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| author | Joel Stanley <joel@jms.id.au> | 2019-12-12 01:32:01 +0300 |
|---|---|---|
| committer | Joel Stanley <joel@jms.id.au> | 2019-12-12 01:32:06 +0300 |
| commit | fdc60468f3e452364d432f1a7c3f83d58bba1b84 (patch) | |
| tree | de7197f150958ae72cb87b6cf4885610f3edd704 /arch/x86/include/asm/segment.h | |
| parent | 20572eecd7248b66d855a8e4812debd9f828ccba (diff) | |
| parent | 8539dfa4fcbcf58c3c2f92ac57b964add884d12b (diff) | |
| download | linux-dev-5.3.tar.xz | |
Merge tag 'v5.3.15' into dev-5.3dev-5.3
This is the 5.3.15 stable release
Signed-off-by: Joel Stanley <joel@jms.id.au>
Diffstat (limited to 'arch/x86/include/asm/segment.h')
| -rw-r--r-- | arch/x86/include/asm/segment.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index ac3892920419..6669164abadc 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -31,6 +31,18 @@ */ #define SEGMENT_RPL_MASK 0x3 +/* + * When running on Xen PV, the actual privilege level of the kernel is 1, + * not 0. Testing the Requested Privilege Level in a segment selector to + * determine whether the context is user mode or kernel mode with + * SEGMENT_RPL_MASK is wrong because the PV kernel's privilege level + * matches the 0x3 mask. + * + * Testing with USER_SEGMENT_RPL_MASK is valid for both native and Xen PV + * kernels because privilege level 2 is never used. + */ +#define USER_SEGMENT_RPL_MASK 0x2 + /* User mode is privilege level 3: */ #define USER_RPL 0x3 |