user/sven/linux.git/arch, branch v4.4.266

bpf, x86: Validate computation of branch displacements for x86-64

2021-04-10T11:01:57Z

commit e4d4d456436bfb2fe412ee2cd489f7658449b098 upstream. The branch displacement logic in the BPF JIT compilers for x86 assumes that, for any generated branch instruction, the distance cannot increase between optimization passes. But this assumption can be violated due to how the distances are computed. Specifically, whenever a backward branch is processed in do_jit(), the distance is computed by subtracting the positions in the machine code from different optimization passes. This is because part of addrs[] is already updated for the current optimization pass, before the branch instruction is visited. And so the optimizer can expand blocks of machine code in some cases. This can confuse the optimizer logic, where it assumes that a fixed point has been reached for all machine code blocks once the total program size stops changing. And then the JIT compiler can output abnormal machine code containing incorrect branch displacements. To mitigate this issue, we assert that a fixed point is reached while populating the output image. This rejects any problematic programs. The issue affects both x86-32 and x86-64. We mitigate separately to ease backporting. Signed-off-by: Piotr Krysiuk Reviewed-by: Daniel Borkmann Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman

ia64: mca: allocate early mca with GFP_ATOMIC

2021-04-10T11:01:57Z

[ Upstream commit f2a419cf495f95cac49ea289318b833477e1a0e2 ] The sleep warning happens at early boot right at secondary CPU activation bootup: smp: Bringing up secondary CPUs ... BUG: sleeping function called from invalid context at mm/page_alloc.c:4942 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.12.0-rc2-00007-g79e228d0b611-dirty #99 .. Call Trace: show_stack+0x90/0xc0 dump_stack+0x150/0x1c0 ___might_sleep+0x1c0/0x2a0 __might_sleep+0xa0/0x160 __alloc_pages_nodemask+0x1a0/0x600 alloc_page_interleave+0x30/0x1c0 alloc_pages_current+0x2c0/0x340 __get_free_pages+0x30/0xa0 ia64_mca_cpu_init+0x2d0/0x3a0 cpu_init+0x8b0/0x1440 start_secondary+0x60/0x700 start_ap+0x750/0x780 Fixed BSP b0 value from CPU 1 As I understand interrupts are not enabled yet and system has a lot of memory. There is little chance to sleep and switch to GFP_ATOMIC should be a no-op. Link: https://lkml.kernel.org/r/20210315085045.204414-1-slyfox@gentoo.org Signed-off-by: Sergei Trofimovich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

x86/build: Turn off -fcf-protection for realmode targets

2021-04-10T11:01:57Z

[ Upstream commit 9fcb51c14da2953de585c5c6e50697b8a6e91a7b ] The new Ubuntu GCC packages turn on -fcf-protection globally, which causes a build failure in the x86 realmode code: cc1: error: ‘-fcf-protection’ is not compatible with this target Turn it off explicitly on compilers that understand this option. Signed-off-by: Arnd Bergmann Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210323124846.1584944-1-arnd@kernel.org Signed-off-by: Sasha Levin

