Dupe State - Revision history

Ruh at 23:37, 5 July 2025

2025-07-05T23:37:47Z

← Older revision		Revision as of 23:37, 5 July 2025
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	[[File:Dupe State Eco.gif\|frame\|Collecting blue eco while in dupe state on console (PS2).]]		[[File:Dupe State Eco.gif\|frame\|Collecting blue eco while in dupe state on console (PS2).]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.		'''Dupe state''' is a "state" that Jak can enter while performing the [[Duplication Glitch\|duplication exploit]] on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.

	The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.

Ruh at 23:37, 5 July 2025

2025-07-05T23:37:23Z

← Older revision		Revision as of 23:37, 5 July 2025
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	[[File:Dupe State Eco.gif\|frame\|Collecting ~~[[Blue Eco\|~~blue eco]] while in dupe state.]]		[[File:Dupe State Eco.gif\|frame\|Collecting blue eco while in dupe state on console (PS2).]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.		'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.

Ruh: /* Tutorial */

2024-10-01T18:22:42Z

Tutorial

← Older revision		Revision as of 18:22, 1 October 2024
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	== Tutorial ==		== Tutorial ==
	To activate dupe state, ~~you need to load~~ a ~~save file (without saving) on a specific frame of a spin kick while collecting~~ a scout fly. ~~Once you load back in~~, the ~~dupe state~~ will be ~~active. It works best~~ on ~~Geyser Rock with~~ the ~~first scout fly you encounter~~. ~~You are able to~~ load ~~any~~ save file ~~once you have the initial spin kick set up~~, ~~allowing~~ the state ~~to carry over with Jak to any level you load him~~ in to.		To activate dupe state, enter a level where no scout flies have been collected. Find a scout fly crate and open it. Stand next to the scout fly and press Circle and Start at roughly the same time. If done correctly, the scout fly will no longer be present on screen and Jak's foot will be slightly lifted off the ground. Now, load a save file. Dupe state will now be active.

			If in Debug Mode (not [[Cheat Mode]]), loading a save file while simply standing in front of the elevator door in Gol and Maia's Citadel will result in a 50% chance of dupe state being active. If the hint text is present in the top left of the screen during the pause, it will work.

	<youtube>https://www.youtube.com/watch?v=FYUAW7dEvBk</youtube>		<youtube>https://www.youtube.com/watch?v=FYUAW7dEvBk</youtube>

Ruh at 01:34, 1 October 2024

2024-10-01T01:34:12Z

← Older revision		Revision as of 01:34, 1 October 2024
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	The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.

	~~Dupe state's broken hint detection~~ can travel across save files, which is a trait not seen in any other known exploit in the game.		This de-referenced pointer can travel across save files, which is a trait not seen in any other known exploit in the game.

	== Technical ==		== Technical ==

Ruh at 01:33, 1 October 2024

2024-10-01T01:33:49Z

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	[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]		[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving ~~the~~ hint ~~detection system that leads to undefined behavior~~.		'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.

	The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.

Ruh at 01:31, 1 October 2024

2024-10-01T01:31:15Z

← Older revision		Revision as of 01:31, 1 October 2024
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	== Technical ==		== Technical ==
	~~When the first scout fly in an area is collected, a~~ <code>hint ~~detected!~~</code> notice will flash for a single frame in the top left debug text area (if Cheat Mode/Debug Mode is enabled). If the player pauses and loads a save file while this hint notice is on screen, the hint detection will begin writing out of bounds in process memory. So far, it is known to ~~be able to access the~~ <code>~~cspace~~-~~array</code> and <code>sparticle~~-~~launch~~-~~control~~</code> ~~areas of memory~~.		[[File:Dupe State hint-semaphore.png\|thumb\|Debug subtitle text showing that <code>hint-semaphore</code> now points to <code>med-res-level-1</code>.]]
			Technical write-up by Hat Kid.

			There is a variable called <code>hint-semaphore</code> that is either always set to <code>#f</code> or, if a hint is playing, a process is spawned for that hint, and <code>hint-semaphore</code> stores a pointer to that hint. When you perform the scout fly dupe, the process pointer stored in <code>hint-semaphore</code> no longer points to the hint process, because that got killed by loading the save file, but <code>hint-semaphore</code> is still storing that value. Because <code>hint-semaphore</code> is not <code>#f</code>, the subtitle debug code that displays the hint in the top left is de-referencing that pointer. In this screenshot (loading a Geyser save), the process pointer that was stored just so happens to now point to the process for the <code>med-res-level-1</code> entity, so the subtitle debug code is de-referencing the pointer as if it were a level-hint, which happens to lead to the med-res-level's <code>cspace-array</code> (and the text ID is pointing to its root).

