mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-22 17:55:57 +01:00
e4847e4b40
Also:
* fix fops.c on both kernels:
* 5.9: the out of space error code was 1 not 8
* 6.6: for whatever reason we can't read the user buffer as before on the
diagnostic print, it leads to segfault and oops
* create memfile.c which is like fops.c but of unlimited size
52 lines
895 B
Bash
Executable File
52 lines
895 B
Bash
Executable File
#!/bin/sh
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set -e
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# Helpers
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odraw() (
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od -A n -t x1 -v "$@" | tr -d '\n' | cut -c 2-
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)
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# Setup
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f=/sys/kernel/debug/lkmc_memfile
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mod="${1:-memfile.ko}"
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shift
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insmod "$mod" "$@"
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# Starts off empty
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[ -z "$(cat "$f")" ]
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# write and check it is there
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printf 12 > "$f"
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[ 12 = "$(cat "$f")" ]
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# Append and check that it is there
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printf 34 >> "$f"
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[ 1234 = "$(cat "$f")" ]
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# Restart
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printf 56 > "$f"
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[ 56 = "$(cat "$f")" ]
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# skip
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printf 1234 > "$f"
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[ 23 = "$(dd if="$f" bs=1 count=2 skip=1)" ]
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# seek
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printf 1234 > "$f"
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printf xy | dd bs=1 of="$f" seek=1 conv=notrunc
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[ 1xy4 = "$(cat "$f")" ]
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# seek past the end
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printf 1234 > "$f"
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printf xy | dd bs=1 of="$f" seek=6 conv=notrunc
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[ '31 32 33 34 00 00 78 79' = "$(odraw "$f")" ]
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# Allocate 1 GB for fun.
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dd if=/dev/zero of="$f" bs=1k count=1M
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[ '00 00' = "$(dd if="$f" bs=1 count=2 skip=500M | odraw)" ]
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# Teardown
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rmmod memfile
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echo passed
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