valgrind crashes with "insufficient stack space" on armhf

[Mate Kukri]

Valgrind is unusable on armhf (at least when hosted inside qemu):
```
root@autopkgtest:~# valgrind
[ 1030.480535] Insufficient stack space to handle exception!
[ 1030.480583] Task stack: [0xf0b40000..0xf0b42000]
[ 1030.480708] IRQ stack: [0xf0800000..0xf0802000]
[ 1030.480751] Overflow stack: [0xc2d73000..0xc2d74000]
[ 1030.480800] Internal error: kernel stack overflow: 0 [#4] SMP ARM
[ 1030.480857] Modules linked in: cfg80211 binfmt_misc nls_iso8859_1 uio_pdrv_genirq uio dm_multipath drm efi_pstore dmi_sysfs ip_tables x_tables autofs4 btrfs blake2b_neon blake2b_generic xor xor_neon raid6_pq libcrc32c gpio_keys
[ 1030.481165] CPU: 0 PID: 820 Comm: memcheck-arm-li Tainted: G D 6.5.0-9-generic #9-Ubuntu
[ 1030.481238] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-2 09/23/2023
[ 1030.481293] PC is at vfp_entry+0x70/0x98
[ 1030.481351] LR is at vfp_entry+0x58/0x98
[ 1030.481409] pc : [<c040473c>] lr : [<c0404724>] psr: 60000013
[ 1030.481460] sp : ffffffe8 ip : 00000000 fp : 00000000
[ 1030.481512] r10: dd100bf8 r9 : c0401138 r8 : f2000000
[ 1030.481568] r7 : 00000001 r6 : 00000001 r5 : 00000000 r4 : f3044f54
[ 1030.481623] r3 : 00000000 r2 : 00000000 r1 : 00000000 r0 : 00000000
[ 1030.481675] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 1030.481732] Control: 30c5387d Table: 5e1b8540 DAC: 00000001
[ 1030.481777] Register r0 information: NULL pointer
[ 1030.481832] Register r1 information: NULL pointer
[ 1030.481880] Register r2 information: NULL pointer
[ 1030.481929] Register r3 information: NULL pointer
[ 1030.481978] Register r4 information: vmalloc memory
[ 1030.482028] Register r5 information: NULL pointer
[ 1030.482076] Register r6 information: non-paged memory
[ 1030.482124] Register r7 information: non-paged memory
[ 1030.482173] Register r8 information: vmalloc memory
[ 1030.482220] Register r9 information: non-slab/vmalloc memory
[ 1030.482276] Register r10 information: slab task_struct start dd100b00 pointer offset 248 size 2816
[ 1030.482405] Register r11 information: NULL pointer
[ 1030.482461] Register r12 information: NULL pointer
[ 1030.482516] Process memcheck-arm-li (pid: 820, stack limit = 0x10cb5b25)
[ 1030.482577] Stack: (0xffffffe8 to 0x00002000)
[ 1030.482622] Backtrace: no frame pointer
[ 1030.482689] Code: e3a01000 e3a02000 e3a03000 e3a0c000 (e89da870)
[ 1030.482753] ---[ end trace 0000000000000000 ]---
[ 1032.427908] note: memcheck-arm-li[820] exited with irqs disabled
Segmentation fault
```

ulimit -s has no effect on this.

[Mate Kukri (mkukri)]

Updated: only reproducible when running on armhf kernel. Valgrind seems to function when running inside an armhf container with an arm64 kernel.

[Pjfloyd (pjfloyd)]

What Valgrind output do you get with debug traces (-d repeat up to a total of 3 times for more traces) and -v (repeat up to a total ot 4 times for more verbosity).