	<~~blockquote~~>
	~~''A lot of the stuff in levels in Jak 1~~ is a ~~"process". So there~~ is a process for ~~each orb~~, ~~enemy, animated thing, camera, Jak,....~~. ~~Each process gets run once per frame by~~ the ~~kernel~~, ~~and each~~ process ~~has some memory associated with it~~ to ~~store its state (like where~~ the ~~item is located~~, ~~what animation it plays...). Many processes have their memory allocated manually, like~~ the ~~orbs~~, ~~which go into a special "collectables" heap~~. ~~But other things, (like flies which spawn from crates~~, ~~eco....) go on~~ the ~~"actor" heap. This actor heap has some really complicated~~ code that ~~will move around~~ the ~~memory for processes to compact them together and get larger chunks of free memory~~. ~~However,~~ this ~~code is really sensitive - if any process using the actor heap accidentally writes past its allocated memory~~, the ~~engine won't be able~~ to ~~maintain~~ the ~~actor heap any more. This means that deleting actors might not work~~, ~~or there could be random memory corruption. Some common side effects of~~ the ~~actor heap getting messed up~~ is ~~objects don't disappear when they are supposed to, because they cannot be deleted from~~ the ~~actor heap. Other times~~, ~~certain objects won't spawn because the actor heap is too full. Or sometimes, when it tries~~ to ~~spawn new enemies, it will just crash because it overwrites something else in~~ the ~~actor heap. I believe in debug mode, it would display "Low Actor Memory" in this case. I am not sure how save data could cause this to happen though.~~''

	- ~~'''[https://github.com/water111 Water111]''', 2019~~
	</~~blockquote~~>

	== Tutorial ==		== Tutorial ==

Ruh at 00:20, 1 October 2024

2024-10-01T00:20:25Z

← Older revision		Revision as of 00:20, 1 October 2024
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	The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.

	Dupe state can travel across save files, which is a trait not seen in any other known exploit in the game.		Dupe state's broken hint detection can travel across save files, which is a trait not seen in any other known exploit in the game.

	== Technical ==		== Technical ==

Ruh at 00:16, 1 October 2024

2024-10-01T00:16:44Z

← Older revision		Revision as of 00:16, 1 October 2024
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	[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]		[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies~~. Some side effects that occur while in dupe state include seemingly random game crashes, [[Statue Glitch\|statue glitch]], failure to load certain parts~~ of ~~the game, and collectable entities not disappearing after collecting them~~. ~~Dupe~~ state ~~can travel across save files, which~~ is a ~~trait not seen~~ in ~~any other known state. This~~ leads ~~some~~ to ~~believe that dupe state is not actually a state~~.		'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving the hint detection system that leads to undefined behavior.

	~~Using yellow eco~~ while dupe state ~~is active will lead to a~~ statue glitch, ~~where~~ Jak ~~becomes frozen in place right~~ after ~~you press the square button to shoot yellow eco~~. ~~This~~ is ~~the only~~ known ~~way to consistently perform~~ the ~~statue glitch~~.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.

			Dupe state can travel across save files, which is a trait not seen in any other known exploit in the game.

	== Technical ==		== Technical ==
	~~The best theory as~~ to ~~what happens during dupe state:~~		When the first scout fly in an area is collected, a <code>hint detected!</code> notice will flash for a single frame in the top left debug text area (if Cheat Mode/Debug Mode is enabled). If the player pauses and loads a save file while this hint notice is on screen, the hint detection will begin writing out of bounds in process memory. So far, it is known to be able to access the <code>cspace-array</code> and <code>sparticle-launch-control</code> areas of memory.



