Ubuntu
laptop-detect package

/dev/mem: Operation not permitted

Bug #1213922 reported by David Henningsson
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
laptop-detect (Ubuntu)
Invalid
Undecided
Unassigned

Bug Description

When running this tool under saucy, on my laptop:

$ laptop-detect
/dev/mem: Operation not permitted
$ echo $?
1

On 12.04, the "/dev/mem: Operation not permitted" error does not appear.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: laptop-detect 0.13.7ubuntu2
ProcVersionSignature: Ubuntu 3.11.0-1.4-generic 3.11.0-rc4
Uname: Linux 3.11.0-1-generic x86_64
ApportVersion: 2.12-0ubuntu3
Architecture: amd64
Date: Mon Aug 19 15:13:55 2013
Dependencies:
 dmidecode 2.12-1
 gcc-4.8-base 4.8.1-9ubuntu1
 libc6 2.17-91ubuntu1
 libgcc1 1:4.8.1-9ubuntu1
 multiarch-support 2.17-91ubuntu1
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-05-08 (102 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130508)
MarkForUpload: True
SourcePackage: laptop-detect
UpgradeStatus: No upgrade log present (probably fresh install)

Revision history for this message
David Henningsson (diwic) wrote :
Revision history for this message
Martin Pitt (pitti) wrote :

That's laptop-detect's way of saying "I need to run as root". Presumably the permissions on /dev/mem got tightened after precise.

As you want to use that in a pm-utils script, the root privilege requirement shouldn't be an issue?

Changed in laptop-detect (Ubuntu):
status: New → Invalid
Revision history for this message
David Henningsson (diwic) wrote :

This is from "strace laptop-test" under precise:

faccessat(AT_FDCWD, "/dev/mem", R_OK) = -1 EACCES (Permission denied)

Revision history for this message
David Henningsson (diwic) wrote :

This is from "strace laptop-test" under saucy:

faccessat(AT_FDCWD, "/dev/mem", R_OK) = 0
geteuid() = 1000
faccessat(AT_FDCWD, "/usr/sbin/dmidecode", X_OK) = 0
pipe([3, 4]) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f03235fea10) = 20344
close(4) = 0
read(3, /dev/mem: Operation not permitted
"", 128)

Revision history for this message
David Henningsson (diwic) wrote :

Sure, on root this is not an issue.

It's actually the other way around for /dev/mem, on precise it's crw-r------ and on saucy it's crw-rw----+ .

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