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| author | Andy Lutomirski <luto@kernel.org> | 2021-01-19 09:40:55 -0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-01-21 20:08:53 +0100 |
| commit | 8ece53ef7f428ee3f8eab936268b1a3fe2725e6b (patch) | |
| tree | d301122cac7f7b02c221441b4824b91144b0ec80 /arch/x86/include/uapi | |
| parent | b86cb29287be07041b81f5611e37ae9ffabff876 (diff) | |
| download | linux-stable-8ece53ef7f428ee3f8eab936268b1a3fe2725e6b.tar.gz linux-stable-8ece53ef7f428ee3f8eab936268b1a3fe2725e6b.tar.bz2 linux-stable-8ece53ef7f428ee3f8eab936268b1a3fe2725e6b.zip | |
x86/vm86/32: Remove VM86_SCREEN_BITMAP support
The implementation was rather buggy. It unconditionally marked PTEs
read-only, even for VM_SHARED mappings. I'm not sure whether this is
actually a problem, but it certainly seems unwise. More importantly, it
released the mmap lock before flushing the TLB, which could allow a racing
CoW operation to falsely believe that the underlying memory was not
writable.
I can't find any users at all of this mechanism, so just remove it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Stas Sergeev <stsp2@yandex.ru>
Link: https://lkml.kernel.org/r/f3086de0babcab36f69949b5780bde851f719bc8.1611078018.git.luto@kernel.org
Diffstat (limited to 'arch/x86/include/uapi')
| -rw-r--r-- | arch/x86/include/uapi/asm/vm86.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/uapi/asm/vm86.h b/arch/x86/include/uapi/asm/vm86.h index d2ee4e307ef8..18909b8050bc 100644 --- a/arch/x86/include/uapi/asm/vm86.h +++ b/arch/x86/include/uapi/asm/vm86.h @@ -97,7 +97,7 @@ struct revectored_struct { struct vm86_struct { struct vm86_regs regs; unsigned long flags; - unsigned long screen_bitmap; + unsigned long screen_bitmap; /* unused, preserved by vm86() */ unsigned long cpu_type; struct revectored_struct int_revectored; struct revectored_struct int21_revectored; @@ -106,7 +106,7 @@ struct vm86_struct { /* * flags masks */ -#define VM86_SCREEN_BITMAP 0x0001 +#define VM86_SCREEN_BITMAP 0x0001 /* no longer supported */ struct vm86plus_info_struct { unsigned long force_return_for_pic:1; |