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Commit a141fd55 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Another round of CR3/PCID related fixes (I think this addresses all
  but one of the known problems with PCID support), an objtool fix plus
  a Clang fix that (finally) solves all Clang quirks to build a bootable
  x86 kernel as-is"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Fix inline asm call constraints for Clang
  objtool: Handle another GCC stack pointer adjustment bug
  x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs
  x86/mm/32: Move setup_clear_cpu_cap(X86_FEATURE_PCID) earlier
  x86/mm/64: Stop using CR3.PCID == 0 in ASID-aware code
  x86/mm: Factor out CR3-building code
parents 16528a3f f5caf621
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+1 −2
Original line number Diff line number Diff line
@@ -218,10 +218,9 @@ static inline int alternatives_text_reserved(void *start, void *end)
#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2,   \
			   output, input...)				      \
{									      \
	register void *__sp asm(_ASM_SP);				      \
	asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
		"call %P[new2]", feature2)				      \
		: output, "+r" (__sp)					      \
		: output, ASM_CALL_CONSTRAINT				      \
		: [old] "i" (oldfunc), [new1] "i" (newfunc1),		      \
		  [new2] "i" (newfunc2), ## input);			      \
}
+11 −0
Original line number Diff line number Diff line
@@ -132,4 +132,15 @@
/* For C file, we already have NOKPROBE_SYMBOL macro */
#endif

#ifndef __ASSEMBLY__
/*
 * This output constraint should be used for any inline asm which has a "call"
 * instruction.  Otherwise the asm may be inserted before the frame pointer
 * gets set up by the containing function.  If you forget to do this, objtool
 * may print a "call without frame pointer save/setup" warning.
 */
register unsigned int __asm_call_sp asm("esp");
#define ASM_CALL_CONSTRAINT "+r" (__asm_call_sp)
#endif

#endif /* _ASM_X86_ASM_H */
+28 −4
Original line number Diff line number Diff line
@@ -286,6 +286,32 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
	return __pkru_allows_pkey(vma_pkey(vma), write);
}

/*
 * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID
 * bits.  This serves two purposes.  It prevents a nasty situation in
 * which PCID-unaware code saves CR3, loads some other value (with PCID
 * == 0), and then restores CR3, thus corrupting the TLB for ASID 0 if
 * the saved ASID was nonzero.  It also means that any bugs involving
 * loading a PCID-enabled CR3 with CR4.PCIDE off will trigger
 * deterministically.
 */

static inline unsigned long build_cr3(struct mm_struct *mm, u16 asid)
{
	if (static_cpu_has(X86_FEATURE_PCID)) {
		VM_WARN_ON_ONCE(asid > 4094);
		return __sme_pa(mm->pgd) | (asid + 1);
	} else {
		VM_WARN_ON_ONCE(asid != 0);
		return __sme_pa(mm->pgd);
	}
}

static inline unsigned long build_cr3_noflush(struct mm_struct *mm, u16 asid)
{
	VM_WARN_ON_ONCE(asid > 4094);
	return __sme_pa(mm->pgd) | (asid + 1) | CR3_NOFLUSH;
}

/*
 * This can be used from process context to figure out what the value of
@@ -296,10 +322,8 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
 */
static inline unsigned long __get_current_cr3_fast(void)
{
	unsigned long cr3 = __pa(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd);

	if (static_cpu_has(X86_FEATURE_PCID))
		cr3 |= this_cpu_read(cpu_tlbstate.loaded_mm_asid);
	unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm),
		this_cpu_read(cpu_tlbstate.loaded_mm_asid));

	/* For now, be very restrictive about when this can be called. */
	VM_WARN_ON(in_nmi() || preemptible());
+4 −6
Original line number Diff line number Diff line
@@ -179,7 +179,6 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
	u64 input_address = input ? virt_to_phys(input) : 0;
	u64 output_address = output ? virt_to_phys(output) : 0;
	u64 hv_status;
	register void *__sp asm(_ASM_SP);

#ifdef CONFIG_X86_64
	if (!hv_hypercall_pg)
@@ -187,7 +186,7 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)

