CLI/opt/--allow-uprobes - Revision history

Radostin at 13:01, 7 October 2025

2025-10-07T13:01:43Z

Radostin: /* Description */

2025-10-07T12:56:25Z

Description

Radostin at 12:55, 7 October 2025

2025-10-07T12:55:47Z

Radostin at 12:44, 7 October 2025

2025-10-07T12:44:18Z

Radostin at 12:42, 7 October 2025

2025-10-07T12:42:47Z

Radostin at 12:41, 7 October 2025

2025-10-07T12:41:38Z

Radostin at 12:40, 7 October 2025

2025-10-07T12:40:59Z

Radostin at 12:34, 7 October 2025

2025-10-07T12:34:45Z

Radostin: Created page with "With the `--allow-uprobes` command-line option, CRIU can create checkpoint when Uprobes (user-space probes) VMAs are present. When this option is used during checkp..."

2025-10-07T11:17:43Z

Created page with "With the <code>--allow-uprobes</code> command-line option, CRIU can create checkpoint when Uprobes (user-space probes) VMAs are present. When this option is used during checkp..."

New page

With the <code>--allow-uprobes</code> command-line option, CRIU can create checkpoint when Uprobes (user-space probes) VMAs are present. When this option is used during checkpoint, it is also required on restore.

@@ Line 5: / Line 5: @@
 == Description ==
-User-space probes (uprobes) let you instrument functions in user processes. When a uprobe is triggered for the first time in a process, the kernel automatically creates a dedicated VMA for uprobes. This mapping is not removed even if the uprobe itself is later deleted. As a result, a process may retain a ''uprobes VMA'' long after probes have been removed.
+User-space probes (uprobes) allow instrumentation of functions in user processes. When a uprobe is triggered for the first time, the kernel automatically creates a dedicated VMA mapping. This mapping is not removed even if the uprobe itself is later deleted. As a result, a process may retain uprobes VMAs long after the probes have been removed.
-By default, CRIU refuses to checkpoint a process that has a uprobes VMA, since restoring it without the corresponding probes can change execution semantics. The <code>--allow-uprobes</code> option tells CRIU to proceed anyway.
+By default, CRIU exits with an error when checkpointing a process that has a uprobes VMA, because restoring that process without the corresponding probes can change execution semantics. The <code>--allow-uprobes</code> option tells CRIU to proceed anyway.
-On restore users need to ensure that any uprobes that were active for the checkpointed processes are still installed on the restore host before resuming execution. If a restored process executes at an address that had been uprobe'd but the probe is no longer active, the kernel delivers <code>SIGTRAP</code>. Without a handler for <code>SIGTRAP</code>, the process will terminate and may produce a core dump.
+On restore, users must ensure that any uprobes that were active for the checkpointed processes are still installed on the restore host before resuming execution. If a restored process executes code at a location that previously had a uprobe installed but the probe is no longer active, the kernel delivers <code>SIGTRAP</code>. Without a handler for <code>SIGTRAP</code>, the process will terminate and may produce a core dump.

← Older revision		Revision as of 12:56, 7 October 2025
Line 7:		Line 7:
	User-space probes (uprobes) let you instrument functions in user processes. When a uprobe is triggered for the first time in a process, the kernel automatically creates a dedicated VMA for uprobes. This mapping is not removed even if the uprobe itself is later deleted. As a result, a process may retain a ''uprobes VMA'' long after probes have been removed.		User-space probes (uprobes) let you instrument functions in user processes. When a uprobe is triggered for the first time in a process, the kernel automatically creates a dedicated VMA for uprobes. This mapping is not removed even if the uprobe itself is later deleted. As a result, a process may retain a ''uprobes VMA'' long after probes have been removed.

−	By default, CRIU refuses to checkpoint a process that has a uprobes VMA, since restoring it without the corresponding probes can change execution semantics. The <code>--allow-uprobes</code> ~~flag~~ tells CRIU to proceed anyway. On restore users need to ensure that any uprobes that were active for the checkpointed processes are still installed on the restore host before resuming execution. If a restored process executes at an address that had been uprobe'd but the probe is no longer active, the kernel delivers <code>SIGTRAP</code>. Without a handler for <code>SIGTRAP</code>, the process will terminate and may produce a core dump.	+	By default, CRIU refuses to checkpoint a process that has a uprobes VMA, since restoring it without the corresponding probes can change execution semantics. The <code>--allow-uprobes</code> option tells CRIU to proceed anyway.
		+
		+	On restore users need to ensure that any uprobes that were active for the checkpointed processes are still installed on the restore host before resuming execution. If a restored process executes at an address that had been uprobe'd but the probe is no longer active, the kernel delivers <code>SIGTRAP</code>. Without a handler for <code>SIGTRAP</code>, the process will terminate and may produce a core dump.

← Older revision		Revision as of 12:55, 7 October 2025
Line 2:		Line 2:

	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}		{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}
		+
		+	== Description ==
		+
		+	User-space probes (uprobes) let you instrument functions in user processes. When a uprobe is triggered for the first time in a process, the kernel automatically creates a dedicated VMA for uprobes. This mapping is not removed even if the uprobe itself is later deleted. As a result, a process may retain a ''uprobes VMA'' long after probes have been removed.
		+
		+	By default, CRIU refuses to checkpoint a process that has a uprobes VMA, since restoring it without the corresponding probes can change execution semantics. The <code>--allow-uprobes</code> flag tells CRIU to proceed anyway. On restore users need to ensure that any uprobes that were active for the checkpointed processes are still installed on the restore host before resuming execution. If a restored process executes at an address that had been uprobe'd but the probe is no longer active, the kernel delivers <code>SIGTRAP</code>. Without a handler for <code>SIGTRAP</code>, the process will terminate and may produce a core dump.

← Older revision		Revision as of 12:44, 7 October 2025
Line 1:		Line 1:
−	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a kernel-created uprobes VMA (~~user-space probes~~ virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.	+	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a kernel-created uprobes VMA (virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.

	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}		{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}

← Older revision		Revision as of 12:42, 7 October 2025
Line 1:		Line 1:
−	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.	+	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.

	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}		{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}

← Older revision		Revision as of 12:41, 7 October 2025
Line 1:		Line 1:
	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.		The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.

−	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes must remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}	+	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes '''must''' remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}

← Older revision		Revision as of 12:40, 7 October 2025
Line 1:		Line 1:
	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.		The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.
		+
		+	{{Note\|If a checkpoint has been created with <code>--allow-uprobes</code>, this option '''must''' be specified during restore and any relevant uprobes must remain active. This option does not create or manage uprobes; it only instructs CRIU to accept the presence of the corresponding VMAs.}}

← Older revision		Revision as of 12:34, 7 October 2025
Line 1:		Line 1:
−	~~With the~~ <code>--allow-uprobes</code> command-line option, CRIU ~~can create~~ checkpoint ~~when Uprobes~~ (user-space probes) ~~VMAs are present~~. ~~When~~ this ~~option~~ is ~~used during~~ checkpoint~~, it is also required on restore~~.	+	The <code>--allow-uprobes</code> command-line option allows CRIU to checkpoint and restore processes that have (or once had) a a kernel-created uprobes VMA (user-space probes virtual memory area). Since this VMA persists even after the probe is removed, CRIU cannot safely infer the probe state at checkpoint time without this option.