[PATCH AUTOSEL 4.19 10/11] s390: don't trace preemption in percpu macros

From: Sasha Levin
Date: Mon Aug 31 2020 - 11:32:01 EST


From: Sven Schnelle <svens@xxxxxxxxxxxxx>

[ Upstream commit 1196f12a2c960951d02262af25af0bb1775ebcc2 ]

Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context}
to per-cpu variables") the lockdep code itself uses percpu variables. This
leads to recursions because the percpu macros are calling preempt_enable()
which might call trace_preempt_on().

Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Reviewed-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/include/asm/percpu.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h
index 0095ddb58ff69..50f6661ba5664 100644
--- a/arch/s390/include/asm/percpu.h
+++ b/arch/s390/include/asm/percpu.h
@@ -29,7 +29,7 @@
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ old__, new__, prev__; \
pcp_op_T__ *ptr__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
prev__ = *ptr__; \
do { \
@@ -37,7 +37,7 @@
new__ = old__ op (val); \
prev__ = cmpxchg(ptr__, old__, new__); \
} while (prev__ != old__); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
new__; \
})

@@ -68,7 +68,7 @@
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
if (__builtin_constant_p(val__) && \
((szcast)val__ > -129) && ((szcast)val__ < 128)) { \
@@ -84,7 +84,7 @@
: [val__] "d" (val__) \
: "cc"); \
} \
- preempt_enable(); \
+ preempt_enable_notrace(); \
}

#define this_cpu_add_4(pcp, val) arch_this_cpu_add(pcp, val, "laa", "asi", int)
@@ -95,14 +95,14 @@
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
asm volatile( \
op " %[old__],%[val__],%[ptr__]\n" \
: [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
: [val__] "d" (val__) \
: "cc"); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
old__ + val__; \
})

@@ -114,14 +114,14 @@
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
asm volatile( \
op " %[old__],%[val__],%[ptr__]\n" \
: [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
: [val__] "d" (val__) \
: "cc"); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
}

#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lan")
@@ -136,10 +136,10 @@
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ ret__; \
pcp_op_T__ *ptr__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = cmpxchg(ptr__, oval, nval); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
ret__; \
})

@@ -152,10 +152,10 @@
({ \
typeof(pcp) *ptr__; \
typeof(pcp) ret__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = xchg(ptr__, nval); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
ret__; \
})

@@ -171,11 +171,11 @@
typeof(pcp1) *p1__; \
typeof(pcp2) *p2__; \
int ret__; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
p1__ = raw_cpu_ptr(&(pcp1)); \
p2__ = raw_cpu_ptr(&(pcp2)); \
ret__ = __cmpxchg_double(p1__, p2__, o1__, o2__, n1__, n2__); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
ret__; \
})

--
2.25.1