Messages in this thread | | | Subject | Re: [PATCH 0/1] __asm_copy_to-from_user: Reduce more byte_copy | From | Akira Tsukamoto <> | Date | Tue, 17 Aug 2021 16:32:52 +0900 |
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Hi Qiu,
On 8/16/2021 6:45 PM, Qiu Wenbo wrote: > Hi Akira, > > > I can reproduce it on my HiFive Unmatched with a custom Gentoo rootfs. As pointed out by Andreas, there might be a missing fixup. I'm going to debug this issue myself since I can reproduce it fairly stable.
Ah! Now I understand the bug.
> + REG_L a5, 0(a1)
should be
+ fixup REG_L a5, 0(a1)
If you do not mind, could you make the patch to add 'fixup' to all REG_S and REG_L? Then I will resubmit them to Palmer with your patch.
Thanks,
Akira
> > > Qiu > > > On 8/16/21 14:24, Akira Tsukamoto wrote: >> Hi Qiu, >> >> On 8/15/2021 11:30 AM, Qiu Wenbo wrote: >>> Hi Akira, >>> >>> >>> This patch breaks my userspace and I can't boot my system after applying this. Here is the stack trace: >>> >>> >>> [ 10.349080] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 >>> [ 10.357116] Oops [#15] >>> [ 10.359433] CPU: 2 PID: 169 Comm: (networkd) Tainted: G D 5.14.0-rc5 #53 >>> [ 10.367422] Hardware name: SiFive HiFive Unmatched A00 (DT) >>> [ 10.372981] epc : __asm_copy_from_user+0x48/0xf0 >>> [ 10.377584] ra : _copy_from_user+0x28/0x68 >>> [ 10.381754] epc : ffffffff8099a280 ra : ffffffff803614a8 sp : ffffffd00416bd90 >>> [ 10.388963] gp : ffffffff811ee540 tp : ffffffe0841b3680 t0 : ffffffd00416bde0 >>> [ 10.396172] t1 : ffffffd00416bdd8 t2 : 0000003ff09ca3a0 s0 : ffffffd00416bdc0 >>> [ 10.403381] s1 : 0000000000000000 a0 : ffffffd00416bdd8 a1 : 0000000000000000 >>> [ 10.410590] a2 : 0000000000000010 a3 : 0000000000000040 a4 : ffffffd00416be18 >>> [ 10.417800] a5 : 0000003ffffffff0 a6 : 000000000000000f a7 : ffffffe085d58540 >>> [ 10.425009] s2 : 0000000000000010 s3 : ffffffd00416bdd8 s4 : 0000000000000002 >>> [ 10.432218] s5 : 0000000000000000 s6 : 0000000000000000 s7 : ffffffe0841b3680 >>> [ 10.439427] s8 : 0000002aad788040 s9 : 0000000000000000 s10: 0000000000000001 >>> [ 10.446636] s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000000000000001 >>> [ 10.453845] t5 : 0000000000000010 t6 : 0000000000040000 >>> [ 10.459144] status: 0000000200040120 badaddr: 0000000000000000 cause: 000000000000000d >>> [ 10.467049] [<ffffffff8099a280>] __asm_copy_from_user+0x48/0xf0 >>> [ 10.472955] [<ffffffff8009a562>] do_seccomp+0x62/0x8be >>> [ 10.478079] [<ffffffff8009af58>] prctl_set_seccomp+0x24/0x32 >>> [ 10.483725] [<ffffffff80020756>] sys_prctl+0xf6/0x450 >>> [ 10.488763] [<ffffffff800034f2>] ret_from_syscall+0x0/0x2 >>> >>> >>> The PC register points to this line: >>> >>> +1: >>> + REG_L a5, 0(a1) >> Thanks for testing! Do you mind teaching me how to reproduce the error? >> >> Akira >> > > >
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