Hi Linus,
A collection of small fixes:
1. There still seem to be problems with asm goto which requires the
empty asm hack.
2. If SMAP is disabled at compile time, don't enable it nor try to
interpret a page fault as an SMAP violation.
3. Fix a case of unbounded recursion while tracing.
The following changes since commit 494479038d97f1b9f76fc633a360a681acdf035c:
Merge tag 'pinctrl-v3.14-2' of
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl (2014-02-08
14:31:39 -0800)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus
for you to fetch changes up to 4640c7ee9b8953237d05a61ea3ea93981d1bc961:
x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off (2014-02-13
08:40:52 -0800)
----------------------------------------------------------------
H. Peter Anvin (2):
x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
Steven Noonan (1):
compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
Steven Rostedt (1):
x86: Use preempt_disable_notrace() in cycles_2_ns()
arch/x86/kernel/cpu/common.c | 7 ++++++-
arch/x86/kernel/tsc.c | 4 ++--
arch/x86/mm/fault.c | 14 +++++++++-----
include/linux/compiler-gcc4.h | 6 +-----
4 files changed, 18 insertions(+), 13 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;
}
/*
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index ded429966c1f..2507fd2a1eb4 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -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
+#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
#if GCC_VERSION >= 40400
--
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