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Merged
merged 4 commits into from
Apr 12, 2021
Merged

A few improvements #184

merged 4 commits into from
Apr 12, 2021

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@ojeda ojeda commented Apr 12, 2021

Please see individual commits.

ojeda added 2 commits April 12, 2021 20:51
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Move panic handler to compiler builtins
f3b3ac5 
It fits better and allows to build `compiler_builtins` independently.

Signed-off-by: Miguel Ojeda <[email protected]>
@ojeda
Add samples/rust/ to the MAINTAINERS file list
cf83f14 
Signed-off-by: Miguel Ojeda <[email protected]>
alex
alex approved these changes Apr 12, 2021
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I'm not completely confident that putting panic handler in compiler builtins is conceptually correct, but I'm ok merging as is. It's a tiny commit if we end up needing to revert :-)

ojeda added 2 commits April 12, 2021 21:34
@ojeda
Improve sorting of the build objects
850dcfb 
Signed-off-by: Miguel Ojeda <[email protected]>
@ojeda
Fix typo
4140620 
Signed-off-by: Miguel Ojeda <[email protected]>
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ojeda commented Apr 12, 2021

If you think it is better to have it inside kernel, I can move it back in the RFC in the kernel commit, that is fine.

The compiler builtins need the panic, though, since they use it; and the kernel of course needs it too. So to avoid a cyclic dependency, it needs to go out. We could have another file, perhaps.

But on the other hand, yeah, it looks strange.

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alex commented Apr 12, 2021 via email

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ojeda commented Apr 12, 2021

Yeah, so compiler_builtins and core need to go together in any case; but without this, then kernel would also need to go together with them.

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ojeda commented Apr 12, 2021 •
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So it makes it possible to compile and link core + compiler_builtins independently of kernel.

I removed a typo I found somewhere else too.

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alex commented Apr 12, 2021 via email

@ojeda ojeda merged commit 1fa10de into Rust-for-Linux:rust Apr 12, 2021
@ojeda ojeda deleted the improv branch April 12, 2021 20:12
ojeda pushed a commit that referenced this pull request Jun 29, 2021
@sean-jc @bonzini
KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message
f31500b 
Use the __string() machinery provided by the tracing subystem to make a
copy of the string literals consumed by the "nested VM-Enter failed"
tracepoint.  A complete copy is necessary to ensure that the tracepoint
can't outlive the data/memory it consumes and deference stale memory.

Because the tracepoint itself is defined by kvm, if kvm-intel and/or
kvm-amd are built as modules, the memory holding the string literals
defined by the vendor modules will be freed when the module is unloaded,
whereas the tracepoint and its data in the ring buffer will live until
kvm is unloaded (or "indefinitely" if kvm is built-in).

This bug has existed since the tracepoint was added, but was recently
exposed by a new check in tracing to detect exactly this type of bug.

  fmt: '%s%s
  ' current_buffer: ' vmx_dirty_log_t-140127  [003] ....  kvm_nested_vmenter_failed: '
  WARNING: CPU: 3 PID: 140134 at kernel/trace/trace.c:3759 trace_check_vprintf+0x3be/0x3e0
  CPU: 3 PID: 140134 Comm: less Not tainted 5.13.0-rc1-ce2e73ce600a-req #184
  Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014
  RIP: 0010:trace_check_vprintf+0x3be/0x3e0
  Code: <0f> 0b 44 8b 4c 24 1c e9 a9 fe ff ff c6 44 02 ff 00 49 8b 97 b0 20
  RSP: 0018:ffffa895cc37bcb0 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: ffffa895cc37bd08 RCX: 0000000000000027
  RDX: 0000000000000027 RSI: 00000000ffffdfff RDI: ffff9766cfad74f8
  RBP: ffffffffc0a041d4 R08: ffff9766cfad74f0 R09: ffffa895cc37bad8
  R10: 0000000000000001 R11: 0000000000000001 R12: ffffffffc0a041d4
  R13: ffffffffc0f4dba8 R14: 0000000000000000 R15: ffff976409f2c000
  FS:  00007f92fa200740(0000) GS:ffff9766cfac0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000559bd11b0000 CR3: 000000019fbaa002 CR4: 00000000001726e0
  Call Trace:
   trace_event_printf+0x5e/0x80
   trace_raw_output_kvm_nested_vmenter_failed+0x3a/0x60 [kvm]
   print_trace_line+0x1dd/0x4e0
   s_show+0x45/0x150
   seq_read_iter+0x2d5/0x4c0
   seq_read+0x106/0x150
   vfs_read+0x98/0x180
   ksys_read+0x5f/0xe0
   do_syscall_64+0x40/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: Steven Rostedt <[email protected]>
Fixes: 380e005 ("KVM: nVMX: trace nested VM-Enter failures detected by H/W")
Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: Steven Rostedt (VMware) <[email protected]>
Message-Id: <[email protected]>
ojeda pushed a commit that referenced this pull request Dec 9, 2024
@bibo-mao @chenhuacai
LoongArch: Add architecture specific huge_pte_clear()
7cd1f5f 
When executing mm selftests run_vmtests.sh, there is such an error:

