.470051] x8 : 0000000000000000 x7 : 00000000990c4001 x6 :
> 0000000000000007
> [ 1179.477177] x5 : ffff000016d1df60 x4 : 0000000000000000 x3 :
> ffff00000a7d8000
> [ 1179.484306] x2 : 00000000000001ff x1 : 0000000000000000 x0 :
> 0000000000000000
> [ 1179.491433] Call trace:
> [ 1179.493872]  pvr_mmu_op_context_unmap_curr_page+0x6c/0x134
> [powervr] (P)
> [ 1179.500582]  pvr_mmu_map+0x31c/0x388 [powervr]
> [ 1179.505027]  pvr_vm_gpuva_map+0x40/0x88 [powervr]
> [ 1179.509732]  __drm_gpuvm_sm_map+0x250/0x44c [drm_gpuvm]
> [ 1179.514952]  drm_gpuvm_sm_map+0x48/0x5c [drm_gpuvm]
> [ 1179.519822]  pvr_vm_bind_op_exec+0x64/0x70 [powervr]
> [ 1179.524785]  pvr_vm_map+0x1f8/0x2a8 [powervr]
> [ 1179.529142]  pvr_ioctl_vm_map+0x12c/0x188 [powervr]
> [ 1179.534018]  drm_ioctl_kernel+0xb8/0x128
> [ 1179.537941]  drm_ioctl+0x21c/0x4ec
> [ 1179.541337]  __arm64_sys_ioctl+0xac/0x108
> [ 1179.545344]  invoke_syscall+0x44/0x100
> [ 1179.549091]  el0_svc_common.constprop.0+0x40/0xe0
> [ 1179.553790]  do_el0_svc+0x1c/0x28
> [ 1179.557106]  el0_svc+0x34/0xf0
> [ 1179.560159]  el0t_64_sync_handler+0xd0/0xe4
> [ 1179.564334]  el0t_64_sync+0x198/0x19c
> [ 1179.567996] Code: 54000300 35000360 f9402261 79409a62 (f9400421)
> [ 1179.574081] ---[ end trace 0000000000000000 ]---
> 
> Fixes: ff5f643de0bf ("drm/imagination: Add GEM and VM related code")
> Signed-off-by: Brajesh Gupta <brajesh.gupta@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/imagination/pvr_mmu.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c
> b/drivers/gpu/drm/imagination/pvr_mmu.c
> index 3cac482e1034..175f0ba4d993 100644
> --- a/drivers/gpu/drm/imagination/pvr_mmu.c
> +++ b/drivers/gpu/drm/imagination/pvr_mmu.c
> @@ -12,6 +12,7 @@
>  #include "pvr_rogue_mmu_defs.h"
> 
>  #include <drm/drm_drv.h>
> +#include <drm/drm_print.h>
>  #include <linux/atomic.h>
>  #include <linux/bitops.h>
>  #include <linux/dma-mapping.h>
> @@ -2553,7 +2554,9 @@ pvr_mmu_map_sgl(struct pvr_mmu_op_context
> *op_ctx, struct scatterlist *sgl,
> 
>  err_destroy_pages:
>         memcpy(&op_ctx->curr_page, &ptr_copy, sizeof(op_ctx-
> >curr_page));
> -       err = pvr_mmu_op_context_unmap_curr_page(op_ctx, page);
> +       if (pvr_mmu_op_context_unmap_curr_page(op_ctx, page))
> +               drm_err(from_pvr_device(op_ctx->mmu_ctx->pvr_dev),
> "%s : Failure in unmapping pages\n",
> +                       __func__);
> 
>         return err;
>  }
> 
> --
> 2.43.0
> 
Reviewed by: Alexandru Dadu <alexandru.dadu@xxxxxxxxxx>

Thanks,
Alexandru Dadu