kernel/arch, branch linux-5.16.y

powerpc/64: Fix build failure with allyesconfig in book3s_64_entry.S

2022-04-13T18:03:26Z

commit af41d2866f7d75bbb38d487f6ec7770425d70e45 upstream. Using conditional branches between two files is hasardous, they may get linked too far from each other. arch/powerpc/kvm/book3s_64_entry.o:(.text+0x3ec): relocation truncated to fit: R_PPC64_REL14 (stub) against symbol `system_reset_common' defined in .text section in arch/powerpc/kernel/head_64.o Reorganise the code to use non conditional branches. Fixes: 89d35b239101 ("KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C") Signed-off-by: Christophe Leroy [mpe: Avoid odd-looking bne ., use named local labels] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/89cf27bf43ee07a0b2879b9e8e2f5cd6386a3645.1648366338.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

x86,static_call: Fix __static_call_return0 for i386

2022-04-13T18:03:26Z

commit 1cd5f059d956e6f614ba6666ecdbcf95db05d5f5 upstream. Paolo reported that the instruction sequence that is used to replace: call __static_call_return0 namely: 66 66 48 31 c0 data16 data16 xor %rax,%rax decodes to something else on i386, namely: 66 66 48 data16 dec %ax 31 c0 xor %eax,%eax Which is a nonsensical sequence that happens to have the same outcome. *However* an important distinction is that it consists of 2 instructions which is a problem when the thing needs to be overwriten with a regular call instruction again. As such, replace the instruction with something that decodes the same on both i386 and x86_64. Fixes: 3f2a8fc4b15d ("static_call/x86: Add __static_call_return0()") Reported-by: Paolo Bonzini Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220318204419.GT8939@worktop.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman

x86/bug: Prevent shadowing in __WARN_FLAGS

2022-04-13T18:03:26Z

commit 9ce02f0fc68326dd1f87a0a3a4c6ae7fdd39e6f6 upstream. The macro __WARN_FLAGS() uses a local variable named "f". This being a common name, there is a risk of shadowing other variables. For example, GCC would yield: | In file included from ./include/linux/bug.h:5, | from ./include/linux/cpumask.h:14, | from ./arch/x86/include/asm/cpumask.h:5, | from ./arch/x86/include/asm/msr.h:11, | from ./arch/x86/include/asm/processor.h:22, | from ./arch/x86/include/asm/timex.h:5, | from ./include/linux/timex.h:65, | from ./include/linux/time32.h:13, | from ./include/linux/time.h:60, | from ./include/linux/stat.h:19, | from ./include/linux/module.h:13, | from virt/lib/irqbypass.mod.c:1: | ./include/linux/rcupdate.h: In function 'rcu_head_after_call_rcu': | ./arch/x86/include/asm/bug.h:80:21: warning: declaration of 'f' shadows a parameter [-Wshadow] | 80 | __auto_type f = BUGFLAG_WARNING|(flags); \ | | ^ | ./include/asm-generic/bug.h:106:17: note: in expansion of macro '__WARN_FLAGS' | 106 | __WARN_FLAGS(BUGFLAG_ONCE | \ | | ^~~~~~~~~~~~ | ./include/linux/rcupdate.h:1007:9: note: in expansion of macro 'WARN_ON_ONCE' | 1007 | WARN_ON_ONCE(func != (rcu_callback_t)~0L); | | ^~~~~~~~~~~~ | In file included from ./include/linux/rbtree.h:24, | from ./include/linux/mm_types.h:11, | from ./include/linux/buildid.h:5, | from ./include/linux/module.h:14, | from virt/lib/irqbypass.mod.c:1: | ./include/linux/rcupdate.h:1001:62: note: shadowed declaration is here | 1001 | rcu_head_after_call_rcu(struct rcu_head *rhp, rcu_callback_t f) | | ~~~~~~~~~~~~~~~^ For reference, sparse also warns about it, c.f. [1]. This patch renames the variable from f to __flags (with two underscore prefixes as suggested in the Linux kernel coding style [2]) in order to prevent collisions. [1] https://lore.kernel.org/all/CAFGhKbyifH1a+nAMCvWM88TK6fpNPdzFtUXPmRGnnQeePV+1sw@mail.gmail.com/ [2] Linux kernel coding style, section 12) Macros, Enums and RTL, paragraph 5) namespace collisions when defining local variables in macros resembling functions https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl Fixes: bfb1a7c91fb7 ("x86/bug: Merge annotate_reachable() into_BUG_FLAGS() asm") Signed-off-by: Vincent Mailhol Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Nick Desaulniers Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20220324023742.106546-1-mailhol.vincent@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