	__asm__ __volatile__("mov %4, %%r8\n"
			     "call *%5"
			     : "=a" (hv_status), "+r" (__sp),
			     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
			       "+c" (control), "+d" (input_address)
			     :  "r" (output_address), "m" (hv_hypercall_pg)
			     : "cc", "memory", "r8", "r9", "r10", "r11");
@@ -202,7 +201,7 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)

	__asm__ __volatile__("call *%7"
			     : "=A" (hv_status),
			       "+c" (input_address_lo), "+r" (__sp)
			       "+c" (input_address_lo), ASM_CALL_CONSTRAINT
			     : "A" (control),
			       "b" (input_address_hi),
			       "D"(output_address_hi), "S"(output_address_lo),
@@ -224,12 +223,11 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
{
	u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;
	register void *__sp asm(_ASM_SP);

#ifdef CONFIG_X86_64
	{
		__asm__ __volatile__("call *%4"
				     : "=a" (hv_status), "+r" (__sp),
				     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
				       "+c" (control), "+d" (input1)
				     : "m" (hv_hypercall_pg)
				     : "cc", "r8", "r9", "r10", "r11");
@@ -242,7 +240,7 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
		__asm__ __volatile__ ("call *%5"
				      : "=A"(hv_status),
					"+c"(input1_lo),
					"+r"(__sp)
					ASM_CALL_CONSTRAINT
				      :	"A" (control),
					"b" (input1_hi),
					"m" (hv_hypercall_pg)
+7 −7
Original line number Diff line number Diff line
@@ -459,8 +459,8 @@ int paravirt_disable_iospace(void);
 */
#ifdef CONFIG_X86_32
#define PVOP_VCALL_ARGS							\
	unsigned long __eax = __eax, __edx = __edx, __ecx = __ecx;	\
	register void *__sp asm("esp")
	unsigned long __eax = __eax, __edx = __edx, __ecx = __ecx;

#define PVOP_CALL_ARGS			PVOP_VCALL_ARGS

#define PVOP_CALL_ARG1(x)		"a" ((unsigned long)(x))
@@ -480,8 +480,8 @@ int paravirt_disable_iospace(void);
/* [re]ax isn't an arg, but the return val */
#define PVOP_VCALL_ARGS						\
	unsigned long __edi = __edi, __esi = __esi,		\
		__edx = __edx, __ecx = __ecx, __eax = __eax;	\
	register void *__sp asm("rsp")
		__edx = __edx, __ecx = __ecx, __eax = __eax;

#define PVOP_CALL_ARGS		PVOP_VCALL_ARGS

#define PVOP_CALL_ARG1(x)		"D" ((unsigned long)(x))
@@ -532,7 +532,7 @@ int paravirt_disable_iospace(void);
			asm volatile(pre				\
				     paravirt_alt(PARAVIRT_CALL)	\
				     post				\
				     : call_clbr, "+r" (__sp)		\
				     : call_clbr, ASM_CALL_CONSTRAINT	\
				     : paravirt_type(op),		\
				       paravirt_clobber(clbr),		\
				       ##__VA_ARGS__			\
@@ -542,7 +542,7 @@ int paravirt_disable_iospace(void);
			asm volatile(pre				\
				     paravirt_alt(PARAVIRT_CALL)	\
				     post				\
				     : call_clbr, "+r" (__sp)		\
				     : call_clbr, ASM_CALL_CONSTRAINT	\
				     : paravirt_type(op),		\
				       paravirt_clobber(clbr),		\
				       ##__VA_ARGS__			\
@@ -569,7 +569,7 @@ int paravirt_disable_iospace(void);
		asm volatile(pre					\
			     paravirt_alt(PARAVIRT_CALL)		\
			     post					\
			     : call_clbr, "+r" (__sp)			\
			     : call_clbr, ASM_CALL_CONSTRAINT		\
			     : paravirt_type(op),			\
			       paravirt_clobber(clbr),			\
			       ##__VA_ARGS__				\
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