Commit 161aa772 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 Peter Anvin:
 "A collection of small fixes:

   - There still seem to be problems with asm goto which requires the
     empty asm hack.
   - If SMAP is disabled at compile time, don't enable it nor try to
     interpret a page fault as an SMAP violation.
   - Fix a case of unbounded recursion while tracing"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
  x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
  compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
  x86: Use preempt_disable_notrace() in cycles_2_ns()
parents eef445ee 4640c7ee

arch/x86/kernel/cpu/common.c

+6 −1
Original line number Diff line number Diff line
@@ -284,8 +284,13 @@ static __always_inline void setup_smap(struct cpuinfo_x86 *c) 
	raw_local_save_flags(eflags);

	BUG_ON(eflags & X86_EFLAGS_AC);



	if (cpu_has(c, X86_FEATURE_SMAP))

	if (cpu_has(c, X86_FEATURE_SMAP)) {

#ifdef CONFIG_X86_SMAP

		set_in_cr4(X86_CR4_SMAP);

#else

		clear_in_cr4(X86_CR4_SMAP);

#endif

	}

}



/*

arch/x86/kernel/tsc.c

+2 −2
Original line number Diff line number Diff line
@@ -209,7 +209,7 @@ static inline unsigned long long cycles_2_ns(unsigned long long cyc) 
	 * dance when its actually needed.

	 */



	preempt_disable();

	preempt_disable_notrace();

	data = this_cpu_read(cyc2ns.head);

	tail = this_cpu_read(cyc2ns.tail);
@@ -229,7 +229,7 @@ static inline unsigned long long cycles_2_ns(unsigned long long cyc) 
		if (!--data->__count)

			this_cpu_write(cyc2ns.tail, data);

	}

	preempt_enable();

	preempt_enable_notrace();



	return ns;

}

arch/x86/mm/fault.c

+9 −5
Original line number Diff line number Diff line
@@ -1001,6 +1001,12 @@ static int fault_in_kernel_space(unsigned long address) 


static inline bool smap_violation(int error_code, struct pt_regs *regs)

{

	if (!IS_ENABLED(CONFIG_X86_SMAP))

		return false;



	if (!static_cpu_has(X86_FEATURE_SMAP))

		return false;



	if (error_code & PF_USER)

		return false;
@@ -1087,12 +1093,10 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	if (unlikely(error_code & PF_RSVD))

		pgtable_bad(regs, error_code, address);



	if (static_cpu_has(X86_FEATURE_SMAP)) {

	if (unlikely(smap_violation(error_code, regs))) {

		bad_area_nosemaphore(regs, error_code, address);

		return;

	}

	}



	/*

	 * If we're in an interrupt, have no user context or are running

include/linux/compiler-gcc4.h

+1 −5
Original line number Diff line number Diff line
@@ -75,11 +75,7 @@ 
 *

 * (asm goto is automatically volatile - the naming reflects this.)

 */

#if GCC_VERSION <= 40801

#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)

#else

# define asm_volatile_goto(x...)	do { asm goto(x); } while (0)

#endif



#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP

#if GCC_VERSION >= 40400

CRA Git | Maintained and supported by SUSTech CRA and CCSE