Hi, On Thu, May 5, 2011 at 1:20 AM, Arnaud Lacombe <lacombar_at_gmail.com> wrote: > Hi, > > On Wed, May 4, 2011 at 5:38 PM, Jack Vogel <jfvogel_at_gmail.com> wrote: >> I have had my validation engineer busy all day, we have tried both >> a 9 kernel as well as 8.2, using the code from HEAD, and we >> cannot reproduce this problem. >> > Actually, it can be trivially reproduced by tainting `error'. As it is > uninitialized in HEAD, it's value can be _anything_, so let's mark it > as explicitly invalid. > > diff -u ./if_em.c /data/src/freebsd/em-7.2.2/src/if_em.c > --- ./if_em.c 2011-02-18 01:18:23.000000000 -0500 > +++ /data/src/freebsd/em-7.2.2/src/if_em.c 2011-05-05 > 01:12:01.000000000 -0400 > _at__at_ -3912,7 +3912,7 _at__at_ > struct adapter *adapter = rxr->adapter; > struct em_buffer *rxbuf; > bus_dma_segment_t seg[1]; > - int i, j, nsegs, error; > + int i, j, nsegs, error = -1; > > The error pointed out in this thread pops up in the next boot. > I put a call to kdb_enter() at the beginning of the function, helped with some textdump I got all the backtrace [0] for all the time em_setup_receive_ring() is called. All are exactly the same: kdb_enter_why(0,c09f6511,f391aaa8,c09be1e2,c09f6511,...) at kdb_enter_why+0x3b kdb_enter(c09f6511,0,3810,ffffffff,5dc,...) at kdb_enter+0x19 em_setup_receive_ring(c3c8d600,c3c8d7a4,c3c96004,310000fa,c3c8d600,...) at em_setup_receive_ring+0x22 em_setup_receive_structures(c3c96000,f15f2000,38,8100,3,...) at em_setup_receive_structures+0x26 em_init_locked(c3c96000,0,c09f5de5,414,10000,...) at em_init_locked+0x2f2 em_ioctl(c3c7d000,80206934,c3ce9d00,c07b7a0b,c3f2a230,...) at em_ioctl+0x1c3 ifhwioctl(c3f2a230,f391ac34,c07b7a0b,c3f3e3d0,c08df1c0,...) at ifhwioctl+0x4b8 ifioctl(c3f3e3d0,80206934,c3ce9d00,c3f2a230,c3f2a230,...) at ifioctl+0x82 kern_ioctl(c3f2a230,3,80206934,c3ce9d00,c3ce9d00,...) at kern_ioctl+0xa8 ioctl(c3f2a230,f391acf8,c,c,f391ad2c,...) at ioctl+0xc5 syscall(f391ad38) at syscall+0x17d Xint0x80_syscall() at Xint0x80_syscall+0x20 --- syscall (54, FreeBSD ELF32, ioctl), eip = 0x4816ee23, esp = 0xbfbfe67c, ebp = 0xbfbfe698 --- This fully explain why the main loop in em_setup_receive_ring() is never entered, as we always verify `j == rxr->next_to_check' (provided that mbuf have been refreshed if some packet were transfered) and return the value on the stack. As of now, beside changing the call-site of em_setup_receive_ring() to ensure it is never re-entered, I'd guess that the patch I sent earlier today, is the only way to ensure that no junk is returned. I'd guess that the driver _is_ able to transmit, if the code was not explicitly calling em_stop() upon em_setup_receive_structures() failure. - Arnaud [0]: I wish that would have been as easy as in Linux, where a WARN() call do all the job automatically, but still, I should not hope for that much unless I am the one implementing it ... yes, free whining, it's 2a.m. ... > - Arnaud > >> The data your netstat -m shows suggests to me that what's happening >> is somehow setup of the receive ring is running more than once maybe?? >> >> You asked at one point how this could go into STABLE, well, because >> not only here at Intel, but at lots of external customers this code has been >> used and tested thoroughly. >> >> I am not calling into question your problem, but until I understand what it >> is I cannot "fix" it :) >> >> The thing I am guessing right now is the culprit is the setup code, the >> reason >> is that when I ported to the igb driver I found that it did not work on our >> newer >> hardware, and so I went back to the older version of setup for igb. Now, >> even >> though I have not seen hardware fail with em, maybe there is some. >> >> To help me give me a complete pciconf -lv, and if its a namebrand system >> tell me that, including all hardware in it. >> >> If you like Olivier I can make a version of em for you that also reverts the >> setup code the way I did for igb, see if that fixes it for you? >> >> Thanks for your patience, >> >> Jack >> _______________________________________________ >> freebsd-current_at_freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org" >> >Received on Thu May 05 2011 - 04:03:49 UTC
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