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| author | Nicholas Piggin <npiggin@gmail.com> | 2022-09-26 15:56:20 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-09-28 19:22:13 +1000 |
| commit | e1100cee059ad0bea6a668177e835baa087a0c65 (patch) | |
| tree | 30d137b21beef7499d9fcc7d27a4cc9199e33b84 /arch/powerpc/kernel/head_64.S | |
| parent | 519b2e317e39ac99ce589a7c8480c47a17d62638 (diff) | |
| download | lwn-e1100cee059ad0bea6a668177e835baa087a0c65.tar.gz lwn-e1100cee059ad0bea6a668177e835baa087a0c65.zip | |
powerpc/64s/interrupt: halt early boot interrupts if paca is not set up
Ensure r13 is zero from very early in boot until it gets set to the
boot paca pointer. This allows early program and mce handlers to halt
if there is no valid paca, rather than potentially run off into the
weeds. This preserves register and memory contents for low level
debugging tools.
Nothing could be printed to console at this point in any case because
even udbg is only set up after the boot paca is set, so this shouldn't
be missed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926055620.2676869-6-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/head_64.S')
| -rw-r--r-- | arch/powerpc/kernel/head_64.S | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index c63e0c086f03..cfc09a96a420 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -487,6 +487,9 @@ __start_initialization_multiplatform: /* Make sure we are running in 64 bits mode */ bl enable_64b_mode + /* Zero r13 (paca) so early program check / mce don't use it */ + li r13,0 + /* Get TOC pointer (current runtime address) */ bl relative_toc |