x86/tlb: Flush global mappings when KAISER is disabled

2021-03-30T12:44:59Z

Jim Mattson reported that Debian 9 guests using a 4.9-stable kernel are exploding during alternatives patching: kernel BUG at /build/linux-dqnRSc/linux-4.9.228/arch/x86/kernel/alternative.c:709! invalid opcode: 0000 [#1] SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.0-13-amd64 #1 Debian 4.9.228-1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: swap_entry_free swap_entry_free text_poke_bp swap_entry_free arch_jump_label_transform set_debug_rodata __jump_label_update static_key_slow_inc frontswap_register_ops init_zswap init_frontswap do_one_initcall set_debug_rodata kernel_init_freeable rest_init kernel_init ret_from_fork triggering the BUG_ON in text_poke() which verifies whether patched instruction bytes have actually landed at the destination. Further debugging showed that the TLB flush before that check is insufficient because there could be global mappings left in the TLB, leading to a stale mapping getting used. I say "global mappings" because the hardware configuration is a new one: machine is an AMD, which means, KAISER/PTI doesn't need to be enabled there, which also means there's no user/kernel pagetables split and therefore the TLB can have global mappings. And the configuration is new one for a second reason: because that AMD machine supports PCID and INVPCID, which leads the CPU detection code to set the synthetic X86_FEATURE_INVPCID_SINGLE flag. Now, __native_flush_tlb_single() does invalidate global mappings when X86_FEATURE_INVPCID_SINGLE is *not* set and returns. When X86_FEATURE_INVPCID_SINGLE is set, however, it invalidates the requested address from both PCIDs in the KAISER-enabled case. But if KAISER is not enabled and the machine has global mappings in the TLB, then those global mappings do not get invalidated, which would lead to the above mismatch from using a stale TLB entry. So make sure to flush those global mappings in the KAISER disabled case. Co-debugged by Babu Moger . Reported-by: Jim Mattson Signed-off-by: Borislav Petkov Acked-by: Hugh Dickins Reviewed-by: Paolo Bonzini Tested-by: Babu Moger Tested-by: Jim Mattson Link: https://lkml.kernel.org/r/CALMp9eRDSW66%2BXvbHVF4ohL7XhThoPoT0BrB0TcS0cgk=dkcBg@mail.gmail.com Signed-off-by: Sasha Levin

ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign

2021-03-30T12:44:59Z

[ Upstream commit 61bf318eac2c13356f7bd1c6a05421ef504ccc8a ] In https://bugs.gentoo.org/769614 Dmitry noticed that `ptrace(PTRACE_GET_SYSCALL_INFO)` does not return error sign properly. The bug is in mismatch between get/set errors: static inline long syscall_get_error(struct task_struct *task, struct pt_regs *regs) { return regs->r10 == -1 ? regs->r8:0; } static inline long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs) { return regs->r8; } static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { if (error) { /* error < 0, but ia64 uses > 0 return value */ regs->r8 = -error; regs->r10 = -1; } else { regs->r8 = val; regs->r10 = 0; } } Tested on v5.10 on rx3600 machine (ia64 9040 CPU). Link: https://lkml.kernel.org/r/20210221002554.333076-2-slyfox@gentoo.org Link: https://bugs.gentoo.org/769614 Signed-off-by: Sergei Trofimovich Reported-by: Dmitry V. Levin Reviewed-by: Dmitry V. Levin Cc: John Paul Adrian Glaubitz Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls

2021-03-30T12:44:59Z

[ Upstream commit 0ceb1ace4a2778e34a5414e5349712ae4dc41d85 ] In https://bugs.gentoo.org/769614 Dmitry noticed that `ptrace(PTRACE_GET_SYSCALL_INFO)` does not work for syscalls called via glibc's syscall() wrapper. ia64 has two ways to call syscalls from userspace: via `break` and via `eps` instructions. The difference is in stack layout: 1. `eps` creates simple stack frame: no locals, in{0..7} == out{0..8} 2. `break` uses userspace stack frame: may be locals (glibc provides one), in{0..7} == out{0..8}. Both work fine in syscall handling cde itself. But `ptrace(PTRACE_GET_SYSCALL_INFO)` uses unwind mechanism to re-extract syscall arguments but it does not account for locals. The change always skips locals registers. It should not change `eps` path as kernel's handler already enforces locals=0 and fixes `break`. Tested on v5.10 on rx3600 machine (ia64 9040 CPU). Link: https://lkml.kernel.org/r/20210221002554.333076-1-slyfox@gentoo.org Link: https://bugs.gentoo.org/769614 Signed-off-by: Sergei Trofimovich Reported-by: Dmitry V. Levin Cc: Oleg Nesterov Cc: John Paul Adrian Glaubitz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

powerpc/4xx: Fix build errors from mfdcr()

