On Mon, Jun 24, 2024 at 3:28 PM Geliang Tang <geliang@xxxxxxxxxx> wrote: > > From: Geliang Tang <tanggeliang@xxxxxxxxxx> > > Run the following BPF selftests on loongarch: > > # ./test_progs -t sockmap_basic > > A Kernel panic occurs: > > ''' > Oops[#1]: > CPU: 22 PID: 2824 Comm: test_progs Tainted: G OE 6.10.0-rc2+ #18 > Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018-V4.0.11 > pc 9000000004162774 ra 90000000048bf6c0 tp 90001000aa16c000 sp 90001000aa16fb90 > a0 0000000000000000 a1 0000000000000000 a2 0000000000000000 a3 90001000aa16fd70 > a4 0000000000000800 a5 0000000000000000 a6 000055557b63aae8 a7 00000000000000cf > t0 0000000000000000 t1 0000000000004000 t2 0000000000000048 t3 0000000000000000 > t4 0000000000000001 t5 0000000000000002 t6 0000000000000001 t7 0000000000000002 > t8 0000000000000018 u0 9000000004856150 s9 0000000000000000 s0 0000000000000000 > s1 0000000000000000 s2 90001000aa16fd70 s3 0000000000000000 s4 0000000000000000 > s5 0000000000004000 s6 900010009284dc00 s7 0000000000000001 s8 900010009284dc00 > ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560 > ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0 > CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) > PRMD: 0000000c (PPLV0 +PIE +PWE) > EUEN: 00000007 (+FPE +SXE +ASXE -BTE) > ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) > ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) > BADV: 0000000000000040 > PRID: 0014c011 (Loongson-64bit, Loongson-3C5000) > Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack > Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=000000001cba0874) > Stack : 0000000000000001 fffffffffffffffc 0000000000000000 0000000000000000 > 0000000000000018 0000000000000000 0000000000000000 90000000048bf6c0 > 90000000052cd638 90001000aa16fd70 900010008bf51580 900010009284f000 > 90000000049f2b90 900010009284f188 900010009284f178 90001000861d4780 > 9000100084dccd00 0000000000000800 0000000000000007 fffffffffffffff2 > 000000000453e92f 90000000049aae34 90001000aa16fd60 900010009284f000 > 0000000000000000 0000000000000000 900010008bf51580 90000000049f2b90 > 0000000000000001 0000000000000000 9000100084dc3a10 900010009284f1ac > 90001000aa16fd40 0000555559953278 0000000000000001 0000000000000000 > 90001000aa16fdc8 9000000005a5a000 90001000861d4780 0000000000000800 > ... > Call Trace: > [<9000000004162774>] copy_page_to_iter+0x74/0x1c0 > [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560 > [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0 > [<90000000049aae34>] inet_recvmsg+0x54/0x100 > [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0 > [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0 > [<900000000481e27c>] sys_recvfrom+0x1c/0x40 > [<9000000004c076ec>] do_syscall+0x8c/0xc0 > [<9000000003731da4>] handle_syscall+0xc4/0x160 > > Code: 0010b09b 440125a0 0011df8d <28c10364> 0012b70c 00133305 0013b1ac 0010dc84 00151585 > > ---[ end trace 0000000000000000 ]--- > Kernel panic - not syncing: Fatal exception > Kernel relocated by 0x3510000 > .text @ 0x9000000003710000 > .data @ 0x9000000004d70000 > .bss @ 0x9000000006469400 > ---[ end Kernel panic - not syncing: Fatal exception ]--- > ''' > > This is because "page" is NULL in that case. This patch adds null > check for it in sk_msg_recvmsg() to fix this error. > Why would @page be NULL only for this architecture ? Please elaborate, and add a Fixes: tag > Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx> > --- > net/core/skmsg.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/core/skmsg.c b/net/core/skmsg.c > index fd20aae30be2..bafcc1e2eadf 100644 > --- a/net/core/skmsg.c > +++ b/net/core/skmsg.c > @@ -432,6 +432,8 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, > sge = sk_msg_elem(msg_rx, i); > copy = sge->length; > page = sg_page(sge); > + if (!page) > + goto out; > if (copied + copy > len) > copy = len - copied; > copy = copy_page_to_iter(page, sge->offset, copy, iter); > -- > 2.43.0 >
