This is a note to let you know that I've just added the patch titled s390: don't trace preemption in percpu macros to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-don-t-trace-preemption-in-percpu-macros.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 73b1514318909b3745bfb14067f1764e01b4ac72 Author: Sven Schnelle <svens@xxxxxxxxxxxxx> Date: Thu Aug 20 09:48:23 2020 +0200 s390: don't trace preemption in percpu macros [ 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> diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h index 6d6556ca24aa2..f715419a72cf0 100644 --- a/arch/s390/include/asm/percpu.h +++ b/arch/s390/include/asm/percpu.h @@ -28,7 +28,7 @@ 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 { \ @@ -36,7 +36,7 @@ new__ = old__ op (val); \ prev__ = cmpxchg(ptr__, old__, new__); \ } while (prev__ != old__); \ - preempt_enable(); \ + preempt_enable_notrace(); \ new__; \ }) @@ -67,7 +67,7 @@ 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)) { \ @@ -83,7 +83,7 @@ : [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) @@ -94,14 +94,14 @@ 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__; \ }) @@ -113,14 +113,14 @@ 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") @@ -135,10 +135,10 @@ 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__; \ }) @@ -151,10 +151,10 @@ ({ \ 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__; \ }) @@ -170,11 +170,11 @@ 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__; \ })