New: Kernel 5.2-rc1 fails to boot on a Mac Mini G4: dt_headr_start=0x01501000
https://bugzilla.kernel.org/show_bug.cgi?id=203699
Bug ID: 203699
Summary: Kernel 5.2-rc1 fails to boot on a Mac Mini G4:
dt_headr_start=0x01501000
Product: Platform Specific/Hardware
Version: 2.5
Kernel Version: Kernel 5.2
Hardware: PPC-32
OS: Linux
Tree: Mainline
Status: NEW
Severity: blocking
Priority: P1
Component: PPC-32
Assignee: [email protected]
Reporter: [email protected]
Regression: No
From: Christophe Leroy <>
I found the issue. In order to be able to support KASAN, the setup of segments have moved earlier in the boot. Your problem is a side effect of this change.
Function setup_disp_bat() is supposed to setup BAT3 for btext data. But setup_disp_bat() rely on someone setting in disp_BAT the values to be loaded into BATs. This is done by btext_prepare_BAT() which is called by bootx_init().
The problem is that bootx_init() is never called, so setup_disp_bat() does nothing and the access to btext data is possible because the bootloader has set an entry for it in the hash table.
But by setting up the segment earlier, we break the bootloader hash table, which shouldn't be an issue if the BATs had been set properly as expected.
The problematic commit is 215b823707ce ("powerpc/32s: set up an early static hash table for KASAN)"
Here is a dirty fix that works for me when CONFIG_KASAN is NOT set. Of course, the real fix has to be to setup the BATs properly, but I won't have time to look at that before June. Maybe you can ?
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[Bug 203699] Kernel 5.2-rc1 fails to boot on a Mac Mini G4: dt_headr_start=0x01501000
https://bugzilla.kernel.org/show_bug.cgi?id=203699
--- Comment #1 from Mathieu Malaterre ([email protected]) --- Created attachment 282929
--> https://bugzilla.kernel.org/attachment.cgi?id=282929&action=edit
Fix symptoms
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[Bug 203699] Kernel 5.2-rc1 fails to boot on a Mac Mini G4: dt_headr_start=0x01501000
In reply to [email protected]https://bugzilla.kernel.org/show_bug.cgi?id=203699
Michael Ellerman ([email protected]) changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |NEEDINFO
CC| |[email protected]--- Comment #2 from Michael Ellerman ([email protected]) --- Did this get fixed along the way?
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[Bug 203699] Kernel 5.2-rc1 fails to boot on a Mac Mini G4: dt_headr_start=0x01501000
In reply to [email protected]https://bugzilla.kernel.org/show_bug.cgi?id=203699
Michael Ellerman ([email protected]) changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEEDINFO |CLOSED
Resolution|--- |CODE_FIX--- Comment #3 from Michael Ellerman ([email protected]) --- v5.19-rc2 is booting on my mac mini with KASAN enabled, so I'm going to close this as fixed.
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