mt7622: belkin-rt3200: r22602-42eeb22450: Kernel panic: kernel stack overflow

[Felix Fietkau]

On 21.04.23 09:11, Petr Štetiar wrote:
> Hi,
> 
> I've just noticed, that daily CI runtime testing job on belkin-rt3200
> failed[1] due to following:
> 
>   Insufficient stack space to handle exception!
>   ESR: 0x0000000096000047 -- DABT (current EL)
>   FAR: 0xffffffc008c47fe0
>   Task stack:     [0xffffffc008c48000..0xffffffc008c4c000]
>   IRQ stack:      [0xffffffc008008000..0xffffffc00800c000]
>   Overflow stack: [0xffffff801feb00a0..0xffffff801feb10a0]
>   CPU: 1 PID: 1 Comm: swapper/0 Tainted: G S                5.15.107 #0
>   Hardware name: Linksys E8450 (DT)
>   pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>   pc : dequeue_entity+0x0/0x250
>   lr : dequeue_task_fair+0x98/0x290
>   sp : ffffffc008c48030
>   x29: ffffffc008c48030 x28: 0000000000000001 x27: ffffff801feb6380
>   x26: 0000000000000001 x25: ffffff801feb6300 x24: ffffff8000068000
>   x23: 0000000000000001 x22: 0000000000000009 x21: 0000000000000000
>   x20: ffffff801feb6380 x19: ffffff8000068080 x18: 0000000017a740a6
>   x17: ffffffc008bae748 x16: ffffffc008bae6d8 x15: ffffffffffffffff
>   x14: ffffffffffffffff x13: 0000000000000000 x12: 0000000f00000101
>   x11: 0000000000000449 x10: 0000000000000127 x9 : 0000000000000000
>   x8 : 0000000000000125 x7 : 0000000000116da1 x6 : 0000000000116da1
>   x5 : 00000000001165a1 x4 : ffffff801feb6e00 x3 : 0000000000000000
>   x2 : 0000000000000009 x1 : ffffff8000068080 x0 : ffffff801feb6380
>   Kernel panic - not syncing: kernel stack overflow
>   SMP: stopping secondary CPUs
>   SMP: failed to stop secondary CPUs 0-1
>   Kernel Offset: disabled
>   CPU features: 0x00003000,00000802
>   Memory Limit: none
> 
> Last working version was r22580-e11d00d44c[2], and first failing version was
> yesterday 1416b9bbe9, so possibly the regression was introduced in one of the
> following commits:
> 
>   1416b9bbe9d3 tools/dwarves: update to 1.25
>   9931188edcbc kernel: fix up qrtr packaging after 5.15.107 bump
>   f4989239cc91 kernel: bump 5.15 to 5.15.107
>   89f6ac5fd1ad tools/cmake: update to 3.26.3
>   ab3f151aa874 mwlwifi: update to version 10.3.9.0-20230311
>   5ec781c4448b bmips: pci-bcm6348: load IO resource from DT ranges
>   16b0cbbde057 bmips: drop unneeded ath9k fixup
>   db4f158c0330 bmips: hg556a: switch to kmod-owl-loader
>   36150ff6ffb2 tools/bzip2: add `bzip2` binaries
>   b691362d1dbe Revert "tools/bzip2: add `bzip2` binaries"
>   f7f47b136991 mac80211: ath11k: replace 160MHz fix with upstream pending one
>   4ab4b9ea818d build: fix incorrect initramfs gzip compression
>   69bc620180d2 build: fix incorrect initramfs bzip2 compression
>   394d7134ec42 tools/bzip2: add `bzip2` binaries
>   5264296ce480 ath79: mikrotik: update kernel on NAND using Yafut
>   27acf2413e91 yafut: add a kernel update tool for MikroTik NAND
>   fa4dc86e9808 kernel: backport MEMREAD ioctl
>   e722b667c5a5 mac80211: update to v6.1.24

Since the crash happens right after snand driver initialization, I think 
the most likely candidate is this one:
fa4dc86e9808 kernel: backport MEMREAD ioctl

Maybe there are still some stack declarations of struct mtd_oob_ops left 
that aren't fully initialized.

- Felix