 BUG: Bad page state in process uffd-unit-tests  pfn:00000
 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
 flags: 0xffff0000002000(reserved|node=0|zone=0|lastcpupid=0xffff)
 raw: 00ffff0000002000 ffffbf0000000008 ffffbf0000000008 0000000000000000
 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
 Modules linked in: snd_seq_dummy snd_seq snd_seq_device rfkill vfat fat
    virtio_balloon efi_pstore virtio_net pstore net_failover failover fuse
    nfnetlink virtio_scsi virtio_gpu virtio_dma_buf dm_multipath efivarfs
 CPU: 2 UID: 0 PID: 1913 Comm: uffd-unit-tests Not tainted 6.12.0 #184
 Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
 Stack : 900000047c8ac000 0000000000000000 9000000000223a7c 900000047c8ac000
         900000047c8af690 900000047c8af698 0000000000000000 900000047c8af7d8
         900000047c8af7d0 900000047c8af7d0 900000047c8af5b0 0000000000000001
         0000000000000001 900000047c8af698 10b3c7d53da40d26 0000010000000000
         0000000000000022 0000000fffffffff fffffffffe000000 ffff800000000000
         000000000000002f 0000800000000000 000000017a6d4000 90000000028f8940
         0000000000000000 0000000000000000 90000000025aa5e0 9000000002905000
         0000000000000000 90000000028f8940 ffff800000000000 0000000000000000
         0000000000000000 0000000000000000 9000000000223a94 000000012001839c
         00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
         ...
 Call Trace:
 [<9000000000223a94>] show_stack+0x5c/0x180
 [<9000000001c3fd64>] dump_stack_lvl+0x6c/0xa0
 [<900000000056aa08>] bad_page+0x1a0/0x1f0
 [<9000000000574978>] free_unref_folios+0xbf0/0xd20
 [<90000000004e65cc>] folios_put_refs+0x1a4/0x2b8
 [<9000000000599a0c>] free_pages_and_swap_cache+0x164/0x260
 [<9000000000547698>] tlb_batch_pages_flush+0xa8/0x1c0
 [<9000000000547f30>] tlb_finish_mmu+0xa8/0x218
 [<9000000000543cb8>] exit_mmap+0x1a0/0x360
 [<9000000000247658>] __mmput+0x78/0x200
 [<900000000025583c>] do_exit+0x43c/0xde8
 [<9000000000256490>] do_group_exit+0x68/0x110
 [<9000000000256554>] sys_exit_group+0x1c/0x20
 [<9000000001c413b4>] do_syscall+0x94/0x130
 [<90000000002216d8>] handle_syscall+0xb8/0x158
 Disabling lock debugging due to kernel taint
 BUG: non-zero pgtables_bytes on freeing mm: -16384

On LoongArch system, invalid huge pte entry should be invalid_pte_table
or a single _PAGE_HUGE bit rather than a zero value. And it should be
the same with invalid pmd entry, since pmd_none() is called by function
free_pgd_range() and pmd_none() return 0 by huge_pte_clear(). So single
_PAGE_HUGE bit is also treated as a valid pte table and free_pte_range()
will be called in free_pmd_range().

  free_pmd_range()
        pmd = pmd_offset(pud, addr);
        do {
                next = pmd_addr_end(addr, end);
                if (pmd_none_or_clear_bad(pmd))
                        continue;
                free_pte_range(tlb, pmd, addr);
        } while (pmd++, addr = next, addr != end);

Here invalid_pte_table is used for both invalid huge pte entry and
pmd entry.

Cc: [email protected]
Fixes: 09cfefb ("LoongArch: Add memory management")
Signed-off-by: Bibo Mao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
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