2021-03-30T12:44:58Z

[ Upstream commit eead089311f4d935ab5d1d8fbb0c42ad44699ada ] lkp reported a build error in fsp2.o: CC arch/powerpc/platforms/44x/fsp2.o {standard input}:577: Error: unsupported relocation against base Which comes from: pr_err("GESR0: 0x%08x\n", mfdcr(base + PLB4OPB_GESR0)); Where our mfdcr() macro is stringifying "base + PLB4OPB_GESR0", and passing that to the assembler, which obviously doesn't work. The mfdcr() macro already checks that the argument is constant using __builtin_constant_p(), and if not calls the out-of-line version of mfdcr(). But in this case GCC is smart enough to notice that "base + PLB4OPB_GESR0" will be constant, even though it's not something we can immediately stringify into a register number. Segher pointed out that passing the register number to the inline asm as a constant would be better, and in fact it fixes the build error, presumably because it gives GCC a chance to resolve the value. While we're at it, change mtdcr() similarly. Reported-by: kernel test robot Suggested-by: Segher Boessenkool Signed-off-by: Michael Ellerman Acked-by: Feng Tang Link: https://lore.kernel.org/r/20210218123058.748882-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin

x86/ioapic: Ignore IRQ2 again

2021-03-24T09:57:01Z

commit a501b048a95b79e1e34f03cac3c87ff1e9f229ad upstream. Vitaly ran into an issue with hotplugging CPU0 on an Amazon instance where the matrix allocator claimed to be out of vectors. He analyzed it down to the point that IRQ2, the PIC cascade interrupt, which is supposed to be not ever routed to the IO/APIC ended up having an interrupt vector assigned which got moved during unplug of CPU0. The underlying issue is that IRQ2 for various reasons (see commit af174783b925 ("x86: I/O APIC: Never configure IRQ2" for details) is treated as a reserved system vector by the vector core code and is not accounted as a regular vector. The Amazon BIOS has an routing entry of pin2 to IRQ2 which causes the IO/APIC setup to claim that interrupt which is granted by the vector domain because there is no sanity check. As a consequence the allocation counter of CPU0 underflows which causes a subsequent unplug to fail with: [ ... ] CPU 0 has 4294967295 vectors, 589 available. Cannot disable CPU There is another sanity check missing in the matrix allocator, but the underlying root cause is that the IO/APIC code lost the IRQ2 ignore logic during the conversion to irqdomains. For almost 6 years nobody complained about this wreckage, which might indicate that this requirement could be lifted, but for any system which actually has a PIC IRQ2 is unusable by design so any routing entry has no effect and the interrupt cannot be connected to a device anyway. Due to that and due to history biased paranoia reasons restore the IRQ2 ignore logic and treat it as non existent despite a routing entry claiming otherwise. Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") Reported-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Tested-by: Vitaly Kuznetsov Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210318192819.636943062@linutronix.de Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Fix exclusive limit for IPA size

2021-03-17T15:07:23Z

Commit 262b003d059c6671601a19057e9fe1a5e7f23722 upstream. When registering a memslot, we check the size and location of that memslot against the IPA size to ensure that we can provide guest access to the whole of the memory. Unfortunately, this check rejects memslot that end-up at the exact limit of the addressing capability for a given IPA size. For example, it refuses the creation of a 2GB memslot at 0x8000000 with a 32bit IPA space. Fix it by relaxing the check to accept a memslot reaching the limit of the IPA space. Fixes: c3058d5da222 ("arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE") Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 4.4, 4.9 Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20210311100016.3830038-3-maz@kernel.org Signed-off-by: Greg Kroah-Hartman

powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()

2021-03-17T15:07:23Z

commit cea15316ceee2d4a51dfdecd79e08a438135416c upstream. 'lis r2,N' is 'addis r2,0,N' and the instruction encoding in the macro LIS_R2 is incorrect (it currently maps to 'addis r0,r2,N'). Fix the same. Fixes: c71b7eff426f ("powerpc: Add ABIv2 support to ppc_function_entry") Cc: stable@vger.kernel.org # v3.16+ Reported-by: Jiri Olsa Signed-off-by: Naveen N. Rao Acked-by: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210304020411.16796-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman