kernel/git/stable/linux.git/arch/powerpc, branch linux-5.12.y

powerpc/bpf: Fix detecting BPF atomic instructions

2021-07-20T14:02:21+00:00

[ Upstream commit 419ac821766cbdb9fd85872bb3f1a589df05c94c ] Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and added a way to distinguish instructions based on the immediate field. Existing JIT implementations were updated to check for the immediate field and to reject programs utilizing anything more than BPF_ADD (such as BPF_FETCH) in the immediate field. However, the check added to powerpc64 JIT did not look at the correct BPF instruction. Due to this, such programs would be accepted and incorrectly JIT'ed resulting in soft lockups, as seen with the atomic bounds test. Fix this by looking at the correct immediate value. Fixes: 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") Reported-by: Jiri Olsa Signed-off-by: Naveen N. Rao Tested-by: Jiri Olsa Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4117b430ffaa8cd7af042496f87fd7539e4f17fd.1625145429.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin

powerpc/boot: Fixup device-tree on little endian

2021-07-20T14:02:11+00:00

[ Upstream commit c93f80849bdd9b45d834053ae1336e28f0026c84 ] This fixes the core devtree.c functions and the ns16550 UART backend. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras Reviewed-by: Segher Boessenkool Acked-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YMwXrPT8nc4YUdJ9@thinks.paulus.ozlabs.org Signed-off-by: Sasha Levin

powerpc/mm/book3s64: Fix possible build error

2021-07-20T14:02:09+00:00

[ Upstream commit 07d8ad6fd8a3d47f50595ca4826f41dbf4f3a0c6 ] Update _tlbiel_pid() such that we can avoid build errors like below when using this function in other places. arch/powerpc/mm/book3s64/radix_tlb.c: In function ‘__radix__flush_tlb_range_psize’: arch/powerpc/mm/book3s64/radix_tlb.c:114:2: warning: ‘asm’ operand 3 probably does not match constraints 114 | asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1) | ^~~ arch/powerpc/mm/book3s64/radix_tlb.c:114:2: error: impossible constraint in ‘asm’ make[4]: *** [scripts/Makefile.build:271: arch/powerpc/mm/book3s64/radix_tlb.o] Error 1 m With this fix, we can also drop the __always_inline in __radix_flush_tlb_range_psize which was added by commit e12d6d7d46a6 ("powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline") Signed-off-by: Aneesh Kumar K.V Reviewed-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210610083639.387365-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/ps3: Add dma_mask to ps3_dma_region

2021-07-20T14:02:08+00:00

[ Upstream commit 9733862e50fdba55e7f1554e4286fcc5302ff28e ] Commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 (dma-direct: Fix potential NULL pointer dereference) added a null check on the dma_mask pointer of the kernel's device structure. Add a dma_mask variable to the ps3_dma_region structure and set the device structure's dma_mask pointer to point to this new variable. Fixes runtime errors like these: # WARNING: Fixes tag on line 10 doesn't match correct format # WARNING: Fixes tag on line 10 doesn't match correct format ps3_system_bus_match:349: dev=8.0(sb_01), drv=8.0(ps3flash): match WARNING: CPU: 0 PID: 1 at kernel/dma/mapping.c:151 .dma_map_page_attrs+0x34/0x1e0 ps3flash sb_01: ps3stor_setup:193: map DMA region failed Signed-off-by: Geoff Levand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/562d0c9ea0100a30c3b186bcc7adb34b0bbd2cd7.1622746428.git.geoff@infradead.org Signed-off-by: Sasha Levin

powerpc/powernv/vas: Release reference to tgid during window close

2021-07-19T08:01:14+00:00

commit 91cdbb955aa94ee0841af4685be40937345d29b8 upstream. The kernel handles the NX fault by updating CSB or sending signal to process. In multithread applications, children can open VAS windows and can exit without closing them. But the parent can continue to send NX requests with these windows. To prevent pid reuse, reference will be taken on pid and tgid when the window is opened and release them during window close. The current code is not releasing the tgid reference which can cause pid leak and this patch fixes the issue. Fixes: db1c08a740635 ("powerpc/vas: Take reference to PID and mm for user space windows") Cc: stable@vger.kernel.org # 5.8+ Reported-by: Nicholas Piggin Signed-off-by: Haren Myneni Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/6020fc4d444864fe20f7dcdc5edfe53e67480a1c.camel@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/barrier: Avoid collision with clang's __lwsync macro

2021-07-19T08:01:13+00:00

commit 015d98149b326e0f1f02e44413112ca8b4330543 upstream. A change in clang 13 results in the __lwsync macro being defined as __builtin_ppc_lwsync, which emits 'lwsync' or 'msync' depending on what the target supports. This breaks the build because of -Werror in arch/powerpc, along with thousands of warnings: In file included from arch/powerpc/kernel/pmc.c:12: In file included from include/linux/bug.h:5: In file included from arch/powerpc/include/asm/bug.h:109: In file included from include/asm-generic/bug.h:20: In file included from include/linux/kernel.h:12: In file included from include/linux/bitops.h:32: In file included from arch/powerpc/include/asm/bitops.h:62: arch/powerpc/include/asm/barrier.h:49:9: error: '__lwsync' macro redefined [-Werror,-Wmacro-redefined] #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") ^ :308:9: note: previous definition is here #define __lwsync __builtin_ppc_lwsync ^ 1 error generated. Undefine this macro so that the runtime patching introduced by commit 2d1b2027626d ("powerpc: Fixup lwsync at runtime") continues to work properly with clang and the build no longer breaks. Cc: stable@vger.kernel.org Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Link: https://github.com/ClangBuiltLinux/linux/issues/1386 Link: https://github.com/llvm/llvm-project/commit/62b5df7fe2b3fda1772befeda15598fbef96a614 Link: https://lore.kernel.org/r/20210528182752.1852002-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Fix lockup on kernel exec fault

