[PATCH 1/1] powerpc: Fix incorrect stw{,ux,u,x} instructions in __set_pte_at

The placeholder for instruction selection should use the second
argument's operand, which is %1, not %0. This could generate incorrect
assembly code if the instruction selection for argument %0 ever differs
from argument %1.

Fixes: 9bf2b5cdc5fe ("powerpc: Fixes for CONFIG_PTE_64BIT for SMP support")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Christophe Leroy <redacted>
Cc: Kumar Gala <redacted>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: <redacted> # v2.6.28+
---
 arch/powerpc/include/asm/book3s/32/pgtable.h | 2 +-
 arch/powerpc/include/asm/nohash/pgtable.h    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 224912432821..f1467b3c417a 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h

@@ -529,7 +529,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 	__asm__ __volatile__("\
 		stw%U0%X0 %2,%0\n\
 		eieio\n\
-		stw%U0%X0 %L2,%1"
+		stw%U1%X1 %L2,%1"
 	: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
 	: "r" (pte) : "memory");
 

diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 4b7c3472eab1..a00e4c1746d6 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h

@@ -199,7 +199,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 		__asm__ __volatile__("\
 			stw%U0%X0 %2,%0\n\
 			eieio\n\
-			stw%U0%X0 %L2,%1"
+			stw%U1%X1 %L2,%1"
 		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
 		: "r" (pte) : "memory");
 		return;

-- 
2.11.0

Hi

[This is an automated email]

This commit has been processed because it contains a "Fixes:" tag
fixing commit: 9bf2b5cdc5fe ("powerpc: Fixes for CONFIG_PTE_64BIT for SMP support").

The bot has tested the following trees: v5.7.8, v5.4.51, v4.19.132, v4.14.188, v4.9.230, v4.4.230.

v5.7.8: Build OK!
v5.4.51: Build OK!
v4.19.132: Build OK!
v4.14.188: Failed to apply! Possible dependencies:
    45201c8794693 ("powerpc/nohash: Remove hash related code from nohash headers.")
    4e003747043d5 ("powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with CONFIG_PPC_BOOK3S_64")
    d5808ffaec817 ("powerpc/nohash: Use IS_ENABLED() to simplify __set_pte_at()")

v4.9.230: Failed to apply! Possible dependencies:
    45201c8794693 ("powerpc/nohash: Remove hash related code from nohash headers.")
    4546561551106 ("powerpc/asm: Use OFFSET macro in asm-offsets.c")
    4e003747043d5 ("powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with CONFIG_PPC_BOOK3S_64")
    5d451a87e5ebb ("powerpc/64: Retrieve number of L1 cache sets from device-tree")
    7c5b06cadf274 ("KVM: PPC: Book3S HV: Adapt TLB invalidations to work on POWER9")
    83677f551e0a6 ("KVM: PPC: Book3S HV: Adjust host/guest context switch for POWER9")
    902e06eb86cd6 ("powerpc/32: Change the stack protector canary value per task")
    a3d96f70c1477 ("powerpc/64s: Fix system reset vs general interrupt reentrancy")
    bd067f83b0840 ("powerpc/64: Fix naming of cache block vs. cache line")
    d5808ffaec817 ("powerpc/nohash: Use IS_ENABLED() to simplify __set_pte_at()")
    e2827fe5c1566 ("powerpc/64: Clean up ppc64_caches using a struct per cache")
    e9cf1e085647b ("KVM: PPC: Book3S HV: Add new POWER9 guest-accessible SPRs")
    f4c51f841d2ac ("KVM: PPC: Book3S HV: Modify guest entry/exit paths to handle radix guests")

v4.4.230: Failed to apply! Possible dependencies:
    1ca7212932862 ("powerpc/mm: Move PTE bits from generic functions to hash64 functions.")
    26b6a3d9bb48f ("powerpc/mm: move pte headers to book3s directory")
    371352ca0e7f3 ("powerpc/mm: Move hash64 PTE bits from book3s/64/pgtable.h to hash.h")
    3dfcb315d81e6 ("powerpc/mm: make a separate copy for book3s")
    ab537dca2f330 ("powerpc/mm: Move hash specific pte width and other defines to book3s")
    b0412ea94bcbd ("powerpc/mm: Drop pte-common.h from BOOK3S 64")
    cbbb8683fb632 ("powerpc/mm: Delete booke bits from book3s")


NOTE: The patch will not be queued to stable trees until it is upstream.

How should we proceed with this patch?

-- 
Thanks
Sasha