Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull two arm64 fixes from Catalin Marinas:
- switch_mm() fix where init_mm.pgd ends up in the user TTBR0;
swapper_pg_dir is not suitable for user mappings
- this_cpu accessors fix for preemption safety
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: percpu: Make this_cpu accessors pre-empt safe
arm64: Use the reserved TTBR0 if context switching to the init_mm
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index cb95930..d8c25b7 100644
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -246,14 +246,30 @@
__ret; \
})
-#define this_cpu_cmpxchg_1(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
-#define this_cpu_cmpxchg_2(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
-#define this_cpu_cmpxchg_4(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
-#define this_cpu_cmpxchg_8(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
+#define _protect_cmpxchg_local(pcp, o, n) \
+({ \
+ typeof(*raw_cpu_ptr(&(pcp))) __ret; \
+ preempt_disable(); \
+ __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
+ preempt_enable(); \
+ __ret; \
+})
-#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
- cmpxchg_double_local(raw_cpu_ptr(&(ptr1)), raw_cpu_ptr(&(ptr2)), \
- o1, o2, n1, n2)
+#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+
+#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
+({ \
+ int __ret; \
+ preempt_disable(); \
+ __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \
+ raw_cpu_ptr(&(ptr2)), \
+ o1, o2, n1, n2); \
+ preempt_enable(); \
+ __ret; \
+})
#define cmpxchg64(ptr,o,n) cmpxchg((ptr),(o),(n))
#define cmpxchg64_local(ptr,o,n) cmpxchg_local((ptr),(o),(n))
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index a9eee33..101a42b 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -151,6 +151,15 @@
{
unsigned int cpu = smp_processor_id();
+ /*
+ * init_mm.pgd does not contain any user mappings and it is always
+ * active for kernel addresses in TTBR1. Just set the reserved TTBR0.
+ */
+ if (next == &init_mm) {
+ cpu_set_reserved_ttbr0();
+ return;
+ }
+
if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next)
check_and_switch_context(next, tsk);
}
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h
index 09da25b..4fde8c1 100644
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -204,25 +204,47 @@
return ret;
}
-#define _percpu_add(pcp, val) \
- __percpu_add(raw_cpu_ptr(&(pcp)), val, sizeof(pcp))
+#define _percpu_read(pcp) \
+({ \
+ typeof(pcp) __retval; \
+ preempt_disable(); \
+ __retval = (typeof(pcp))__percpu_read(raw_cpu_ptr(&(pcp)), \
+ sizeof(pcp)); \
+ preempt_enable(); \
+ __retval; \
+})
-#define _percpu_add_return(pcp, val) (typeof(pcp)) (_percpu_add(pcp, val))
+#define _percpu_write(pcp, val) \
+do { \
+ preempt_disable(); \
+ __percpu_write(raw_cpu_ptr(&(pcp)), (unsigned long)(val), \
+ sizeof(pcp)); \
+ preempt_enable(); \
+} while(0) \
+
+#define _pcp_protect(operation, pcp, val) \
+({ \
+ typeof(pcp) __retval; \
+ preempt_disable(); \
+ __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \
+ (val), sizeof(pcp)); \
+ preempt_enable(); \
+ __retval; \
+})
+
+#define _percpu_add(pcp, val) \
+ _pcp_protect(__percpu_add, pcp, val)
+
+#define _percpu_add_return(pcp, val) _percpu_add(pcp, val)
#define _percpu_and(pcp, val) \
- __percpu_and(raw_cpu_ptr(&(pcp)), val, sizeof(pcp))
+ _pcp_protect(__percpu_and, pcp, val)
#define _percpu_or(pcp, val) \
- __percpu_or(raw_cpu_ptr(&(pcp)), val, sizeof(pcp))
-
-#define _percpu_read(pcp) (typeof(pcp)) \
- (__percpu_read(raw_cpu_ptr(&(pcp)), sizeof(pcp)))
-
-#define _percpu_write(pcp, val) \
- __percpu_write(raw_cpu_ptr(&(pcp)), (unsigned long)(val), sizeof(pcp))
+ _pcp_protect(__percpu_or, pcp, val)
#define _percpu_xchg(pcp, val) (typeof(pcp)) \
- (__percpu_xchg(raw_cpu_ptr(&(pcp)), (unsigned long)(val), sizeof(pcp)))
+ _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val))
#define this_cpu_add_1(pcp, val) _percpu_add(pcp, val)
#define this_cpu_add_2(pcp, val) _percpu_add(pcp, val)