Regression in backport MEMREAD ioctl ? [Was: Re: mt7622: belkin-rt3200: r22602-42eeb22450: Kernel panic: kernel stack overflow]

[Petr Štetiar]

Felix Fietkau <nbd at nbd.name> [2023-04-21 12:03:23]:

[ adding Michał and Christian to the mail loop]

> 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.

thanks for looking into that Felix, Michał any idea what might be wrong here?

Cheers,

Petr