This is a note to let you know that I've just added the patch titled powerpc/mm: Fix lazy icache flush on pre-POWER5 to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-mm-fix-lazy-icache-flush-on-pre-power5.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From dd7b2f035ec41a409f7a7cec7aabc0ec0eacf476 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Date: Tue, 29 Nov 2016 13:13:46 +1100 Subject: powerpc/mm: Fix lazy icache flush on pre-POWER5 From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> commit dd7b2f035ec41a409f7a7cec7aabc0ec0eacf476 upstream. On 64-bit CPUs with no-execute support and non-snooping icache, such as 970 or POWER4, we have a software mechanism to ensure coherency of the cache (using exec faults when needed). This was broken due to a logic error when the code was rewritten from assembly to C, previously the assembly code did: BEGIN_FTR_SECTION mr r4,r30 mr r5,r7 bl hash_page_do_lazy_icache END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE) Which tests that: (cpu_features & (NOEXECUTE | COHERENT_ICACHE)) == NOEXECUTE Which says that the current cpu does have NOEXECUTE, but does not have COHERENT_ICACHE. Fixes: 91f1da99792a ("powerpc/mm: Convert 4k hash insert to C") Fixes: 89ff725051d1 ("powerpc/mm: Convert __hash_page_64K to C") Fixes: a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C") Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> [mpe: Change log verbosification] Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/mm/hash64_4k.c | 2 +- arch/powerpc/mm/hash64_64k.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/powerpc/mm/hash64_4k.c +++ b/arch/powerpc/mm/hash64_4k.c @@ -55,7 +55,7 @@ int __hash_page_4K(unsigned long ea, uns */ rflags = htab_convert_pte_flags(new_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); --- a/arch/powerpc/mm/hash64_64k.c +++ b/arch/powerpc/mm/hash64_64k.c @@ -87,7 +87,7 @@ int __hash_page_4K(unsigned long ea, uns subpg_pte = new_pte & ~subpg_prot; rflags = htab_convert_pte_flags(subpg_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) { /* @@ -258,7 +258,7 @@ int __hash_page_64K(unsigned long ea, un rflags = htab_convert_pte_flags(new_pte); - if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + if (cpu_has_feature(CPU_FTR_NOEXECUTE) && !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); Patches currently in stable-queue which might be from benh@xxxxxxxxxxxxxxxxxxx are queue-4.8/powerpc-mm-fix-lazy-icache-flush-on-pre-power5.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html