2021-07-19T08:01:13+00:00

commit cd5d5e602f502895e47e18cd46804d6d7014e65c upstream. The powerpc kernel is not prepared to handle exec faults from kernel. Especially, the function is_exec_fault() will return 'false' when an exec fault is taken by kernel, because the check is based on reading current->thread.regs->trap which contains the trap from user. For instance, when provoking a LKDTM EXEC_USERSPACE test, current->thread.regs->trap is set to SYSCALL trap (0xc00), and the fault taken by the kernel is not seen as an exec fault by set_access_flags_filter(). Commit d7df2443cd5f ("powerpc/mm: Fix spurious segfaults on radix with autonuma") made it clear and handled it properly. But later on commit d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") removed that handling, introducing test based on error_code. And here is the problem, because on the 603 all upper bits of SRR1 get cleared when the TLB instruction miss handler bails out to ISI. Until commit cbd7e6ca0210 ("powerpc/fault: Avoid heavy search_exception_tables() verification"), an exec fault from kernel at a userspace address was indirectly caught by the lack of entry for that address in the exception tables. But after that commit the kernel mainly relies on KUAP or on core mm handling to catch wrong user accesses. Here the access is not wrong, so mm handles it. It is a minor fault because PAGE_EXEC is not set, set_access_flags_filter() should set PAGE_EXEC and voila. But as is_exec_fault() returns false as explained in the beginning, set_access_flags_filter() bails out without setting PAGE_EXEC flag, which leads to a forever minor exec fault. As the kernel is not prepared to handle such exec faults, the thing to do is to fire in bad_kernel_fault() for any exec fault taken by the kernel, as it was prior to commit d3ca587404b3. Fixes: d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Christophe Leroy Acked-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/024bb05105050f704743a0083fe3548702be5706.1625138205.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

powerpc/preempt: Don't touch the idle task's preempt_count during hotplug

2021-07-14T15:00:33+00:00

commit 2c669ef6979c370f98d4b876e54f19613c81e075 upstream. Powerpc currently resets a CPU's idle task preempt_count to 0 before said task starts executing the secondary startup routine (and becomes an idle task proper). This conflicts with commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"). which initializes all of the idle tasks' preempt_count to PREEMPT_DISABLED during smp_init(). Note that this was superfluous before said commit, as back then the hotplug machinery would invoke init_idle() via idle_thread_get(), which would have already reset the CPU's idle task's preempt_count to PREEMPT_ENABLED. Get rid of this preempt_count write. Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled") Reported-by: Bharata B Rao Signed-off-by: Valentin Schneider Tested-by: Guenter Roeck Tested-by: Bharata B Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210707183831.2106509-1-valentin.schneider@arm.com Signed-off-by: Greg Kroah-Hartman

powerpc/64s/interrupt: preserve regs->softe for NMI interrupts

2021-07-14T15:00:27+00:00

[ Upstream commit 1b0482229c302a3c6afd00d6b3bf0169cf279b44 ] If an NMI interrupt hits in an implicit soft-masked region, regs->softe is modified to reflect that. This may not be necessary for correctness at the moment, but it is less surprising and it's unhelpful when debugging or adding checks. Make sure this is changed back to how it was found before returning. Fixes: 4ec5feec1ad0 ("powerpc/64s: Make NMI record implicitly soft-masked code as irqs disabled") Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210630074621.2109197-6-npiggin@gmail.com Signed-off-by: Sasha Levin

powerpc: Fix is_kvm_guest() / kvm_para_available()

2021-07-14T15:00:26+00:00

[ Upstream commit 95839225639ba7c3d8d7231b542728dcf222bf2d ] Commit a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") added is_kvm_guest() and changed kvm_para_available() to use it. is_kvm_guest() checks a static key, kvm_guest, and that static key is set in check_kvm_guest(). The problem is check_kvm_guest() is only called on pseries, and even then only in some configurations. That means is_kvm_guest() always returns false on all non-pseries and some pseries depending on configuration. That's a bug. For PR KVM guests this is noticable because they no longer do live patching of themselves, which can be detected by the omission of a message in dmesg such as: KVM: Live patching for a fast VM worked To fix it make check_kvm_guest() an initcall, to ensure it's always called at boot. It needs to be core so that it runs before kvm_guest_init() which is postcore. To be an initcall it needs to return int, where 0 means success, so update that. We still call it manually in pSeries_smp_probe(), because that runs before init calls are run. Fixes: a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210623130514.2543232-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin