IMX8MP galcore_deamon Undefined instruction

James33 — Wed, 13 May 2026 02:01:03 GMT

Dear NXP Technical Support Team,

Hello!

BOARD: IMX8MP
Yocto: scarthgap 6.6.23

On the i.MX8mp development board, I encountered this error.

## imx8mp-lpddr4-evk kernel: Internal error: Oops - Undefined instruction: 0000000002000000 [#1] PREEMPT SMP ## imx8mp-lpddr4-evk kernel: Modules linked in: fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_fsl_asoc_card dw_hdmi_cec snd_soc_fsl_sai snd_soc_fsl_micfil snd_soc_fsl_xcvr imx8_media_dev(C) snd_soc_imx_audmux snd_soc_fsl_aud2htx snd_soc_fsl_easrc snd_soc_fsl_utils snd_soc_fsl_asrc imx_pcm_dma rtc_ds1307 snd_soc_wm8962 caam secvio error imx_dsp_rproc xt_conntrack nf_conntrack nf_defrag_ipv4 iptable_filter fuse ## imx8mp-lpddr4-evk kernel: CPU: 3 PID: 79 Comm: galcore_deamon/ Tainted: G C 6.6.23-lts-next-dirty #1 ## imx8mp-lpddr4-evk kernel: Hardware name: YTX FT Release Distro (DT) ## imx8mp-lpddr4-evk kernel: pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) ## imx8mp-lpddr4-evk kernel: pc : dma_fence_signal+0x58/0x64 ## imx8mp-lpddr4-evk kernel: lr : gckOS_Signal+0x180/0x244 ## imx8mp-lpddr4-evk kernel: sp : ffff800082a6bd00 ## imx8mp-lpddr4-evk kernel: x29: ffff800082a6bd10 x28: 0000000000000000 x27: ffff800082a6be10 ## imx8mp-lpddr4-evk kernel: x26: 0000000000000000 x25: ffff800081b3c008 x24: ffff000026b7f3c4 ## imx8mp-lpddr4-evk kernel: x23: ffff0000d1b6c1e0 x22: ffff0000d0d64044 x21: 0000000000000000 ## imx8mp-lpddr4-evk kernel: x20: ffff0000d0d64048 x19: ffff000026b7f3c0 x18: 0000000000000000 ## imx8mp-lpddr4-evk kernel: x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffff8db25538 ## imx8mp-lpddr4-evk kernel: x14: 0000000000000000 x13: 0000000000000209 x12: 0000000000000002 ## imx8mp-lpddr4-evk kernel: x11: 0000000000000040 x10: ffff0000d0d64050 x9 : ffff0000d0d64048 ## imx8mp-lpddr4-evk kernel: x8 : ffff000006433b78 x7 : 0000000000000000 x6 : 000002a5fe056003 ## imx8mp-lpddr4-evk kernel: x5 : 00ffffffffffffff x4 : ffff0000d1b6c210 x3 : 0000000000000000 ## imx8mp-lpddr4-evk kernel: x2 : 0000000000000000 x1 : ffff0000d02b6740 x0 : 0000000000000000 ## imx8mp-lpddr4-evk kernel: Call trace: ## imx8mp-lpddr4-evk kernel: dma_fence_signal+0x58/0x64 ## imx8mp-lpddr4-evk kernel: gckOS_UserSignal+0x7c/0xb0 ## imx8mp-lpddr4-evk kernel: gckEVENT_Notify+0x21c/0x410 ## imx8mp-lpddr4-evk kernel: gckHARDWARE_Notify+0x68/0xc8 ## imx8mp-lpddr4-evk kernel: gckKERNEL_Notify+0x20/0x2c ## imx8mp-lpddr4-evk kernel: threadRoutine+0x1c/0x78 ## imx8mp-lpddr4-evk kernel: kthread+0x110/0x114 ## imx8mp-lpddr4-evk kernel: ret_from_fork+0x10/0x20 ## imx8mp-lpddr4-evk kernel: Code: 2a1303e0 a94153f3 a8c27bfd d50323bf (d65f03c0) ## imx8mp-lpddr4-evk kernel: ---[ end trace 0000000000000000 ]---

According to "dma_fence_signal+0x58/0x64", I checked the "dma_fence_signal" function and found that the instruction corresponding to the 0x58 position is the "ret" instruction.

