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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-04-17 11:58:36 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-04-22 20:24:02 +1000 |
| commit | feb8e960d780e170e992a70491eec9dd68f4dbf2 (patch) | |
| tree | f39964da6fd4d8526bdb818e915dd584087f5893 | |
| parent | b61c38baa98056d4802ff5be5cfb979efc2d0f7a (diff) | |
| download | linux-feb8e960d780e170e992a70491eec9dd68f4dbf2.tar.bz2 | |
powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32
CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.
Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().
Change dependency to PPC32 and use r0 instead of r4 in _switch()
Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index a6371fb8f761..8420abd4ea1c 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -732,7 +732,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE) stw r10,_CCR(r1) stw r1,KSP(r3) /* Set old stack pointer */ - kuap_check r2, r4 + kuap_check r2, r0 #ifdef CONFIG_SMP /* We need a sync somewhere here to make sure that if the * previous task gets rescheduled on another CPU, it sees all diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 0c3c1902135c..27a81c291be8 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -397,7 +397,7 @@ config PPC_KUAP config PPC_KUAP_DEBUG bool "Extra debugging for Kernel Userspace Access Protection" - depends on PPC_KUAP && (PPC_RADIX_MMU || PPC_32) + depends on PPC_KUAP && (PPC_RADIX_MMU || PPC32) help Add extra debugging for Kernel Userspace Access Protection (KUAP) If you're unsure, say N. |