[Bug 1922593] [NEW] using init_on_alloc or init_on_free kernel parameters on ppc64el prevent boot

Public bug reported:

[Impact]
init_on_alloc and init_on_free kernel parameters cannot be used on ppc64el.

[Test case]
Boot the system with and without init_on_alloc and init_on_free kernel parameters, both with 0 and 1 as values.

[Fix]
Upstream commit 04013513cc84c401c7de9023ff3eda7863fc4add ("mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters") defers setting the static branches to mm_init, which is after jump_label_init has been called, while on ppc64el, parse_early_param is called before that, leading to the crash very early at boot.

[Potential regression]
Boot can be broken, or init_on_alloc/init_on_free may not be properly functioning during early boot or even after that, allowing kernel data leak to happen in the presence of bugs.

** Affects: linux (Ubuntu)
Importance: Undecided
Status: Invalid

** Affects: linux (Ubuntu Focal)
Importance: Low
Assignee: Thadeu Lima de Souza Cascardo (cascardo)
Status: Confirmed

** Affects: linux (Ubuntu Groovy)
Importance: Low
Assignee: Thadeu Lima de Souza Cascardo (cascardo)
Status: Confirmed

** Also affects: linux (Ubuntu Focal)
Importance: Undecided
Status: New

** Also affects: linux (Ubuntu Groovy)
Importance: Undecided
Status: New

** Changed in: linux (Ubuntu)
Status: New => Invalid

** Changed in: linux (Ubuntu Focal)
Status: New => Confirmed

** Changed in: linux (Ubuntu Groovy)
Status: New => Confirmed

** Changed in: linux (Ubuntu Groovy)
Assignee: (unassigned) => Thadeu Lima de Souza Cascardo (cascardo)

** Changed in: linux (Ubuntu Focal)
Assignee: (unassigned) => Thadeu Lima de Souza Cascardo (cascardo)

** Changed in: linux (Ubuntu Groovy)
Importance: Undecided => Low

** Changed in: linux (Ubuntu Focal)
Importance: Undecided => Low

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https://bugs.launchpad.net/bugs/1922593

Title:
using init_on_alloc or init_on_free kernel parameters on ppc64el
prevent boot

Status in linux package in Ubuntu:
Invalid
Status in linux source package in Focal:
Confirmed
Status in linux source package in Groovy:
Confirmed

Bug description:
[Impact]
init_on_alloc and init_on_free kernel parameters cannot be used on ppc64el.

[Test case]
Boot the system with and without init_on_alloc and init_on_free kernel parameters, both with 0 and 1 as values.

[Fix]
Upstream commit 04013513cc84c401c7de9023ff3eda7863fc4add ("mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters") defers setting the static branches to mm_init, which is after jump_label_init has been called, while on ppc64el, parse_early_param is called before that, leading to the crash very early at boot.

[Potential regression]
Boot can be broken, or init_on_alloc/init_on_free may not be properly functioning during early boot or even after that, allowing kernel data leak to happen in the presence of bugs.

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