Revert "powerpc: Set max_mapnr correctly"

2022-04-13T18:03:25Z

commit 1ff5c8e8c835e8a81c0868e3050c76563dd56a2c upstream. This reverts commit 602946ec2f90d5bd965857753880db29d2d9a1e9. If CONFIG_HIGHMEM is enabled, no highmem will be added with max_mapnr set to max_low_pfn, see mem_init(): for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) { ... free_highmem_page(); } Now that virt_addr_valid() has been fixed in the previous commit, we can revert the change to max_mapnr. Fixes: 602946ec2f90 ("powerpc: Set max_mapnr correctly") Signed-off-by: Kefeng Wang Reviewed-by: Christophe Leroy Reported-by: Erhard F. [mpe: Update change log to reflect series reordering] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220406145802.538416-2-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman

powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit

2022-04-13T18:03:25Z

commit ffa0b64e3be58519ae472ea29a1a1ad681e32f48 upstream. mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000. Because of the way __pa() works we have: __pa(0x8000000000000000) == 0, and therefore virt_to_pfn(0x8000000000000000) == 0, and therefore virt_addr_valid(0x8000000000000000) == true Which is wrong, virt_addr_valid() should be false for vmalloc space. In fact all vmalloc addresses that alias with a valid PFN will return true from virt_addr_valid(). That can cause bugs with hardened usercopy as described below by Kefeng Wang: When running ethtool eth0 on 64-bit Book3E, a BUG occurred: usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)! kernel BUG at mm/usercopy.c:99 ... usercopy_abort+0x64/0xa0 (unreliable) __check_heap_object+0x168/0x190 __check_object_size+0x1a0/0x200 dev_ethtool+0x2494/0x2b20 dev_ioctl+0x5d0/0x770 sock_do_ioctl+0xf0/0x1d0 sock_ioctl+0x3ec/0x5a0 __se_sys_ioctl+0xf0/0x160 system_call_exception+0xfc/0x1f0 system_call_common+0xf8/0x200 The code shows below, data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN)); copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true on 64-bit Book3E, which leads to the panic. As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in the virt_addr_valid() for 64-bit, also add upper limit check to make sure the virt is below high_memory. Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start of lowmem, high_memory is the upper low virtual address, the check is suitable for 32-bit, this will fix the issue mentioned in commit 602946ec2f90 ("powerpc: Set max_mapnr correctly") too. On 32-bit there is a similar problem with high memory, that was fixed in commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that commit breaks highmem and needs to be reverted. We can't easily fix __pa(), we have code that relies on its current behaviour. So for now add extra checks to virt_addr_valid(). For 64-bit Book3S the extra checks are not necessary, the combination of virt_to_pfn() and pfn_valid() should yield the correct result, but they are harmless. Signed-off-by: Kefeng Wang Reviewed-by: Christophe Leroy [mpe: Add additional change log detail] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220406145802.538416-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman

x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation

2022-04-13T18:03:25Z

commit 063452fd94d153d4eb38ad58f210f3d37a09cca4 upstream. ARCH_REQ_XCOMP_PERM is supposed to add the requested feature to the permission bitmap of thread_group_leader()->fpu. But the code overwrites the bitmap with the requested feature bit only rather than adding it. Fix the code to add the requested feature bit to the master bitmask. Fixes: db8268df0983 ("x86/arch_prctl: Add controls for dynamic XSTATE components") Signed-off-by: Yang Zhong Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Cc: Paolo Bonzini Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220129173647.27981-2-chang.seok.bae@intel.com [chang: Backport for 5.16] Signed-off-by: Chang S. Bae Signed-off-by: Greg Kroah-Hartman

