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author | 2019-07-11 13:54:00 -0700 | |
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committer | 2019-07-11 13:54:00 -0700 | |
commit | 753c8d9b7d81206bb5d011b28abe829d364b028e (patch) | |
tree | dacd394bc1fa375be9f214934b1ab3daadfd7360 /arch/x86/include/asm/special_insns.h | |
parent | Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/... (diff) | |
parent | x86/stacktrace: Prevent infinite loop in arch_stack_walk_user() (diff) | |
download | linux-753c8d9b7d81206bb5d011b28abe829d364b028e.tar.gz linux-753c8d9b7d81206bb5d011b28abe829d364b028e.tar.bz2 linux-753c8d9b7d81206bb5d011b28abe829d364b028e.zip |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A collection of assorted fixes:
- Fix for the pinned cr0/4 fallout which escaped all testing efforts
because the kvm-intel module was never loaded when the kernel was
compiled with CONFIG_PARAVIRT=n. The cr0/4 accessors are moved out
of line and static key is now solely used in the core code and
therefore can stay in the RO after init section. So the kvm-intel
and other modules do not longer reference the (read only) static
key which the module loader tried to update.
- Prevent an infinite loop in arch_stack_walk_user() by breaking out
of the loop once the return address is detected to be 0.
- Prevent the int3_emulate_call() selftest from corrupting the stack
when KASAN is enabled. KASASN clobbers more registers than covered
by the emulated call implementation. Convert the int3_magic()
selftest to a ASM function so the compiler cannot KASANify it.
- Unbreak the build with old GCC versions and with the Gold linker by
reverting the 'Move of _etext to the actual end of .text'. In both
cases the build fails with 'Invalid absolute R_X86_64_32S
relocation: _etext'
- Initialize the context lock for init_mm, which was never an issue
until the alternatives code started to use a temporary mm for
patching.
- Fix a build warning vs. the LOWMEM_PAGES constant where clang
complains rightfully about a signed integer overflow in the shift
operation by converting the operand to an ULL.
- Adjust the misnamed ENDPROC() of common_spurious in the 32bit entry
code"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/stacktrace: Prevent infinite loop in arch_stack_walk_user()
x86/asm: Move native_write_cr0/4() out of line
x86/pgtable/32: Fix LOWMEM_PAGES constant
x86/alternatives: Fix int3_emulate_call() selftest stack corruption
x86/entry/32: Fix ENDPROC of common_spurious
Revert "x86/build: Move _etext to actual end of .text"
x86/ldt: Initialize the context lock for init_mm
Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
-rw-r--r-- | arch/x86/include/asm/special_insns.h | 41 |
1 files changed, 2 insertions, 39 deletions
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index b2e84d113f2a..219be88a59d2 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -18,9 +18,7 @@ */ extern unsigned long __force_order; -/* Starts false and gets enabled once CPU feature detection is done. */ -DECLARE_STATIC_KEY_FALSE(cr_pinning); -extern unsigned long cr4_pinned_bits; +void native_write_cr0(unsigned long val); static inline unsigned long native_read_cr0(void) { @@ -29,24 +27,6 @@ static inline unsigned long native_read_cr0(void) return val; } -static inline void native_write_cr0(unsigned long val) -{ - unsigned long bits_missing = 0; - -set_register: - asm volatile("mov %0,%%cr0": "+r" (val), "+m" (__force_order)); - - if (static_branch_likely(&cr_pinning)) { - if (unlikely((val & X86_CR0_WP) != X86_CR0_WP)) { - bits_missing = X86_CR0_WP; - val |= bits_missing; - goto set_register; - } - /* Warn after we've set the missing bits. */ - WARN_ONCE(bits_missing, "CR0 WP bit went missing!?\n"); - } -} - static inline unsigned long native_read_cr2(void) { unsigned long val; @@ -91,24 +71,7 @@ static inline unsigned long native_read_cr4(void) return val; } -static inline void native_write_cr4(unsigned long val) -{ - unsigned long bits_missing = 0; - -set_register: - asm volatile("mov %0,%%cr4": "+r" (val), "+m" (cr4_pinned_bits)); - - if (static_branch_likely(&cr_pinning)) { - if (unlikely((val & cr4_pinned_bits) != cr4_pinned_bits)) { - bits_missing = ~val & cr4_pinned_bits; - val |= bits_missing; - goto set_register; - } - /* Warn after we've set the missing bits. */ - WARN_ONCE(bits_missing, "CR4 bits went missing: %lx!?\n", - bits_missing); - } -} +void native_write_cr4(unsigned long val); #ifdef CONFIG_X86_64 static inline unsigned long native_read_cr8(void) |