file path: imx8mp-xwayland/tmp/work-shared/imx8mp-lpddr4-evk/kernel-source/drivers/dma-buf/dma-fence.c int dma_fence_signal(struct dma_fence *fence) { unsigned long flags; int ret; bool tmp; if (!fence) return -EINVAL; tmp = dma_fence_begin_signalling(); spin_lock_irqsave(fence->lock, flags); ret = dma_fence_signal_timestamp_locked(fence, ktime_get()); spin_unlock_irqrestore(fence->lock, flags); dma_fence_end_signalling(tmp); return ret; } EXPORT_SYMBOL(dma_fence_signal);

## aarch64-linux-gnu-objdump -r -d vmlinux | grep -A 30 \<dma_fence_signal\>: ffff8000809bcfe8 <dma_fence_signal>: ffff8000809bcfe8: d503233f paciasp ffff8000809bcfec: a9be7bfd stp x29, x30, [sp, #-32]! ffff8000809bcff0: 910003fd mov x29, sp ffff8000809bcff4: a90153f3 stp x19, x20, [sp, #16] ffff8000809bcff8: b4000260 cbz x0, ffff8000809bd044 <dma_fence_signal+0x5c> ffff8000809bcffc: aa0003f3 mov x19, x0 ffff8000809bd000: f9400000 ldr x0, [x0] ffff8000809bd004: 942b4fed bl ffff800081490fb8 <_raw_spin_lock_irqsave> ffff8000809bd008: aa0003f4 mov x20, x0 ffff8000809bd00c: 97dd9d70 bl ffff8000801245cc <ktime_get> ffff8000809bd010: aa0003e1 mov x1, x0 ffff8000809bd014: aa1303e0 mov x0, x19 ffff8000809bd018: 97ffff6e bl ffff8000809bcdd0 <dma_fence_signal_timestamp_locked> ffff8000809bd01c: 2a0003e2 mov w2, w0 ffff8000809bd020: aa1403e1 mov x1, x20 ffff8000809bd024: f9400260 ldr x0, [x19] ffff8000809bd028: 2a0203f3 mov w19, w2 ffff8000809bd02c: 942b4eb5 bl ffff800081490b00 <_raw_spin_unlock_irqrestore> ffff8000809bd030: 2a1303e0 mov w0, w19 ffff8000809bd034: a94153f3 ldp x19, x20, [sp, #16] ffff8000809bd038: a8c27bfd ldp x29, x30, [sp], #32 ffff8000809bd03c: d50323bf autiasp ffff8000809bd040: d65f03c0 ret ffff8000809bd044: 128002b3 mov w19, #0xffffffea // #-22 ffff8000809bd048: 17fffffa b ffff8000809bd030 <dma_fence_signal+0x48>

I would like to know why the "ret" instruction is causing the problem? And what should I do to avoid this error? This is an occasional occurrence. I don't yet know what kind of action caused this problem to happen. I am unable to manually reproduce this issue.

Re: IMX8MP galcore_deamon Undefined instruction

Zhiming_Liu — Fri, 15 May 2026 02:51:29 GMT

Hi @James33

Are you using the standard Linux kernel or PREEMPT Linux?

Best Regards,
Zhiming

Re: IMX8MP galcore_deamon Undefined instruction

James33 — Fri, 15 May 2026 05:54:14 GMT

The yocto version is scarthgap6.6.23. I did not make any modifications to the linux-imx_6.6.bb file, nor did I modify the galcore related drivers. I only modified the dts file of the kernel. So it should be the standard Linux kernel.Sometimes the error occurs in other functions, and dma_fence_signal is just one of them.

## zcat /proc/config.gz | grep PREEMPT
CONFIG_PREEMPT_BUILD=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_PREEMPTION=y
# CONFIG_PREEMPT_DYNAMIC is not set
CONFIG_PREEMPT_RCU=y
CONFIG_HAVE_PREEMPT_DYNAMIC=y
CONFIG_HAVE_PREEMPT_DYNAMIC_KEY=y
CONFIG_PREEMPT_NOTIFIERS=y
# CONFIG_DEBUG_PREEMPT is not set

topic Re: IMX8MP galcore_deamon Undefined instruction in i.MX Processors

IMX8MP galcore_deamon Undefined instruction

Re: IMX8MP galcore_deamon Undefined instruction

Re: IMX8MP galcore_deamon Undefined instruction