Re: port-macppc/55326: gem(4): memory corruption by RX DMA

["David H. Gutteridge" <david%gutteridge.ca@localhost>]

The following reply was made to PR port-macppc/55326; it has been noted by GNATS.

From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-macppc/55326: gem(4): memory corruption by RX DMA
Date: Sun, 31 May 2020 14:47:53 -0400

 FWIW, I reported a similar backtrace in PR port-macppc/54331:
 
  [   20.6900578] panic: pr_phinpage_check: [mclpl] item 0x1fb2f040 not
 part of pool
  [   20.6900578] cpu0: Begin traceback...
  [   20.6900578] 0x10007da0: at vpanic+0x144
  [   20.7300428] 0x10007dd0: at panic+0x50
  [   20.7300428] 0x10007e20: at pool_cache_put_paddr+0x25c
  [   20.7600388] 0x10007e50: at m_ext_free+0x130
  [   20.7600388] 0x10007e60: at m_free+0x9c
  [   20.7600388] 0x10007e70: at m_freem.part.8+0xc
  [   20.7600388] 0x10007e80: at ether_input+0x67c
  [   20.7600388] 0x10007eb0: at if_percpuq_softint+0xb4
  [   20.7600388] 0x10007ed0: at softint_dispatch+0x1d0
  [   20.7600388] 0x10007f20: at softint_fast_dispatch+0xdc
  [   20.8700561] 0x10007fe8: at 0xfffffffc
  [   20.8700561] cpu0: End traceback...
  Stopped in pid 0.3 (system)
 at  netbsd:vpanic+0x148:    or       r3,  r29,  r29
  gem0: receive error: RX overflow sc->rxptr 0, complete 4
 
 (Since the rest of PR 54331 is addressed, and this PR contains
 analysis and a patch, I'll close 54331.)
 
 Thanks,
 
 Dave