From 6175b70df95ed3b8fe177cb20b9b00b1f9008cc4 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Wed, 22 Feb 2023 23:01:15 -0800 Subject: [PATCH 1/2] powerpc/pseries: RTAS work area requires GENERIC_ALLOCATOR The RTAS work area allocator uses code that is built by GENERIC_ALLOCATOR, so the PSERIES Kconfig should select the required Kconfig symbol to fix multiple build errors. powerpc64-linux-ld: arch/powerpc/platforms/pseries/rtas-work-area.o: in function `.rtas_work_area_allocator_init': rtas-work-area.c:(.init.text+0x288): undefined reference to `.gen_pool_create' powerpc64-linux-ld: rtas-work-area.c:(.init.text+0x2dc): undefined reference to `.gen_pool_set_algo' powerpc64-linux-ld: rtas-work-area.c:(.init.text+0x310): undefined reference to `.gen_pool_add_owner' powerpc64-linux-ld: rtas-work-area.c:(.init.text+0x43c): undefined reference to `.gen_pool_destroy' powerpc64-linux-ld: arch/powerpc/platforms/pseries/rtas-work-area.o:(.toc+0x0): undefined reference to `gen_pool_first_fit_order_align' powerpc64-linux-ld: arch/powerpc/platforms/pseries/rtas-work-area.o: in function `.__rtas_work_area_alloc': rtas-work-area.c:(.ref.text+0x14c): undefined reference to `.gen_pool_alloc_algo_owner' powerpc64-linux-ld: rtas-work-area.c:(.ref.text+0x238): undefined reference to `.gen_pool_alloc_algo_owner' powerpc64-linux-ld: arch/powerpc/platforms/pseries/rtas-work-area.o: in function `.rtas_work_area_free': rtas-work-area.c:(.ref.text+0x44c): undefined reference to `.gen_pool_free_owner' Fixes: 43033bc62d34 ("powerpc/pseries: add RTAS work area allocator") Signed-off-by: Randy Dunlap Reviewed-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://msgid.link/20230223070116.660-2-rdunlap@infradead.org --- arch/powerpc/platforms/pseries/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index b481c5c8bae1..21b22bf16ce6 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -7,6 +7,7 @@ config PPC_PSERIES select OF_DYNAMIC select FORCE_PCI select PCI_MSI + select GENERIC_ALLOCATOR select PPC_XICS select PPC_XIVE_SPAPR select PPC_ICP_NATIVE From f2c7e3562b4c4f1699acc1538ebf3e75f5cced35 Mon Sep 17 00:00:00 2001 From: Russell Currey Date: Fri, 10 Mar 2023 16:08:34 +1100 Subject: [PATCH 2/2] powerpc/mm: Fix false detection of read faults MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To support detection of read faults with Radix execute-only memory, the vma_is_accessible() check in access_error() (which checks for PROT_NONE) was replaced with a check to see if VM_READ was missing, and if so, returns true to assert the fault was caused by a bad read. This is incorrect, as it ignores that both VM_WRITE and VM_EXEC imply read on powerpc, as defined in protection_map[]. This causes mappings containing VM_WRITE or VM_EXEC without VM_READ to misreport the cause of page faults, since the MMU is still allowing reads. Correct this by restoring the original vma_is_accessible() check for PROT_NONE mappings, and adding a separate check for Radix PROT_EXEC-only mappings. Fixes: 395cac7752b9 ("powerpc/mm: Support execute-only memory on the Radix MMU") Reported-by: Michal Suchánek Link: https://lore.kernel.org/r/20230308152702.GR19419@kitsune.suse.cz Tested-by: Benjamin Gray Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://msgid.link/20230310050834.63105-1-ruscur@russell.cc --- arch/powerpc/mm/fault.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 2bef19cc1b98..af46aa88422b 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -271,11 +271,16 @@ static bool access_error(bool is_write, bool is_exec, struct vm_area_struct *vma } /* - * Check for a read fault. This could be caused by a read on an - * inaccessible page (i.e. PROT_NONE), or a Radix MMU execute-only page. + * VM_READ, VM_WRITE and VM_EXEC all imply read permissions, as + * defined in protection_map[]. Read faults can only be caused by + * a PROT_NONE mapping, or with a PROT_EXEC-only mapping on Radix. */ - if (unlikely(!(vma->vm_flags & VM_READ))) + if (unlikely(!vma_is_accessible(vma))) return true; + + if (unlikely(radix_enabled() && ((vma->vm_flags & VM_ACCESS_FLAGS) == VM_EXEC))) + return true; + /* * We should ideally do the vma pkey access check here. But in the * fault path, handle_mm_fault() also does the same check. To avoid