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authorLinus Torvalds <torvalds@linux-foundation.org>2014-02-14 11:09:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-02-14 11:09:11 -0800
commit161aa772f972ec75b292f25d65816a6f1cd285cf (patch)
treecc05205d0c646b14c561a6f77a6386647d541d41 /arch
parenteef445eedcd80aa4f3646cecf285cf934d264eb6 (diff)
parent4640c7ee9b8953237d05a61ea3ea93981d1bc961 (diff)
downloadlinux-stericsson-161aa772f972ec75b292f25d65816a6f1cd285cf.tar.gz
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()
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/common.c7
-rw-r--r--arch/x86/kernel/tsc.c4
-rw-r--r--arch/x86/mm/fault.c14
3 files changed, 17 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 24b6fd10625a..8e28bf2fc3ef 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -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
+ }
}
/*
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 19e5adb49a27..acb3b606613e 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -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;
}
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9d591c895803..6dea040cc3a1 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -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;
@@ -1087,11 +1093,9 @@ __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 (unlikely(smap_violation(error_code, regs))) {
+ bad_area_nosemaphore(regs, error_code, address);
+ return;
}
/*