	<blockquote>		<blockquote>
	''A lot of the stuff in levels in Jak 1 is a "process". So there is a process for each orb, enemy, animated thing, camera, Jak,..... Each process gets run once per frame by the kernel, and each process has some memory associated with it to store its state (like where the item is located, what animation it plays...). Many processes have their memory allocated manually, like the orbs, which go into a special "collectables" heap. But other things, (like flies which spawn from crates, eco....) go on the "actor" heap. This actor heap has some really complicated code that will move around the memory for processes to compact them together and get larger chunks of free memory. However, this code is really sensitive - if any process using the actor heap accidentally writes past its allocated memory, the engine won't be able to maintain the actor heap any more. This means that deleting actors might not work, or there could be random memory corruption. Some common side effects of the actor heap getting messed up is objects don't disappear when they are supposed to, because they cannot be deleted from the actor heap. Other times, certain objects won't spawn because the actor heap is too full. Or sometimes, when it tries to spawn new enemies, it will just crash because it overwrites something else in the actor heap. I believe in debug mode, it would display "Low Actor Memory" in this case. I am not sure how save data could cause this to happen though.''		''A lot of the stuff in levels in Jak 1 is a "process". So there is a process for each orb, enemy, animated thing, camera, Jak,..... Each process gets run once per frame by the kernel, and each process has some memory associated with it to store its state (like where the item is located, what animation it plays...). Many processes have their memory allocated manually, like the orbs, which go into a special "collectables" heap. But other things, (like flies which spawn from crates, eco....) go on the "actor" heap. This actor heap has some really complicated code that will move around the memory for processes to compact them together and get larger chunks of free memory. However, this code is really sensitive - if any process using the actor heap accidentally writes past its allocated memory, the engine won't be able to maintain the actor heap any more. This means that deleting actors might not work, or there could be random memory corruption. Some common side effects of the actor heap getting messed up is objects don't disappear when they are supposed to, because they cannot be deleted from the actor heap. Other times, certain objects won't spawn because the actor heap is too full. Or sometimes, when it tries to spawn new enemies, it will just crash because it overwrites something else in the actor heap. I believe in debug mode, it would display "Low Actor Memory" in this case. I am not sure how save data could cause this to happen though.''

	- '''[https://github.com/water111 Water111]'''		- '''[https://github.com/water111 Water111]''', 2019
	</blockquote>		</blockquote>

Ruh at 17:56, 15 July 2024

2024-07-15T17:56:28Z

← Older revision		Revision as of 17:56, 15 July 2024
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	Using yellow eco while dupe state is active will lead to a statue glitch, where Jak becomes frozen in place right after you press the square button to shoot yellow eco. This is the only known way to consistently perform the statue glitch.		Using yellow eco while dupe state is active will lead to a statue glitch, where Jak becomes frozen in place right after you press the square button to shoot yellow eco. This is the only known way to consistently perform the statue glitch.

	~~Currently, there is no use for dupe state in any speedruns of Jak and Daxter: The Precursor Legacy.~~

	== Technical ==		== Technical ==

Ruh at 17:56, 15 July 2024

2024-07-15T17:56:07Z

← Older revision		Revision as of 17:56, 15 July 2024
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	[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]		[[File:Dupe State Eco.gif\|frame\|Collecting [[Blue Eco\|blue eco]] while in dupe state.]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies. Some side effects that occur while in dupe state include seemingly random ~~hardlocks~~, statue glitch, failure to load certain parts of the game, and collectable entities not disappearing after collecting them. Dupe state can travel across save files, which is a trait not seen in any other known state. This leads some to believe that dupe state is not actually a state.		'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies. Some side effects that occur while in dupe state include seemingly random game crashes, [[Statue Glitch\|statue glitch]], failure to load certain parts of the game, and collectable entities not disappearing after collecting them. Dupe state can travel across save files, which is a trait not seen in any other known state. This leads some to believe that dupe state is not actually a state.

	Using yellow eco while dupe state is active will lead to a statue glitch, where Jak becomes frozen in place right after you press the square button to shoot yellow eco. This is the only known way to consistently perform the statue glitch.		Using yellow eco while dupe state is active will lead to a statue glitch, where Jak becomes frozen in place right after you press the square button to shoot yellow eco. This is the only known way to consistently perform the statue glitch.

← Older revision		Revision as of 23:37, 5 July 2025
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	[[File:Dupe State Eco.gif\|frame\|Collecting blue eco while in dupe state on console (PS2).]]		[[File:Dupe State Eco.gif\|frame\|Collecting blue eco while in dupe state on console (PS2).]]
	'''Dupe state''' is a "state" that Jak can enter while performing the duplication exploit on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.		'''Dupe state''' is a "state" that Jak can enter while performing the [[Duplication Glitch\|duplication exploit]] on scout flies which allows for a degree of arbitrary code execution. The state is essentially a buffer overflow in the <code>actor</code> heap involving <code>hint-semaphore</code> de-referencing a pointer.

	The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.		The known side effects and behaviors that can occur while in dupe state include seemingly random game crashes, infinite loops, [[Statue Glitch\|statue glitch]] with red and yellow eco, baby spiders in Spider Cave not hatching, orb vents not opening while powered with blue eco, Jak's idle animation being disabled, and collectable entities or actors not disappearing after collecting them.