From becef184dfe9bfef522c80501d22a5e02efba8d8 Mon Sep 17 00:00:00 2001 From: Luc Van Oostenryck Date: Wed, 4 Dec 2019 02:06:23 +0100 Subject: percpu: fix __percpu annotation in asm-generic The generic implementation of raw_cpu_generic_add_return() is: #define raw_cpu_generic_add_return(pcp, val) \ ({ \ typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \ \ *__p += val; \ *__p; \ }) where the 'pcp' argument is a __percpu lvalue. There, the variable '__p' is declared as a __percpu pointer the type of the address of 'pcp') but: 1) the value assigned to it, the return value of raw_cpu_ptr(), is a plain (__kernel) pointer, not a __percpu one. 2) this variable is dereferenced just after while a __percpu pointer is implicitly __noderef. So, fix the declaration of the 'pcp' variable to its correct type: the plain (non-percpu) pointer corresponding to pcp's address, using the fact that typeof() ignores the address space and the 'noderef' attribute of its agument. Same for raw_cpu_generic_xchg(), raw_cpu_generic_cmpxchg() & raw_cpu_generic_cmpxchg_double(). This removes 209 warnings on ARM, 525 on ARM64, 220 on x86 & more than 2600 on ppc64 (all of them with the default config). Cc: Tejun Heo Cc: Nicholas Piggin Reported-by: Ben Dooks Signed-off-by: Luc Van Oostenryck Acked-by: Christoph Lameter Signed-off-by: Dennis Zhou --- include/asm-generic/percpu.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index c2de013b2cf4..35e4a53b83e6 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -74,7 +74,7 @@ do { \ #define raw_cpu_generic_add_return(pcp, val) \ ({ \ - typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \ + typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \ \ *__p += val; \ *__p; \ @@ -82,7 +82,7 @@ do { \ #define raw_cpu_generic_xchg(pcp, nval) \ ({ \ - typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \ + typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \ typeof(pcp) __ret; \ __ret = *__p; \ *__p = nval; \ @@ -91,7 +91,7 @@ do { \ #define raw_cpu_generic_cmpxchg(pcp, oval, nval) \ ({ \ - typeof(&(pcp)) __p = raw_cpu_ptr(&(pcp)); \ + typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \ typeof(pcp) __ret; \ __ret = *__p; \ if (__ret == (oval)) \ @@ -101,8 +101,8 @@ do { \ #define raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \ ({ \ - typeof(&(pcp1)) __p1 = raw_cpu_ptr(&(pcp1)); \ - typeof(&(pcp2)) __p2 = raw_cpu_ptr(&(pcp2)); \ + typeof(pcp1) *__p1 = raw_cpu_ptr(&(pcp1)); \ + typeof(pcp2) *__p2 = raw_cpu_ptr(&(pcp2)); \ int __ret = 0; \ if (*__p1 == (oval1) && *__p2 == (oval2)) { \ *__p1 = nval1; \ -- cgit v1.2.3 From 264b0d2bee148073c117e7bbbde5be7125a53be1 Mon Sep 17 00:00:00 2001 From: Erdem Aktas Date: Fri, 13 Dec 2019 13:31:46 -0800 Subject: percpu: Separate decrypted varaibles anytime encryption can be enabled CONFIG_VIRTUALIZATION may not be enabled for memory encrypted guests. If disabled, decrypted per-CPU variables may end up sharing the same page with variables that should be left encrypted. Always separate per-CPU variables that should be decrypted into their own page anytime memory encryption can be enabled in the guest rather than rely on any other config option that may not be enabled. Fixes: ac26963a1175 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED") Cc: stable@vger.kernel.org # 4.15+ Signed-off-by: Erdem Aktas Signed-off-by: David Rientjes Signed-off-by: Dennis Zhou --- include/linux/percpu-defs.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index a6fabd865211..176bfbd52d97 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -175,8 +175,7 @@ * Declaration/definition used for per-CPU variables that should be accessed * as decrypted when memory encryption is enabled in the guest. */ -#if defined(CONFIG_VIRTUALIZATION) && defined(CONFIG_AMD_MEM_ENCRYPT) - +#ifdef CONFIG_AMD_MEM_ENCRYPT #define DECLARE_PER_CPU_DECRYPTED(type, name) \ DECLARE_PER_CPU_SECTION(type, name, "..decrypted") -- cgit v1.2.3