Difference between revisions of "Fault injection"

Latest revision as of 17:45, 26 September 2016

Fault injection testing is used to validate error paths in CRIU. Faults are artificially generated in peeked places of the code to check for particular roll-backs.

Faults are enforced by setting the CRIU_FAULT env before executing CRIU binary. Values are described in criu/include/fault-injection.h header file.

Fatal faults[edit]

These make CRIU abort the current operation and exit with error.

Abort dump early[edit]

FI_DUMP_EARLY == 1. Makes CRIU abort duming right after infecting the task with parasite code. Checks that parasite unloading on error works OK.

Abort restore early[edit]

FI_RESTORE_ROOT_ONLY == 2. Makes CRIU stop restoring right after spawning (and pre-restoring) the root task. Checks that early preparations (such as invisible files pre-creation) doesn't leave garbage in the system.

Abort link-remap file opening[edit]

FI_RESTORE_OPEN_LINK_REMAP == 3. Make CRIU fail the very first attempt opening the link remap file. Additional check for invisible files cleanup.

Abort connection to parasite code[edit]

FI_PARASITE_CONNECT == 4. Makes CRIU simulate impossibility for parasite code to connect back to CRIU.

Non fatal faults[edit]

These just make CRIU chose different paths on dump/restore, trying harder to get work done.

Abort open-by-handle[edit]

FI_CHECK_OPEN_HANDLE == 128. Simulates failure of the open_by_handle_at system call. Forces the irmap engine to work.

Abort memfd creation[edit]

FI_NO_MEMFD == 129. Forces parasite code use shmem-based blob instead of memfd-based. Used for older kernels (not having the memfd_create() system call) to work.

Abort breakpoints injectioin[edit]

FI_NO_BREAKPOINTS == 130. Disables breakpoints and makes CRIU unload code blobs by step-by-step tracing.

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-[[Category:Empty articles]]
+Fault injection testing is used to validate error paths in CRIU. Faults are artificially generated in peeked places of the code to check for particular roll-backs.
+Faults are enforced by setting the <code>CRIU_FAULT</code> [[environment variables|env]] before executing CRIU binary. Values are described in <code>criu/include/fault-injection.h</code> header file.
+== Fatal faults ==
+These make CRIU abort the current operation and exit with error.
+=== Abort dump early ===
+<code>FI_DUMP_EARLY == 1</code>. Makes CRIU abort duming right after infecting the task with [[parasite code]]. Checks that parasite unloading on error works OK.
+=== Abort restore early ===
+<code>FI_RESTORE_ROOT_ONLY == 2</code>. Makes CRIU stop restoring right after spawning (and pre-restoring) the root task. Checks that early preparations (such as [[invisible files]] pre-creation) doesn't leave garbage in the system.
+=== Abort link-remap file opening ===
+<code>FI_RESTORE_OPEN_LINK_REMAP == 3</code>. Make CRIU fail the very first attempt opening the [[invisible files|link remap]] file. Additional check for invisible files cleanup.
+=== Abort connection to parasite code ===
+<code>FI_PARASITE_CONNECT == 4</code>. Makes CRIU simulate impossibility for [[parasite code]] to connect back to CRIU.
+== Non fatal faults ==
+These just make CRIU chose different paths on dump/restore, trying harder to get work done.
+=== Abort open-by-handle ===
+<code>FI_CHECK_OPEN_HANDLE == 128</code>. Simulates failure of the <code>open_by_handle_at</code> system call. Forces the [[irmap]] engine to work.
+=== Abort memfd creation ===
+<code>FI_NO_MEMFD == 129</code>. Forces [[parasite code]] use shmem-based blob instead of memfd-based. Used for older kernels (not having the <code>memfd_create()</code> system call) to work.
+=== Abort breakpoints injectioin ===
+<code>FI_NO_BREAKPOINTS == 130</code>. Disables breakpoints and makes CRIU unload [[code blobs]] by step-by-step tracing.
 [[Category:Testing]]