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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 10:12:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 10:12:28 -0800 |
| commit | 5c4a1c090d8676d8b84e2ac40671602be44afdfc (patch) | |
| tree | 1fc8c456266e37a7e5c2e584eeed546587142da0 /arch/x86/include/asm/segment.h | |
| parent | 53a07a148fd05dc6d317745688270bc79fe73121 (diff) | |
| parent | 4a13b0e3e10996b9aa0b45a764ecfe49f6fcd360 (diff) | |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"These are the fixes left over from the v5.4 cycle:
- Various low level 32-bit entry code fixes and improvements by Andy
Lutomirski, Peter Zijlstra and Thomas Gleixner.
- Fix 32-bit Xen PV breakage, by Jan Beulich"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry/32: Fix FIXUP_ESPFIX_STACK with user CR3
x86/pti/32: Calculate the various PTI cpu_entry_area sizes correctly, make the CPU_ENTRY_AREA_PAGES assert precise
selftests/x86/sigreturn/32: Invalidate DS and ES when abusing the kernel
selftests/x86/mov_ss_trap: Fix the SYSENTER test
x86/entry/32: Fix NMI vs ESPFIX
x86/entry/32: Unwind the ESPFIX stack earlier on exception entry
x86/entry/32: Move FIXUP_FRAME after pushing %fs in SAVE_ALL
x86/entry/32: Use %ss segment where required
x86/entry/32: Fix IRET exception
x86/cpu_entry_area: Add guard page for entry stack on 32bit
x86/pti/32: Size initial_page_table correctly
x86/doublefault/32: Fix stack canaries in the double fault handler
x86/xen/32: Simplify ring check in xen_iret_crit_fixup()
x86/xen/32: Make xen_iret_crit_fixup() independent of frame layout
x86/stackframe/32: Repair 32-bit Xen PV
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 ac38929204194..6669164abadcb 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 |