Bug 206527

Summary:	Kernel 5.6-rc1 w. CONFIG_VMAP_STACK=y + CONFIG_KASAN=y fails to boot on a PowerMac G4 3,6
Product:	Platform Specific/Hardware	Reporter:	Erhard F. (erhard_f)
Component:	PPC-32	Assignee:	platform_ppc-32
Status:	RESOLVED CODE_FIX
Severity:	normal	CC:	christophe.leroy
Priority:	P1
Hardware:	PPC-32
OS:	Linux
Kernel Version:	5.6.0-rc1	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	screenshot of stuck boot process

Description Erhard F. 2020-02-13 20:40:31 UTC

Created attachment 287361 [details]
screenshot of stuck boot process

Happens on my G4 DP with kernel 5.6.0-rc1 and KASAN (outline) enabled + CONFIG_VMAP_STACK enabled. kernel is patched with Christophe's '[v2] powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACK' (https://patchwork.ozlabs.org/patch/1237387/)

The kernel loads but booting gets stuck at a stage where the display is initialized but before kernel dmesg gets show (see screenshot).

The machine boots with either CONFIG_VMAP_STACK=y or CONFIG_KASAN=y enabled but not with both of them enabled together.

Comment 1 Christophe Leroy 2020-02-14 09:55:16 UTC

Can you test v3, https://patchwork.ozlabs.org/patch/1237954/

Comment 2 Erhard F. 2020-02-14 13:06:41 UTC

Excellent, with v3 KASAN (outline + inline) now work together with CONFIG_VMAP_STACK=y!

Comment 3 Erhard F. 2020-02-26 15:33:39 UTC

Fix landed in 5.6-rc3, works now as expected. Thanks!