inject(8) System Manager's Manual inject(8)
NAME
inject - injects appropriate error into function if input call chain
and predicates are satisfied. Uses Linux eBPF/bcc.
SYNOPSIS
inject -h [-I header] [-P probability] [-v] [-c count] <mode> <spec>
DESCRIPTION
inject injects errors into specified kernel functionality when a given
call chain and associated predicates are satisfied.
WARNING: This tool injects failures into key kernel functions and may
crash the kernel. You should know what you're doing if you're using
this tool.
This makes use of a Linux 4.16 feature (bpf_override_return())
Since this uses BPF, only the root user can use this tool.
OPTIONS
-h Print usage message.
-v Display the generated BPF program, for debugging or modifica-
tion.
-I header
Necessary headers to be included.
-P probability
Optional probability of failure, default 1.
-c count
Number of errors to inject before stopping, default never stops.
MODE
kmalloc
Make the following function indicate failure
int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
bio Make the following function indicate failure
int should_fail_bio(struct bio *bio)
alloc_page
Make the following function indicate failure
bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int
order)
SPEC
FUNCTION([ARGS])[(TEST)] [=> ...]
A list of predicates separated by "=>". A predicate is a function sig-
nature (name and arguments) in a call stack and a test on the func-
tion's arguments.
Missing predicates are implicitly true. Missing tests are implicitly
true. Specifying the function arguments is optional if the test does
not use them. If the error injection function is not listed as the
first predicate, it is implicitly added.
Functions are listed in the reverse order that they are called, ie. if
a() calls b(), the spec would be "b() => a()".
REQUIREMENTS
CONFIG_BPF, CONFIG_BPF_KPROBE_OVERRIDE, bcc
EXAMPLES
inject kmalloc -v 'SyS_mount()'
inject kmalloc -v 'mount_subtree() => btrfs_mount()'
inject -P 0.5 -c 100 alloc_page "should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) (order == 1) => qlge_refill_bq()"
Please see the output of '-h' and tools/inject_example.txt for more ex-
amples.
SOURCE
This is from bcc.
https://github.com/iovisor/bcc
Also look in the bcc distribution for a companion _examples.txt file
containing example usage, output, and commentary for this tool.
OS
Linux
STABILITY
Unstable - in development.
AUTHOR
Howard McLauchlan
USER COMMANDS 2018-03-16 inject(8)
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