Bug 28497
| Summary: | dmesg corrupted buffer/output | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Ralph Seguin <rseguin> |
| Component: | kern | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 4.0-RELEASE | ||
| Hardware: | Any | ||
| OS: | Any | ||
State Changed From-To: open->closed State Changed From-To: closed->feedback Woops, I tried to abort the modification here. I believe this was fixed fairly recently, after it turned up during bsdcon in Europe. Were you experiencing these troubles on a laptop system? State Changed From-To: feedback->closed Feedback timeout. |
There appears to be an intermittent bug with the dmesg buffer or dmesg program. About 1 time in 15, the output from dmesg is corrupted with binary characters which make the output unsuitable for parsing to obtain information about the machine. The output is still recognizable as the normal kernel message output, but it is littered with garbage binary characters. bash-2.03# /sbin/dmesg \^D +\^D\^D\^A\^P\^D\^D\^H\^D\^B\^H @\M^@\^P\^F\^H\M-`\^O\M-p\^_\^H\M-p\M^?\^O\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^F\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^E\^L\^D\^A\^P@ \^D\^P\^H\^P \^B@\M^@@\M^@\M^@\^P@\^A@\^B\M^@ \^P\^P\^A\M^@\^AFACS@ 1986, 1989, 1991, 1993 The Regents of the University of California. All rights reserved. FreeBSD 4.0-RELEASE #2: Thu Mar 22 12:49:32 GMT 2001 bwong@bwong3.adc.rsv.ricoh.com:/usr/home/bwong/work/FBSD/sys/compile/eCabinet Timec\M-ountar "i8254" frequency 1193182 Hz CPU: Pentium III/Pentium III Xeon (797.42-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x683 Stepping = 3 Features=0x387f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,XMM> real memory = 535822336 (523264K bytes) avail memory = 515235840 (503160K bytes) pnpbios: Bad PnP BIOS data checksum Preloaded elf kernel "kernel" at 0xc03ce000. Pentium Pro MTRR support enabled md0: Malloc disk npx0: <math processor> on motharboard [... snip] pci0: <Intel 82801AA (ICH) USB controller> at 31.2 irq 10 pci0: <unknown card> (vendor=0x8086, dev=0x2413) at 31.3 irq 9 fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0 fdc0: FIFO enabled, 8 bytes \M-u\^A\^K\M-(\M^?\^H\M-x\^G\^A\^A@\M-P\M-P\M^@"@\M^?\M^@\M^?\240\M-v\240\M-v\^B@\^G\^A\^B\^K \^K \M-P \^P\M-@\^O43`\^O\^A\M-!\M^?\^G\M-#\^C\M-#\^E\^B\^B\^Q\^D\^E\^E\M^A\M-o \^C\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?\M^?System console> on isa0 sc0: VGA <16 virtual consoles, flags=0x200> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A bash-2.03# dmesg | head -20 reserved. FreeBSD 4.0-R\M-ELEASE #2: Thu Mar 22 12:49:32 GMT 2001 bwong@bwong3.adc.rsv.ricoh.com:/usr/home/bwong\^Owork/FBSD\M-/sys/compile/eCabinet Timecounter "i8254" frequency 1193182 Hz CPU: Pentium III/Pentium III Xeon (797.42-MHz 686-slass CPU) Origin = "Gen\^?ineInte," Id =$0x686 Stepping = 6 Features=0x387v9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,XMM> real memory = 535822336 (523264K bytes) avail memory!= 515235840 (503160K bytes) pnpbios: Bad PnP BIOS data checksum Prmloaded elf kernel "ke2nel" at 0xc03ce000. Pentium Pro MTRR suppord enabled md0: M`lloc disk npx0: <math processor> on motherboard np80: INT 16 inperface apm0: <APM BIMS> on mouherboard ipm: found APM BIOS v1.2, connected at w1.2 pcib0: <Intel 82810E (i810E GMCH) @ost To Hub bridge> on motherboard pci0: <PCI bus> on pcib0 pci0: <Intel 82810E \^Hi810E GMCH) SVGA controller> at 1.0 irq 11 Broken pipe How-To-Repeat: 1. Check output from /sbin/dmesg 2. If not garbled, reboot and go to step 1. If it is garbled, you've reproduced it.