Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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()
+18
-13
+6
-1
arch/x86/kernel/cpu/common.c
+6
-1
arch/x86/kernel/cpu/common.c
···
284
284
raw_local_save_flags(eflags);
285
285
BUG_ON(eflags & X86_EFLAGS_AC);
286
286
287
-
if (cpu_has(c, X86_FEATURE_SMAP))
287
+
if (cpu_has(c, X86_FEATURE_SMAP)) {
288
+
#ifdef CONFIG_X86_SMAP
288
289
set_in_cr4(X86_CR4_SMAP);
290
+
#else
291
+
clear_in_cr4(X86_CR4_SMAP);
292
+
#endif
293
+
}
289
294
}
290
295
291
296
/*
+2
-2
arch/x86/kernel/tsc.c
+2
-2
arch/x86/kernel/tsc.c
···
209
209
* dance when its actually needed.
210
210
*/
211
211
212
-
preempt_disable();
212
+
preempt_disable_notrace();
213
213
data = this_cpu_read(cyc2ns.head);
214
214
tail = this_cpu_read(cyc2ns.tail);
215
215
···
229
229
if (!--data->__count)
230
230
this_cpu_write(cyc2ns.tail, data);
231
231
}
232
-
preempt_enable();
232
+
preempt_enable_notrace();
233
233
234
234
return ns;
235
235
}
+9
-5
arch/x86/mm/fault.c
+9
-5
arch/x86/mm/fault.c
···
1001
1001
1002
1002
static inline bool smap_violation(int error_code, struct pt_regs *regs)
1003
1003
{
1004
+
if (!IS_ENABLED(CONFIG_X86_SMAP))
1005
+
return false;
1006
+
1007
+
if (!static_cpu_has(X86_FEATURE_SMAP))
1008
+
return false;
1009
+
1004
1010
if (error_code & PF_USER)
1005
1011
return false;
1006
1012
···
1093
1087
if (unlikely(error_code & PF_RSVD))
1094
1088
pgtable_bad(regs, error_code, address);
1095
1089
1096
-
if (static_cpu_has(X86_FEATURE_SMAP)) {
1097
-
if (unlikely(smap_violation(error_code, regs))) {
1098
-
bad_area_nosemaphore(regs, error_code, address);
1099
-
return;
1100
-
}
1090
+
if (unlikely(smap_violation(error_code, regs))) {
1091
+
bad_area_nosemaphore(regs, error_code, address);
1092
+
return;
1101
1093
}
1102
1094
1103
1095
/*
+1
-5
include/linux/compiler-gcc4.h
+1
-5
include/linux/compiler-gcc4.h
···
75
75
*
76
76
* (asm goto is automatically volatile - the naming reflects this.)
77
77
*/
78
-
#if GCC_VERSION <= 40801
79
-
# define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
80
-
#else
81
-
# define asm_volatile_goto(x...) do { asm goto(x); } while (0)
82
-
#endif
78
+
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
83
79
84
80
#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
85
81
#if GCC_VERSION >= 40400