KVM: SVM: Allow AVIC support on system w/ physical APIC ID > 255

2022-04-13T18:03:24Z

commit 4a204f7895878363ca8211f50ec610408c8c70aa upstream. Expand KVM's mask for the AVIC host physical ID to the full 12 bits defined by the architecture. The number of bits consumed by hardware is model specific, e.g. early CPUs ignored bits 11:8, but there is no way for KVM to enumerate the "true" size. So, KVM must allow using all bits, else it risks rejecting completely legal x2APIC IDs on newer CPUs. This means KVM relies on hardware to not assign x2APIC IDs that exceed the "true" width of the field, but presumably hardware is smart enough to tie the width to the max x2APIC ID. KVM also relies on hardware to support at least 8 bits, as the legacy xAPIC ID is writable by software. But, those assumptions are unavoidable due to the lack of any way to enumerate the "true" width. Cc: stable@vger.kernel.org Cc: Maxim Levitsky Suggested-by: Sean Christopherson Reviewed-by: Sean Christopherson Fixes: 44a95dae1d22 ("KVM: x86: Detect and Initialize AVIC support") Signed-off-by: Suravee Suthikulpanit Message-Id: <20220211000851.185799-1-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini [modified due to the conflict caused by the commit 391503528257 ("KVM: x86: SVM: move avic definitions from AMD's spec to svm.h")] Signed-off-by: Suravee Suthikulpanit Signed-off-by: Greg Kroah-Hartman

perf/x86/intel: Don't extend the pseudo-encoding to GP counters

2022-04-13T18:03:22Z

commit 4a263bf331c512849062805ef1b4ac40301a9829 upstream. The INST_RETIRED.PREC_DIST event (0x0100) doesn't count on SPR. perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0 Performance counter stats for 'CPU(s) 0': 607,246 cpu/event=0xc0,umask=0x0/ 0 cpu/event=0x0,umask=0x1/ The encoding for INST_RETIRED.PREC_DIST is pseudo-encoding, which doesn't work on the generic counters. However, current perf extends its mask to the generic counters. The pseudo event-code for a fixed counter must be 0x00. Check and avoid extending the mask for the fixed counter event which using the pseudo-encoding, e.g., ref-cycles and PREC_DIST event. With the patch, perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0 Performance counter stats for 'CPU(s) 0': 583,184 cpu/event=0xc0,umask=0x0/ 583,048 cpu/event=0x0,umask=0x1/ Fixes: 2de71ee153ef ("perf/x86/intel: Fix ICL/SPR INST_RETIRED.PREC_DIST encodings") Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1648482543-14923-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Greg Kroah-Hartman

x86/mm/tlb: Revert retpoline avoidance approach

2022-04-13T18:03:22Z

commit d39268ad24c0fd0665d0c5cf55a7c1a0ebf94766 upstream. 0day reported a regression on a microbenchmark which is intended to stress the TLB flushing path: https://lore.kernel.org/all/20220317090415.GE735@xsang-OptiPlex-9020/ It pointed at a commit from Nadav which intended to remove retpoline overhead in the TLB flushing path by taking the 'cond'-ition in on_each_cpu_cond_mask(), pre-calculating it, and incorporating it into 'cpumask'. That allowed the code to use a bunch of earlier direct calls instead of later indirect calls that need a retpoline. But, in practice, threads can go idle (and into lazy TLB mode where they don't need to flush their TLB) between the early and late calls. It works in this direction and not in the other because TLB-flushing threads tend to hold mmap_lock for write. Contention on that lock causes threads to _go_ idle right in this early/late window. There was not any performance data in the original commit specific to the retpoline overhead. I did a few tests on a system with retpolines: https://lore.kernel.org/all/dd8be93c-ded6-b962-50d4-96b1c3afb2b7@intel.com/ which showed a possible small win. But, that small win pales in comparison with the bigger loss induced on non-retpoline systems. Revert the patch that removed the retpolines. This was not a clean revert, but it was self-contained enough not to be too painful. Fixes: 6035152d8eeb ("x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()") Reported-by: kernel test robot Signed-off-by: Dave Hansen Signed-off-by: Borislav Petkov Acked-by: Nadav Amit Cc: Link: https://lkml.kernel.org/r/164874672286.389.7021457716635788197.tip-bot2@tip-bot2 Signed-off-by: Greg Kroah-Hartman

x86/msi: Fix msi message data shadow struct

2022-04-13T18:03:22Z

commit 59b18a1e65b7a2134814106d0860010e10babe18 upstream. The x86 MSI message data is 32 bits in total and is either in compatibility or remappable format, see Intel Virtualization Technology for Directed I/O, section 5.1.2. Fixes: 6285aa50736 ("x86/msi: Provide msi message shadow structs") Co-developed-by: Adrian-Ken Rueegsegger Signed-off-by: Adrian-Ken Rueegsegger Signed-off-by: Reto Buerki Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220407110647.67372-1-reet@codelabs.ch Signed-off-by: Greg Kroah-Hartman