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# rpm -q x86info x86info-1.29-1.fc16.x86_64 # x86info x86info v1.29. Dave Jones 2001-2011 Feedback to <davej>. readEntry: Operation not permitted Found 2 identical CPUs Can't read /dev/mem, here's the strace output open("/dev/mem", O_RDONLY) = 3 lseek(3, 1038, SEEK_SET) = 1038 read(3, "\0\0", 2) = 2 lseek(3, 1043, SEEK_SET) = 1043 read(3, "\0\0", 2) = 2 lseek(3, 67107840, SEEK_SET) = 67107840 read(3, 0x7fff6dff2700, 1024) = -1 EPERM (Operation not permitted) dup(2) = 4 fcntl(4, F_GETFL) = 0x8402 (flags O_RDWR|O_APPEND|O_LARGEFILE) fstat(4, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc9fa5e9000 lseek(4, 0, SEEK_CUR) = -1 ESPIPE (Illegal seek) write(4, "readEntry: Operation not permitt"..., 35readEntry: Operation not permitted ) = 35 close(4) = 0 munmap(0x7fc9fa5e9000, 4096) = 0 write(1, "Found 2 identical CPUs", 22Found 2 identical CPUs) = 22 exit_group(1) = ?
The dmesg log [ 26.657234] Program x86info tried to access /dev/mem between 3fff000->3fff400.
what system is this ? can you attach the whole dmesg log ?
Created attachment 526726 [details] full dmesg This is an F16 (3.1.0-0.rc6.git0.3.fc16.x86_64) PV Xen guest running on a RHEL5 host. The full dmesg is now attached.
I think this might be a xen bug. On real hardware, the EBDA table which lives in low memory points to a reserved area of memory where the MP tables live. This area is marked in e820 as reserved. On Xen that doesn't seem to happen.
Ah yes, the PV environment isn't a perfect emulation of hardware. I'd argue that x86info should print warnings when it doesn't find something it expects, such as mptables, rather than die though. Anything that still works should be output. In this case I only really wanted a cpuid dump. Strangely, if I run x86info as root and only specify '-r' it still tries to read the mptables which fails the whole thing, but if I run 'x86info -r' as a non-root user, then I get what I want.
I started adding some better handling of failure in the mptable code yesterday. It still needs to propagate the failure up to higher levels rather than just exit(EXIT_FAILURE), but it's getting there. I'll poke at it some more today.
This *exact* error (same memory range, even!) also occurs in x86info v1.25 in Ubuntu 12.04 running under ESXi5.0. Like the original reporter, when run as non-root, it executes and displays most of the information I want.
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle. Changing version to '19'. (As we did not run this process for some time, it could affect also pre-Fedora 19 development cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.) More information and reason for this action is here: https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19
This message is a notice that Fedora 19 is now at end of life. Fedora has stopped maintaining and issuing updates for Fedora 19. It is Fedora's policy to close all bug reports from releases that are no longer maintained. Approximately 4 (four) weeks from now this bug will be closed as EOL if it remains open with a Fedora 'version' of '19'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 19 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Fedora 19 changed to end-of-life (EOL) status on 2015-01-06. Fedora 19 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.