Mount points and nodev options
Clash Royale CLAN TAG#URR8PPP
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I'm studying device files and I've seen some mount points cannot accept the device file creation (if nodev option is set).
Considering my mount output:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
.....
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
I've tried to create a device file in /sys/kernel/debug (the directory has been chosen only because it doesn't have the nodev option) but the operation is not permitted. I don't understand the rationale behind it: why is the operation not possible?
mount
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
asked 31 mins ago
andrew
1
add a comment |Â
up vote
0
down vote
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I'm studying device files and I've seen some mount points cannot accept the device file creation (if nodev option is set).
Considering my mount output:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
.....
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
I've tried to create a device file in /sys/kernel/debug (the directory has been chosen only because it doesn't have the nodev option) but the operation is not permitted. I don't understand the rationale behind it: why is the operation not possible?
mount
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
asked 31 mins ago
andrew
1
add a comment |Â
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I'm studying device files and I've seen some mount points cannot accept the device file creation (if nodev option is set).
Considering my mount output:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
.....
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
I've tried to create a device file in /sys/kernel/debug (the directory has been chosen only because it doesn't have the nodev option) but the operation is not permitted. I don't understand the rationale behind it: why is the operation not possible?
mount
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
asked 31 mins ago
andrew
1
I'm studying device files and I've seen some mount points cannot accept the device file creation (if nodev option is set).
Considering my mount output:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
.....
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
I've tried to create a device file in /sys/kernel/debug (the directory has been chosen only because it doesn't have the nodev option) but the operation is not permitted. I don't understand the rationale behind it: why is the operation not possible?
mount
mount
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
asked 31 mins ago
andrew
1
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
asked 31 mins ago
andrew
1
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
edited 20 mins ago
Rui F Ribeiro
37.6k1475119
37.6k1475119
asked 31 mins ago
andrew
1
asked 31 mins ago
andrew
1
asked 31 mins ago
andrew
1
1
add a comment |Â
add a comment |Â
1 Answer
1
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votes
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0
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You can’t write to /sys/kernel/debug because it’s not a general-purpose file system; it’s the kernel’s debugfs, which exists to allow the kernel to export debug information to user space.
As to why nodev is important, see Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?
answered 5 mins ago
Stephen Kitt
152k23338406
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
You can’t write to /sys/kernel/debug because it’s not a general-purpose file system; it’s the kernel’s debugfs, which exists to allow the kernel to export debug information to user space.
As to why nodev is important, see Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?
answered 5 mins ago
Stephen Kitt
152k23338406
add a comment |Â
up vote
0
down vote
You can’t write to /sys/kernel/debug because it’s not a general-purpose file system; it’s the kernel’s debugfs, which exists to allow the kernel to export debug information to user space.
As to why nodev is important, see Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?
answered 5 mins ago
Stephen Kitt
152k23338406
add a comment |Â
up vote
0
down vote
up vote
0
down vote
You can’t write to /sys/kernel/debug because it’s not a general-purpose file system; it’s the kernel’s debugfs, which exists to allow the kernel to export debug information to user space.
As to why nodev is important, see Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?
answered 5 mins ago
Stephen Kitt
152k23338406
You can’t write to /sys/kernel/debug because it’s not a general-purpose file system; it’s the kernel’s debugfs, which exists to allow the kernel to export debug information to user space.
As to why nodev is important, see Why is "nodev" in /etc/fstab so important? How can character devices be used for hacking?
answered 5 mins ago
Stephen Kitt
152k23338406
answered 5 mins ago
Stephen Kitt
152k23338406
answered 5 mins ago
Stephen Kitt
152k23338406
answered 5 mins ago
Stephen Kitt
152k23338406
152k23338406
add a comment |Â
add a comment |Â
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