On 7/15/22 2:28 PM, Marek Szyprowski wrote:
> Hi,
>
> On 14.07.2022 13:02, Dylan Yudaken wrote:
>> this is in preparation for multishot receive from io_uring, where it needs
>> to have access to the original struct user_msghdr.
>>
>> functionally this should be a no-op.
>>
>> Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx>
>> Signed-off-by: Dylan Yudaken <dylany@xxxxxx>
>
> This patch landed in linux next-20220715 as commit 1a3e4e94a1b9 ("net:
> copy from user before calling __get_compat_msghdr"). Unfortunately it
> causes a serious regression on the ARM64 based Khadas VIM3l board:
>
> Unable to handle kernel access to user memory outside uaccess routines
> at virtual address 00000000ffc4a5c8
> Mem abort info:
> ESR = 0x000000009600000f
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x0f: level 3 permission fault
> Data abort info:
> ISV = 0, ISS = 0x0000000f
> CM = 0, WnR = 0
> user pgtable: 4k pages, 48-bit VAs, pgdp=0000000001909000
> [00000000ffc4a5c8] pgd=0800000001a7b003, p4d=0800000001a7b003,
> pud=0800000001a0e003, pmd=0800000001913003, pte=00e800000b9baf43
> Internal error: Oops: 9600000f [#1] PREEMPT SMP
> Modules linked in:
> CPU: 0 PID: 247 Comm: systemd-udevd Not tainted 5.19.0-rc6+ #12437
> Hardware name: Khadas VIM3L (DT)
> pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : get_compat_msghdr+0xd0/0x1b0
> lr : get_compat_msghdr+0xcc/0x1b0
> ...
> Call trace:
> get_compat_msghdr+0xd0/0x1b0
> ___sys_sendmsg+0xd0/0xe0
> __sys_sendmsg+0x68/0xc4
> __arm64_compat_sys_sendmsg+0x28/0x3c
> invoke_syscall+0x48/0x114
> el0_svc_common.constprop.0+0x60/0x11c
> do_el0_svc_compat+0x1c/0x50
> el0_svc_compat+0x58/0x100
> el0t_32_sync_handler+0x90/0x140
> el0t_32_sync+0x190/0x194
> Code: d2800382 9100f3e0 97d9be02 b5fffd60 (b9401a60)
> ---[ end trace 0000000000000000 ]---
>
> This happens only on the mentioned board, other my ARM64 test boards
> boot fine with next-20220715. Reverting this commit, together with
> 2b0b67d55f13 ("fix up for "io_uring: support multishot in recvmsg"") and
> a8b38c4ce724 ("io_uring: support multishot in recvmsg") due to compile
> dependencies on top of next-20220715 fixes the issue.
>
> Let me know how I can help fixing this issue.
How are you reproducing this?
--
Jens Axboe
